Low-pressure molding system

Abstract

The present invention relates to an extrusion molding machine and a method for manufacturing extruded products, and provides an extrusion molding machine and manufacturing method that take into account material properties and changes in the pressure of the extruded material by adjusting the operating parameters of the extrusion molding machine during the execution of extrusion molding. [Solution] A method for performing plastic molding at a substantially constant relatively low pressure, comprising the steps of (a) using a rotating screw to introduce a molten thermoplastic material into at least one mold cavity of a molding apparatus and performing extrusion molding at a low, substantially constant melt pressure, and (b) maintaining the melt pressure substantially constant at less than 6000 psi, wherein the thermoplastic material has a melt flow index of about 0.1 g / 10 min to about 500 g / 10 min.

Description

Technical Field

[0001] This specification also discloses a method of performing extrusion molding at a low substantially constant melt pressure. Embodiments of the disclosed method now result in better energy efficiency and cost efficiency than conventional extrusion molding processes, and enable an extrusion method that provides a better and more consistent product than conventional extrusion molding processes. Embodiments of the disclosed method surprisingly fill an extrusion molding die cavity at a lower melt pressure and, for example, with a cooling built-in, have a longer die profile, enabling a straighter and more consistent extrusion profile with fewer sink marks and a more homogeneous material composition. Furthermore, the constant pressure method can enable better temperature control / profile of the plastic during extrusion molding. Furthermore, a novel and innovative hot runner system having at least one cold runner portion in a die part and / or die section is reheated during all molding cycles prior to injection of the next partial melt plastic material, for example using overall or partial conductive heating. This heating modality often has a short heating process lasting less than 0.5 seconds.

Background Art

[0002]

[0003]

[0004] The present invention relates to an extrusion molding machine and a method for manufacturing an extruded molded product, and more specifically, to an extrusion molding machine that adjusts operating parameters of the extrusion molding machine during execution of extrusion molding to account for changes in material properties and pressure of an extrusion material, and to a method that accounts for changes in properties of an extrusion molding material during execution of extrusion molding and / or during blending of materials.

[0005]

Summary of the Invention

[0005] This specification also discloses a method for performing extrusion molding at a low, substantially constant melting pressure. The embodiment of the method described is now more energy-efficient and cost-efficient than conventional extrusion processes. This results in better and more consistent products than conventional extrusion processes. This enables a method of extraction. The embodiments of the disclosed method, surprisingly, enable lower melting pressure. The extrusion mold cavity is filled by force, and for example, a longer mold profile can be achieved with built-in cooling. Equipped with a straighter and more consistent extrusion process, resulting in less sink marks and a more homogeneous material composition. Enables file filing.

[0006] Furthermore, the constant pressure method allows for better temperature control / processing of plastics during extrusion molding. It can make it possible.

[0007] Furthermore, the mold component and / or mold portion comprises at least one cold runner portion. This new and innovative hot runner system is designed for the injection of partially molten plastic materials. It is reheated during all molding cycles, for example, by using conductive heating in whole or in part. The heating method often involves a short heating step lasting less than 0.5 seconds. [Means for solving the problem]

[0008] 1. Disclosure Areas

[0009] This disclosure relates to methods for extrusion molding, injection molding and blow molding, and more specifically, This invention relates to a method for controlling viscosity and melting temperature by performing extrusion molding at a low, substantially constant melting pressure. For example, it is arranged in an extruder, an injection unit, and / or a hot runner manifold Supported by the pressure and shear heat measured before and / or after the breaker plate(s) arranged. This is made possible by the size and shape of the holes in the breaker plate, for example, in combination with the breaker plate, the temperature can be controlled by heating and / or cooling, and / or the flow hole size can be adjusted during the molding process. For example, in combination with the breaker plate, the temperature is controlled by heating and / or cooling, and / or the flow hole size can be adjusted during the molding process. This new process also promotes the mixing of composite materials and the separation of different / contaminated plastics in recycled plastic materials, for example. For example, the separation of different / contaminated plastics in recycled plastic materials. This new process also promotes the mixing of composite materials and the separation of different / contaminated plastics in recycled plastic materials.

[0010] Furthermore, a new and innovative hot runner system with at least one cold runner part in the mold part and / or mold section Is reheated during all molding cycles before the injection of the next partially molten plastic material, for example, using conductive heating either entirely or partially. This heating mode often has a short heating process lasting less than 0.5 seconds. This heating mode often has a short heating process lasting less than 0.5 seconds.

[0011] 2. Brief description of related technologies that can be improved by the disclosed invention.

[0012] Plastic extrusion is a mass production process that melts raw plastic and forms it into a continuous profile. Extrusion is used to produce items such as pipes / tubes, weather strips, fences, deck handrails, window frames, plastic films and sheets, thermoplastic coatings, and wire insulation. This process starts by feeding the plastic material (pellets, granules, flakes or powder) from the hopper into the barrel of the extruder. The material is conveyed by a rotating screw.

[0013] This process starts by feeding the plastic material (pellets, granules, flakes or powder) from the hopper into the barrel of the extruder. The material is conveyed by a rotating screw. The mechanical energy generated is gradually melted by the heater arranged along the barrel. The molten polymer is then pushed into the die, and the die forms the polymer into a shape that solidifies during cooling.

[0014] In plastic extrusion, the raw material composite is usually in the form of pellets (small beads, often called resin) that are supplied by gravity from a material hopper attached above to the barrel of the extruder. Additives such as colorants and UV inhibitors (in liquid or pellet form) are often used and can be mixed into the resin before arriving at the hopper. This process has many similarities with plastic injection molding in terms of extruder technology, but is usually a continuous process which is different in this regard. Pulling forming can usually provide many similar profiles in a continuous length with a reinforcing material added, which is achieved by pulling the finished product out of the die instead of extruding the molten polymer through the die. The material enters through a feed port (an opening near the rear of the barrel) and contacts the screw.

[0015] A rotating screw (usually rotating at 120 rpm etc.) pushes the plastic beads into the heated barrel. Due to viscous heating and other effects, it is almost never the case that the desired extrusion temperature equals the set temperature of the barrel. In most processes, a heating profile with three or more independent PID-controlled heater zones is set for the barrel to gradually increase the temperature of the barrel from the rear (the side where the plastic enters) towards the front. This enables the plastic beads to gradually melt as they are pushed through the barrel, reducing the risk of overheating that could cause degradation of the polymer. ​​​​​​​​​​​

[0016] The strong pressure and friction generated inside the barrel cause excess heat to be produced. In fact, the extrusion process If the machine is producing a specific material at a sufficiently high speed, the heater will stop and the pressure inside the barrel will be reduced. The melting temperature can be maintained by friction alone. In most extruders, the heat generated is too much. A cooling fan is installed to keep the temperature below a set value when the device is running. Forced air cooling is insufficient. In some cases, a cast-in cooling jacket is used.

[0017] At the front of the barrel, the molten plastic separates from the screw and passes through the screen pack. Remove all contaminants from the molten material. The pressure at this point should exceed 5,000 psi. Therefore, the screen is reinforced with a breaker plate (a thick metal pack with many holes). It is being reinforced. The screen pack / breaker plate assembly is also located inside the barrel. It also plays a role in generating pressure. Back pressure is necessary for the uniform melting and proper mixing of polymers. The magnitude of the pressure generated depends on the screen pack's configuration (number of screens, wire weave). This can be "adjusted" by changing the size and other parameters. The combination of a raker plate and screen pack also produces a "rotational record" of molten plastic. Remove the "memory" and create a "vertical memory" instead.

[0018] The breaker plate is originally used in extruders to cover the filter screen and extrude the metal. Breakers are necessary to uniformly melt and mix the polymer before it enters the mold. The number of holes in the plate, the diameter of the holes, and the thickness of the breaker plate are related to the time required for the molding process. It directly affects the situation.

[0019] By using breaker plates in the extrusion process, sealing between extruder barrels and the 2. To enable a means of constructing back pressure through the use of screen packs, and to achieve two objectives. It can be accomplished.

[0020] However, because the screen is too fine, some of the ingredients are filtered out, and back pressure occurs during the production process. An increase in these factors can lead to adverse effects.

[0021] The solution is to design a breaker plate with the same surface, meaning smaller holes. The goal is to achieve the same back pressure without using a screen by reducing the number of screens.

[0022] An optimized breaker plate, for example, maximizes the number of holes of different sizes. It is possible to design different hole configurations for a given break plate shape. By providing this, the optimized design is made from different plastic materials and / or composite plastics. Homogeneous / consistent output of tic materials, stress distribution and deformation under different molding / extrusion conditions. It can be evaluated.

[0023] Furthermore, to avoid excessive deformation due to stress generation, the thickness from end to end between consecutive holes This was also important. After iterative calculations considering different parameters, the maximum was achieved. Three optimal breaker plates with a sufficient number of holes, while keeping stress and deformation within acceptable limits. A design was proposed.

[0024] The molten plastic passes through the breaker plate and then enters the extrusion mold. The mold determines the profile of the final product, and the molten plastic forms a cylindrical profile. The design needs to ensure that the material flows uniformly from the file into the product's profile shape. The uneven flow at each stage resulted in unwanted residual stress at specific locations in the product profile. This can produce a material that may cause warping during cooling. Limited to continuous profiles, It is possible to create a variety of shapes.

[0025] Next, the product needs to be cooled, which is usually done by passing the extruded product through a water bath. This is achieved. Because plastic has very high thermal insulation properties, rapid cooling is difficult. Steel Compared to iron, plastic conducts heat 2,000 times slower. In this process, a carefully controlled vacuum is applied to a sealed tank, and newly formed and still dissolved water is then used. To prevent the melting tube or pipe from collapsing. In this product, cooling is performed by pulling through a set of cooling rolls. For very thin sheets, as with blow film extrusion molding, the first cooling step involves air. Cooling is effective.

[0026] Plastic extruders also process recycled plastic after cleaning, sorting, and / or mixing. It is widely used to reprocess waste materials or other raw materials. This material is generally Specifically, to be cut into beads or pellets to be used as a precursor for further processing. It is extruded onto a suitable filament.

[0027] Typically, thermoplastic resin screws have five possible zones. In industry terminology... Because they are not standardized, these zones may be called by different names. The screw design varies depending on the type, and some incorporate all possible zones. Some are not there.

[0028] Many screws, Supply zone (also called solid transport zone): This is the zone where resin is supplied to the extruder. The channel depth is usually the same across the entire zone. Melting zone (also called transport zone or compression zone): Most polymers are in this zone. It melts in minutes, and the channel depth gradually decreases, Weighing zone (also called melting and conveying zone): This zone melts and evens out the last particles. Mix to achieve a uniform temperature and composition. Similar to the supply zone, this zone also has channels. The depth is constant. It has three zones.

[0029] Also, the bent (two-stage) screw is, Decompression Zone: In this zone, the channel suddenly deepens at about two-thirds of the way down the screw. This releases the pressure, and all trapped gases (moisture, air, solvent, etc.) are released. This allows for the vacuum extraction of the reactants, and Second metering zone: This zone is similar to the first metering zone, but the channel depth is greater. It is being repressurized and its role is to pass through the resistance of the screen and die. to fulfill It is equipped with.

[0030] In many cases, the length of a screw is expressed in terms of the L:D ratio relative to its diameter. For example, a screw with a diameter of 6 inches... A 150mm (inch) screw length is 144 inches (12 feet) in a 24:1 ratio. Therefore, a 32:1 aspect ratio is 192 inches (16 feet). The L:D ratio is generally 25:1. However, to achieve more mixing and output with the same screw diameter, 40: Some machines raise it to level 1. Two-stage (bent) screws take into account two extra zones. The usual ratio is 36:1.

[0031] Each zone is equipped with one or more thermocouples on the barrel wall for temperature control. The "profile," or the temperature of each zone, is extremely important for the quality and characteristics of the final extruder. It is essential.

[0032] Typical plastic materials used in extrusion include polyethylene (PE) and polypropylene. Repropylene, acetal, acrylic, nylon (polyamide), polystyrene, polysalt Polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), and polycarbonate There are other options, but they are not limited to these.

[0033] The manufacture of plastic films for products such as shopping bags and continuous sheets is This is achieved using a blow film line.

[0034] This process is the same as normal extrusion up to the die. The die used in this process is There are mainly three types: annular (or crosshead), spider, and spiral. Yes, there is. An annular die is the simplest, and the entire cross-section of the die before the molten polymer leaves the die. Because it relies on flowing along the body, the flow can be uneven. Spider Dye It consists of a central mandrel attached to the outer diling via many "legs". Compared to annular dyes, the flow is more symmetrical, but the numerous wells weaken the film. A weld line is generated. The spiral die solves the problems of weld lines and asymmetric flow. Deleting it is by far the most complex task.

[0035] The molten material cools slightly before leaving the die, becoming a weak, semi-solid tube. The diameter of the tube is rapidly expanded by air pressure, and the tube is pulled upward by rollers. The plastic is stretched in both the lateral and pull directions. Through stretching and blowing, The film is thinner than the extruded tube, and the part where the most plastic strain is observed is also thinner. The polymer molecular chains are preferentially aligned in that direction. When the draw is greater than the blow (final chain (When the tube diameter is close to the extrusion diameter), the polymer molecules are highly aligned with the drawing direction, and in that direction The resulting film is strong but weak in the transverse direction. Films with a diameter significantly larger than the extrusion diameter will be weak in the transverse direction. The strength in the direction is high, but the strength in the stretching direction is low.

[0036] In the case of polyethylene and other semi-crystalline polymers, when the film cools, freeze lines appear. Crystallization occurs in known areas. As the film continues to cool, the film develops several sets of nickel It is passed through a roller to become a flat tube, and then wound up or slit into two or more sheets. It can become that.

[0037] Sheet / film extrusion molding is used for plastic sheets or films that are too thick for blow molding. Used to extrude material. Two types of dies are used: T-shaped and coat hanger-shaped. These dies are of a type. The purpose of these dies is to direct the flow of molten polymer through a single circular output from the extruder. The goal is to redirect the flow from there into a thin, flat plane. With either type of die, Ensure a consistent and uniform flow across the entire cross-section of the die. Cooling is typically performed with a set of cooling rods. This is done by pulling through the rolls. In sheet extrusion, these rolls are necessary. In addition to providing cooling, it also determines the sheet's thickness and surface texture. UV absorption, texture, and durability. To obtain specific properties such as oxygen permeability or energy reflectivity, one or more layers are applied to the substrate. Co-extrusion is a common practice.

[0038] A common post-injection process for plastic sheet materials is thermoforming, which is used for sheet materials. The material (plastic) is heated until softened, and then molded into a new shape using a mold. When using air, it is often referred to as vacuum forming. Orientation (i.e.) The capacity / utilization of sheets drawn into molds, where the depth can typically vary from 1 to 36 inches. Possible density is very important and significantly impacts the molding cycle time of most plastics. To have an influence.

[0039] Extruded tubes such as PVC pipes are very different from those used in blow film extrusion molding. It is manufactured using a die similar to this. To obtain the correct final dimensions, a pin is inserted. This involves applying positive pressure to the internal cavity or applying negative pressure to the outer diameter using a vacuum sizer. Yes, it is possible. By adding the appropriate inner mandrel to the die, the lumen or hole can be increased. You may add more.

[0040] Multilayer tubing also has a constant presence in the automotive, plumbing and heating, and packaging industries. ru.

[0041] Overjacket extrusion molding involves creating a plastic outer layer on top of existing wires or cables. This allows for application. This is a typical process for insulating electrical wires.

[0042] The mold tool for coating on the wire includes tubing (or jacketing). There are two different types: (dieting) and pressurizing. Jacketing tools use a die-casting tool. The molten polymer does not come into contact with the inner wire until just before the pressurizing tool. It contacts the inner wire well before reaching the die lip. This ensures good melting. This is done under high pressure to ensure adhesion. Close contact between the new layer and the existing wire. Alternatively, if bonding is necessary, use a pressure tool. If bonding is undesirable / unnecessary. Instead, use a jacketing tool.

[0043] Co-extrusion is the process of simultaneously extruding layers of multiple materials. This type of extrusion molding is performed by two Using more than one extruder, various viscous plastics are melted and the material is extruded into the desired shape. This technology provides a stable volume throughput to a single extrusion head (die). Any of the above processes (blow film, overjacket, tube, sheet) It is used for this purpose. The thickness of the layers depends on the relative speed and size of the individual extruders that supply the material. It is controlled in that way.

[0044] In many real-world scenarios, a single polymer cannot meet all the requirements of an application. In composite extrusion, blended materials can be extruded, whereas in co-extrusion, separate materials can be extruded. Because these are retained as different layers in the extruded product, oxygen permeability, strength, rigidity and wear resistance are maintained. It is possible to appropriately arrange materials with different properties.

[0045] Co-extrusion is a process in which two or more plastic materials are extruded from a single extrusion die. It can also be defined as follows: In this process, two or more orifices are used to conjoin the extruded material. Arranged to allow for inlet junction and welding, a layered structure is formed before cooling. Co-extrusion So, separate extruders are used to supply each material to the extrusion mold, but each extruder is the same The orifice can also be positioned to supply two or more layers of the same material.

[0046] Co-extrusion is used in film blowing, extrusion coating, and free film. It is sometimes used in the aluminum extrusion process. The advantage of co-extrusion is that, generally, heat seal This involves imparting necessary properties such as flexibility, rigidity, and impermeability to each layer in the lamination process. All of these things cannot be achieved using a single material.

[0047] Co-extrusion is clearly a superior process to monolayer extrusion. For example, In the fencing industry, co-extrusion is used to adjust the layers based on whether or not they will be exposed to wind and rain. The process is used. Generally, a thin layer of compound containing expensive weather-resistant additives is pressed. This extrusion process is performed on the outside, and the inside is made more suitable for structural performance and impact resistance. There is an additive package.

[0048] Advantages of co-extrusion

[0049] Co-extrusion processes are continuously used in the production procedures of various internationally established and well-known companies. According to the company, this process has many advantages. In short, High-quality single-layer extrusion coatings at a wider range of line speeds and widths. By using low-cost materials for filling purposes, it is possible to save on the amount of high-quality resin. It is possible to create multi-layered and multi-functional structures in a single pass. Reduction of the number of steps in a typical extrusion molding process, By using a specific polymer in a specific layer, the desired performance can be achieved. Reduction of setup and trim scrap, and Potential use of recycled layers, These are some examples.

[0050] Disadvantages of co-extrusion

[0051] According to many globally renowned companies, there are several drawbacks associated with the co-extrusion process. Yes, there are some of these drawbacks. Slight differences in physical properties make a combination desirable, but these differences also affect the combination. This is also a cause of non-conformity. In this process, the polymers must have similar melt viscosities in order to maintain laminar flow. There is. All differences in viscosity are more or less due to the position of the material within the composite structure and the thickness of the layer. There are cases where it is tolerable. More advanced extruders and operators are required, and this involves equipment maintenance. This means that extra costs will be incurred, System design requires considerable planning and foresight. This is one example.

[0052] Extrusion coating is applied to existing paper using a blow or cast film process. To coat an additional layer onto roll material, foil, or film. For example, this process This involves enhancing the properties of paper, such as increasing its water resistance by coating it with polyethylene. It can be used to improve the material. Also, the extruded layer connects the other two materials. It can also be used as an adhesive.

[0053] Compound extrusion involves mixing one or more polymers with additives and / or fillers. This is the process for obtaining a plastic compound. Additives and / or filler materials are tensile It can affect strength, toughness, heat resistance, color, transparency, etc. For example, polypropylene Adding talc to plastics is a good example of this. Filler materials used in plastics Most of these are mineral or glass-based filler materials. Filler materials include fine particles. There are two main subgroups: fibers and microparticles. - These are small particles, and their size and aspect ratio are important. Fibers come in a variety of shapes, and many In this case, it is a very long, small circular strand with a very high aspect ratio.

[0054] The supplies may be pellets, powders, and / or liquids, but the compounded products are This is the form of pellets commonly used in other plastic molding processes such as extrusion molding and injection molding. Similar to conventional extrusion molding, the machine size can be adjusted depending on the application and desired processing volume. There is a range. Conventional extrusion may use single-screw or twin-screw extruders, but compound extrusion Since thorough mixing is necessary, a twin-screw extruder is almost essential.

[0055] Twin-screw extruders have two subtypes: co-rotating and counter-rotating. This indicates the direction in which each screw rotates relative to the other. Same-direction rotation In this type, both screws rotate either clockwise or counterclockwise, and in the opposite direction, one of them rotates... One screw rotates clockwise, and the other screw rotates counterclockwise. Given the cross-sectional area and - In terms of the degree of burr lap (meshing), co-rotating twin-screw extruders have better axial speed and The degree of mixing is shown to be high. However, the pressure increase is greater in the reverse-rotating extruder. The price will increase. Screw designs are generally modular, allowing for various conveying components and mixing. The components are positioned on the shaft, and the process may change due to damage from wear or corrosion. This allows for quick reconfiguration for the replacement of individual components.

[0056] injection molding

[0057] The injection unit of an injection molding machine is very similar to an extruder. The injection device melts the polymer resin. Then, the molten polymer is injected into the mold. This involves a hopper that supplies plastic pellets. - It consists of a barrel supplied from one end by -. The unit is a ram feed Alternatively, a screw feed may be used.

[0058] The injection unit consists of a granulation hopper, cylinder, screw, nozzle, heat band, and hydraulic drive. It consists of a moving mechanism and is responsible for melting and injecting the molding material.

[0059] Nozzle shut-off valves are used in plastic injection molding machines. From the injection device, or This is done by opening and closing a shut-off valve using the pressure of the plastic inside the injection device. In one embodiment, the plastic Reciprocating screw type or pneumatic type used for handling sticky and elastomer materials. This concerns an improved nozzle shutoff valve for use in Langer-type injection molding machines. ru.

[0060] Conventional reciprocating screw molding machines typically include a plasticizing cylinder or bore. The screw includes a screw, where the plasticizing screw allows the solid molding material to enter the cylinder and screw It rotates in such a way that it becomes plasticized as it moves in the direction of the feed. At one end of the plasticizing cylinder A nozzle is attached that communicates with the mold sprue, which leads to the mold cavity. When the material is processed and accumulates in the metering section or the front end of the screw, back pressure is generated and the screw As it retracts within the cylinder bore, and the plasticized material reaches a predetermined amount or shot size... The retracted screw then contacts the limit switch and stops rotating. This completes the mold cavity The screw is ready to be injected into the tee, and generally receives a signal from the clamp. The shot is ejected by a hydraulic and / or electric propulsion system. Afterwards, the plasticizing screw is re As it begins to rotate and new shots accumulate inside the plasticizing cylinder, it gradually retracts. Thus, the screw reciprocates once per machine cycle to plasticize and shock the material. It launches a projectile.

[0061] A shut-off valve is used to block the flow of molten material from the nozzle to the mold sprue. This often happens. This valve prevents leakage by blocking the flow of material at the nozzle. The advantage is that it minimizes or completely suppresses this and provides the ability to plasticize while the mold is open. It has. Generally, plasticization is a process to harden a part in order to prevent the plasticized material from leaking out. It is done during the transformation process.

[0062] Various arrangements of hydraulic motors, pneumatic pistons and cylinders, as well as the position of several components. Depending on the direction, a force is applied to open the nozzle shut-off valve in preparation for the injection cycle.

[0063] In a valve gate hot runner system, the shut-off valve(s) are used to shut off individual cavities. It is also possible to place them inside the mold using the "i" (multiple) method.

[0064] A hot runner system is a process that injects plastic into the cavity of an injection molding die. It is an assembly of heated parts (hot half, nozzle and gate, etc.). This typically includes a heated manifold and a number of heated nozzles. The manifold is The plastic that enters the mold is dispensed into a nozzle, which accurately measures and dispenses the contents into the cavity. It supplies fuel to the injection point. A hot runner has what is called a hot runner controller. It is equipped with a unique temperature control system.

[0065] A hot runner controller is used to control the temperature within the hot runner. This is a temperature control device. This allows the temperature of individual gate locations to be changed. This results in the highest consistency of the molded product and allows for balanced filling of the cavity(s). It will become.

[0066] On the other hand, the cold runner was simply a channel formed between the two halves of the mold. It then plays the role of transporting plastic from the nozzle of the injection molding machine to the cavity. Each time a newly formed plastic part is ejected, the material inside the runner is also ejected. Therefore, waste occurs.

[0067] A hot runner system typically includes a heating manifold and a number of heated nozzles. The main role of the manifold is to distribute the plastic entering the mold to various nozzles, precisely. The process involves measuring the material and supplying it to the injection point within the cavity.

[0068] The hot runner system is a fairly complex system, and the internal plastic material While uniform heating is necessary, other parts of the injection mold are needed to quickly solidify the product. It is cooled.

[0069] Hot runners typically have high mold manufacturing and running costs, but plastic This reduces plastic waste and eliminates the need to wait for the conventional runner to freeze. This allows for savings by shortening the cycle time.

[0070] The advantages of hot runners are, Short cycle time: No runners to control cooling time. Easy to start: No need to remove runners, and auto-cycles are performed faster and more frequently. ru, Reduced sink marks and underfill parts: Plastic passes through the cold runner and mold This is different from when heat is lost to the plate. Design flexibility: It is possible to place gates in various positions on the parts, and Balanced melt flow: Individual melt channels are insulated from the surrounding mold plate. In the externally heated manifold, That is the case.

[0071] From a technical standpoint, valve gate technology makes it possible to manufacture injection molded parts with low stress. In most cases, it meets the requirement of very low traceability. As a result, in valve gate systems Low stress is important when performing gating. When using a valve gate, small To achieve the gate diameter, there is no need to control the traces. Of course, the gate diameter is As the size increases, the shear rate increases, which inevitably leads to a higher degree of orientation. The parts with a high degree of orientation are on the inside. Because it causes stress in the area, there is a high risk of warping in the part. For example, shot weight 1 If a component weighing 0g has a gate diameter of 0.8mm, the local shear rate will be approximately 150,000 ¹ / s. Furthermore, when using a valve gate with a needle diameter of 2.5 mm, the shear rate at the gate is approximately 6 This results in ,0001 / s.

[0072] When using a valve gate system, safety must also be considered. For example, Valve gate systems are used in high-speed circulating molds to prevent stringing. Stringing occurs when the molten material in the gate does not have a chance to freeze properly within a given time. This phenomenon inevitably occurs in molds with fast cycles, large gate diameters, and temperature control. This can occur if the procedure is inappropriate. Using valve gate technology, most In all cases, stringing can be avoided. Mechanical blocking prevents stringing regardless of the gate diameter. This ensures that the gate is properly sealed. However, the needle diameter is very large. In some cases, even valve gate systems can experience problems. When operating, the needle accumulates a lot of heat during injection, causing a blob in the needle area. A ding effect may occur.

[0073] Furthermore, by using a valve gate, the shut-off time can be precisely controlled, and the processability To improve the process when molding multi-gate parts, sequentially releasing the needles improves the flora. This method can be used to avoid the formation of ions. It also allows for control of melt flow. This allows for avoiding head-on collisions in the flow, or placing parts in less critical areas. It is possible.

[0074] Gate variations of valve gate systems

[0075] Two important seals are necessary for processing thermoplastics using valve gate systems. The principle has been established. One of them is the shape of the cone-shaped needle. While closed, The conical needle moves to the corresponding gate shape of the mold insert. This principle is used. In such cases, limit the closing force of the needle drive to avoid damaging the mold insert. It is necessary. When the needle closes, the molten material is discharged through the narrowed gap.

[0076] Cylindrical needles are also commonly used instead of conical ones. In this case, they are used as mold inserts. It typically has a conical opening leading to a short cylindrical bore. The molten material in the cylindrical portion is only It's only about one-tenth of a millimeter, but it needs to be pushed into the part when closing the needle. Considering the small amount of melted material and shrinkage, this usually does not affect the molded product.

[0077] The needle, which protrudes diagonally from the side towards the gate, slightly obstructs the melt flow in the open position. Since it only does that, it has several advantages. However, this gate method is asymmetrical layout Due to its high wear rate, it is not well-received in the market.

[0078] Needle drive integrated valve gate system

[0079] The inline valve gate with built-in needle drive is more versatile compared to standard designs. It is a typical system. Due to the nozzle structure, the valve gate is a "conventional" hot runner system It can be handled in the same way as M. As shown in the description of function and mounting position, fixed The mold half includes a standard clamp plate and a manifold frame with a standard manifold. It consists of a plate and a nozzle retainer plate. The inline valve gate is German It can also be used as a standalone single chip. No structural changes are required. Examples of uses are shown below.

[0080] When used in stack molds, inline valve gates offer a decisive advantage. By placing the needle drive behind the manifold, the needle is routed through the manifold. Because there is no need for guidance, it is possible to arrange the cavities perfectly symmetrically. This means the optimal use of molds and machinery. Furthermore, two are positioned directly opposite each other. The inline valve gate nozzle does not require the use of an accumulator cavity. It can be used to perform leak-free molten transfer in the center of a stacked mold.

[0081] For large molds where the nozzle is deeply submerged, a very long needle is required. Sometimes the nozzle is screwed to the manifold. When the manifold is heated and expands due to thermal expansion... To ensure the needle reaches the desired position, the system should be kept cool. Failure to properly fit the needle can lead to needle jamming and wear of the needle guide. There is a problem with the final stage of the long nozzle, which has a needle drive integrated valve gate. This can be resolved by using a stem. The valve gate position is fixed within the mold. The flexible pipe connects the valve gate to the manifold. The needle is the valve gate. Because it is housed within the assembly, the expansion is small, and other elements such as manifold expansion are not required. It is not affected by this.

[0082] Standard valve gate

[0083] Standard valve gates are important when a low system height is required. Needle drive Because Eve is positioned within the clamp plate, the overall height of the system is the same as a normal hot runner. It is similar to the stem. However, when using this method, the manifold of the hot runner system The hold needs to be specially adjusted to the valve gate system. A sealing element needs to be added. Either do this, or at least install a clearance bore for the needle. The bore must be positioned so as not to interfere with the molten channel in the manifold. In such situations, an inlet with a needle drive that can be operated mechanically, hydraulically, or pneumatically is available. An in-valve gate nozzle is useful.

[0084] Multi-component valve gate

[0085] A coaxial valve gate was developed by applying the principle of a standard valve gate. This technology is one It allows two components to be injected through the inlet. These components are injected simultaneously or with a delay. It may be injected. Considering mold technology, inner layer / outer layer, outer layer / inner layer (simple layer), outer layer A layer configuration of inner and outer layers (sandwich) is possible. This is especially true for multi-cavity molds. The possibility of using a sandwich method for direct gating holds promise for a wide range of applications. For example, the manufacture of preforms with a barrier layer, or thick wall components (foam to counteract shrinkage). It is possible to manufacture core components. By using materials with different structures for the inner and outer layers, special It is possible to create an appearance with a specific tactile feel.

[0086] Furthermore, coaxial valve gates are also suitable for partial hot runner solutions. For example, when used as a machine nozzle, there are various methods. First, additional machine One way to use it is as a "universal single nozzle" within the plate. In this configuration, A combination of a standard two-component molding machine and a conventional runner solution (3-plate mold) In addition, it is possible to manufacture sandwich components. In this case, it is called a "sandwich." Because of the "touch plate," most of the mold's daylight width cannot be utilized, Not only the individual components, but the cold runner system itself also needs to have sufficient dimensions.

[0087] This problem can be solved by using a two-part machine nozzle. In this case, both injections Because the unit needs to be connected with a coaxial valve gate nozzle, a machine with a special configuration is used. It is necessary to use it. The coaxial valve gate system facilitates the simultaneous injection of two liquids. By adjusting the simultaneous phases of the cycle, the penetration of the core components can be changed. Using the above mechanical configuration, both injection units can be used independently for normal injection molding. It is possible to create shapes. In the case of molded products that require two-color molding, the color change can be achieved in a single injection. ru.

[0088] Of course, two-part molding is also possible with "conventional" valve gate systems. One method is the transfer method, which involves a rotary table or handling system. It requires a stem. Another is the core-back method. Neither is suitable for layer configurations. Not used, mainly for additional sealing lips, grip area and two adjacently positioned parts. It is used in the manufacture of articles having colored areas or injected polymer windows.

[0089] "Hot runner" is a term used in injection molding, referring to a machine that injects molten plastic into a machine. Cavities of various mold tools combined to form the shell of a part from a nozzle A system of parts that are physically heated for more efficient use in order to be transported to a location. This refers to the term "hot runner." These are sometimes called "hot sprues." It is the opposite of that and is contrasted with the historically more common "cold runner". Yes, it is possible. A cold runner is used to remove molten plastic after it exits the nozzle into the mold tool cavity. It is simply an unheated physical channel that leads to [the target]. The main difference is, The difference is that hot runners are heated, while cold runners are not.

[0090] While hot runners are not essential in the injection molding process, they allow for the production of higher-quality parts. This is effective for that purpose. In particular, it is necessary to reduce errors in the flow characteristics of molten plastics. It is effective for parts with complex shapes (e.g., when the flow becomes uneven due to improper cooling or temperature differences). (If there is a possibility of this happening). Furthermore, hot runners are effective in reducing plastic waste during mass production. Because the cold runner is unheated, the channel needs to be larger, and in each cycle... A large amount of resin needs to be poured. When molding a large number of parts while modifying the design, The cost of plastics could easily exceed the cost of the runner assembly. Yes. The drawback of hot runner technology is that it requires more default setup than cold runner setup. And it is expensive.

[0091] The advantage of hot runners is that, if properly designed, they allow plastic to escape from the machine's nozzle. The goal is for the molten plastic to flow more uniformly to the gate position. The gate position is where the molten plastic is injected. This refers to the position where the plastic enters the cavity of the molding die. Factors include gate position, plastic temperature, and metal. The design of the cavity inside the mold, the material properties of the plastic itself (for example, virgin material) The characteristics of the regrind / recycled materials and molds used for different preforms are all different. This has a significant impact on the success or failure of the ejection molding process.

[0092] Hot runners maximize manufacturing productivity by reducing cycle times. Designed to be such as, the internally heated hot runner design is at the internal boundary of the channel. The plastic solidifies, and the molten plastic becomes more localized at the location of a specific heater. This leads to solidification. On the other hand, an externally heated hot runner uses a heating nozzle and a heating manifold. By using the high thermal conductivity of metal, the internal flow properties of the plastic are maintained more uniformly. It is possible to possess it.

[0093] External heating type: This system design uses a cartridge-type heating manifold with an internal flow path. A rud is adopted. To separate it from the other parts of the mold, the manifold reduces heat loss. It has some insulating properties. It does not require a heater that obstructs the flow, and all plastics Because it is molten, the externally heated hot runner channel is the most important component in all runner systems. This method results in the lowest pressure loss. This method ensures that no color freezes within the runner system. It is effective for color changes. Furthermore, since it does not have a surface that deteriorates due to material adhesion, external heating This method is suitable for heat-sensitive materials.

[0094] Internal heating type: The internal heating type runner system has an annular flow path, which is located within the flow path. It is heated by the placed probe and torpedo. Utilizing the insulating effect of the molten rubber, This reduces heat loss to other parts of the mold. However, this method requires high molding pressure. Yes, and changing the color becomes quite difficult. Also, the material has many areas where it adheres to the surface, leading to deterioration. Materials that are sensitive to heat should not be used in the manufacturing process.

[0095] The runner is heated by a coil, cartridge heater, heating rod, heating pipe and van This can be done through various materials such as heaters. This ensures a stable flow and distribution of the molten material.

[0096] Insulated runners: These are non-heated and maintain moltenness during continuous cycling. A very thick runner channel is required for this. This mold is very thick on the mold plate. A large channel is formed there. In the manufacturing process, the size of this channel and each shot The heat applied to the manifold opens the molten flow path. This inexpensive system allows for manifolds. This eliminates the need for additional costs for lumber and drop, and provides flexible gaiters for heated hot runner systems. It achieves this. Color changes are also easy.

[0097] In a 3-plate mold, if part of the cold runner system is on a different plane from the injection position... Used in combination. The runner system of the 3-plate mold has a second division parallel to the main division surface. It rests on the surface. This second dividing surface allows the runner and sprue to be ejected when the mold is opened. It can be released.

[0098] Injection screw

[0099] Reciprocating screw machines are the most common type. In this design, plus The same barrel is used for melting and injecting the chip.

[0100] Once the mold is closed, the screw moves the plastic forward through its rotation, and the screw The pipe retracts while filling a predetermined volume just before reaching the nozzle, and then stops rotating. Next, once the empty mold is closed, the screw is used as a plunger, and warm The plastic is poured into an empty mold, and the filled mold cavity is left to harden until the plastic solidifies. The mold is held under pressure. After a predetermined cooling time has elapsed, the mold opens, and the solidified plastic inside the mold is released. The parts are ejected, the mold closes again, and this process is repeated.

[0101] There is also another type that uses separate barrels for polymer plasticization and injection. This is called a screw pre-plasticizer or two-stage device. Plastic pellets are placed in a hopper. -It is introduced into the first stage, in which the polymer is advanced and dissolved using a screw. Melt. This barrel supplies the molten material to a second barrel that uses a plunger to inject the molten material into the mold. In older machines, a single plunger-driven barrel is used to melt and dissolve plastic. It was injecting material. This device is called a plunger-type injection molding machine.

[0102] Selection of injection molding screws

[0103] Using the appropriate injection molding screw ensures the continuous production of high-quality parts. This is extremely important for maximizing production volume.

[0104] To select the appropriate screw, you need to know the details of the specific part to be molded (i.e., the material of the part). It is necessary to know the quality, weight, size, and wall thickness, etc. The basic design of the mold is also important. Yes, all factors such as the distance from the gate, the weight of the shot, and the runner system are taken into consideration. It will be done.

[0105] Choosing screws without any knowledge of the parts is like buying a car without considering your preferences for performance and ease of use. It's eel.

[0106] The basic design of the screw is, in the longitudinal direction, 1. Supply Zone 2. Transition Zone 3. Weighing Zone There are three zones.

[0107] In the supply zone, solid plastic pellets supplied from the hopper are used in the pellets. The material is transported to a transition zone where it is compressed by a change in the screw shape. This compression causes the material to be compressed. The molten metals are pushed up against each other as they melt. This is called "shearing." After that, the metering zone The molten material is then transported to the front of the screw, preparing it for injection into the mold cavity.

[0108] In the transition zone, the material changes the depth of the screw channel from the supply zone to the metering zone. It is compressed by chemicalization. The ratio of the change in depth is called the compression ratio, and this applies to materials such as PP and PE. In a screw, it is usually 2-3. The length of the transition zone is the screw diameter in a general-purpose screw. A ratio of 4 to 7 times is typical.

[0109] Another aspect of screw design is its major axis, which is how long it is relative to its diameter. There is a ratio (L / D). For example, the L / D ratio of PP and PE is in the range of 20 to 30:1.

[0110] In the case of typical screws, longer screws produce higher quality molten material. This is generally preferred because it allows for the production of higher-quality parts.

[0111] The advantage of general-purpose screws is that they can be used with most plastics such as PP, PE, nylon, PET, and PC. Highly flexible and suitable for use with plastic materials, this molding machine can shape a variety of materials. It is suitable for makers.

[0112] One drawback is that, depending on the material, it may require a more advanced injection molding screw, such as a barrier screw. - Compared to the design, the quality and production rate of the parts may decrease.

[0113] This type of screw produces better quality molten material faster compared to general-purpose screws. We offer a variety of barrier screws, with different flight depths and channels. The widths are different.

[0114] It is necessary to select the exact design that suits the intended use.

[0115] Double flight screws have different designs but are an alternative to barrier screws. These are designed to supply high-quality molten material at high speed. ru.

[0116] This design allows the plastic to reach the compression zone before it does, something impossible with conventional screws. Ensure that the molten material is completely dissolved.

[0117] The double-flight injection molding screw is made of PP (polypropylene) and a barrier screw. It can be used for thin-walled PA technical components that do not plasticize well.

[0118] There are two reasons why the screw diameter is important. The first reason is the maximum usable injection pressure. This determines the usable pressure, with smaller diameters resulting in higher flow rates. This is extremely important for parts with long path lengths and for plastic materials that are difficult to injection mold.

[0119] The second reason is that the maximum shot size that can be used is determined by the diameter. The smaller the diameter, the smaller the shot size.

[0120] Thus, the selection of the screw diameter depends on the balance between the shot size and the injection pressure. This can be understood. Initially, the aim was to have flexibility in the types and sizes of parts that could be produced by a single machine. It might seem advantageous to choose the largest diameter, but that's a mistaken idea.

[0121] The screw diameter must be selected according to the application; otherwise, quality and / or production will be affected. The rate is compromised. The injection machine maintains a constant filling time and, as a result, maintains quality. It is necessary to have the capability to generate sufficient injection pressure (including reserve pressure).

[0122] Using heat-treated screws and barrels is more effective than using unheat-treated parts. It will last longer, so it needs to be seriously considered. This is because the material contains a certain amount of reinforcing material. When reinforced, it has better abrasive properties than materials without reinforcement, and wears down the screw and barrel faster. It is especially important for causing wear and tear.

[0123] When the screw and barrel begin to wear down, the quality of the parts starts to deteriorate and they will need to be replaced. It's only a matter of time before this happens. This is due not only to the cost of replacing the screws, but also to the reduction in production. This also represents a significant cost.

[0124] The key point is the check valve located at the front of the screw, which allows the molten material to pass through during the plasticization stage. This allows for injection, but prevents molten material from flowing back into the screw during the injection stage.

[0125] There are two basic designs: ball check valves and slide-ring check valves. Generally, Ring-type check valves are preferred over ball-type check valves because they allow for a more favorable path for molten material to pass through. Therefore, ring-type check valves are suitable for shear-sensitive materials such as PC.

[0126] However, a drawback of ring-type check valves is that they are prone to wear, so regular ring checks are necessary. It is necessary to check the condition of the valve. Typical signs of wear include the valve during machining. The problem is that the sensation is not consistent.

[0127] In today's competitive environment, injection molding manufacturers are trying to reduce manufacturing costs and shorten lead times. Therefore, it is true that we need to manufacture parts as efficiently as possible.

[0128] To achieve this, using an injection molding screw suitable for the part plays a crucial role.

[0129] Plasticizing cylinder

[0130] Screw position at the end of the administration process; the plasticized material is in front of the screw tip. The screw position after the injection process; the plasticized material is injected into the mold. In the foreground, a cushion of material remains for injection into the mold during the holding pressure stage.

[0131] Blow molding is a specific manufacturing process that allows for the molding and joining of hollow plastic parts. This is a process. It is also used for molding glass bottles or other hollow shapes.

[0132] Generally, blow molding includes extrusion blow molding, injection blow molding, and injection stretch blow molding. There are three main types.

[0133] The blow molding process involves melting plastic to form parisons, or injection molding and injection stretching. In the case of raw material forming (ISB), the process begins with forming a preform. A parison is a tubular plastic with a hole at one end through which compressed air can pass. It is.

[0134] Next, the parison is placed in the mold and air is blown in. Then, the air pressure causes the plastic to... The plastic is extruded according to the mold. Once the plastic cools and hardens, the mold opens and the part is ejected. The cost of blow-molded parts is higher than that of injection-molded parts, but lower than that of rotationally molded parts.

[0135] In extrusion blow molding, plastic is melted and extruded into a hollow cylindrical (parison) shape. The parison is then enclosed and taken into the cooled mold. Next, air is blown into the parison. Then inflate it into the shape of a hollow bottle, container, or part. After the plastic has cooled sufficiently... The mold is opened and the parts are ejected. As a variation of extrusion blow molding, continuous molding There are two types: shape and intermittent molding. In continuous extrusion blow molding, parisons are continuously extruded, and individual parisons are formed. The parts are cut with the appropriate knife. Intermittent blow forming has two steps. Straight Intermittent injection molding is similar to injection molding, where the screw rotates, then stops, and extrudes the molten material. The accumulator method collects molten plastic in an accumulator, and the previous mold cools down. Once enough plastic has accumulated, the rod pushes the molten plastic to form a parison. . In this case, the screw may rotate continuously or intermittently. In the case of continuous extrusion, the parison is dragged by its weight, making it difficult to calibrate the wall thickness. The accumulator head method or the rotating screw method uses a hydraulic system to quickly extrude the parison, so it is less affected by weight, and the wall thickness can be accurately controlled by adjusting the die gap with a parison programming device. The parison is dragged by its weight, making it difficult to calibrate the wall thickness. The accumulator head method or the rotating screw method uses a hydraulic system to quickly extrude the parison, so it is less affected by weight, and the wall thickness can be accurately controlled by adjusting the die gap with a parison programming device. The accumulator head method or the rotating screw method uses a hydraulic system to quickly extrude the parison, so it is less affected by weight, and the wall thickness can be accurately controlled by adjusting the die gap with a parison programming device. The accumulator head method or the rotating screw method uses a hydraulic system to quickly extrude the parison, so it is less affected by weight, and the wall thickness can be accurately controlled by adjusting the die gap with a parison programming device.

[0136] Containers such as bottles often have excess material coming out during the molding process. This is trimmed by rotating a knife around the container to cut off the material. This excess plastic is reused to make new molded products. Spin trimmers are used for many materials such as PVC, HDPE, and PE+LDPE. The physical properties vary depending on the type of material, which affects trimming. For example, molded products made from amorphous materials are much more difficult to trim than those made from crystalline materials. Blades coated with titanium instead of standard steel are often used to extend the life by 30 times. Containers such as bottles often have excess material coming out during the molding process. This is trimmed by rotating a knife around the container to cut off the material. This excess plastic is reused to make new molded products. Spin trimmers are used for many materials such as PVC, HDPE, and PE+LDPE. The physical properties vary depending on the type of material, which affects trimming. For example, molded products made from amorphous materials are much more difficult to trim than those made from crystalline materials. Blades coated with titanium instead of standard steel are often used to extend the life by 30 times. Blades coated with titanium instead of standard steel are often used to extend the life by 30 times.

[0137] The injection blow molding process is used to mass-produce hollow glass and plastic products. In the injection blow molding process, the polymer is injection molded onto a core pin, and then the core pin is rotated to a blow molding station to be inflated and cooled. This process is the least frequently used among the three types of blow molding processes and is usually used for the manufacture of small medical bottles and single-use bottles. This process is divided into three stages: injection, blow, and ejection. In the injection blow molding process, the polymer is injection molded onto a core pin, and then the core pin is rotated to a blow molding station to be inflated and cooled. This process is the least frequently used among the three types of blow molding processes and is usually used for the manufacture of small medical bottles and single-use bottles. This process is divided into three stages: injection, blow, and ejection. This process is the least frequently used among the three types of blow molding processes and is usually used for the manufacture of small medical bottles and single-use bottles. This process is the least frequently used among the three types of blow molding processes and is usually used for the manufacture of small medical bottles and single-use bottles. This process is divided into three stages: injection, blow, and ejection. This process is the least frequently used among the three types of blow molding processes and is usually used for the manufacture of small medical bottles and single-use bottles. This process is divided into three stages: injection, blow, and ejection.

[0138] An injection blow molding device includes an extruder barrel, a screw assembly for melting the polymer, and It is based on the following. The molten polymer is supplied to the hot runner manifold and then to the nozzle. It is injected into the heated cavity and core pin. The cavity mold forms the outer shape. It is fixed around the core rod that forms the inner shape of the preform. The preform is completely It consists of a thick polymer tube attached to the neck of a formed bottle / jar. It forms a body that resembles a test tube with a curved neck.

[0139] The preform mold opens, the core rod rotates, and solidifies into the hollow, cooled blow mold. The end of the core rod opens and compressed air is introduced into the preform, and the preform Inflate the mixture to the shape of the finished product.

[0140] After a cooling period, the blow mold opens and the core rod is rotated to the injection position. The finished product is the core It can be detached from the rod, and as an option, a leak test can be performed before holding pressure. Preform and blow molds can have many cavities, and the size of the molded product And depending on the required production volume, there are usually 3 to 16 units. There are 3 sets of core rods, These enable simultaneous injection molding, blow molding, and ejection of preforms.

[0141] Compression molding typically involves first heating the molding material in a heated, open mold cavity. This is a molding method that involves placing the material into a tee. The mold is closed with a top force or plug member, and pressure is applied. In addition, the molding material is brought into contact with the entire surface of the mold, and heat and pressure are maintained until the molding material hardens. In this process, the parts, which are in the state of granules, putty masses, or preforms, are processed. A thermosetting resin that has been cured in stages is used.

[0142] Compression molding is a high-volume and high-pressure method suitable for molding complex and high-strength glass fiber reinforcements. Advanced composite thermoplastics can also be compression molded in the form of unidirectional tapes, woven fabrics, randomly oriented fibers mats or chopped strands. The advantage of compression molding is that it can mold large and fairly complex parts. Also, compared to other molding methods such as transfer molding and injection molding, it is one of the lowest-cost molding methods. Moreover, since there is relatively little waste of materials, it is advantageous when dealing with expensive materials. However, compression molding often has low product consistency, is difficult to control flashing, and is unsuitable for some types of parts. Compared to injection molding, the generation of knit lines is less obvious, and the deterioration of fiber length is less noticeable. Also, compression molding is suitable for the production of basic shapes that exceed the capabilities of extrusion technology and are extremely large.

[0143] Compression molding was originally developed for manufacturing composite parts for metal replacement applications. Compression molding is usually used to make parts with large, flat or moderately curved surfaces. This molding method is widely used in the manufacture of automotive parts such as bonnets, fenders, scoops and spoilers, as well as smaller and more complex parts. The material to be molded is placed in the mold cavity, and the heated platen is closed by a hydraulic ram. The bulk molding material or sheet molding

[0144] material is adapted to the mold shape by the applied pressure and heated until a curing reaction occurs. The supply material of SMC is usually cut according to the surface area of the mold. Then, the mold is cooled and the part is removed. This molding method is widely used in the manufacture of automotive parts such as bonnets, fenders, scoops and spoilers, as well as smaller and more complex parts. The material to be molded is placed in the mold cavity, and the heated platen is closed by a hydraulic ram. The bulk molding material or sheet molding material is adapted to the mold shape by the applied pressure and heated until a curing reaction occurs. The supply material of SMC is usually cut according to the surface area of the mold. Then, the mold is cooled and the part is removed. After that, the mold is cooled and the part is removed.

[0145] The material may be loaded into the mold in the form of pellets or sheets, or the mold may be a plasticizing extruder. It may also be loaded from there. The material is heated above its melting point, molded, and cooled. The more uniformly the material is distributed across the mold surface, the less flow orientation occurs during the compression phase.

[0146] Compression molding involves sandwiches that incorporate core materials such as honeycomb or polymer foam. It is also widely used in the manufacture of structures.

[0147] Thermoplastic resin matrices are common in mass production industries. Typical examples include automotive applications, such as long fiber-reinforced thermoplastics and glass fiber mat-reinforced thermoplastics. Resin is the primary technology.

[0148] In compression molding, Determining the appropriate amount of material, Determining the minimum amount of energy required to heat the material, Determining the shortest time required to heat the material, Determining the appropriate heating method, Predicting the force needed to ensure the shot takes the correct shape, and Designing a mold so that the material is rapidly cooled after being compressed into the mold. These are six important points that engineers should keep in mind.

[0149] Extruder for 3D printers

[0150] Types of extruders by drive

[0151] Extruders come in two types depending on the type of drive: direct drive and Bowden drive. Yes, in a direct-drive extruder, as the name suggests, the gears of the extruder are connected to the hot end. The lament moves in a straight line. There are also systems that combine these two parts.

[0152] On the other hand, in a Bowden extruder, the connection to the hot end is via the PT through which the filament passes. This is done via FE tubing.

[0153] The main function of an extruder is to transfer filament from the reel to the hot end in the most precise way and The key is to move it at a speed suitable for 3D printing.

[0154] Type of extruder: Direct drive

[0155] A direct-drive extruder, as the name suggests, processes the filler directly from the extruder's gears to the hot end. The tents are running through. Like the Titan Aero, these two parts There are also systems where the character "ツ" is included.

[0156] In a direct-drive extruder, regardless of the filament composition, hard and soft materials (1 It can print 0.75mm and 2.85mm. Another advantage is the retraction length. This shortens the printing time and extends the lifespan of the extruder motor. Yes, there is. The main drawback is that inertia is generated in the printer's axis as the extruder moves, which is This is caused by weight and an imbalance between the center of mass and the axis. Another drawback is, In closed-type printers, and in printers with reinforced chambers, the motor inside the extruder moves This means that the temperature may reach a level that affects the performance of the device.

[0157] Extruder type: Bowden type

[0158] In a Bowden extruder, unlike a direct extruder, the PTFE tube through which the filament passes... It connects to the hot end via a cable.

[0159] These extruders have a small inertial force on the displacement axis of the hot end. In the Bowden type, the extruder And because the extruder motor is fixed to the 3D printer chassis, the impression The inertia in the motion to provide the motion is greatly reduced. Therefore, it is very fast and high It can produce high-quality prints. The main drawback is the flexible filler with a diameter of 1.75 mm. Printing on Menthol (TPE) is extremely difficult. This is because of the flexibility of the filament. The filament bent and followed the Bowden PTFE tube all the way to the hot end. This is because it is not possible to maintain a constant pressure within the filament. However, 2.85mm The Bowden method allows for printing flexible filaments at low speeds.

[0160] Direct drive extruder

[0161] advantage: 1.75mm and 2.85mm PLA Soft or both TPU and TPE, etc. Printing on flexible materials It can print all kinds of materials without any problems, regardless of wear caused by specific filaments. To print 3D abrasives, use brass with ruby ​​tips that have virtually unlimited lifespan. Use of a nozzle is recommended. This system requires short retractions to obtain good 3D prints, and this This reduces the possibility of clogging, and Retraction refers to preventing material sagging when the vacuum extruder moves and displaces during 3D printing. This refers to the recoil motion of the filament necessary for that process.

[0162] The parameters that make up the retract are: Retract distance: The length of material that retracts during the retract process. (Material type, extrusion type) It varies depending on the type of hot end (direct drive or Bowden type). Flexible materials, special For TPE type, to prevent the filament from wrapping around the extruder's pinion, Therefore, the retract needs to be disabled, Retract speed: The speed at which the extruder motor retracts the filament. This parameter allows for... When used at high speeds (over 70mm / second), the film will not continue 3D printing. It may leave marks on the surface, so extreme caution is necessary.

[0163] Disadvantages: There is considerable inertia in the axis around which the injection mechanism and hot end move. This is especially true for 3D printers with multiple... If an injection molding machine is included, the weight of the entire set (injector, injection motor, hot end) will be moved. Because it must be done, this factor is a major factor when you want to create 3D prints quickly. to become, and Temperature issues with the electric motor of the injection machine. Pre-filled 3D printers with sealed chambers and reinforced chambers. In some extruders, the temperature inside the motor can reach levels that affect its operating performance.

[0164] Bowden extruder

[0165] advantage: The hot end has little inertia in its displacement axis. In the Bowden type, the extruder and extruder motor are Because it is fixed to the 3D printer chassis, it is used for the motion of giving an impression. The inertia is significantly reduced, enabling extremely high-speed, high-quality printing. , and The filament has high resistance. Most 3D printers that use this extrusion system, It is equipped with a set of pinions (gearboxes) that increase the drag torque of the filament, It can move coils that are larger than usual.

[0166] Disadvantages: Problems when printing with flexible filament with a diameter of 1.75 mm. Because it is a ment, when flowing the filament, it flows along the Bowden PTFE tube. This is because it is impossible to maintain a constant pressure within the filament all the way to the end. The 2.85mm Bowden type allows for slow printing of flexible filaments. .

[0167] Types of hot ends according to the diameter of the material

[0168] The hot end is responsible for melting the filament to create the desired artwork. Depending on the type, quality, and finish of the work you want, choose the type of hot end (V6 or Volc The nozzle is configured according to the diameter of the material (ano). Here, the injection machine is V6 type and V After classifying them into olcano types, the advantages and disadvantages of these two types of hot ends are discussed. do.

[0169] Advantages and disadvantages of the Hot End V6

[0170] advantage: The V6 is the most versatile hot end on the market, and for all types of impressions... It is compatible with various materials and is also effective for flexible materials. (Especially when using 2.85 / 3mm filament) (If used). With Hot End V6, you can achieve exceptional finish quality on all kinds of parts. It can be created using [this method].

[0171] Disadvantages: The recommended maximum nozzle diameter for this type of extruder is 0.80 mm / 1 mm. This is because, beyond a certain diameter, flow continuity problems typically arise.

[0172] Advantages and disadvantages of the Hotend Volcano

[0173] advantage: Because the heater cartridge is positioned parallel to the nozzle, the heating area is larger. Therefore, it offers excellent controllability and stability regarding filament melting. This allows for 3D printing with a larger nozzle diameter (1.2 mm), which enables manufacturing This enables faster printing and higher layer heights than the V6, and This results in stronger components. By creating a high-layer structure using laminar flow (a state without bubbles), the chemical bonds between the materials are strengthened. The bond becomes stronger, resulting in a component with higher rigidity and resistance.

[0174] Disadvantages: A surface finish with minimal detail. Due to the high layer height, the pieces have different heights. The curved parts are constructed with steps or other modifications.

[0175] Understanding viscosity in extrusion molding

[0176] Viscosity calculations require consideration of both the power coefficient and the consistency index.

[0177] The viscosity of non-Newtonian polymers is determined by a combination of increasing temperature and shear rate. η = mγ n-1 This is described by the following relationship: Here, viscosity (η) is given by consistency index (m) × shear It is equal to the value obtained by subtracting 1 from the product of velocity (γ) and the exponent (n).

[0178] Generally, the effect of consistency indices is discussed only by rheology experts. Yes. The consistency index, or viscosity change with increasing temperature, is due to the rotation of the screw. It largely depends on the energy input to the polymer by shearing. In other words, shearing is viscous When the polymer temperature is increased by dissipation or conversion of mechanical power into temperature, the viscosity becomes higher. It decreases due to the temperature and is added to the shear viscosity reduction. The consistency index decreases with increasing temperature. This represents the rate of decrease.

[0179] The shear viscosity reduction of various polymers is often classified solely by the power coefficient, but consistency The viscosity index can also have a significant impact on the final viscosity, so it needs to be taken into consideration. .

[0180] As a result, two polymers with similar melt index or melt flow were found to be less effective during processing due to high shear stress. The viscosity can vary greatly depending on the cross-sectional rate. Melt by capillary rheometer The index and melt flow measurements were performed at very low shear rates where shear thinning was minimal. It is determined that the temperature can be determined at the same shear rate due to the multiplicative effect of the power coefficient and the consistency index. The difference between HDPE and PP is that HDPE has three times the viscosity of PP. This can occur. This is because the HDPE melts when using screws of the same design. This means the melting point is much higher than that of PP.

[0181] Using simple viscosity calculations is possible without using shear rate / viscosity graphs, This is extremely useful for analyzing the power requirements, melting temperature, and polymer flow of polymer extruders.

[0182] Interestingly, some polymers have a viscosity that is proportional to the shear rate or screw speed. The temperature is reduced, further heating due to viscous dissipation is minimized, and power requirements increase only slightly. No, it is almost self-generating or it may reach an adiabatic shear rate.

[0183] Calculating the motor load using the calculated viscosity is extremely complex and generally Computer simulation is required. However, the calculated viscosity is Calculation and combination of viscosity dissipation of different polymers in unscrew extruders with different iss and L / D ratios. Combined, it is a useful tool for approximating viscosity and the resulting screw power requirements. It is possible. Power coefficient and consistency data can be found on the internet or polymer sites. It is available from pliers.

[0184] Viscosity: Definition

[0185] Viscosity in relation to plastic injection molding is a measure of how thick or thin a material flows. Therefore, a good comparison is the difference between molasses and water. If you pour water and molasses at the same time, the water will... It flows much more easily than molasses. Molasses is thick and flows slowly. Water is thin and much It flows quickly. Molasses is considered to have high viscosity, while water has low viscosity.

[0186] The same terminology is used for different plastic injection molding materials. Low viscosity materials are used thinly. Materials that flow quickly and have high viscosity flow slowly and densely. For example, nylon flows thinner and faster than styrene, therefore nylon has lower viscosity than styrene. Styrene is located in the middle of the material scale and is considered an average value. Therefore, Styrene Materials with higher viscosity than styrene are recorded as positive. In MSDS data, materials with lower viscosity than styrene are recorded as positive. The material is recorded as a negative value.

[0187] Viscosity vs. Temperature

[0188] Temperature plays a crucial role in adjusting viscosity. A general rule of thumb is: When heat is applied, the viscosity of the material decreases, causing the flow to become narrower and faster. The important point here is As the temperature rises, the cycle time increases, and more gas is generated, leading to degradation. One disadvantage is that the temperature becomes unfavorable as the process progresses. The barrel temperature is what the machine manufacturer proposes. To ensure that the melt temperature is within the acceptable range of the melt window, measure the melting temperature. It is necessary, and Lowering the temperature makes the flow thicker and slows down the filling rate. Lowering the temperature increases the cycle time. The process becomes faster, but if the temperature is too low, the plastic device will wear down quickly. Here too, the melting temperature is measured. It is important to ensure that the heating is within the melt window.

[0189] Viscosity vs. Filling Time

[0190] Viscosity has little effect on filling time. A thinner flowfront flows more easily. The injection speed is set using a scientific procedure to average from low to high speed. The speed is controlled using valves and servos. However, it is not possible to determine the correct filling speed. There is a change in the amount of energy used to satisfy the set value. Increased energy consumption sometimes leads to higher production costs, and if energy decreases... The opposite is true. Based on the need for productivity improvement or the value calculation, one of them is more beneficial. There are situations where this happens.

[0191] Viscosity vs. Peak Pressure

[0192] Viscosity is also directly related to peak pressure. The thicker the flow front and the lower the temperature, the higher the peak pressure. The pressure increases. The thinner the flow front and the higher the temperature, the lower the peak pressure. When heat is applied, viscosity and peak pressure decrease, and when heat is reduced, viscosity and peak pressure increase. Garu.

[0193] Defect countermeasures using viscosity

[0194] Here, we will discuss some common molding defects and how viscosity changes can be used to improve the quality of molded products. This article lists ways to improve this. It presents the theory that viscosity solves all molding defects. However, if adjusting the viscosity can improve the function and / or appearance of the part. There are many such situations, and how viscosity can be used to improve and resolve problems. List the methods.

[0195] Hike

[0196] There are several types of sink marks, including heat sink marks and sink marks on ribs or deep contours in mold designs. Sink marks can be directly related to viscosity. Heat shrinkage: Heat shrinkage occurs when the temperature of the mold or material is too high. Cycle time also plays a role. This could be one of the contributing factors. In some cases, lowering the barrel temperature can alleviate heat-induced shrinkage. It can be reduced or eliminated. Sink marks on ribs / Details: Sink marks on ribs can be related to the following two different situations. . 1. If the material inside the rib is still too hot, shrinkage may occur on the rib. In this case, Lowering the viscosity can reduce the heat in the rib area, which may improve its condition. 2. Sink marks can also occur due to overfilling caused by the material flowing too slowly across the ribs. This can occur due to tensile shrinkage during the ejection of parts. In that case, applying heat thins the flow, allowing it to flow faster across the ribs and reducing the amount of filling needed. This can be done. When the part is discharged, the rib filling is reduced, so the part To make it easier to remove.

[0197] Bari

[0198] There are several situations where burrs can be directly caused by viscosity. For example, hairline burrs The occurrence of this condition is evidence that the material's viscosity is too high, and to improve this condition, the temperature should be lowered. It is necessary to reduce the heat. If there is damage to the parting line in the mold, reducing the heat will reduce the damage. It can actually improve the burrs that are a direct result of the wound.

[0199] Knit line

[0200] The knit line is created when plastic passes through the cavity of a part, resulting in different flow rates. It occurs when the front parts come together. In the case of mold details, knit is the wind of detail It occurs above. Imagine a rock in a stream, and when the water hits the rock, the rock creates resistance. Try this. The water flows around the rock, and the two streams merge and reorganize at the back, but the water The faster the flow, the longer it takes for the two flows to recombine into one. However, this also applies when shaping around details. When the flow speeds up, the stitches become thinner and longer. If the flow is slow, the stitches will be thicker and shorter. Regarding viscosity, the higher the temperature, the faster the flow. At lower temperatures, the flow slows down. Filling around the detail can crack / show in the knit line. To prevent scorching, improve the sealing and strength of the knit line. Reduce fever.

[0201] As described above, viscosity can often be used to correct defects in molding conditions. When standardizing the process, first determine the viscosity based on the melting temperature and set it lower, and the viscosity will be used for molding. If it seems directly related to the problem, increase the temperature to adjust. This will help the cycle time The process is definitely optimized, and efficiency improves. Less scrap and higher efficiency means This leads to a high return rate on molded products.

[0202] Plastic recycling involves collecting waste or waste plastic and converting the materials into useful products. This refers to the process of reprocessing. Since most plastics are not biodegradable, recycling is Plastics in the flow of waste, especially the approximately 8 million tons of waste plastics that flow into the world's oceans every year. This is part of a global effort to reduce sticking.

[0203] Compared to profitable metal recycling, and similar to the recycling of low-value glass, plastic Recycling sticky polymers is often difficult due to their low density and low value. Furthermore, there are numerous technical hurdles to overcome in plastic recycling. The facility is responsible for sorting and processing plastics, but as of 2019, it is struggling economically. ru.

[0204] When different types of plastics are melted together, they separate into phases like oil and water, and their layers... It tends to solidify. This phase boundary leads to structural weakness and delamination of the material. Polymer blends are only useful for limited applications. The two most commonly manufactured types are... Polypropylene and polyethylene, which are plastics, behave in this way. The usefulness of these recycled materials is limited. To help improve the integrity of the materials, plastic Each time the stick is recycled, new material needs to be added. In other words, recycled plus New plastic materials have also been added to the plastic. The same plastic pieces are of lower quality. It can only be recycled about 2-3 times before it becomes unusable.

[0205] Centrifugal separation

[0206] One of the most commonly used devices in biochemistry laboratories to separate materials into fractions is a centrifugal separator. It is a centrifuge. A centrifuge rotates a liquid sample at high speed, thereby generating a strong centripetal force. By creating this effect, denser substances can move towards the bottom of the centrifuge tube faster than they would under normal gravity. It is a device used for moving things around.

[0207] Induction heating offers accuracy, speed, and repeatability for heating metals and other conductive materials. It is a technology that is efficient and non-contact.

[0208] The induction heating system uses an induction power supply that converts line power into alternating current and supplies it to the workhead. It consists of a work coil that generates an electromagnetic field within the coil, and the workpiece is It is placed inside the coil, and this electromagnetic field induces an electric current in the workpiece, causing the workpiece to heat up. To make someone do it.

[0209] Water-cooled coils are placed around or at the boundary of the workpiece. Heat is generated only by the induced current transmitted through the workpiece, without any contact with the workpiece. The materials used to create the pieces include copper, aluminum, iron, or brass. The genus can be used. Also, semiconductors such as graphite, carbon, or silicon carbide can be used. good.

[0210] For heating non-conductive materials such as plastics and glass, conductive materials such as graphite are used. One method involves inductively heating an electrostatic susceptor and transferring that heat to a non-conductive material.

[0211] Induction heating ranges from low temperatures (100°C / 212°F) to high temperatures (3000°C / 5432°F) It is used in processes up to ). Also, short heating processes of less than 0.5 seconds and for several months. It is also used in heating processes.

[0212] Induction heating is used in heat treatment, soldering, welding preheating and melting, shrink fitting and sealing in the industry. In several applications such as brazing, hardening, and research and development, it is used in both household and commercial cooking. It is used by [person / group].

[0213] How induction heating works

[0214] Induction generates an electromagnetic field in a coil and transfers energy to the workpiece to be heated. When water flows through a power line, a magnetic field is generated around that power line.

[0215] Main advantages of induction

[0216] The advantages of induction are, Efficient and rapid heating Accurate and reproducible heating Because it does not produce flames, it provides safe heating, and Extending the lifespan of appliances through precise heating. These are some examples.

[0217] Method of induction heating

[0218] Induction heating is performed in two ways. The first method is derived from the resistivity of the workpiece material. 2 It is called eddy current heating due to the loss of R. The second method is called hysteresis heating, which changes the magnetic polarity of the component. This device generates energy within a component through an alternating magnetic field created by a coil. That is the case.

[0219] As the permeability of the material decreases to 1 and hysteresis heating decreases, up to the Curie temperature, Hysteresis heating occurs in the product. Eddy current heating constitutes the remaining inductive heating effect.

[0220] When the direction of the electric current (alternating current) changes, the generated magnetic field collapses, and the direction of the current reverses. Therefore, a magnetic field is generated in the opposite direction. When the second wire is placed in that alternating magnetic field, the second wire An alternating current is generated.

[0221] The current flowing through the second wire and the current flowing through the first wire are proportional to each other, and the distance between them is It is also proportional to the reciprocal of the square of the distance.

[0222] If you replace the wires in this model with coils, an electromagnetic field will be generated by the alternating current flowing through the coils. While the heated workpiece is in the electromagnetic field, the workpiece is connected to the second wire. This generates an alternating current in the workpiece. The material resistivity of the workpiece is l 2 Due to the R loss, Heat is generated in the workpiece due to the material resistivity of the workpiece. This is called eddy current heating.

[0223] Today's plastics manufacturers encounter many obstacles in autonomously performing injection molding operations. This means that the lever that controls the stability of the molding process is difficult for the processor to control. This is because, in some cases, the changes are so drastic that they are impossible to overcome. To achieve this, 1) a robust process that can withstand normal fluctuations in materials, molds, machinery, and the environment, 2) A control system capable of intelligently adapting to external fluctuations is required.

[0224] iMFLUX Technology

[0225] The actual filling process using plastic pressure is controlled to fill and hold the mold at a low, constant plastic pressure. It works by doing so. The key to a successful process is to eliminate stagnation in the flow and during filling. This is a unique control system that holds the component in place and reduces pressure loss within the mold. Plastic flows at a much slower speed than conventional processing technologies, and cycle times are short at low pressure. This enables a streamlined process and allows for real-time response to changes in molding conditions.

[0226] iMFLUX controls the filling process by keeping the resin pressure lower and more constant. Troll. This will allow the process to withstand fluctuations that would otherwise halt the conventional process. It becomes inherently less susceptible to it.

[0227] The reason the process is robust is because it is the biggest factor affecting the quality and stability of plastic injection molded parts. This is because it actively controls the resin pressure during molding, which is a contributing factor. Although the rate is kept constant, the resin pressure changes due to changes in material and molding conditions. This overcomes the contradictions of conventional controlled processing. iMFLUX technology enables self-molding. Therefore, controlling the process based on resin pressure, which is a truly important factor, offers significant advantages. It becomes a point.

[0228] iMFLUX makes it much easier than traditional processes to remove things that are far outside the normal range. The process can be adapted to handle fluctuations. This is because iMFLUX This is possible because it is basically a simple process of pressure and time. In ejection molding, to adapt to changes, injection speed, transport position (or cavity pressure), and holding pressure must be adjusted. And several variables, such as retention time, need to be changed. Moreover, retention time itself is complex. We must deal with fluctuations that have complex interactions.

[0229] In iMFLUX technology, adjustment is basically done by plastic pressure (pressing plastic into a mold) It is limited to the pressure (applied) and time (the duration for which this pressure is applied). This simple process allows, iMFLUX can handle variations far beyond the practical limits of conventional injection molding technology. This allows for the creation of advanced control algorithms.

[0230] Processors are being asked to handle more recycled and lower-cost materials. Therefore, the ability to reliably handle variable materials is one of the industry's greatest needs. Because the material has varying viscosities, it is very difficult to handle. Conventional injection molding is static The parts are set to operate under process conditions, and even with relatively small material variations... However, it is necessary to adjust the process in order to maintain the quality of the molded products. Recent technological advancements Although conventional injection molding has made it easier to control material variations, it is sensitive to the transport position and pressure. Because it is based on feeling, it remains an inherently unstable process. iMFLUX technology is Because there is no transport position and it responds in real time to the rheological changes of the material, such changes The impact of chemical changes is far less.

[0231] Cavity blockage

[0232] Conventional molding processes, regardless of whether the mold can accept the quantity, A fixed amount of plastic is set to be injected into the mold. Therefore, the gate closes Problems arise when a blockage or part is not completely ejected, leaving the plastic with nowhere to go. This can occur. Depending on the number and volume of cavities in the mold, defects may occur. This could result in defects being generated or damage to the mold.

[0233] iMFLUX technology continuously controls the process and monitors the pressure of the plastic. Therefore, the operation is different. If the mold cavity becomes blocked, the system will detect the change. It instantly recognizes the current state of the mold and profiles the injection speed required. This not only prevents mold damage, but also ensures that the remaining cavity produces high-quality parts. It is possible to create this. Like the automatic brakes in a car, to optimally fill the cavity... The system knows when to slow down the clew's movement. This function is a process Multi-cavity molds that require the mold to continue operating even when cavitation is less than complete. It is particularly useful in molds. In this case, without developing a new modification process, the mold cavity All you have to do is turn off the power. This is something that is impossible with conventional injection molding.

[0234] Check ring leakage and barrel wear

[0235] In conventional speed-based process control, in order to keep the amount of polymer during transport constant, It is necessary to maintain a consistent locking mechanism. Even slight variations can significantly impact the quality of the components. This may cause problems. Using iMFLUX technology, the process is real-time. Because it is entirely dependent on the plastic pressure fed back to the IM, the leakage of the check ring is virtually It does not affect the process. If there is a gap in the check ring, iMFLUX will simply The screw is accelerated to compensate for leakage. Conventional injection molding relies on static process settings. As a result, dynamic adjustments cannot be made to the inconsistent performance of the check ring. With iMFLUX technology, as long as the press can build up plastic pressure, these adjustments No adjustments are necessary, and a completely reproducible process can be obtained. This is a matter of reproducibility. This is true whether it is consistent from shot to shot or essentially sporadic. In order to achieve autonomous molding in this sense, the process must be able to respond to such general fluctuations. It is necessary to be able to do so, and if that is not possible, the effect of achieving a stable and reproducible process will not be achieved. I can't.

[0236] iMFLUX released an advanced feature called Automatic Viscosity Adjustment (AVA) earlier this year. As a result, iMFLUX technology is subject to even greater changes than the underlying iMFLUX technology. It is now possible to support this. This new feature supports viscosity shifts of ±50 MFI or more. VA detects changes in viscosity and adjusts the filling pressure to achieve the same filling time between shots. This is the mechanism. This process does not require operator input and is adjusted in real time. This is due to variations in recycled materials, the proportion of recycled materials, changes in colorants, the moisture level of the material, or temperature. This applies regardless of the variable factors, including degree of variation. Basically, when the machine melts... If possible, it can be processed using iMFLUX technology.

[0237] Furthermore, other recently announced features allow the control system to change the density of the material between shots. It can compensate for the damage. This technique, called Precision Shot, first involves the shot This machine works by increasing the pressure to a predetermined threshold and then metering and supplying the shots to the mold. This is only possible when the process is controlled by the plastic melting pressure, and check ring The system accurately determines that the object has been seated and that the target compression of the molten material has been achieved. It is possible.

[0238] The embodiments described in the drawings are illustrative in nature and are not defined by the claims. It is not intended to limit the subjects that can be discussed. [Brief explanation of the drawing]

[0239] [Figure 1] Figure 1 shows a schematic front view of a plastic extruder according to one or more embodiments shown and described herein. [Figure 2] Figure 2 shows an explanatory diagram of a breaker plate for extrusion molding at a low, substantially constant pressure according to an embodiment of the present disclosure. [Figure 3] Figure 3 shows an explanatory diagram of a blow molding machine that molds at a low, substantially constant pressure, according to another embodiment of the present disclosure. [Figure 4] Figure 4 shows a schematic diagram of a parison that enters a blow mold. [Figure 5] Figure 5 shows a schematic diagram of a bottle blow molding process that is formed at a low, substantially constant pressure, according to another embodiment of the present disclosure. [Figure 6] Figure 6 shows a schematic front view of a plastic injection molding machine according to one or more embodiments shown and described herein. [Figure 7] Figure 7 shows a schematic front view of a hot runner mold that can be improved by an injection molding method at a low, substantially constant pressure according to embodiments of the present disclosure. [Figure 8] Figure 8 shows a more detailed schematic front view of the hot runner mold. [Figure 9]Figure 9 shows a schematic diagram illustrating the thickness, thinness, and girth of the iMFLUX low-pressure process molding in this PP demo part. This application requires automated control software and sensors that provide an absolutely constant filling pressure, enabling a 0.030 inch thickness without hesitation. The runner, with a 3-inch diameter and length of "filament" section, fills the cavity without freezing before entering the part's cavity. [Modes for carrying out the invention]

[0240] All pressures disclosed in this book are gauge pressures, which are relative pressures to ambient pressure.

[0241] This specification discloses a method of injection molding at a low, substantially constant melting pressure. The embodiment of this method now offers greater energy efficiency and cost efficiency than conventional high-speed injection molding processes. This enables a highly effective injection molding method. The embodiments of the disclosed method are, surprisingly, gold Undesirable premature curing of thermoplastic material in mold cavity, and constant temperature or heated gold To fill the mold cavity at a low melting pressure without the need to maintain the mold cavity. To enable. As detailed below, a person skilled in the art can use a non-heated mold cavity or cooler. When using a mold cavity, the constant pressure method can be used without such premature curing of thermoplastic materials. They probably didn't expect it to be possible to do it with pressure.

[0242] Embodiments of the disclosed method also involve the mold cavity pressure before injection and the injection of thermoplastic material. High-quality injection molding that does not produce undesirable shrinkage or warping, without the need to balance the injection pressure. This makes it possible to form a molded article. Therefore, embodiments of the disclosed method are at atmospheric pressure. This can be carried out using mold cavity pressure, and does not require the mold cavity to include pressurizing means. Eliminate the essentials.

[0243] This embodiment of the method also provides a temperature for thermoplastic materials compared to the conventional high-pressure injection molding process. We manufacture high-quality injection molded parts with significantly low sensitivity to variations in viscosity and other such properties. It can be manufactured. In one embodiment, this essentially means batch-to-batch variation in material properties. Formed from recycled plastics (for example, recycled plastics after consumer use) This can advantageously enable the use of thermoplastic materials.

[0244] Furthermore, the low melting pressure used in the disclosed method results in lower manufacturing costs and energy consumption. - Enables the use of mold cavity materials with higher efficiency, lower hardness, and higher thermal conductivity. This is possible. For example, the mold cavity has a surface hardness of less than 30 Rockwell C(RC). It can be formed from a material with a thermal conductivity exceeding 30 BTU / HR FT °F. In terms of form, the mold cavity is made of, for example, aluminum alloy 6061 Al and 7075 It can be formed from aluminum alloys such as Al.

[0245] Embodiments of the disclosed method can further enable the formation of high-quality thin-walled parts. For example, molded products in which the flow-to-thickness ratio (L / T) of molten thermoplastic resin exceeds 100. This can be formed using an embodiment of the present method. An embodiment of the present method has an L / T ratio It is also possible to form molded parts larger than 200, and in some cases larger than 250. This is the intended outcome.

[0246] Generally, the value obtained by dividing the length L of the flow channel by the thickness T of the flow channel is greater than 100. If (L / T > 100), the molded product is considered thin-walled.

[0247] The sensor may be placed near the end of the filling process in the mold. The sensor may provide an indicator of when the filling of the mold is nearing completion. The sensor is pressure The sensor may sense temperature, optical or other means of identifying the presence of polymers. When measured by the system, this measurement is used to communicate with the central control unit to set the target for the molded part. It can provide "holding pressure". The signal generated by the sensor indicates the viscosity of the material and the mold. The central control unit adjusts for temperature, melting temperature, and other fluctuations that affect the filling rate. These adjustments can be used to control the molding process. It can be done immediately during the cycle, or corrected in a later cycle. Several measurements are averaged over multiple cycles and used by a central control system to adjust the molding process. It can be used. In this way, the current injection cycle is one or more earlier points in time. It can be corrected based on the measurements that occurred in the cycle. In one embodiment, the sensor The measurements are averaged over many cycles to achieve process consistency. It is possible.

[0248] Once the mold is completely filled, the melting pressure and mold pressure are simultaneously increased to atmospheric pressure (if necessary). This lowers the mold cavity, allowing it to open. During this time, if using an injection molding machine, The reciprocating screw stops moving forward. Advantageously, under low, substantially constant pressure conditions... This allows for rapid cooling of shots made of molten thermoplastic material within the mold, and this In various embodiments, this substantially reduces the melting pressure and the mold cavity to atmospheric pressure. This can occur simultaneously. Therefore, shots made of molten thermoplastic material in the mold cavity After filling, the injection-molded product can be quickly ejected from the mold.

[0249] melting pressure

[0250] As used herein, the term "melting pressure" refers to the pressure applied when a molten thermoplastic material is subjected to the molding pressure of a molding apparatus. This refers to the pressure of the molten thermoplastic material as it is introduced into and filled into the cavity. While the material is substantially filled, the melting pressure of the shot made of molten thermoplastic material is 6 It is maintained at a virtually constant level below 000 psi. It effectively fills the entire mold cavity. The melting pressure of a shot made of molten thermoplastic material during the process is used in conventional injection molding processes. The injection and filling melt pressure recommended by the manufacturer of thermoplastic materials for use in injection molding processes. It is significantly lower than that. Other suitable melting pressures include, for example, less than 5000 psi and 4500 psi. This includes less than SI, less than 4000 psi, and less than 3000 psi. For example, melting pressure. This ranges from approximately 1000 psi to less than 6000 psi, approximately 1500 psi to approximately 5500 psi, and approximately 2000psi ~ approx. 5000psi, approx. 2500psi ~ approx. 4500psi, approx. 3000 Effective pressure ranges from approximately 4000 psi to less than 3000 psi to less than 6000 psi. It is possible to maintain a constant pressure.

[0251] As mentioned above, "substantially constant pressure" refers to a shot made of molten thermoplastic material. When filling the mold cavity substantially, the desired melting pressure is raised or lowered. This refers to a pressure that does not fluctuate by more than 30%. For example, a substantially constant pressure is a pressure that does not increase from the melting pressure. (or as a decrease) approximately 0% to approximately 30%, approximately 2% to approximately 25%, approximately 4% to approximately 20%, approximately 6% to approximately A fluctuation of 15%, and approximately 8% to 10%, is acceptable. Other appropriate fluctuation amounts include approximately 0, 2. 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 and 30% Therefore, the melting pressure while filling the entire mold cavity is, for example, at a constant rate. These can be increased or decreased, and the melting pressure during filling the mold cavity substantially is The pressure shall be considered substantially constant unless the maximum increase or decrease exceeds 30% of the desired melting pressure. This is possible. In yet another embodiment, melting when filling substantially the entire mold cavity Pressure may increase over a portion of time and decrease over the remaining portion of time. This variation is such that the maximum increase or decrease in melting pressure during filing is 30% of the desired melting pressure. As long as it is below a certain percentage, it is considered to be virtually constant pressure.

[0252] The melting pressure of the thermoplastic material filling the mold cavity is, for example, located at the filling location. It can be measured using a pressure transducer or the like. In a molding apparatus, molten thermoplastic The position where the material enters the mold cavity. For example, a single mold cavity coupled to a nozzle. In the case of a molding apparatus equipped with a nozzle, the filling point shall be at the nozzle position or a position adjacent to the nozzle. This can be done. Alternatively, multiple mold cavities and molten thermoplastic material can be supplied from a nozzle to each mold. In a molding apparatus equipped with a runner system for transporting material into a cavity, the filling point is the runner system It may also be a contact point between the stem and each mold cavity. The molten thermoplastic material is the runner - During transport through the system, it is maintained at a substantially constant melting pressure. Generally, a runner system is used to transport shots of molten thermoplastic material into the mold cavity. It is a heated runner system that maintains the melting temperature of the shot during transport.

[0253] The melting pressure of the thermoplastic material while filling virtually the entire mold cavity is, for example, no The melting pressure is measured using a pressure transducer placed in the sulphure, and the pressure at the nozzle is kept constant. This can be maintained by... In another embodiment, substantially the entire mold cavity The melting pressure of the shot made of thermoplastic material during filing is applied to the mold opposite the gate. The pressure can be measured using a pressure transducer placed in the cavity.

[0254] In another embodiment, once substantially the entire mold cavity is filled, the melting pressure is increased to form the mold The remaining portion of the cavity can be filled and held in place.

[0255] Maintaining a virtually constant pressure

[0256] A closed-loop controller and / or other pressure regulator can be used instead of a closed-loop controller. It may be used. For example, a pressure regulating valve (not shown) or a pressure relief valve (not shown) may be used as a control. Instead of rollers, the melting pressure of the molten thermoplastic material may be adjusted. More specifically, the pressure The control valve and pressure relief valve can prevent overpressure of the mold. Another alternative mechanism for this is to activate an alarm when an overpressure condition is detected. be.

[0257] Therefore, in another embodiment, the molding apparatus has a breaker plate and a mold cavity and It may include a pressure relief valve positioned between them. The pressure relief valve is for filling the mold. It has a predetermined pressure setting point that is equal to the desired melting pressure. The melting pressure is the pressure applied to the molten thermoplastic material, causing the molten thermoplastic material to move from the predetermined set point. This is maintained at a virtually constant level by passing the molten material through the pressure relief valve at a high melting pressure. Subsequently, the pressure relief valve is used to melt the thermoplastic material that passes through the pressure relief valve and is introduced into the mold cavity. Reduce the melting pressure. The reduced melting pressure of the molten thermoplastic material fills the mold cavity. Corresponding to the desired melting pressure, substantially equal to the predetermined set value of the pressure relief valve. It will be maintained at a constant level.

[0258] In one embodiment, the melting pressure causes a portion of the thermoplastic material to be diverted to the outlet of a pressure relief valve. This is reduced. The bypassed portion of the thermoplastic material can be maintained in a molten state. For example, it can be re-integrated into the injection system through a heated barrel.

[0259] Mold cavity pressure

[0260] As used herein, "mold cavity pressure" refers to closed mold cavities and / or open mold cavities. This refers to the pressure inside the mold cavity and / or the mold for blow molding. / or open extrusion molds, and / or blow molds. Pressure is, for example, in the mold cavity. Pressure transducers located in and / or open extrusion molds and / or blow molds. Measurement can be performed using [a specific method]. In this embodiment of the method, the molten thermoplastic material is [a specific method]. Before introducing into a tee and / or open extrusion mold and / or blow molding mold, the mold key Cavity pressure is different from the pressure of the molten thermoplastic material. For example, mold cavity pressure is The pressure can be lower than that of the molten thermoplastic material. In another embodiment, the mold cavity The pressure can be higher than the pressure of the molten thermoplastic material. The mold cavity pressure is , can have a pressure higher than atmospheric pressure. In yet another embodiment, the mold cavity The system can be maintained under vacuum before and / or during filling.

[0261] In various embodiments, the mold cavity and / or breaker plate pressure is such that the melting While filling substantially the entire mold cavity with shots made of thermoplastic material, It can be maintained at a constant level. The term used herein in relation to the melting pressure of thermoplastic materials is " The term "substantially constant pressure" refers to a deviation from the baseline melting pressure of a thermoplastic material. This means that no significant change in physical properties occurs. For example, "substantially constant pressure" This includes, but is not limited to, pressure fluctuations in which the viscosity of the molten thermoplastic material does not change significantly. No. In this respect, the term "substantially constant" is up to approximately 30% from the baseline melting pressure. This includes deviations. For example, the term "a substantially constant pressure of about 4600 psi" is about 6 000 psi (30% higher than 4600 psi) to approximately 3200 psi (4600 psi) Includes pressure fluctuations within a range of 30% lower than the stated pressure. As long as it remains within a certain limit, it is considered substantially constant.

[0262] For example, the substantially constant pressure is approximately 0% to approximately (as an increase or decrease) from the melting pressure. 30%, approximately 2% to 25%, approximately 4% to 20%, approximately 6% to 15%, and approximately 8% to 10% It can vary by %. Other appropriate amounts of variation are approximately 0, 2, 4, 6, 8, 10 This includes 12, 14, 16, 18, 20, 22, 24, 26, 28 and 30%. Cavity pressure can be maintained at a substantially constant pressure higher than atmospheric pressure.

[0263] The mold cavity has one or more features to keep the mold cavity pressure substantially constant, for example. Vents may be included. To keep the mold cavity pressure substantially constant, the vents may be opened. It can be controlled to close.

[0264] In one embodiment, the entire mold cavity is substantially filled with molten thermoplastic. It is possible to maintain a vacuum during this time. Maintaining a vacuum in the mold cavity during injection is possible. Because there is no air forcibly expelled from the mold cavity during filling, the cavity is filled. This allows for a favorable reduction in the amount of melting pressure required. Furthermore, it reduces the air resistance to flow. Due to the lack of resistance and the increase in pressure drop between the melting pressure and the filling end pressure, molten thermoplastic material The flow length of the shot, which consists of the ingredients, can also be longer.

[0265] Molding temperature

[0266] In this embodiment of the method, the mold cavity is prepared before filling the mold with molten thermoplastic material. It is maintained at room temperature or cooled. The mold surface is heated by contact with the molten thermoplastic material. The temperature may rise, but less than the outermost surface in contact with the thermoplastic material of the mold cavity. All 2mm, at least 3mm, at least 4mm, at least 5mm, at least 6mm m, at least 7mm, at least 8mm, at least 9mm, or at least 10mm The spaced-out interior portions are maintained at a lower temperature. Typically, this temperature is suitable for thermoplastic materials. The non-flow temperature of the material is below the non-flow temperature. As used herein, "non-flow temperature" refers to the viscosity of the thermoplastic material. This refers to a temperature at which the fluid is practically unable to flow due to its extremely high temperature. Therefore, the internal part of the mold can be maintained at a temperature of less than 100°C. For example, the above The internal temperature ranges are approximately 10°C to 99°C, 20°C to 80°C, and 30°C to 70°C. It can be maintained at temperatures of approximately 40°C to 60°C, and approximately 20°C to 50°C. Other suitable temperatures include approximately 10, 15, 20, 25, 30, 35, 40, and 45. , including 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 99°C. In one embodiment, the internal portion is maintained at a temperature of less than 50°C.

[0267] Until now, when filling at a low constant pressure, the filling speed was reduced compared to conventional filling methods. This means that the polymer cooled for a longer time before the mold was completely filled. This means contact with the molded surface. Therefore, more heat needs to be removed before filling. Yes, and as a result, it is expected that the material will freeze before the mold is filled. Even though a portion of the cavity is below the non-flow temperature of the thermoplastic material, a low, substantially one It was unexpectedly discovered that thermoplastic materials flow under constant pressure conditions. If present, under these conditions, the thermoplastic material will continue to flow and fill the entire mold cavity. Rather, the idea is to freeze the thermoplastic material and seal the mold cavity. This would be common. While not intended to be constrained by theory, the low performance of embodiments of the disclosed method. Under substantially constant pressure conditions, dynamic fluidity is produced throughout the mold cavity during filling. It is thought that this will make it possible to have a continuously moving melt front (i.e., a mold cavity). There is no stagnation in the flow of molten thermoplastic material that flows to fill the mold cavity, and therefore the mold cavity Even though at least a portion of the flow is below the non-flow temperature of the thermoplastic material, the flow There is no opportunity to lead. Furthermore, as a result of the dynamic flow conditions, the molten thermoplastic material is sheared. Despite being exposed to such temperatures within the mold cavity as a result of heating, It is thought that a temperature higher than the flow temperature can be maintained. Furthermore, the dynamic flow conditions are When a thermoplastic material initiates a freeze process within it, the thermoplastic material changes its crystalline structure. It is thought that this prevents formation. The formation of a crystal structure increases the viscosity of thermoplastic materials. This can hinder proper flow for filling the cavity. This can impede crystal structure formation and Due to the reduction in crystal structure size, the thermoplastic material flows into the cavity, and the non-material properties of the material This allows for a reduction in the viscosity of thermoplastic materials when exposed to low temperatures in molds below the flow temperature. It is possible.

[0268] In various embodiments, the mold maintains the entire mold cavity at a temperature below the non-flow temperature. A cooling system may be included for a mold cavity in contact with a molten thermoplastic material. Even the surface of the tee can be cooled to maintain a lower temperature. Any suitable cooling temperature This can be used. For example, the mold can be kept at virtually room temperature. By incorporating such a cooling system, the molded plastic parts will separate from the mold. This allows you to gain an advantage in terms of speed.

[0269] Thermoplastic materials

[0270] Various thermoplastic materials are used in the injection molding method at low, substantially constant pressure according to this disclosure. This is possible. In one embodiment, the molten thermoplastic material is heated to a temperature of about 230°C and 2.16 As measured by ASTM D1238, which is performed by weight in kg, approximately 0.1 g / kg It has viscosity defined by a melt flow index of 0 min to approximately 500 g / 10 min. For example, In the case of polypropylene, the melt flow index is approximately 0.5g / 10 min to approximately 200g / 10 min. It can be within the range of minutes. Other appropriate melt flow indices are approximately 1g / 10 min to approximately 400g / 1 0 minutes, about 10g / 10 minutes to about 300g / 10 minutes, about 20 to about 200g / 10 minutes, about 30g / 10 minutes ~ approx. 100g / 10 minutes, approx. 50g / 10 minutes ~ approx. 75g / 10 minutes, approx. 0.1g / 1 Includes 0 minutes to approximately 1g / 10 minutes, or approximately 1g / 10 minutes to approximately 25g / 10 minutes. The MFI of the ingredients is The selection is based on the intended use and application of the molded product. For example, MFI is 0.1g / 10min~ Approximately 5g / 10min of thermoplastic material is used for preforms in injection stretch blow molding (ISBM) applications. It may be suitable for use as such. Thermoplastic materials with MFI of 5g / 10 min to approximately 50g / 10 min are used for caps and stoppers of packaging supplies. It may be suitable for use as follows: MFI is 50g / 10 min to approximately 150g / 10 min. Thermoplastic materials may be suitable for use in the manufacture of buckets or bathtubs. Thermoplastic materials with a viscosity of 150g / 10 min to approximately 500g / 10 min are extremely high, such as thin sheets. It may be suitable for molded articles having an L / T ratio. Manufacturers of such thermoplastic materials Generally, melt pressures exceeding 6000 psi, and often significantly exceeding 6000 psi. It is instructed that the material should be injection molded using force. Contrary to conventional teachings regarding injection molding of materials, embodiments of the low steady-state injection molding method of this disclosure are Using such thermoplastic materials, less than 6000 psi, and in some cases 6000 ps Processing at a melting pressure far below i is advantageous for forming high-quality injection molded parts. Make it Noh.

[0271] Thermoplastic materials can be, for example, polyolefins. Examples of polyolefins include poly It contains propylene, polyethylene, polymethylpentene, and polybutene-1, however These are not limited to the aforementioned polyolefins, including biopolypropylene or biopolypropylene. To manufacture polyethylene, bio-based raw materials such as sugarcane or other agricultural products are used. It can be procured from raw materials. Polyolefins exhibit advantageous shear reduction in the molten state. Shear deviscation is the decrease in viscosity of a fluid when compressive stress is applied. This advantageously allows for maintaining the flow of thermoplastic materials throughout the molding process. Although not intended to be bundled, due to the shear viscosity reduction of thermoplastic materials, especially polyolefins It is thought that when materials are processed at low pressure, the variation in the viscosity of the material will be reduced. As a result, embodiments of the methods of the present disclosure are derived, for example, from colorants and other additives and processing conditions. It may not be significantly affected by variations in the thermoplastic material. This reduced sensitivity to fluctuations is also applicable to post-industrial waste and after use using embodiments of the methods of the present disclosure. This can advantageously enable the processing of recycled plastics after consumer consumption. Recycled plastics after industrial waste and after consumer consumption are classified according to their respective life cycles. Obtained from the final product after completion, otherwise it would have been discarded as solid waste. Such a blend of recycled plastics and thermoplastic materials is essentially its material It exhibits significant batch-to-batch variability in its characteristics.

[0272] Thermoplastic materials can also be, for example, polyester. This includes, but is not limited to, polyethylene terphthalate (PET). The polymer is produced from sugarcane or to manufacture partially or completely bio-PET polymers. It can be sourced from bio-based raw materials such as other agricultural products. Other suitable thermoplastic materials The materials include polypropylene and polyethylene copolymers, and thermoplastic elastomers. Polymers and copolymers, polyesters, polystyrenes, polycarbonates, poly(acrylic) Lilonitrile-butadiene-styrene), poly(lactic acid), polyethylene (furanate) Bio-based polyesters such as hydroxyalkanoates, poly(ethylene furanoates) (T), (considered to be a substitute for PET or a drop-in substitute), polyhydroxyalkali Noate, polyamide, polyacetal, ethylene-α-olefin rubber, and styrene- It contains butadiene-styrene block copolymer. Furthermore, thermoplastic materials have multiple high properties. A blend of molecular and non-polymeric materials may also be used. Thermoplastic materials are, for example, multi Blends of high, medium, and low molecular weight polymers that produce modal or bimodal blends. It is possible for multimodal materials to have excellent flow properties while being satisfactory. Thermoplastics can be designed to have chemical / physical properties. The material can also be a blend of a polymer and one or more low-molecular-weight additives. These small molecules, for example, improve the fluidity of polymer materials when added to thermoplastic materials. It may be a siloxane or other lubricating molecule.

[0273] Other additives include foaming agents and other leavening agents, calcium carbonate, calcium sulfate, Talc, clay (e.g., nanoclay), aluminum hydroxide, CaSiO3, fibers or Glass formed on microspheres, crystalline silica (e.g., quartz, novacite, crystallobai) (T) Magnesium hydroxide, mica, sodium sulfate, lithopone, magnesium carbonate, acid Inorganic fillers such as iron compounds, or rice husks, straw, hemp fibers, wood flour, wood, bamboo, or sugarcane fibers. It contains organic fillers such as fiber.

[0274] Other suitable thermoplastic materials include, for example, polymers directly derived from living organisms (but not limited to these). Renewable polymers such as (not recyclable), for example, polyhydroxyalkanoates ( For example, poly(β-hydroxyalkanoate), poly(3-hydroxybutyrate-c) o-3-hydroxyvalerate, NODAX®, and bacterial cellulose; plant , polymers extracted from agriculture and forests, and polysaccharides and their derivatives (e.g., gum, Cellulose, cellulose esters, chitin, chitosan, starch, chemically modified starch, vinegar Acidic cellulose particles), proteins (e.g., zein, whey, gluten, collagen), fats Biomass such as cellulose, lignin, and natural rubber; starch or chemically produced from starch. Thermoplastic starch, as well as biopolyethylene, biopolypropylene, polytri Methylene terephthalate, polylactic acid, NYLON 11, alkyd resin, succinic acid base Polyester, and naturally derived monomers such as biopolyethylene terephthalate and This includes current polymers derived from derivatives.

[0275] A suitable thermoplastic material is a blend of different thermoplastic materials, as in the example cited above. It may contain mixtures. Similarly, different materials may be virgin bio-derived or petroleum-derived materials. Materials, or combinations of materials derived from recycled materials of bio or petroleum origin Even if one or more thermoplastic materials in the blend are biodegradable. Good. Also, in the case of unblended thermoplastic materials, even if the material is biodegradable... good.

[0276] Examples of thermoplastic resins and their recommended operating pressure ranges are shown in the table below.

[0277] Injection pressure, material, full name of material, range (PSI), company name, brand name, pp, po Repropylene, 10000-15000, RTP (Reverse Processing Power) 100 Imagineering series, plastic, polypropylene Ilon 10000-18000 RTP RTP 200 Imagineering series, plastic, nylon, ABS Acrylonitrile 8000-20000 Marplex Astalac, Butadie ABS, Styrene, PET, Polyester 5800-14500 Asia AI E PET International 401 F Acetal 7000-17000 API Kolon Kocetal, Copolymer PC Polycarbonate 10000-15 000 RTP RTP 300 Imagineering series, plastic, polycarbonate PS Polystyrene 10000- 15000 RTP RTP 400 Imagineering series, plastic Stick SAN Styrene 10000-15000 RTP RTP 500 Acrylonitrile Imagineering series, plastic Stick PE LDPE & 10000-15000 RTP RTP 700 HDPE Imagineering series, Plastic TPE Thermoplastic resin 10000-15000 RTP RTP 1500 Elastomer Imagineering series, plastic PVDF (Polyvinylidene 10000- 15000 RTP RTP 3300 Fluoride Imagineering Series, Plastic PTI Poly- 10000- 15000 RTP RTP 4700 trimethylene Imagineering series, Te Lefthalate plastic (PBT) Polybutylene 10000-15000 RTP R TP 1000 Terephthalate Imagineering serie s, Plastic PLA Polylactic Acid 8000-15000 RTP RTP 209 9 Imagineering series Plastics

[0278] Maintaining the melting pressure of the molten thermoplastic material at a substantially constant pressure of less than 6000 psi. On the other hand, certain thermoplastic materials benefit from the present invention at different constant pressures. Specifically, PP, Nylon, PC, PS, SAN, PE, TPE, PVDF, PTI, PBT and PLA are At a substantially constant pressure of less than 10,000 psi; ABS at a substantially constant pressure of less than 8,000 psi At a constant pressure; PET at a substantially constant pressure of less than 5800 psi; acetal copolymer The pressure is virtually constant at less than 7000 psi; furthermore, poly(ethylene flane) Polyhydroxyalkanoate, polyethylene flucanate (also known as PEF) is 10,000 Actual pressures of less than psi, 8000psi, 7000psi, 6000psi, or 5800psi The aforementioned benefits are obtained under a qualitatively consistent pressure.

[0279] As mentioned above, the method using low, virtually constant pressure is one of the differences from conventional molding processes. The above advantages can be achieved, for example, high cost-effectiveness, mold cavity and thermoplasticity. An efficient process that does not require balancing the pre-injection pressure of the material, using atmospheric pressure in the mold cavity. A simplified mold structure that allows for the use of force and thus eliminates the need for pressurizing means. Manufacturing, more cost-effective, easier to machine, and with lower hardness and higher thermal conductivity, mold cavities The ability to use certain materials affects the temperature, viscosity, and other material properties of thermoplastic materials. A more robust processing method that is less susceptible to damage, and accelerated hardening of thermoplastic materials in mold cavities, and High-quality injection molding at low pressure without the need for heating or maintaining a constant temperature within the mold cavity. This includes the ability to manufacture goods.

[0280] Parts molded using conventional high-pressure processes are typically inferior to parts molded using low-constant-pressure processes. The number of orientation bands is generally small.

[0281] Parts molded using a low-constant-pressure process may experience less stress during the molding process. The process involves a speed-controlled filling process and a transition or switch to higher pressure control. The combination may result in parts with high levels of undesirable forming stress. Conventionally If the filling pressure is set too high during this process, the gate area of ​​the part often becomes overfilled. stomach.

[0282] Furthermore, those skilled in the art will see that the teachings disclosed herein apply to stack molds, rotary molds and core bars. In constructing multi-material molds, including insert molds, we handle mold interior decoration, insert molding, and mold interior assembly. They will realize that they can be used in combination.

[0283] While specific embodiments are illustrated and / or described herein, the spirit and scope of the claimed subject matter remain unchanged. Please understand that various other changes and modifications are possible without deviating from the established framework. Furthermore, various aspects of the claimed subject matter have been described herein, but such aspects are combined They do not need to be used together. Therefore, the attached claims are the claimed claims. It is intended to encompass all such changes and modifications that fall within the scope of the subject matter.

[0284] This method and / or machine also uses constant low-pressure molding in the injection blow molding process. This allows for controlling the actual plastic pressure filling process, thereby enabling a low constant plastic pressure. Pressure is used to fill and hold the mold and / or part of the mold. This prevents stagnation of the flow. This eliminates the need to maintain pressure on the parts during filling and reduces pressure loss within the mold during filling. The polymer is The core pin is injection molded onto it, and then the core pin is rotated to the blow molding station. It is expanded and cooled. This process is divided into three steps: injection, blowing, and ejection. It can be done.

[0285] This method and / or machine also uses constant low-pressure molding in the extrusion blow molding process. This allows for controlling the actual plastic pressure filling process, thereby enabling a low constant plastic pressure. Pressure is used to fill and hold the mold and / or part of the mold. This prevents stagnation of the flow. This eliminates the need for pressure retention during filling, reduces pressure loss within the mold during filling, and minimizes plastic pressure loss. The material is melted and extruded into a hollow tube (parison). Then, this parison is cooled. It is trapped and captured in a mold. Then, air is blown into the parison, creating a hollow bore. Inflate the plastic into the shape of a container or part. After the plastic has cooled sufficiently, open the mold. Then, the parts are ejected. Variations of extrusion blow molding include continuous molding and intermittent molding. In continuous extrusion blow molding, parisons are extruded continuously, and individual parts are properly formed. It is cut with a knife. Intermittent blow molding has two processes: straight intermittent and injection. Similar to molding, the screw rotates and then stops, pushing out the molten material. In the accumulator method, the accumulator collects the molten plastic, and as the previous mold cools, the plastic... When enough molten plastic has accumulated, the rod pushes against the molten plastic to form a parison. In addition, the screw may rotate continuously or intermittently. In the case of continuous extrusion, the weight of the parison This causes the parison to be dragged, making it difficult to calibrate the wall thickness. Accumulator head system or rotation The screw type uses a hydraulic system to quickly push out the parison, thus reducing the impact of weight. By adjusting the die gap with a parison programming device, the wall thickness can be precisely controlled. It is possible to control it.

[0286] This method and / or machine can also be used, for example, in an extruder for 3D printing (depending on the drive unit). Constant low-pressure molding can be used, controlling the process with the actual plastic pressure exiting the nozzle. For example, by providing an adjustable nozzle and / or breaker plate / pressure valve. This means that the nozzle can distribute the material at a low, constant plastic pressure, eliminating flow stagnation. There are two types of extruders for 3D printing: direct drive and Bowden type, depending on the type of drive unit. There are two types. In a direct-drive extruder, as the name suggests, the hot earth is extruded from the gears of the extruder. The filament flows directly to the end. There are also systems that combine these two parts.

[0287] This method and / or machine also performs injection molding, provided that a certain low-pressure molding is performed. The machine can also perform constant low-pressure extrusion, and control the filling process by actual plastic pressure filling. This allows for filling and / or holding pressure into molds and / or parts of molds using a low, constant plastic pressure. This is done to eliminate stagnation in the flow, maintain pressure on the parts during filling, and keep a constant low pressure. To create the necessary back pressure, fill the area using at least one breaker plate. Sometimes, it reduces pressure loss inside the mold. The holes in the breaker plate automatically reduce some pressure. To generate frictional heat, the breaker plate has heat sensors on both sides. It is possible to improve the control and uniformity of plastic materials passing through car plates, for example. The temperature of the breaker plate can be controlled by means of cooling and / or heating. ru.

[0288] This method and / or machine also includes a breaker plate and / or pressure valve added to the injection device. and / or incorporated into a manifold bolted to a mold within the machine, and / or injection molding incorporated into a part of such mold, for example, a hot runner manifold. The machine can also have a constant low-pressure extrusion. Breaker plate and / or pressure The device that holds the force valve controls shear adiabatic energy and / or generates shear adiabatic energy while interfering with the process. It is also possible to measure the temperature of materials entering and / or exiting obstacles / passages. For example, the breaker plate may be able to control the size of the passage that generates shear insulation. Yes, this involves controlling heat, cooling, pressure, and flow rate to obtain the desired output. .

[0289] This method and / or machine also controls the uniformity of the material composition, including temperature, at least Assuming that a certain low-pressure molding process is performed using another breaker plate, A breaker plate can also be installed in the injection molding machine's injection unit. The t can also be placed in the hot runner manifold of the injection molding machine's mold. Here, the advantage is that the hot runner system is already set up for temperature control. Also, for example, the size of the holes in the breaker plate is the gate to the cavity(s) If the size is the same, it is also possible to control the frictional heat.

[0290] This method and / or machine also has different densities and viscosities, and for example, the material through which it passes A trap enables the separation of materials with temperature differences, such as those with high-temperature and low-temperature regions. It is also possible to perform a constant extrusion on at least the breaker plate into which the p is incorporated. Constant low pressure prevents plastic degradation, enabling recycling from virgin materials and the recycling process. This greatly improves both recycling and disposal. When different types of plastics are melted together... The phases separate, like oil and water, and these layers tend to solidify. This phase boundary is the resulting material. Due to structural fragility and delamination, polymer blends are only useful for limited applications. This is how polypropylene and polyethylene, the most widely manufactured materials, behave. Therefore, there are limits to the usefulness of these for recycling. Also, plastics are recycled Each time it is processed, virgin material needs to be added to improve the integrity of the material. Therefore, even recycled plastic is, in most cases, new plastic A plastic material has been added. The same plastic can only be recycled about 2-3 times before its quality deteriorates and it becomes unusable. It is not possible. Constant low pressure protects plastic materials from degradation and greatly improves recycling, and Furthermore, when processed through an extruder under constant low pressure, for example, when directed in a certain direction toward different materials It is possible to remove unnecessary and / or necessary materials from a specific extrusion profile. Allows separation and / or centering to the central core, and removes scratches and layers from the surface of the extruded product. Minimize interstitial separation.

[0291] This method and / or machine can also be used with materials having different densities, viscosities, and, for example, through which materials pass. This enables the promotion of mixing / formulation of materials with temperature differences, such as those with high-temperature and low-temperature regions. A trap is incorporated that allows for constant extrusion on at least the breaker plate. Yes, it is possible. For example, additives such as glass fibers or foaming agents in the center of the melt flow are completed. The surface of the product can be improved, which makes constant low pressure possible. As a result, there is no stagnation in the flow front, allowing for longer flow within the extrusion mold with additional cooling. This allows for profiling, resulting in a straighter and more uniform extrusion profile coming out of the extruder. It is possible.

[0292] This method and / or machine also involves different screws and materials passing through the extruder. In a twin extruder, for example, one with temperature deviations such as having high-temperature and low-temperature regions / zones, It incorporates traps that allow for the separation of materials with different densities and viscosities, such as viscosity. At least a certain amount of extrusion can be performed on the breaker plate. This is injection molding. The uneven filling rate within the mold cavity allows for a smooth transition from thick to thin, and then to thick again. This was made possible by considering a constant low pressure, which has proven to have an excellent success rate in returning to its original state. Low pressure prevents degradation of plastic materials and facilitates recycling and processing of virgin materials. This will significantly improve both recycling processes.

[0293] This method and / or machine also assumes constant low-pressure molding and constant extrusion in an injection molding machine It is also possible to perform this, and conventional injection units can use plasticized material in front of the screw tip. Not only does it inject plastic, but it also pushes plastic into the cavity(s) (multiple cavities are possible), much larger This allows for a greater humogen plasticization output. Also, during the holding pressure stage, gold To inject the material into the mold, a material cushion needs to be left in front of the screw.

[0294] This method and / or machine also assumes constant low-pressure molding and constant extrusion in an injection molding machine It is also possible to perform this, and when using the extrusion function in the injection unit of a conventional injection molding machine, a certain low At least one breaker plate to build the back pressure necessary to maintain the pressure This is used to prevent material degradation within the injection unit in a given injection molding machine. This allows for a much wider range of shot weights to be used.

[0295] This method and / or machine also assumes constant low-pressure molding and constant extrusion in an injection molding machine It is also possible to perform this, and when using the extrusion function in the injection unit of a conventional injection molding machine, a certain At least one breaker plate to build the back pressure necessary to maintain low pressure Use the following: For example, the combination of an extrusion function and the injection of plasticizing material before the screw. By combining these methods, the amount of material that can be introduced into the cavity(s) within the machine is increased. For example, to hold a cushion while the mold is opening and closing and / or during the holding pressure phase of the molding process. Therefore, the space in front of the screw can be used to apply a constant extrusion of the material. These features include the three main types of blow molding, namely extrusion blow molding, injection blow molding, and It can also be used in one of the following processes: molding or injection stretch blow molding.

[0296] This method and / or machine also fills cavities with a smooth, low, and constant filling. It may also have a blow mold having (bottle neck and thread), where filling The material is held under pressure during filling, and after filling the neck and thread, the space for injection is machined. Extrusion is performed by opening the mold and / or by using a low, constant plastic pressure. Alternatively, when filling and holding a portion of the mold with actual plastic pressure, the filling process can be controlled. This further extrudes the parison. This eliminates stagnation in the flow and maintains pressure on the molded product during filling. The pressure loss inside the mold during filling is reduced. Next, the parison is fixed to the mold and air is blown in. Hmm. And the air pressure pushes the plastic out into the mold. Once it cools and hardens, the mold opens and the part is ejected.

[0297] This method and / or machine also involves constant extrusion in a blow molding machine, assuming constant low-pressure molding. It is also possible to perform this, and in order to build the back pressure necessary to maintain a constant low pressure, Another breaker plate and / or pressure valve is used. This is the rest of the parison. After functioning as an extrusion die, during filling, for example, the inlet (neck and s) of a bottle blow molding. This allows the red section to be held in place. Next, the parison is fixed to the mold and air is blown in. It is pressed in. Then, the air pressure pushes the plastic out into the mold. Once the material cools and hardens, the mold opens and the part is ejected.

[0298] This method and / or machine also assumes constant low-pressure molding, and a constant pressure in a blow molding machine. It can also be used to create the back pressure necessary to maintain a constant low pressure, with less Each uses one breaker plate and / or pressure valve. Fillable part of blow mold For example, a movable slide and / or core pull relative to the rest of the blow mold. This has the ability to hold pressure in the blow mold when filling, for example, bottle blow molds. This makes it possible to maintain pressure during filling of the mold entrance portion (neck and thread portion), and the part The part is movable relative to the rest of the blow mold, for example, a slide and / or core. It has a .

[0299] This method and / or machine also assumes constant low pressure molding within a blow molding machine. It can also perform pressure extrusion, and a small amount of back pressure is needed to build the back pressure necessary to maintain a constant low pressure. Use at least one breaker plate and / or pressure valve. This will allow the actual plasticity Using a low, constant plastic pressure, the mold and / or a part of the mold can be filled and held in place. This makes it possible to eliminate flow stagnation, maintain pressure during part filling, and extrude blow molding. , one of the three main types of blow molding: injection blow molding and injection stretch blow molding. When using a mold to partially and / or completely fill and hold the material, pressure loss within the mold occurs. Reduce.

[0300] This method and / or machine also involves constant extrusion in a blow molding machine, assuming constant low-pressure molding. It is also possible to do so, and in order to build the back pressure necessary to maintain a constant low pressure, at least Use one breaker plate and / or pressure valve. This allows parison and / or This allows for better and more consistent pressure retention of the material in the preform, resulting in superior blow-molded products. This makes it possible.

[0301] This method and / or machine also involves constant extrusion in a blow molding machine, assuming constant low-pressure molding. It is also possible to do so, and in order to build the back pressure necessary to maintain a constant low pressure, at least Use one breaker plate. This allows for, for example, the bottle blow mold during filling. This makes it possible to maintain pressure at the entry point (neck and thread area).

[0302] This method and / or machine controls the filling process by actual plastic pressure, and maintains a low, constant plasticity. Pressure is used to fill and hold pressure in the extrusion mold and / or part of the mold. This allows the flow This eliminates stagnation, maintains pressure on the parts during filling, and reduces losses within the mold during filling. The first plastic profile comes out of the extrusion tool from one or more angles / surfaces. It can also have a compression molding function that compresses objects at times.

[0303] This method and / or machine also comes out of the extrusion tool from one or more angles / surfaces It comprises a continuous compression cavity and / or core for molding the initial plastic profile. It may also have a compression molding function equipped with one or more compression wheels.

[0304] This method and / or machine also presses a plastic profile from one or more angles / faces. As it comes out of the tool, the continuous low-pressure labeling applied to the plastic profile It can also have a lu.

[0305] This method and / or machine also presses a plastic profile from one or more angles / faces. As the plastic profile emerges from the tool, a continuous low barrier is applied. It may also have a label.

[0306] This method and / or machine also presses a plastic profile from one or more angles / faces. When the part comes out of the tool, continuous stamping of the part from the plastic profile / Cutting and / or shaping can also be performed.

[0307] This method and / or machine also uses plastic profiles for continuous reuse. When the excess material comes out of the extruder tool, it returns to the extruder. It is also possible to perform continuous stamping / cutting and / or molding of parts from the casing.

[0308] This method and / or machine also allows a plastic profile to be removed from one or more angles / surfaces When coming out of the extrusion tool, a spare plastic profile for, for example, a shoe sole. It is also possible to perform continuous stamping / cutting and / or molding of foamed preforms, Afterward, the preform is placed in the heated mold cavity for final expansion and / or compression. ru.

[0309] This method and / or machine also allows a plastic profile to be removed from one or more angles / surfaces As the part emerges from the extrusion tool, continuous stamping of the plastic profile. Cutting and / or shaping can also be performed. Here, one operation is to profile the hinge function By pressing it into the file and bending the hinge to stretch the plastic molecules in the direction that opens them, The goal is to improve the function and lifespan of the unit.

[0310] Furthermore, this method and / or machine also uses a low, constant plastic pressure to modify the mold and / or the mold. A constant low-pressure technique that controls the filling process by filling and holding a portion of the material with actual plastic pressure. From the possibilities of the technique, it is also possible to have a new and innovative hot runner system, and with this This eliminates stagnation in the flow, maintains pressure on the parts during filling, and reduces pressure loss within the mold during filling. This makes it possible to fill cavities that are unbalanced and / or of different sizes. It has been proven that this is possible. Therefore, the manifold of this new hot runner system Gold does not require an extra layer to balance the different hot runner drops. Therefore, the required height is lower. This new system, for example, requires 10 hot runners - To accommodate a linear supply line to the drop, for example, small brakes of different shapes We were able to install a car license plate.

[0311] This method and / or machine also fills cavities of uneven and / or different sizes. With certain low-pressure technologies that have been proven to make this possible, a new and innovative hot runner —It is also possible to equip this system with a hot runner system. The manifold requires less height and, in a given template, is suitable for hot runner drops. Therefore, it can have more cavities to fill, which is for today's injection molding. Similar to hot runner systems, a balanced supply system is required for design freedom. It depends on the degree.

[0312] This method and / or machine also fills cavities of uneven and / or different sizes. With certain low-pressure technologies that have been proven to make this possible, a new and innovative hot runner —It is also possible to equip this system with a hot runner system. The manifold is extruded and blow-molded in different forms, and features a cold runner. In standard injection molding dies, a long, narrow cold runner line is used in the filling pattern. And / or demonstrates that it can supply thick-walled components into the cavity with little to no stagnation. This could allow them to benefit from these new hot runner systems. This indicates.

[0313] This method and / or machine also enables constant low-pressure technology, which allows for, for example, 0.030 inches. It can also be equipped with a new, innovative hot runner system based on its capabilities. Without entering the cavity of the part, it has a 3-inch long "filament" section before filling. In diameter runners, the diameter and length can vary depending on the size of the part and the choice of material. The molten plastic material is reheated during every molding cycle before injection of the next portion. By having at least one cold runner section, the thin filament can be remelted. Because the filament diameter is relatively thin, it can be reheated relatively quickly, making it an expensive standard There is no need to use Hot Runner Drops.

[0314] This method and / or machine also enables constant low-pressure technology, which allows for, for example, 0.030 inches. It can also be equipped with a new, innovative hot runner system based on its capabilities. Without entering the cavity of the part, it has a 3-inch long "filament" section before filling. In diameter runners, the diameter and length can vary depending on the size of the part and the choice of material. The molten plastic material is reheated during every molding cycle before injection of the next portion. By having at least one cold runner section, the thin filament can be remelted. Because the filament has a relatively thin diameter, it can be reheated relatively quickly.

[0315] To heat non-conductive materials such as plastics, induction is used, such as graphite. A conductive susceptor is heated, and that heat is transferred to a non-conductive material. Induction generates an electromagnetic field in the coil. To generate and heat the workpiece, energy is transferred to create the workpiece. The materials include metals such as copper, aluminum, steel, brass, or alloys, and materials with strength and conductivity. It may be a mixed material made for that purpose. Also, graphite, carbon or silicon It may also be a semiconductor such as a byte. Induction heating is performed at a low temperature of 100°C (212°F) or It is used in processes with temperatures up to 3000°C (5432°F).

[0316] The filament portion of the mold can be reheated using other heating applications. Furthermore, this new and innovative hot runner system can also be used for high-pressure injection molding applications. It may be possible. The filament portion is reheated for a predetermined time during each injection molding cycle. This is a more conventional form of gate design present within mold parts / components. It is also possible.

[0317] This method and / or machine can also be combined, for example, with a conventional heated hot runner manifold. In addition, a novel and innovative hot runner having conductive heating as all or part of the heating source. It is also possible to equip the system. All or part of the conductive heating as a heat source is called Three plates used when part of the Drunner system is on a different plane from the ejection position. It can also be used in combination with a mold. The runner system for a 3-plate mold is It rests on a second dividing surface parallel to the main dividing surface. This second dividing surface allows the mold to open when it is opened. Runners and sprues can be discharged. Conductive heating, either as a whole or as part of a heat source, is typically used in combination with an unheated insulated runner. It can also be used. This type of runner maintains a molten state during continuous cycling. Therefore, it requires a very thick runner channel. These molds feature oversized passages formed in the mold plate. In the manufacturing process, The size of the passage and the heat applied with each shot open the molten flow path. A cost-effective system eliminates the additional costs of manifolds and drops, but heated hot runners - Provides a flexible gate for the system. Allows for easy color changes.

[0318] The above proposal is for creating new claims for current and / or dependent patent applications. In this context, without being limited to any of the described molding techniques, both individually and in combination, It is also intended to be used in partial combinations.

Claims

1. A method for performing plastic molding at a substantially constant and relatively low pressure, (a) Using a rotating screw, transfer the molten thermoplastic material into at least one mold of the molding apparatus The steps include introducing the material into the cavity and performing extrusion molding at a low, substantially constant melting pressure, (b) The step of maintaining the melting pressure substantially constant at less than 6000 psi, Includes, The aforementioned thermoplastic material has a melt flow index of approximately 0.1 g / 10 min to approximately 500 g / 10 min. possess, The aforementioned method.

2. The molding apparatus has a heated run that is in fluid communication with the at least one mold cavity. A back pressure structure such as a breaker plate or pressure relief valve is located inside a manifold with a ner A construction means is provided, where the molten thermoplastic material passes from the inlet point through the back pressure construction means. While being transported to the heated runner, the melting pressure of the molten thermoplastic material is substantially The method according to claim 1, wherein the constant is maintained.

3. The step of filling the last mold cavity with the molten thermoplastic material is This includes applying pressure to a molten thermoplastic material, wherein the constant molten pressure is maintained. The step is the molten thermoplastic material as it enters the at least one mold cavity. The melting pressure and the molten thermoplastic material filling the at least one mold cavity The melting pressure is monitored, and the molten heat entering the at least one mold cavity is controlled. A claim comprising: adjusting the pressure applied to the plastic material to maintain the constant melting pressure. The method described in 1.

4. The molding apparatus is located between the breaker plate and the at least one mold cavity. A pressure relief valve is provided, and the pressure relief valve is determined at a substantially constant melting pressure. The set point has a melting pressure higher than the predetermined set point, and melting heat is passed through the pressure relief valve. The pressure relief valve, which maintains the substantially constant melting pressure in the plastic material, is the thermoplastic. When the material passes through the pressure relief valve and enters the at least one mold cavity, The method described in claim 1, which reduces the melting pressure of the thermoplastic material to maintain the constant melting pressure. Method of loading.

5. The molding apparatus compensates for fluctuations in the fluidity and / or temperature of the molten plastic material. Therefore, the method for automatically adjusting the extrusion process is The step of providing an extrusion molding machine having at least one mold cavity, A molding controller is provided that includes a pressure control output configured to generate control signals. A step, wherein the control signal is for the extrusion process of the extrusion molding machine. The step of determining the pressure and / or temperature, at least partially. During the first hour of the extrusion cycle, the pressure control output and / or temperature output are generated. The steps include measuring the first control signal, In the same extrusion cycle, in the second time following the first time, the pressure control output The steps include measuring a second control signal generated from and / or a temperature output, The first control signal generated from the pressure control output and / or temperature output, and the pressure control The comparison result is obtained by comparing it with the second control signal generated from the power output and / or temperature output. Steps and In the third hour following the second hour, based at least in part on the comparison results, the pressure The steps include determining a third control signal for the force control output and / or temperature output, The method according to claim 1, including the method described in claim 1.

6. The comparison results are used as the soft sensor melt viscosity input by the controller. The flow factor (FF) is The method according to claim 5.

7. The aforementioned FF is, Formula FF=(CS1-CS2) / T Determined by, In the formula, CS1 is the first control signal, CS2 is the second control signal, and T is the time difference between CS1 and CS2. The method according to claim 6.

8. The method according to claim 7, wherein the third control signal is proportional to the flow factor.

9. The method according to claim 7, wherein T is between 0.1 milliseconds and 10 milliseconds.

10. The comparison results are used as the soft sensor melt viscosity input by the controller. The method according to claim 5, which is used as the basis for the viscosity change index (VCI) used.

11. The aforementioned VC I is, Formula VCI=(CS1-CS2) / S Determined by, In the formula, CS1 is the first control signal, CS2 is the second control signal, and S is the positional difference of the melting transfer machine component. The method according to claim 10.

12. The step of comparing the first control signal and the second control signal is performed by the first control signal This includes comparing the second control signal with the optimal control signal based on the optimal pressure curve, The method is, During the first hour of the extrusion molding cycle, generated from the pressure control output of the controller. The first control signal is measured using a control signal measuring device, In the same extrusion cycle, during the second time following the first time, the controller The second control signal generated from the pressure control output is measured using the control signal measuring device. The steps to take, The first control signal generated from the pressure control output of the controller and the controller The comparison result is obtained by comparing it with the second control signal generated from the pressure control output of the pressure control unit. Step and, In the third hour following the second hour, based at least in part on the comparison results, the pressure The process includes the step of determining a third control signal for force control output. The method according to claim 5.

13. The step of providing the extrusion molding machine involves providing a rotary screw type melting transfer machine component. The method, which includes the above, further includes, The steps include measuring the first position of the melting transfer machine component at the first time, The steps include measuring the second position of the melting transfer machine component at the second time, The step includes determining the positional difference between the first position and the second position, The comparison step is performed based at least partially on the position difference, the first control signal This includes comparing the number and the second control signal to obtain the comparison result, The method according to claim 5.

14. Assuming constant low-pressure molding, the step of performing constant low-pressure extrusion in an injection molding machine is further... This includes, so that the conventional injection unit can inject plastic into the at least one mold. This allows for a much larger and more homogeneous plasticizing output to be extruded into the bit, The method described in item 1.

15. The further step includes performing constant low-pressure extrusion in an injection molding machine, wherein the breaker The plate and / or pressure valve is bolted to the mold of the injection molding machine in the manifold. The mold incorporated into the do and / or incorporated into the hot runner manifold The method according to claim 14, which is part of the method.

16. Extruding a plasticizing material into the at least one cavity, and the at least one By combining the injection of the plasticizing material into the cavity of the molding machine, The steps of increasing the amount of material that can be introduced into at least one of the cavities inside, and the During the holding pressure phase of the molding process, while the mold opens and closes, the space in front of the screw is used to move forward The steps include applying a constant low-pressure extrusion of the material to hold a cushion of molten plasticizer material, and The method according to claim 14, further comprising the following:

17. A method for performing plastic molding at a substantially constant and relatively low pressure, (a) In at least one mold cavity of a molding apparatus equipped with a hot runner system, The molten thermoplastic material is filled using a low, constant plastic pressure, and the pressure inside the mold during filling is Steps to reduce losses, (b) While filling the mold cavity with the molten thermoplastic material, The method comprising the step of maintaining the melting pressure substantially constant at less than 6000 psi, Law.

18. The method includes the step of filling an unbalanced manifold, the manifold being Please supply a heated runner that is in fluid communication with at least one mold cavity. The method described in item 17.

19. The mold is reheated during each molding cycle before injecting the next portion of the molten plastic material. A hot runner system having at least one cold runner portion within the component further The method according to claim 17, including the method described in claim 17.

20. The step of reheating at least one cold runner portion using conductive heating is The method according to claim 19, further comprising:

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