Material of large bracket as well as equipment and process for preparing material

Abstract

The invention discloses a material, forming equipment, a forming process technology, a design scheme and an auxiliary drying equipment technology for manufacturing industrial large-scale parts by using macromolecular resin. A chemical fiber raw material is subjected to water washing, sorting, additive adding and melting, and plastic particles are obtained through granulation and slicing equipment; then the materials pass through the first extrusion equipment and are melted and plasticized, the materials in the molten state enter the second extrusion equipment to be gradually cooled to reach the softening state, the materials are further cooled and extruded to the blank mold and the forming mold, and compression molding solves the problem that large resin components cannot be formed; by optimizing the raw materials and the design structure, the stacking volume of the product is reduced by 30%-50%. Microwave drying equipment is used, molecular chains of hydrates are directly broken, and energy is saved by 70%. The strength requirement is met through material optimization and structural design, and the cost is greatly reduced; the stacking size is reduced, and the logistics cost is reduced; the large product forming process technology and the forming equipment technology are achieved; the problem of recycling of chemical fiber waste is solved, the environmental protection benefit and the economic benefit are huge, and the manufactured large clamping plate is low in manufacturing cost, excellent in performance and high in bearing capacity.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, manufacturing equipment, process technology and product design technology, and specifically to a molding device and process technology for a large freight bracket and a large bracket product. Background Art

[0002] Freight racks are one of the most frequently used and widely used logistics equipment in modern logistics production. At present, the market stock of this single product in China is about 150 billion yuan; each year, the value of overseas and domestic losses due to logistics exports is 50 billion yuan, and 120 million tons of plastics are used, with a value of 40 billion yuan.

[0003] Traditional plastic freight pallets use polypropylene PP materials; however, the resin material PET of the present invention is low in price and has excellent wear resistance, chemical resistance, and high mechanical strength. The toughness strength of PET is 150% of that of PP: the rigidity strength of PET is 180% of that of PP; the bearing strength of PET pallets is 120% of that of PP; however, PET has relatively high glass transition temperature and melting point, high mold temperature, uneven crystal structure, difficult molding, long molding cycle, high water absorption and other disadvantages, which make it impossible to mold large products using PET, greatly limiting the application of PET.

[0004] It can be seen that PET materials are superior to PP materials in terms of performance and cost, but PET is difficult to shape. The present invention solves this technical problem through innovative continuous double extrusion and three-step molding process design, and uses more energy-saving microwave drying technology to prepare large-scale freight pallets with excellent performance. In addition, the price of the PET recycled material of the present invention is only 60% of that of PP, which is low in cost. Therefore, the present invention can save 15 billion yuan every year. Furthermore, the PET of the present invention is mostly derived from discarded chemical fiber raw materials that are not recycled by anyone, and the social and environmental benefits are particularly huge. Summary of the invention

[0005] The object of the present invention is to provide a preparation method for manufacturing large-scale components for industrial use, so as to solve the problems existing in the prior art.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A method for manufacturing large-scale components for industrial use, characterized in that it comprises the following preparation steps:

[0008] (1) The PET raw material is supplied to the first extruder, the temperature range of the first extruder is set to 290-180 degrees Celsius, and the temperature of each section from the feed port to the discharge port is gradually reduced.

[0009] (2) supplying the hot melt raw material extruded by the first extruder to the second extruder, the temperature range of the second extruder is set to 200-150 degrees, the process temperature of the second extruder is lower than the extrusion temperature of the first extruder, and the temperature of each section of the second extruder from the feed port to the outlet port is reduced successively;

[0010] (3) The blank extruded by the second extruder is supplied to a forming die, and the blank is extruded, cooled and formed in one step to obtain the large-scale component for industrial use, and the temperature of the die is set at 140-35 degrees.

[0011] Furthermore, the first extruder is one of a twin-screw extruder, a single-screw extruder or a conical twin-screw extruder; the second extruder is one of a twin-screw extruder, a single-screw extruder or a conical twin-screw extruder.

[0012] Furthermore, the discharge port of the first extruder is connected to the feed port of one or more second extruders; and the discharge port of the second extruder is connected to one or more sets of molding dies.

[0013] Furthermore, the material extruded from the discharge port of the first extruder directly enters the feed port of the second extruder; or the material extruded from the discharge port of the first extruder enters the feed port of the second extruder through a connecting flow channel.

[0014] Furthermore, a heating device is provided on the connecting flow channel, and a metering pump is designed and installed on the connecting flow channel or no metering pump is provided according to actual conditions.

[0015] Furthermore, the PET raw material is new PET material or recycled PET material, and the raw material is microwave dried at a temperature of 105 to 115° C. for 25 to 40 minutes.

[0016] Furthermore, the recycled PET material comes from waste chemical fiber products and electronic product shells. After sorting, cleaning and drying, it is heated to 245-285 degrees in a pressure-maintaining boiler, melted and granulated, and then passed through a 40-100 mesh screen to produce PET particles.

[0017] Furthermore, the PET material includes additives, which are selected from one or a mixture of glass fiber, talcum powder, calcium carbonate, mica powder, graphene, polypropylene or other compatible resin materials, and the additive addition amount is 2%-20% by weight; the PET material also includes toughening and / or hinge agents, which are selected from one or a mixture of toughening materials compatible with PET such as EVA, SBR, ASA, etc., and the addition amount is 0.5-15%; the mass proportion of PET in the PET material exceeds 75%.

[0018] Furthermore, a device for implementing the preparation method includes a dryer. The present invention further uses an energy-saving and efficient microwave dryer, a first extruder, a second extruder and a molding die; the raw material is dried in the microwave dryer and directly supplied to the first extruder via a feeder, the hot melt raw material extruded by the first extruder is directly supplied or supplied to the second extruder through a flow channel, and the blank extruded by the second extruder is directly supplied to the molding die.

[0019] The recycled materials are mixed and toner is added according to the test performance and color requirements. The toner is 1-5% of the market sales amount. Blue, medium gray and yellow are the main colors used, and the amount is adjusted according to the color card.

[0020] PET materials can be modified by blending. After styrene-butadiene rubber SBR is grafted with maleic anhydride, blending it with PET can greatly improve the impact performance. 15 parts of SBRg with a grafting rate of 0.6% in 100 parts of PET can increase the impact strength of the composite by 30%. According to the physical properties of the raw materials tested, add an appropriate amount of SBRg with a grafting rate of 0.6% to meet the toughness requirements, or add other modified toughening materials to meet the material performance requirements. The addition amount is between 0.5-15%.

[0021] The first extruder A and the second extruder B of the invention are connected in such a way that the material extruded from the discharge port of A directly enters the feed port of the second extruder B; or directly enters the feed port of the second extruder B from the discharge port of the first extruder A through the flow channel. The flow channel needs to be heated, and the device connecting the two extruders can use a metering pump, which is set according to the specific situation.

[0022] The blank from the discharge port of the second extruder B of the present invention enters the forming die D through the blank mold and is formed after being cooled.

[0023] The connection relationship between the extruders A and B of the present invention is that the discharge port of A is connected to the feed port of B; the angle between A and B can be 0 to 180 degrees. The present invention is specially designed that A and B are connected in parallel to form an integrated device, and the discharge port of A and the feed port of B are directly connected to form an integrated device through a flow channel, and further A and B can be connected with or without a metering pump.

[0024] The present invention can be designed as a one-machine dual-mold; after the first extruder A and the second extruder B are connected, a set of molding dies or multiple sets of molding dies are designed for the discharge port D of B; the molding die D can be one, two D+D, or three, D+D+D. The present invention focuses on the use of two sets of molds D+D.

[0025] Further, the second extruder B of the present invention can be designed as two sets of extruders, and the extruded material of the first extruder A is diverted to the second extruder B+B through the flow channel. Each second extruder is equipped with a molding die at the rear end, and the molding die is designed according to the above requirements. After the mold is formed, the product enters the trimming through the transmission equipment to become a finished product.

[0026] The present invention solves the problem of material recycling and reuse of PET in China;

[0027] China restricts the import of recycled plastics, but does not restrict the import of PET recycled materials because the material itself is environmentally friendly. 90% is used in the fields of clothing and drinking water and food packaging. The requirements for recycled materials are extremely high. The colors must be strictly distinguished and the 2000 mesh filtration must be met. Therefore, the recycling and sorting processing costs of such materials are much greater than the price of the materials themselves. For example, the cost of recycling bottle flakes is 800 yuan per ton and 5000 yuan per ton after granulation. The present invention only requires the material to pass through a 200-mesh screen after melting, and the color requirements are not high, so it is easy to recycle. Therefore, a large amount of discarded chemical fiber clothing can be used as the raw material of the present invention, solving social and environmental problems.

[0028] The molding process and equipment of the present invention further solve the problem of manufacturing large-scale products from PET recycled materials.

[0029] The present invention innovatively uses a three-step molding method in which the process temperature is set to a gradually cooling state from high to low. The temperature of the dried material is generally 100-120 degrees. The feeder conveys the material into the feed port of the first extruder A. The screw temperature of the first extruder A from the inlet to the outlet is sequentially designed to be 285 degrees, 275 degrees, 255 degrees, 245 degrees, 245 degrees, 225 degrees, 215 degrees, 200 degrees, and 195 degrees. The material is conveyed to the second extruder B through a heating flow channel, and the temperature of the heating flow channel is set to 185-200 degrees. The screw temperature of B from the inlet to the outlet is sequentially set to 200 degrees, 180 degrees, 170 degrees, 165 degrees, 155 degrees, and 150 degrees to extrude the rough material. The rough material enters the molding mold, the mold temperature is set to 120 degrees, the temperature is reduced to 80 degrees after the mold is closed, the cooling time is 90-150 seconds, and after the mold is opened, the scraps are removed to form a finished product.

[0030] In the past, infrared drying technology was used in the pet processing field. The microwave drying equipment F of the present invention is designed to use microwaves to vibrate water molecules and break the molecular chains of hydrates. The microwave drying of the present invention is designed to use a large-scale flat microwave heater, connected to a power supply and a control system. The control system is a digital temperature control system that can accurately control the process temperature. There must be no metal objects on the top of the microwave heater, and a metal cover plate cannot be used. The circuit part of the microwave heater is available in the market and does not need to be designed separately. The power and size of the microwave heater are adjusted according to actual conditions. A support frame is designed at the bottom of the microwave collector to facilitate heat dissipation. A guardrail is designed around the microwave heater, and the guardrail is a cylindrical design of conductive material.

[0031] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0032] The present invention uses a three-step molding method to prepare a freight pallet. The dried raw material enters the first extruder through a feeder, and the raw material is extruded after hot melting. The extruded hot melt raw material is aligned with the feed port of the second extruder. The screw of the second extruder pushes the raw material and cools it to a suitable temperature during the pushing process to extrude a cylindrical or sheet-shaped rough raw material. The third step is to extrude the rough ingredients into a one-time molding by an automated mold to obtain a product. The present invention first allows the PET material to transition from a fluid state to a soft elastic state through a first extruder, and then, through a second extruder, the PET material is gradually cooled from a soft elastic state to a crystalline state, prolonging the material crystallization process, and increasing the material crystallization rate to meet the requirement of more than 50% material crystallization. The present invention uses a three-step molding method, firstly, the high elastic material after the second extruder is cooled is added to the compression mold used in the present invention, and then the mold is vacuumed to make the material close to the mold to ensure that the molding is fuller, and then the second step is to close the mold, and the other half of the compression mold of the present invention is compressed by an electric or hydraulic push rod to form the product, and then cooled and formed, and automatically trimmed to become a finished product. The present invention uses a vacuum forming process or a blow molding process to initially shape the product, and uses secondary compression molding to increase the plasticity of the material between the soft elastic state and the crystalline state, so that the material further crystallizes into a glass state. The compression molding mold continuously applies pressure to make the material contacting the mold and the material crystallized into a glass state fuller, and then quickly cools and shapes.

[0033] The present invention adopts microwave drying technology to dry the sorted and washed aqueous PET material. The microwave drying process is gentle, which can ensure the stability of the physical and chemical properties of the material, penetrate the inside of the material to heat the water molecules separately, and the crystallization is uniform. The material has better performance after being formed. The present invention uses microwave drying and adjusts specific parameters to achieve fast and efficient drying effects, and saves energy and reduces consumption. The process time and energy consumption are 70% of traditional equipment, which significantly reduces energy costs.

[0034] The weight of the PET pallet prepared by the present invention can reach 12.5-15KG, with a designed load of 4 tons and a destructive load of 7.1 tons. The present invention achieves volume overlap by optimizing the structural design of the product, and the stacking height of 10 pallets of the present invention is reduced from 1300 mm to 650 mm to 800 mm. A 13-ton logistics truck fully loaded with 200 original products can be transported to 360-400, reducing logistics costs.

[0035] The present invention uses discarded chemical fiber products as raw materials to prepare the pallet. The PET raw materials are sorted and melted through a 100-mesh sieve to meet the pallet preparation requirements. The product has low cost, easy raw material recovery, recyclable, and strong environmental protection.

[0036] Furthermore, all the innovations of the present invention can be partially selected for use in practice. The material selection, molding equipment and molding process technology belong to the key rights protection scope of the present invention. The use of the materials and equipment process technology of the present invention in the field of large pallets is the key rights protection scope. As long as the materials and molding equipment process technology of the present invention are used in the actual manufacturing process, regardless of whether auxiliary drying technology and product design are used, it constitutes an infringement of the rights of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0038] The large pallet of the present invention is mainly used for logistics transportation and warehousing and stacking of goods. The specific size of the actual product of the present invention is not limited (because there are many specifications).

[0039] The nine-square grid set design of the present invention meets the requirements of load-bearing performance, and further meets the requirements of stacking overlap in the height direction of products, achieving the requirement of reducing the stacking height of more than two layers by 30%-50%.

[0040] The pallet of the present invention is exemplified below with a product having a length, width and height of 1300 mm, a width of 1100 mm and a height of 150 mm, and the product is named as a nine-grid pallet.

[0041] The rectangle with the length and width of the nine-grid pallet is a face, the upward face is the top face M1, and the downward face is the bottom face M2; the face formed by the sides of the length and width and the height of the nine-grid pallet is, collectively referred to as the side face.

[0042] The upper plane of M1 is designed with downward reinforcement ribs, the thickness of the ribs is 1-2 mm, the spacing between the ribs is 20-50 mm, the horizontal and vertical intersections of the reinforcement ribs can be designed according to aesthetic and mechanical requirements, and the height of the reinforcement ribs is designed to be 20-90 mm; the length and width of each edge plane of M1 are designed with side reinforcement ribs vertically downward, the thickness of the side reinforcement ribs is set to 1.5-5 mm, and the height of the side reinforcement ribs is designed to be 30-100 mm; the plane of M1 can be a plane without exposed reinforcement ribs, or it can be a plane with hollowed-out reinforcement ribs.

[0043] M2 is another plane processed separately, and its external dimensions are consistent with those of M1. The reinforcing rib grid of M2 can be designed separately according to aesthetics and mechanical properties. Support frames are designed along the sides of M1 and M2 respectively. The support frames are formed in one step through the process technology of the present invention, and are connected to M1. The height of the support frame is the height of the product; the ground of M2 does not involve the support frame structure. The support frame structure designed by the present invention is a conical structure, and the position intersecting with the plane of M1 is the upper part, and the downward part is the lower part. The inner diameter of the upper part of the support frame is large, and the lower part is small, thus forming a conical structure with a large upper part and a small lower part; the conical structure is large at the top and small at the bottom, and does not specifically refer to a conical structure in a geometric sense, and can be any geometric shape. It is further required that the external dimensions and shape of the bottom of the support frame can be perfectly placed in the space part of the internal shape and size of the top of the support node, so as to meet the stacking height reduction in the stacking process of the pallet described in the present invention.

[0044] The position design of the support frame satisfies the aforementioned nine-square grid design. The center point Q of each side is found along the edge of the M1 plane, and the point Q1 of 1 / 2R mm is found from the Q point to both sides. The inner diameter size of the top of the support frame is found and set to R mm. At the four fixed angle positions of the M1 plane, 1 / 2R mm and R mm are found to each side. The corresponding 1 / 2R, R, Q1, Q, Q1 positions of the parallel opposite sides of M1 are connected with parallel lines. The intersection position of each side and the center of M1 is the position of the support frame. After such connection and production, the long side, wide side and diagonal line of the M1 plane are all three support frames. The three-dimensional figure is the nine-square grid design claimed in the present invention.

[0045] The M1 plane and the reinforcing rib plane, the support frame structure and the side surface of the present invention are formed by one-time compression molding through the equipment process of the present invention. After molding, the space between the support frame and the adjacent support is a support bridge, which is the insertion working position of the forklift arm during actual use.

[0046] The present invention further meets the needs of some customers and extends a new design structure, a separately formed plane M2. The thickness of M2 is generally designed to be 10-30 mm; the outer dimensions of M2 and M1 are consistent, and a hollow assembly position is designed at the bottom structure position of the support frame corresponding to M2 and M1. The bottom shape of the M1 support frame structure is tightly assembled to the assembly position of M2 to form an assembled large-scale card. The mechanical strength is better and more beautiful.

[0047] In order to more clearly illustrate the method provided by the present invention, the following examples are described in detail:

[0048] Example 1

[0049] (1) sorting and washing chemical fiber waste to obtain recycled PET materials; placing the PET materials in a pressure cooker, heating them to 260° C. for melting and granulation, and then passing through a 60-mesh sieve to obtain PET particles;

[0050] (2) adding maleic anhydride grafted styrene-butadiene rubber (SBR) to PET particles, with the addition amount being 8 parts of SBR with a grafting rate of 0.6% per 100 parts of PET; and adding yellow powder, with the addition amount being 2 wt%;

[0051] (3) placing the PET material obtained in step (2) in a drying device at a drying temperature of 105° C. for 30 min and drying;

[0052] (4) The dried PET material is fed into the first extruder through a feeder, and the screw temperature is set. The screw temperatures of the first extruder from inlet to outlet are sequentially designed to be 285 degrees (inlet), 275 degrees, 255 degrees, 245 degrees, 245 degrees, 225 degrees, 215 degrees, 200 degrees, and 195 degrees (extrusion outlet);

[0053] (5) The material extruded from the first extruder is transported to the second extruder through the heating channel, the temperature of the heating channel is set to 190 degrees, and the screw temperature is set. The screw temperature of the second extruder from the inlet to the outlet is set to 190 degrees (inlet),

[0054] 180 degrees, 170 degrees, 165 degrees, 155 degrees, 150 degrees (extrusion port), extrude the blank, and the blank enters the molding die;

[0055] (6) The forming mold is vacuumed, the blank is added, and the mold is closed for extrusion molding. The mold temperature is set to 120 degrees. After the mold is closed, the temperature is lowered to 80 degrees. The cooling time is 90 seconds. After the mold is opened, the scraps are removed to form the finished product.

[0056] Material performance test: The material sources are mobile phone cases and chemical fiber miscellaneous materials; the materials are divided into four parts PET-1, 2, 3, 4, and all four parts contain the additives, two of which are added with calcium carbonate, and the addition amount is 6%; two of which are added with SBRg with a grafting rate of 0.6%, 2%. Two of them are put into the traditional infrared drying equipment, and the process time is set to 180 minutes and the process temperature is 110 degrees. The other two parts are put into the microwave drying equipment of the present invention for a process time of 40 minutes, and the process temperature is set to 110 degrees.

[0057] Make national standard test strips.

[0058] Test data comparison; Test standard: GB / T1010.1-2006

[0059]

[0060] Through the above comparison, the microwave drying of the present invention saves 70% of the process time and reduces the energy consumption by 70% compared with the traditional infrared drying. The addition of the SBRg toughening agent of the present invention can improve the impact performance of the material by about 30%, and other properties are not greatly affected.

[0061] The above examples are material performance tests, and the following examples are product performance tests;

[0062] Example 2

[0063] The dried PET material is fed into the first extruder through a feeder, and the screw temperature is set. The screw temperatures of the first extruder from inlet to outlet are sequentially designed to be 285 degrees (inlet), 275 degrees, 255 degrees, 245 degrees, 245 degrees, 225 degrees, 215 degrees, 200 degrees, and 195 degrees (extrusion outlet);

[0064] Through the heating flow channel, the heating flow channel temperature is set to 190 degrees, the material extruded by the first extruder is transported to the second extruder, the screw temperature is set, and the screw temperature of the second extruder from inlet to outlet is set to 190 degrees (inlet), 180 degrees, 170 degrees, 165 degrees, 165 degrees, 165 degrees (extrusion port) in sequence, and the blank material is extruded, and the blank material enters the molding die; the mold is closed for extrusion molding, the mold temperature is set to 120 degrees, the temperature is reduced to 80 degrees after closing the mold, the cooling time is 90 seconds, and after opening the mold, the scraps are removed to form the finished product.

[0065] Comparative Example 3

[0066] The dried PET material is fed into the first extruder through a feeder, and the screw temperature is set. The screw temperatures of the first extruder from inlet to outlet are sequentially designed to be 265 degrees (inlet), 265 degrees, 250 degrees, 245 degrees, 245 degrees, 225 degrees, 210 degrees, and 185 degrees (extrusion outlet);

[0067] Through the heating flow channel, the heating flow channel temperature is set to 190 degrees, the material extruded by the first extruder is transported to the second extruder, the screw temperature is set, and the screw temperature of the second extruder from inlet to outlet is set to 190 degrees (inlet), 180 degrees, 170 degrees, 165 degrees, 155 degrees, 150 degrees (extrusion port) in sequence, and the blank material is extruded, and the blank material enters the molding mold; the mold is closed for extrusion molding, the mold temperature is set to 120 degrees, the temperature is reduced to 80 degrees after closing the mold, the cooling time is 90 seconds, and after opening the mold, the scraps are removed to form the finished product.

[0068] The difference between Comparative Example 3 and Example 2 lies in the temperature range of the two extruders. The screw temperatures of the first extruder from inlet to outlet are sequentially designed to be 265 degrees (inlet), 250 degrees, 245 degrees, 245 degrees, 245 degrees, 225 degrees, 210 degrees, and 185 degrees (extrusion port); the screw temperatures of the second extruder from inlet to outlet are sequentially set to be 190 degrees (inlet), 180 degrees, 165 degrees, 165 degrees, 150 degrees, and 150 degrees (extrusion port).

[0069] Comparative Example 4

[0070] The difference between Comparative Example 4 and Example 2 lies in the temperature range of the two extruders. The screw temperatures of the first extruder from inlet to outlet are sequentially designed to be 285 degrees (inlet), 275 degrees, 255 degrees, 245 degrees, 245 degrees, 255 degrees, 275 degrees, and 285 degrees (extrusion port); the screw temperatures of the second extruder from inlet to outlet are sequentially set to 190 degrees (inlet), 180 degrees, 170 degrees, 170 degrees, 180 degrees, and 190 degrees (extrusion port).

[0071] Comparative Example 5: Performance of traditional PP polypropylene products of the same specifications; the specific manufacturing process is a large injection molding machine

[0072] Experiments and data

[0073] The following Table 1 shows the performance analysis results of the samples using Example 2 of the present invention and Comparative Examples 3 to 5.

[0074] Table 1

[0075]

[0076] From the data comparison of the embodiment and the comparative example, it can be found that the present invention uses discarded chemical fiber products as raw materials, prepares PET materials after sorting, and then uses microwave drying technology to dry the sorted and washed water-based PET materials. The microwave drying process is gentle and can ensure the stability of the physical and chemical properties of the material. The present invention uses a three-step molding method to prepare a freight pallet. The dried raw materials enter the first extruder through a feeder, and the raw materials are extruded after hot melting. The extruded hot melt raw materials are aligned with the feed port of the second extruder. The screw of the second extruder pushes the raw materials and cools to a suitable temperature during the pushing process, and extrudes a cylindrical or sheet-shaped rough raw material. The third step is that the automatic mold extrudes the rough ingredients for one-time molding to obtain a product. The present invention first allows the PET material to transition from a fluid state to a soft elastic state through the first extruder, and then, through the second extruder, the PET material is gradually cooled from a soft elastic state to a crystalline state, prolonging the material crystallization process, and increasing the material crystallization rate to meet the material crystallization requirement of more than 50%. The present invention uses a two-step molding method, firstly, the highly elastic material after the second extruder is cooled is added to the compression mold used in the present invention, and then the mold is evacuated to make the material close to the mold to ensure that the molding is fuller, and then the second step is to close the mold, and the other half of the compression mold of the present invention is compressed by an electric or hydraulic push rod to compress the highly elastic material to form the product, and then cool and shape it, and after automatic trimming, it becomes a finished product. The present invention allows the product to be initially formed through the vacuum forming function, and the plasticity of the material between the soft elastic state and the crystalline state is increased through secondary compression molding, and the plastic thickness material further enters the glass state. Because the material shrinks greatly, the compression mold continues to apply pressure to make the material contacting the mold and the material crystallized into the glass state fuller, and then quickly cools and shapes it.

[0077] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and no mark in the claims should be regarded as limiting the claims involved.

Claims

1. A method for manufacturing large-scale components for industrial use, characterized in that: The method comprises the following preparation steps: (1) supplying the PET raw material to a first extruder, wherein the temperature range of the first extruder is set to 290-180 degrees Celsius, and the temperature of each section from the inlet to the outlet is successively reduced; (2) supplying the hot melt raw material extruded by the first extruder to the second extruder, the temperature range of the second extruder is set to 200-150 degrees, the process temperature of the second extruder is lower than the extrusion temperature of the first extruder, and the temperature of each section of the second extruder from the inlet to the outlet is reduced successively; (3) The blank extruded by the second extruder is supplied to a forming die, and the blank is extruded, cooled and formed in one step to obtain the large-scale component for industrial use, and the temperature of the die is set at 120-75 degrees.

2. The preparation method according to claim 1, characterized in that: The first extruder is one of a twin-screw extruder, a single-screw extruder or a conical twin-screw extruder; the second extruder is one of a twin-screw extruder, a single-screw extruder or a conical twin-screw extruder.

3. The preparation method according to claim 1, characterized in that: The discharge port of the first extruder is connected to the feed port of one or more second extruders; the discharge port of the second extruder is connected to one or more sets of molding dies.

4. The preparation method according to claim 1, characterized in that: The material extruded from the discharge port of the first extruder directly enters the feed port of the second extruder; or the material extruded from the discharge port of the first extruder enters the feed port of the second extruder through a connecting flow channel.

5. The preparation method according to claim 4, characterized in that: The connecting flow channel is provided with a heating device or a metering pump is provided on the connecting flow channel.

6. The preparation method according to claim 1, characterized in that: The PET raw material is new PET material or recycled PET material, and the raw material is microwave dried at a temperature of 105-115° C. for 25-40 minutes.

7. The preparation method according to claim 4, characterized in that: The recycled PET material comes from waste chemical fiber products and electronic product shells. After sorting, cleaning and drying, it is heated to 245-285 degrees in a pressure-maintaining boiler, melted and granulated, and then passed through a 60-mesh screen to produce PET particles.

8. The preparation method according to claim 1, characterized in that: The PET material includes additives, which are selected from one or a mixture of glass fiber, talcum powder, calcium carbonate, mica powder, graphene, polypropylene or other compatible resin materials, and the additive addition amount is 2%-20% by weight; the PET material also includes toughening and / or hinge agents, which are selected from one or a combination of EVA, SBR, ASA materials and other tough materials compatible with PET, and the addition amount is 0.5-5%; the mass proportion of pure PET in the PET material exceeds 75%.

9. A large PET pallet component for industrial use, characterized in that: The component is manufactured by the preparation method described in any one of claims 1 to 8, especially the material and equipment process technology are essential items.

10. An apparatus for implementing the preparation method according to any one of claims 1 to 8, characterized in that: The equipment includes a first extruder, a second extruder and a molding die; the raw material is directly supplied to the first extruder via a feeder, the hot melt raw material extruded by the first extruder is directly supplied to the second extruder or supplied through a flow channel, and the blank material extruded by the second extruder is directly supplied to the molding die.

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