A rope tail injection molding method

Abstract

The present application belongs to the field of plastic molding connection technology in high-end equipment manufacturing, and provides a rope pull tail injection molding method. The present application provides an injection mold, and a process flow that cooperates with the injection mold: placing ropes, locking the injection mold, adding rubber, first injection, second injection, applying vibration to the injection mold, pre-ventilation treatment and opening the mold to take out the parts. The present application has a simple process, low production equipment cost, low energy consumption, customizable rope pull tail product shape, and high rope pull tail product quality.

Description

Technical Field

[0001] The present application belongs to the field of plastic molding connection technology in high-end equipment manufacturing, and in particular to a rope tail injection molding method. Background Art

[0002] Rope pulls, also known as rope pulls or rope pull tabs, are usually used together with zippers and are widely used in clothing, luggage, outdoor products and other auxiliary materials.

[0003] The rope tail is composed of two parts: the rope and the tail. The rope is usually woven from fiber materials and is divided into round ropes and flat belts. The tail is connected to the end of the rope. The tail is usually made of polymer materials and metal materials. The polymer materials include ABS (Acrylonitrile Butadiene Styrene), PA (Polyamide, commonly known as nylon), PC (Polycarbonate), PP (Polypropylene), PS (Polystyrene) and other plastics, TPU (Thermoplastic Polyurethane), TPR (Thermoplastic Rubber), TPE (Thermoplastic Elastomer), TPV (Thermoplastic Vulcanizate), and polymers such as organic silicone, acrylic resin, and polyurethane resin.

[0004] At present, rope and strap tails are mainly made by high-temperature injection molding, dipping, or gluing processes.

[0005] The high-temperature injection molding process is to inject heated molten plastic into the injection mold through an injection molding machine to cover the end of the rope to form a rope tail. High-temperature injection molding is the current mainstream manufacturing process. The tails made by high-temperature injection molding have rich shapes, and the rope and the tail are bonded by heat and pressure, which has high firmness. However, high-temperature injection molding equipment is complex, capital investment is large, mold parts are numerous and complex, and the cost is high. The manufacturing process requires heating and high pressure drive, and high energy consumption.

[0006] The dipping process is to immerse the end of the rope in liquid glue, take out the rope hanger for self-leveling, and the glue adheres to the rope to form a pull tail. Dipping is almost always done manually, so the product quality is uneven and the pull tail has a single shape. The dipping process relies on the glue to adhere to the self-leveling to form a water drop shape with irregular shape. The rope and the pull tail are bonded by interface adhesion, with low firmness and easy to peel off.

[0007] The gluing process is to glue the rope end and the tail together to form the rope tail. Gluing is mainly done manually, which often results in defects such as whitening and glue marks on the bonding surface. Usually, the rope and the tail are made of different materials and the bonding area is small, so the bonding strength is not high and there is a risk of falling off.

[0008] Due to the high degree of customization of the shape of rope and tie tail products and frequent updates, the high-temperature injection molding process uses high-pressure, hot-melt injection molding, and the design and production costs of injection molding equipment and injection molds are high. The injection molding process is complex and energy-intensive. The high-temperature injection molding process has increased the manufacturing cost of rope and tie tail products and prolonged the cycle of new products entering the market. However, the dipping and viscose processes cannot meet the needs of beautiful and firm rope and tie products.

[0009] In view of the defects of various processes for manufacturing rope and belt pull tails at present, a rope and belt pull tail manufacturing method with simple process, low production equipment cost, low energy consumption, customizable product shape and high product quality is needed. Summary of the invention

[0010] The embodiment of the present application provides a rope pull tail injection molding method, which aims to solve the problem of how to provide a rope pull tail manufacturing method with simple process, low production equipment cost, low energy consumption, customizable product shape and high product quality.

[0011] The present application provides a method for injection molding of a rope pull tail, which utilizes the injection mold provided by the present application, wherein the injection mold comprises a first half mold body and a second half mold body; the first half mold body and the second half mold body comprise a cavity portion, a feeding cavity portion, a discharge cavity portion and a fixed groove portion corresponding to each other; the first half mold body and the second half mold body together form a cavity, a feeding cavity, a discharge cavity and a fixed groove; the cavity is provided with a gate, and the gate is connected to the external space of the injection mold through the feeding cavity; the cavity is also provided with a discharge port, and the discharge port is connected to the external space of the injection mold through the discharge cavity; the cross-sectional area of ​​the gate is greater than the cross-sectional area of ​​the discharge port; one end of the fixed groove is connected to the cavity, and the other end is connected to the outside of the injection mold; the rope pull tail injection molding method comprises the following steps:

[0012] Step 1: placing a rope in the fixing groove of the first half mold body, with one end of the rope exposed outside the first half mold body and the other end embedded in the cavity of the first half mold body;

[0013] Step 2: closing the first half mold body with the rope and the second half mold body, and applying pressure to the two half mold bodies to lock the injection mold;

[0014] Step 3: Take a room temperature curable liquid rubber with a viscosity range of 5000 to 15000 cPs and put it into the material cylinder of the injection molding mechanism; wherein the room temperature is a temperature range of 25±5°C;

[0015] Step 4: Carry out the first injection of the rubber material, including the injection molding mechanism at 0.1-1 kg / cm 2 The liquid rubber is injected into the mold cavity from the gate by the pressure between the gate and the discharge port, the liquid rubber is compacted by the pressure difference between the gate and the discharge port, and the bubbles in the mold cavity are squeezed toward the discharge port, so that the bubbles and part of the liquid rubber are discharged from the mold cavity from the discharge port, and the injection is stopped when it is detected that the discharge cavity is overflowed and filled to a first preset position;

[0016] Step 5: performing a second injection of the rubber material, including: the injection molding mechanism retreats until the nozzle reaches a second preset position in the feeding cavity, the injection molding mechanism injects the liquid rubber material into the feeding cavity, and when the liquid rubber material fills the feeding cavity to a third preset position, the injection is stopped;

[0017] Step 6: applying vibration to the injection mold in a preset vibration mode, so as to promote the transfer of part of the liquid rubber in the feeding cavity into the cavity under the pressure difference between the gate and the discharge port through the vibration;

[0018] Step 7: After vibrating the injection mold, let the injection mold stand for a preset semi-curing time. After ventilating the cavity and letting it stand for a preset full-curing time, the two half mold bodies are fully opened to take out the cured molded rope tail.

[0019] Optionally, a section of the rope placed in the cavity is a buried section wrapped by colloid; before step 1, the following step is further included:

[0020] The buried section is processed with an anchoring colloid structure.

[0021] Optionally, the buried section is processed with an anchoring colloid structure, including:

[0022] At least one of providing a structure protruding from the surface of the rope in the buried section, providing a structure recessed in the surface of the rope in the buried section, providing a structure penetrating the rope in the buried section, and bending and shaping the buried section.

[0023] Optionally, the structure protruding from the surface of the rope belt includes at least one of a convex ring, a convex pattern, and a convex point;

[0024] The structure sunken in the surface of the rope belt includes at least one of a groove, a concave point, and a concave pattern;

[0025] The structure penetrating the rope belt includes at least one of a through hole and a through groove;

[0026] The bending and shaping of the buried section includes at least one of wave-shaped bending and zigzag bending.

[0027] Optionally, the guide system of the injection mold is composed of a guide column arranged on one of the first half mold body and the second half mold body, and a guide sleeve arranged on the other half mold body;

[0028] In step 2, the first half mold body and the second half mold body on which the rope is placed are closed, and pressure is applied to the two half mold bodies to lock the injection mold, including:

[0029] Through the cooperation of the guide column and the guide sleeve, the first half mold body and the second half mold body on which the rope is placed are preliminarily closed;

[0030] The preliminarily closed injection mold is installed between the front mold plate and the rear mold plate of the clamping mechanism, and pressure is applied to lock the mold.

[0031] Optionally, before step 3, the method further includes preparing the room temperature curing liquid adhesive;

[0032] Wherein, the room temperature curing liquid rubber is a two-component addition room temperature vulcanizing silicone composition; the two-component addition room temperature vulcanizing silicone composition comprises the following components in parts by weight:

[0033] 110 parts of two-component addition-type room temperature curing silicone, 70-150 parts of diluent, and 5-20 parts of color paste.

[0034] Optionally, the two-component addition-type room temperature curing silicone comprises two raw materials, component A and component B, and the component A and the component B are mixed in a weight ratio of 10:1;

[0035] The component A comprises the following components by weight:

[0036] 65-75 parts of the first basic silica gel, 25-35 parts of a reinforcing agent, 1-3 parts of a cross-linking agent, and 0.01-0.1 parts of an inhibitor; wherein the first basic silica gel is vinyl silicone oil, the reinforcing agent is fumed silica, the cross-linking agent is methyl hydrogenated silicone oil, and the inhibitor is acetylene alcohol;

[0037] The B component comprises the following components by weight:

[0038] 90 to 95 parts of a second base silicone, 2 to 5 parts of a chloroplatinic acid catalyst, and 1 to 5 parts of a release agent; wherein the base silicone is vinyl silicone oil, the catalyst is chloroplatinic acid catalyst, and the release agent is methyl silicone oil.

[0039] Optionally, the first preset position is between the discharge port and the position where the discharge cavity is filled to 2 / 3.

[0040] Optionally, the preset vibration mode includes applying vibration once at a frequency of once every 10 to 20 minutes, each application of vibration lasting 15 to 60 seconds, and stopping the application of vibration after applying vibration 2 to 5 times.

[0041] Optionally, the preset semi-curing time is 30 to 60 minutes, and the cavity is ventilated and left to stand for the preset full curing time, which includes:

[0042] Open the two half molds with a gap of 0.3 to 1 mm and let it stand for 1 to 2 hours.

[0043] The present application provides a method for injection molding of rope tails, which utilizes room temperature curing rubber in a specific viscosity range, and closely and organically cooperates with an ultra-low pressure injection molding process and an ultra-low pressure injection molding mold to achieve ultra-low pressure rope tail injection molding at room temperature. It simplifies the design and manufacture of injection molding equipment and molds, reduces equipment and mold costs, and shortens the equipment and mold development cycle. It meets the market demand for rope tail products with a high degree of customization, diverse product shapes, frequent updates, and high product quality requirements. Since heating and pressurization are not required, energy consumption in the production process of rope tails is reduced, and the cost of the production process is reduced.

[0044] The following describes the close connection, interdependence, and synergy among room temperature curing rubber with specific viscosity, ultra-low pressure injection molding process, and injection mold, and jointly solves the technical problem of "how to provide a rope pull tail manufacturing method with simple process, low production equipment cost, low energy consumption, customizable product shape, and high product quality".

[0045] In the first aspect, the present application utilizes a liquid adhesive having a viscosity range of 5000 to 15000 cPs and curing at room temperature, and a viscosity range of 0.1 to 1 kg / cm 2 The ultra-low injection pressure between the two is matched. The room temperature curing liquid rubber in this viscosity range has fluidity so that when the injection molding operation is performed at ultra-low injection pressure, the liquid rubber can fully fill and flow in the cavity of the injection mold to avoid the product lacking glue; at the same time, the viscosity range is not too high to avoid the increase of the impact force on the rope in the injection mold, which may easily cause the rope to deviate from the center line of the cavity and cause the defect of rope exposure; due to the use of ultra-low pressure injection molding, the corresponding clamping pressure can also be reduced, and the viscosity range of the rubber is not too low, which avoids the rubber from easily seeping out from the mold parting surface and the problem of burrs on the parting line of the product after the rubber is dried, thereby improving the quality of the product.

[0046] On the second aspect, the injection mold provided by the present application is provided with a discharge port in the cavity, and a discharge cavity is provided. Since the cross-sectional area of ​​the gate is larger than the cross-sectional area of ​​the discharge port. When the first rubber injection is performed, more rubber is injected into the gate, and less rubber overflows the discharge port. The cavity is filled with the fluidity of the rubber. The pressure difference generated in the cavity can fill and compact the rubber in the cavity, and at the same time, the bubbles in the cavity are squeezed and discharged into the discharge cavity along with the overflow rubber. Different from high-temperature injection molding, in order to melt and compact the rubber, the injection molding equipment needs to be heated and pressurized, and the injection mold needs to be heat-resistant, heat-dissipating, and pressure-bearing. The present application realizes rubber filling, compaction, and bubble discharge under ultra-low injection pressure, which reduces the design cost and manufacturing cost of the injection molding equipment and molds. At the same time, no pressurization and heating are required during the production process, which reduces energy consumption and reduces the production process cost of the rope tail.

[0047] On the third aspect, the rubber will shrink to a certain extent during the curing period, resulting in glue shortage in the process. The injection mold provided in the present application is provided with a feeding cavity. The viscosity range of the rubber in the present application allows the rubber to maintain a certain fluidity even when the viscosity increases when it shrinks, and at the same time cooperates with the preset vibration mode to improve the fluidity of the rubber. By utilizing the pressure generated in the cavity when the colloid shrinks, and the pressure difference caused by the cross-sectional area of ​​the gate being larger than the cross-sectional area of ​​the discharge port, part of the liquid rubber in the feeding cavity is transferred into the cavity in conjunction with the preset vibration mode to make up for the glue shortage caused by the shrinkage of the colloid.

[0048] Fourthly, the ultra-low pressure injection molding process of the present application utilizes the setting of the discharge cavity. By detecting whether the discharged rubber in the discharge cavity reaches the first preset position, it can be conveniently determined whether the amount of rubber injected into the cavity meets the requirements. In the case where the injection mold is a steel film or a non-transparent plastic mold, the degree of automation of the injection molding process is improved, and the injection molding production efficiency is improved. Compared with the solution of using vents, overflow grooves, etc., which cannot detect the amount of overflow glue, the degree of overflow glue is quantified and the defect rate of the product is reduced.

[0049] At the same time, the discharge cavity can collect a part of the rubber during the first injection of the ultra-low pressure injection molding process, and use gravity to separate bubbles and rubber during the second injection of the ultra-low pressure injection molding process. During the period of colloid solidification and shrinkage, the main material in the cavity comes from the rubber in the feeding cavity, but the colloid at the discharge port will inevitably shrink to a certain extent. At this time, the rubber collected in the discharge cavity can make up for this part of the shrinkage, avoiding the lack of glue at the discharge port, thereby improving product quality and improving the yield rate of the product.

[0050] Fifthly, the present application uses a liquid rubber material with a viscosity range of 5000 to 15000 cPs that solidifies at room temperature. Although the ultra-low pressure injection molding process can be realized by using the injection mold provided by the present application, the curing time of the rubber material is correspondingly prolonged. In the ultra-low pressure injection molding process provided by the present application, after applying vibration to the injection mold, the injection mold is left to stand for a first preset period of time, that is, the rubber material in the cavity is initially solidified, and the cavity is ventilated before the two half molds are fully opened. Before the rubber material is completely dried and solidified, pre-ventilation can utilize air convection to promote the volatilization of the diluent in the liquid rubber material in the cavity, shorten the colloid drying time, improve the efficiency of the entire ultra-low pressure injection molding process, and make the ultra-low pressure injection molding process more suitable for large-scale production.

[0051] In the sixth aspect, the first half mold body and the second half mold body are combined to form a cavity, a feeding cavity, a discharge cavity and a fixed groove, that is, the room temperature ultra-low pressure injection mold is composed of two half mold bodies that match each other with a parting surface as a boundary. Due to the use of ultra-low pressure injection molding technology at room temperature, the entire process is completed at room temperature, and the mold does not need to be cooled or heated; injection molding is carried out under ultra-low pressure conditions, and the mold does not need to withstand high injection pressure impact, nor does it need to withstand external large clamping force clamping. As a result, the design of the clamping mechanism of the injection molding equipment can be simplified, and the structural design of the mold itself can be simplified. The injection mold does not require an ejection system or a support system, and the pouring system and guide system can be simplified. At the same time, the performance requirements of the mold material are not high, and even plastic materials can be used to make the injection mold. The design cycle of the injection molding equipment and the injection mold is shortened, and the cost of designing and producing the injection molding equipment and molds is reduced.

[0052] To sum up the above, it can be seen that the realization of a new room temperature and ultra-low pressure injection molding process requires facing the following interrelated sub-topics: the impact of colloid fluidity on the rope, how to compact the colloid, how to discharge bubbles, how to reduce burrs, how to reduce and make up for the lack of glue caused by colloid shrinkage, how to detect the amount of glue overflow, how to shorten the drying time of the colloid, how to reduce costs, and how to save energy.

[0053] In order to solve a single technical problem, the usual design idea is to add new functional components, process flow, or improve the existing functional components and process flow. However, the purpose of this application is to solve the above problems and streamline the process flow, simplify the injection mold and injection molding equipment. Then how to design the coordinated relationship between the process flow, injection mold and injection molding equipment becomes the focus of this application.

[0054] The rope pull tail injection molding method provided in the present application, through the close connection, interdependence and synergy between the viscosity of the liquid rubber solidified at room temperature, the ultra-low injection pressure process flow, and the cleverly designed mold structure, jointly solves the problem of how to provide a rope pull tail manufacturing method with simple process, low production equipment cost, low energy consumption, customizable product shape and high product quality.

[0055] This application simplifies the design and manufacture of injection molding equipment and molds, reduces the cost of equipment and molds, and shortens the equipment and mold development cycle. It meets the market demand for rope and belt pull tail products with high customization, diverse product shapes, frequent updates, and high product quality requirements. Since heating and pressurization are not required, the energy consumption in the production process of rope and belt pull tails is reduced, and the production process cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 Schematic diagram of two half mold bodies of an injection mold provided in an embodiment of the present application;

[0057] Figure 2 It is a three-dimensional schematic diagram of the combination of half mold bodies of the injection mold provided in an embodiment of the present application;

[0058] Figure 3 This is a process flow chart of a rope tail injection molding method provided by an embodiment of the present application;

[0059] Figure 4 is a process flow chart of a rope tail injection molding method provided by another embodiment of the present application;

[0060] Figure 5 It is a heat map of the exposed defect rate of the rope and belt fitted by the embodiment and the comparative example provided in Table 1 of the present application;

[0061] Figure 6 It is a thermodynamic diagram of the adhesive deficiency defect rate fitted by the embodiments and comparative examples provided in Table 1 of the present application;

[0062] Figure 7 It is a heat map of the burr defect rate of the embodiments and comparative examples provided in Table 1 of the present application;

[0063] Figure 8 It is a viscosity-defect rate curve diagram of the embodiments and comparative examples provided in Table 1 of the present application;

[0064] Fig. 9 It is a pressure-defect rate curve diagram of the embodiment and comparative example provided in Table 1 of the present application.

[0065] Reference numerals:

[0066] 100. Injection mold;

[0067] 110, first half mold body; 120, second half mold body;

[0068] 111, cavity part (first half mold body); 121, cavity part (second half mold body);

[0069] 112, feeding cavity (first half mold body); 122, feeding cavity (second half mold body);

[0070] 113, discharge cavity (first half mold body); 123, discharge cavity (second half mold body);

[0071] 114, fixed groove portion (first half mold body); 124, fixed groove portion (second half mold body);

[0072] 101, mold cavity; 102, feeding cavity; 103, discharge cavity; 104, fixed groove;

[0073] 105. Gate, 106. Discharge port. DETAILED DESCRIPTION

[0074] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0075] The inventive concept of this application.

[0076] As described in the background technology of the present application, the rope pull tails made of polymer materials are mainly manufactured by injection molding, dipping, gluing and other processing methods.

[0077] Due to the high degree of customization of the shape of rope and tie tail products and frequent updates, the high-temperature injection molding process uses high-pressure, hot-melt injection molding, and the design and production costs of injection molding equipment and injection molds are high. The injection molding process is complex and energy-intensive. The high-temperature injection molding process has increased the manufacturing cost of rope and tie tail products and prolonged the cycle of new products entering the market. However, the dipping and viscose processes cannot meet the needs of beautiful and firm rope and tie products.

[0078] In view of the defects of various processes for manufacturing rope and belt pull tails at present, a rope and belt pull tail manufacturing method with simple process, low production equipment cost, low energy consumption, customizable product shape and high product quality is needed.

[0079] In order to solve the technical problems faced by this application, there may be various technical ideas.

[0080] Usually, in order to solve a certain technical problem, the general technical idea is to add new functional components, process flow, or adjust and improve the existing functional components and process flow. That is, the idea of ​​addition or modification.

[0081] The applicant of this application considered the technical problem faced by this application from another perspective, whether the process flow, injection mold and injection molding equipment can be simplified and the problem can be solved through the coordination of the three. It can be seen that the inventive concept of this application is a subtractive idea.

[0082] The applicant of the present application starts with the traditional high-temperature injection molding process and attempts to solve the problems faced by the present application from the perspective of lowering the injection molding temperature and lowering the injection molding pressure.

[0083] The traditional high-temperature injection molding process obtains molten injection rubber by heating, and the mold needs to be heated to improve the fluidity of the injection rubber, and the rubber needs to be solidified through the cooling system. Strong pressure is needed to compact the molten rubber, and the pressure is maintained to increase the density to compensate for the shrinkage of the rubber. Even the RIM (Reaction Injection Molding) process requires an injection pressure of about 10MPa.

[0084] The applicant of this application has noticed that room temperature curing liquid adhesives used in dipping and potting processes may be a starting point. However, it should be noted that in these processes, the liquid adhesives are self-leveling and cannot produce products with a certain shape. Moreover, in these processes, the contact area between the colloid and the air is large, which accelerates the curing. If they are transferred to the injection molding process with a relatively closed mold, and if ultra-low pressure injection molding is used to reduce the cost of injection molding equipment and molds, the following interrelated sub-topics need to be faced:

[0085] The impact of colloid fluidity on ropes, how to compact the colloid, how to expel bubbles, how to reduce burrs, how to reduce and make up for the lack of glue caused by colloid shrinkage, how to detect the amount of glue overflow, how to shorten the drying time of the colloid, how to reduce costs, and how to save energy.

[0086] To expand a little:

[0087] The rope is in a relatively closed mold, and the rubber is cured at room temperature. Ultra-low pressure injection can reduce the clamping pressure and the cost of injection molding equipment and injection molds. But how to avoid glue shortage in the product, reduce the generation of burrs on the parting surface, and reduce the influence of the colloid on the position of the rope?

[0088] If a glue that can be cured at room temperature is used and ultra-low pressure injection is adopted at the same time, how should the glue be compacted and how should bubbles be removed?

[0089] Without strong pressure for pressure holding treatment, how to reduce and compensate for the glue shortage caused by colloid shrinkage?

[0090] Although the goal is to simplify processes and equipment, if production cannot be automated, the practical value of the technical solution will be reduced. So how can we use simple methods to improve the degree of automation?

[0091] If room temperature curing adhesive is used, although the heating system is saved, it is different from hot melt adhesive which can be accelerated by cooling system. In this case, how to speed up the curing of the adhesive?

[0092] It can be seen that the above sub-topics are interrelated, and some of the sub-topics even conflict with each other. In order to streamline the process and simplify the injection mold and injection molding equipment, the applicant of this application has proposed the following inventive concept.

[0093] First, based on the basic determination of selecting room temperature curing silicone, this application further faces the sub-topic of how to avoid glue shortage in the product, reduce the generation of burrs, and at the same time reduce the influence of the colloid on the position of the rope.

[0094] In order to avoid the lack of glue in the product and reduce the impact of the colloid on the rope in the injection mold, this application uses a room temperature curing liquid glue with a viscosity range of 5000 to 15000 cPs, combined with 0.1 to 1 kg / cm 2 The ultra-low injection pressure between the two can solve this sub-topic.

[0095] Room temperature curing liquid rubber in this viscosity range can fully fill and flow in the cavity of the injection mold during ultra-low pressure injection molding operations, avoiding glue shortage in the product.

[0096] At the same time, the viscosity range and pressure should not be too high, so as to avoid the increase of the impact force of the liquid rubber on the rope inside the injection mold during ultra-low pressure injection, which may easily cause the rope to deviate from the center line of the cavity.

[0097] The viscosity of the rubber compound should not be too low to prevent the rubber compound from seeping out from the parting surface of the injection mold and causing burrs on the parting line of the product after drying.

[0098] The viscosity of the rubber, the injection pressure and the coordination of the injection mold are used to solve the sub-topic of how to avoid glue shortage in the product, reduce the generation of burrs, and reduce the influence of the colloid on the position of the rope.

[0099] Second, in order to melt and compact the rubber material, the injection molding equipment needs to be designed with heating and pressurization, and the injection mold needs additional heat resistance, heat dissipation, and pressure bearing designs.

[0100] If the present application adopts room temperature curing rubber and ultra-low pressure injection, in order to achieve rubber filling, compaction and bubble discharge, the present application utilizes the injection mold structure and the fluidity of the room temperature curing rubber within a specific viscosity range to solve this sub-topic.

[0101] The injection mold provided in the present application is provided with a discharge port in the mold cavity and a discharge cavity, and the cross-sectional area of ​​the gate is larger than the cross-sectional area of ​​the discharge port.

[0102] During the first injection of rubber, more rubber is injected into the gate and less rubber overflows the discharge port. The cavity is filled with the fluidity of the rubber in a specific viscosity range. The pressure difference generated in the cavity can fill and compact the rubber in the cavity, while squeezing the bubbles in the cavity and discharging them into the discharge cavity along with the overflow rubber.

[0103] The present application utilizes the pressure difference generated by the gate and the discharge port under ultra-low injection pressure, as well as the fluidity of the rubber in a specific viscosity range, to achieve rubber filling, compaction and bubble discharge.

[0104] Unlike high-temperature injection molding, which requires heating to obtain fluidity and pressurization to compact the rubber and expel bubbles, the present application utilizes the injection mold structure and the fluidity of the room-temperature curing rubber within a specific viscosity range. No pressurization and heating are required during the production process, which reduces energy consumption and the production process cost of rope tails. The injection molding equipment and injection molds also do not require additional heat-resistant, heat-dissipating, and pressure-bearing designs, reducing design and production costs.

[0105] Third, high temperature injection molding usually uses pressurization and pressure maintenance to reduce the shrinkage of the rubber during curing and reduce the lack of glue in the process. Even if a high temperature injection mold is equipped with a feeding port, high pressure needs to be applied for feeding.

[0106] However, in order to reduce the design and manufacturing costs of injection molding equipment and molds and reduce the production process costs of rope tails, the present application adopts 0.1-1 kg / cm 2 There is a contradiction between the ultra-low injection pressure used for injection molding and the sub-topic of how to reduce the process glue shortage caused by the shrinkage of the rubber compound.

[0107] This application utilizes the injection mold structure, the fluidity of the room temperature curing rubber in a specific viscosity range, and the process flow to solve this sub-topic.

[0108] The present application sets a feeding cavity between the injection mold gate and the outside atmosphere, sets a second injection step to fill the feeding cavity, and sets a process step of vibrating the injection mold in a preset vibration mode.

[0109] The viscosity range of the rubber material is such that although the viscosity increases when the rubber material shrinks, the rubber material still maintains a certain fluidity. The present application utilizes the pressure generated in the mold cavity when the colloid shrinks, and the pressure difference caused by the cross-sectional area of ​​the gate being larger than the cross-sectional area of ​​the discharge port, in conjunction with a preset vibration mode to increase the fluidity of the rubber material, and transfer part of the liquid rubber material in the feeding cavity into the mold cavity to compensate for the lack of glue caused by the shrinkage of the colloid.

[0110] The present application ingeniously solves the sub-issue of glue shortage caused by the shrinkage of the rubber during curing, by setting a feeding cavity, a secondary injection step and a vibration step, utilizing the pressure difference generated by the gate and the discharge port and coordinating the mold vibration.

[0111] Fourth, the molds used in high-temperature injection molding processes usually have structures such as air holes and overflow grooves for exhaust and discharge of overflow glue. Since high-temperature injection molding also relies on pressure maintenance to reduce the shrinkage of the rubber during curing, it is only necessary to exhaust the gas and simply discharge the overflow glue. The amount of injected rubber is controlled by the injection molding mechanism.

[0112] However, this application uses room temperature curing rubber and performs injection at ultra-low pressure, and sets a feeding chamber to compensate for the lack of rubber in the process, which leads to the sub-topic of how to determine the timing of stopping injection. At the same time, since there is no pressurization to reduce the shrinkage of the rubber during curing, it is bound to cause a certain amount of shrinkage of the rubber at the discharge port, resulting in a lack of rubber at the discharge port.

[0113] Different from high-temperature injection molding, the present application sets up a discharge cavity. By setting two injections in the process flow and detecting whether the rubber discharged from the discharge cavity reaches the first preset position during the first injection, it is convenient to determine whether the amount of rubber injected into the cavity meets the requirement by the rubber position of the feeding cavity, so as to determine the time to stop the injection.

[0114] At the same time, the discharge cavity can collect a part of the rubber during the first injection of the ultra-low pressure injection molding process. During the second injection of the ultra-low pressure injection molding process, the gravity is used to separate the bubbles and rubber in the discharge cavity. During the period of colloid solidification and shrinkage, the main material in the cavity comes from the rubber in the feeding cavity. At this time, the rubber collected in the discharge cavity can also supplement this part of the shrinkage to avoid the lack of rubber defects at the discharge port.

[0115] The present application uses the organic coordination and mutual cooperation between the two ultra-low pressure injections, the feeding cavity, and the discharge cavity, and detects whether the discharged rubber in the discharge cavity reaches the first preset position, so as to conveniently determine whether the amount of rubber injected into the cavity reaches the stop time. In the case where the injection mold is a steel film or a non-transparent plastic mold, the degree of automation of the injection molding process is improved, and the injection molding production efficiency is improved.

[0116] Compared with solutions that cannot detect the amount of glue overflow, such as vent holes and glue overflow grooves, the degree of glue overflow is quantified, reducing the defect rate of products. At the same time, it improves product quality and improves the yield rate of products.

[0117] Fifth, room temperature curing liquid adhesive is often used in dipping and potting processes. Although the injection mold provided by the present application enables ultra-low pressure injection molding, the relatively closed injection mold also prolongs the curing time of the adhesive.

[0118] This application sets up a pre-ventilation process step for the sub-topic of how to accelerate the solidification of the colloid while ensuring that the shape of the colloid after solidification meets the quality requirements.

[0119] In the process flow of the present application, a pre-ventilation operation step is provided. After the injection mold is vibrated, the injection mold is left to stand for a first preset period of time, that is, after the rubber material in the cavity is initially solidified, the cavity is ventilated, and then the two half molds are fully opened.

[0120] Before the rubber is completely dried, pre-ventilation can use air convection to promote the volatilization of the diluent in the liquid rubber in the cavity, shortening the drying time of the colloid. Since the rubber has been initially solidified, the overall shape of the colloid can be maintained to meet the quality requirements.

[0121] The present application provides a pre-ventilation step in the process flow, so that the liquid adhesive with a viscosity range of 5000 to 15000 cPs solidified at room temperature is coordinated with the opening and closing state of the mold, thereby solving the sub-topic of how to accelerate the solidification of the colloid while ensuring that the shape of the colloid after solidification meets the quality requirements, thereby improving the efficiency of the entire ultra-low pressure injection molding process flow and making the ultra-low pressure injection molding process flow more suitable for large-scale production.

[0122] Sixth, this application systematically integrates the process flow and mold design of ultra-low pressure injection molding at room temperature, creating conditions for further simplifying injection molding equipment and injection molds.

[0123] The first half mold body and the second half mold body together form a cavity, a feeding cavity, a discharge cavity and a fixed groove. That is to say, the room temperature ultra-low pressure injection mold is composed of two half mold bodies that match with the parting surface as the boundary. Due to the use of ultra-low pressure injection molding technology at room temperature, the entire process is completed at room temperature, and the mold does not need to be cooled or heated. Injection molding under ultra-low pressure conditions, the mold does not need to withstand high injection pressure impact, nor does it need to withstand external large clamping force clamping.

[0124] Since the injection mold does not need to withstand the external large clamping force, the design of the injection equipment clamping mechanism can be simplified, and the design of the mold locking structure can be simplified. The injection mold does not need an ejection system or a support system, which can simplify the pouring system and the guide system. At the same time, the performance requirements for the mold material are not high, and even plastic materials can be used to make the injection mold. The design cycle of the injection molding equipment and the injection mold is shortened, and the cost of designing and producing the injection molding equipment and molds is reduced.

[0125] The technical concept of the present application is to lower the injection temperature and injection pressure, utilize room temperature curing adhesive commonly used in dipping or potting processes, design a process flow using room temperature curing adhesive under ultra-low injection pressure, and an injection mold that cooperates with the process.

[0126] The process flow provided in this application and the ingeniously designed injection mold organically cooperate and work synergistically to jointly solve several interrelated sub-topics, thereby solving the technical problem faced by this application of "how to provide a rope pull tail manufacturing method with simple process, low production equipment cost, low energy consumption, customizable product shape and high product quality".

[0127] It should also be understood that, limited by the sequential nature of textual expression, the process of obtaining the inventive concept of the present application is not a sequential process limited to the textual expression.

[0128] The inventive concept of the present application is obtained by the applicant starting from the technical problem and from the starting point of lowering the temperature and injection pressure, comprehensively considering the relationship between various sub-topics involved in the injection molding process, repeatedly shuttling between various sub-topics, process flows, and mold designs, and conducting comprehensive thinking.

[0129] Next, the application introduces the specific embodiments of the application through several specific implementation methods. It should be pointed out that due to the disclosure of the application, the specific implementation methods of some embodiments and some alternative improvements become obvious. Those skilled in the art can reasonably adjust the various implementation methods of the various embodiments in the application according to actual needs in order, and combine and increase and decrease the various implementation methods on the basis of the disclosure of the application. It should be understood that these improvements also belong to the protection scope of the application.

[0130] In order to facilitate understanding of the rope tail injection molding method provided in this application, refer to the attached Figure 1 and attached Figure 2 First, an injection mold 100 provided in an embodiment of the present application is introduced. Figure 1 This is a schematic diagram of the two halves of the mold being opened. Figure 2 It is a schematic diagram of the merged state of the two halves of the motif.

[0131] The injection mold 100 comprises a first half mold body 110 and a second half mold body 120. The first half mold body 110 and the second half mold body 120 comprise corresponding cavity parts (111, 121), feeding cavity parts (112, 122), discharge cavity parts (113, 123) and fixed groove parts (114, 124). The first half mold body 110 and the second half mold body 120 together form a cavity 101, a feeding cavity 102, a discharge cavity 103 and a fixed groove 104.

[0132] In some embodiments, the cavity parts (111, 121), the feeding cavity parts (112, 122), the discharge cavity parts (113, 123) and the fixing groove parts (114, 124) of the first half mold body 110 and the second half mold body 120 can be symmetrical mirror-image structures or asymmetrical structures. For example, the cavity part 111 of the first half mold body 110 can be provided with a commercial logo or a pattern molding structure, and the cavity part 121 of the second half mold body 120 is a smooth curved surface structure.

[0133] The mold cavity 101 is provided with a gate 105. The gate 105 is connected to the external space of the injection mold 100 through the feeding cavity 102. The mold cavity 101 is also provided with a discharge port 106. The discharge port 106 is connected to the external space of the injection mold 100 through the discharge cavity 103. The cross-sectional area of ​​the gate 105 is larger than the cross-sectional area of ​​the discharge port 106. One end of the fixing groove 104 is connected to the mold cavity 101, and the other end of the fixing groove 104 is connected to the outside of the injection mold 100.

[0134] The mold cavity 101 is used to shape the outer surface of the pull tail, contain the rubber material and the built-in rope, and its shape is designed and manufactured according to the appearance of the pull tail.

[0135] In some embodiments, the size of the mold cavity 101 is 5% to 15% larger than the outer size of the tail. The specific ratio is determined according to the shrinkage rate of the material. The size here can be the cross-sectional area of ​​the rope and the cavity 101.

[0136] In some embodiments, the ratio of the cross-sectional area of ​​the gate 105 to the cross-sectional area of ​​the discharge port 106 is in the range of 1.4 to 2.6, such as 1.4, 1.5, 1.6 ... 2.6. In some specific examples, the preferred ratio is 1.8, that is, the ratio of the cross-sectional area of ​​the gate 105 to the cross-sectional area of ​​the discharge port 106 is 1.8.

[0137] In some embodiments, the mold is provided with a plurality of cavity points, and the number of cavity points is confirmed according to the production batch. The more the number of mold points is, the higher the output within a cycle is. Thanks to the cavity shaping, standardization and rich product shape, the defects of the single and irregular tail shape manufactured by the dipping process can be compensated.

[0138] The gate 105 is a channel for the colloid to be injected into the cavity 101 , one end of which is connected to the cavity 101 , and the other end of which is connected to the feeding cavity 102 .

[0139] In some embodiments, the gate 105 has a diameter of Φ0.5-1.0 mm. In some specific examples, the gate 105 has a point-shaped shape, which can be easily separated from the tail after drying and demolding without leaving obvious traces and requiring no post-processing. The point-shaped gate is conducive to improving the appearance quality and production efficiency of the product.

[0140] The discharge port 106 is a channel for the rubber in the cavity 101 to overflow and an outlet for the air in the cavity 101 . One end of the discharge port 106 is connected to the cavity 101 , and the other end is connected to the discharge cavity 103 .

[0141] In some embodiments, the diameter of the discharge port 106 can be selected to be 0.3-0.7 mm. In the embodiment provided in the present application, the size of the discharge port 106 must be smaller than the size of the gate 105 .

[0142] In some embodiments, the discharge port 106 is in the shape of a dot-shaped discharge port. The dot-shaped discharge port can be easily separated from the tail after drying and demolding, leaving no obvious traces and requiring no post-processing. The use of a dot-shaped discharge port can improve the appearance quality and production efficiency of the product.

[0143] The fixing groove 104 is used to place and clamp the rope and is connected to the cavity 101. The fixing groove 104 clamps the rope without loosening, so that the rope remains naturally straight in the cavity 101 and is located at the center line of the tail glue position after molding.

[0144] In some embodiments, the size of the fixing groove 104 is 0.1-0.3 mm smaller than the outer size of the rope. The length of the fixing groove 104 is controlled to be 5-20 mm, and the rope can be clamped after the mold is closed.

[0145] The feeding cavity 102 accommodates the additional rubber added after injection molding, and is used to flow to supplement the shortage of rubber caused by the shrinkage of the colloid in the cavity 101, so as to prevent the appearance of voids and lack of rubber after the product is molded. One end of the feeding cavity 102 is connected to the gate 105, and the other end is connected to the space outside the injection mold 100, and is open. The feeding cavity 102 provides a supplementary space for the shortage of rubber shrinkage, increases the feeding function of the mold after injection molding, and makes up for the lack of rubber in the process.

[0146] In some embodiments, the volume of the feeding cavity 102 is 5% to 20% of the volume of the mold cavity 101 .

[0147] The discharge cavity 103 accommodates the overflow rubber discharged from the cavity 101 during injection molding. One end of the discharge cavity 103 is connected to the discharge port 106, and the other end is connected to the space outside the injection mold 100, and is open. During the injection molding process, the rubber flows and fills in the cavity 101. The rubber will inevitably compress and roll in the air in the cavity 101 to form bubbles. The discharge cavity 103 provides a space for the rubber with bubbles to be discharged, preventing bubbles from appearing after the product is molded. The discharge cavity 103 provides a space for accommodating the overflow of the rubber, increases the exhaust function of the mold during injection molding, and eliminates trapped air in the process.

[0148] In some embodiments, the volume of the discharge cavity 103 is 5% to 30% of the volume of the mold cavity 101 .

[0149] The guide system is designed to ensure that the two mold halves are accurately aligned when the mold is closed.

[0150] In some embodiments, the guide system of the injection mold is composed of a guide post (not shown in the drawings) disposed on one of the first mold half 110 and the second mold half 120, and a guide sleeve (not shown in the drawings) disposed on the other. For example, the guide post is disposed on the first mold half 110, and the guide sleeve is disposed on the second mold half 120.

[0151] Since the present application adopts an ultra-low pressure injection molding process at room temperature, the injection molding is performed under ultra-low pressure conditions, and the mold does not need to withstand high injection pressure impacts, nor does it need to withstand external large clamping force clamping. Therefore, the locking structure design of the injection mold 100 itself can be simplified.

[0152] In some embodiments, there is no need for side locks, stoppers, side positioning blocks, etc. to design positioning and guiding for high-pressure injection molding. Only guide pins provided on one of the first half mold body 110 and the second half mold body 120 and guide sleeves provided on the other half mold body can be used to complete the positioning and guiding of the mold. Thus, the guiding mechanism is formed, the mold opening and closing force required is small, and the mold opening and closing operation is convenient.

[0153] Please refer to the following Figure 3 , introduces a rope tail injection molding method provided by an embodiment of the present application. The injection molding method cooperates with the injection mold 100 provided by the embodiment of the present application to complete the injection molding process.

[0154] An embodiment of the present application provides a method for injection molding a rope tail, comprising the following steps:

[0155] Step 1 (S100): Lay out the ropes.

[0156] The rope is placed in the fixing groove of the first half mold body 110 , with one end of the rope exposed outside the first half mold body 110 and the other end embedded in the cavity 111 of the first half mold body 110 .

[0157] In some embodiments, one end of the rope is exposed outside the half mold body, and the other end is built into the half mold body cavity 111. The length of the rope built into the half mold body cavity 111 is slightly shorter than the length of the cavity 101, and the length difference is 1 to 3 mm.

[0158] In some embodiments, the rope is provided with an anchoring colloid structure, and the rope provided with the anchoring colloid structure is placed in a fixing groove of a half mold body.

[0159] Step 2 ( S200 ): Locking the injection mold 100 .

[0160] The first half mold body 110 and the second half mold body 120 with the ropes placed thereon are closed, and pressure is applied to the two half mold bodies to lock the injection mold 100 .

[0161] In some embodiments, the locking injection mold 100 is as follows Figure 4 As shown, the process can be completed by using two sub-steps: preliminary closing of the mold (S210) and locking the mold with a mold locking mechanism (S220).

[0162] The mold is initially closed ( S210 ), and the first half mold body 110 and the second half mold body 120 on which the rope is placed are initially closed through the cooperation of the guide pillar and the guide sleeve, and the rope is clamped and initially fixed on the center line of the mold cavity 101 .

[0163] The mold locking mechanism locks the mold (S220), inserts the preliminarily closed injection mold 100 between the front mold plate and the rear mold plate of the mold locking mechanism, and applies pressure to lock the mold. The rope is further clamped by the mold to prevent it from loosening, and at the same time prevents the liquid colloid from overflowing and seeping out on the mold parting surface.

[0164] Step 3 (S300): Adding rubber material.

[0165] A room temperature curing liquid rubber material with a viscosity ranging from 5000 to 15000 cPs (centipoise seconds) is put into the material cylinder of the injection molding mechanism; wherein the room temperature is a temperature range of 25±5°C.

[0166] In some embodiments, the room temperature curing liquid adhesive with a viscosity of 5000 cPs may have a viscosity of 5000 cPs, 6000 cPs, 7000 cPs, ..., 15000 cPs; or any one between 5000 and 15000 cPs; or a viscosity variation range between 5000 and 15000 cPs.

[0167] In some embodiments, the room temperature range may be one of 20°C, 21°C, 22°C...30°C; it may also be any one between 25±5°C; or the temperature variation range may be between 25±5°C.

[0168] In some embodiments, the room temperature curing liquid adhesive may be selected from room temperature vulcanized silicone, acrylic resin, polyurethane resin, unsaturated polyester resin, epoxy resin and other liquid colloids.

[0169] For example, room temperature vulcanized silicone is preferred, and two-component addition room temperature vulcanized silicone is further preferred. Addition room temperature vulcanized silicone can be vulcanized at room temperature, does not release by-products during vulcanization, and the surface layer and the inner layer are vulcanized at the same time. The vulcanization speed and application period of the silicone can be adjusted through formula design.

[0170] For example, 1cPs is equivalent to water, 1000cPs is equivalent to glycerin, and 10000cPs is equivalent to honey. The higher the proportion of the glue diluent, the lower the viscosity of the liquid silicone composition. When the viscosity exceeds 15000cPs, the liquid silicone composition has poor flow properties, and it is difficult to fully fill and flow in the cavity 101 under ultra-low pressure, which can easily cause the product to lack glue; at the same time, the impact force of the liquid silicone composition on the built-in rope increases during ultra-low pressure injection, which can easily cause the rope to deviate from the center line of the cavity 101, resulting in the rope being exposed. When the viscosity is lower than 5000cPs, the liquid silicone composition has good flow properties, and it is easy to seep out from the mold parting surface under ultra-low pressure, and burrs will appear on the parting line of the product after drying.

[0171] Step 4 (S400): First injection.

[0172] Carry out the first injection of the rubber compound, including the injection molding mechanism at 0.1-1kg / cm 2 The pressure between them injects the liquid glue into the cavity 101 from the gate 105, and the pressure difference between the gate 105 and the discharge port 106 is used to compact the liquid glue, and to squeeze the bubbles in the cavity 101 toward the discharge port 106, so that the bubbles and part of the liquid glue are discharged from the cavity 101 from the discharge port 106, and the injection is stopped when it is detected that the discharge cavity 103 is overflowed and filled to the first preset position.

[0173] In some embodiments, the injection pressure can be 0.1 kg / cm 2 , 0.2kg / cm 2 , 0.3kg / cm 2 ,……1kg / cm 2 One of the following; it can also be 0.1 to 1 kg / cm 2 Any one between 0.1 and 1 kg / cm2. 2 between.

[0174] In some embodiments, the first preset position is between the discharge port 106 and the position where the discharge chamber 103 is filled to 2 / 3. Stopping the injection when the discharge chamber 103 is detected to be filled to the first preset position by overflow can be stopping the pressure when it is detected that the volume of the discharge chamber 103 is filled to about 2 / 3 by overflow. It can be understood that this preset position can be adjusted according to actual production needs.

[0175] In some embodiments, the injection mechanism power control system applies ultra-low pressure, and the plunger pushes the liquid colloid in the material cylinder, and the quantitative ultra-low pressure is injected from the gate 105 to fill the mold cavity 101. The quantitative is set based on the liquid colloid filling the cavity 101 and overflowing the discharge port 106. The liquid colloid gradually overflows from the discharge port 106, and the pressure difference between the gate 105 and the discharge port 106 compacts the liquid colloid in the cavity 101, and at the same time, the air in the cavity 101 is discharged with the overflow.

[0176] In some embodiments, the specific implementation of detecting that the discharge chamber 103 is overflowed and filled to the first preset position becomes obvious due to the disclosure of this application. A sensor can be used to detect the liquid level position of the discharge chamber 103; or the stroke of the plunger when the discharge chamber 103 reaches the first preset position can be pre-recorded, and then the discharge chamber 103 is determined to be overflowed and filled to the first preset position based on the stroke.

[0177] Step 5 (S500): Second injection.

[0178] The second rubber injection includes: the injection mechanism retreats until the nozzle reaches the second preset position in the feeding chamber 102, the injection mechanism injects liquid rubber into the feeding chamber 102, and stops the injection when the liquid rubber fills the feeding chamber 102 to a third preset position.

[0179] In some embodiments, the injection molding mechanism retreats until the nozzle reaches the second preset position in the feeding cavity 102. The injection molding mechanism rises away from the gate 105 and retreats 5 to 10 mm in the feeding cavity 102. The specific retreat distance can be set according to actual production needs.

[0180] In some embodiments, when the liquid glue is filled to the third preset position of the volume of the feeding cavity 102, the injection is stopped. The liquid glue can be injected into the mold feeding cavity 102 from the injection nozzle into the air. When the liquid glue is filled to 2 / 3 of the volume of the feeding cavity 102, the injection is stopped and the injection mechanism retreats and resets.

[0181] Step 6 ( S600 ): Apply vibration to the injection mold 100 .

[0182] Vibration is applied to the injection mold 100 in a preset vibration mode, and the vibration promotes part of the liquid rubber in the feeding cavity 102 to transfer into the cavity 101 under the pressure difference between the gate 105 and the discharge port 106.

[0183] In some embodiments, the preset vibration mode includes applying vibration once at a frequency of once every 10 to 20 minutes, each application of vibration lasting 15 to 60 seconds, and stopping the application of vibration after applying vibration 2 to 5 times.

[0184] In some embodiments, the vibration direction may be vibration along any direction in space, or vibration in multiple directions. The vibration amplitude may be adjusted in actual production.

[0185] Step 7 (S700): Pre-ventilation treatment and mold opening and part removal.

[0186] After vibrating the injection mold 100 , the injection mold 100 is left to stand for a preset semi-curing time. After the cavity 101 is ventilated and left to stand for a preset full-curing time, the two half mold bodies are fully opened to take out the cured molded rope tail.

[0187] In some embodiments, the preset semi-curing time is 30 to 60 minutes, and the cavity 101 is ventilated and left to stand for the preset full curing time, including: opening a gap of 0.3 to 1 mm between the two half molds, and then leaving it to stand for 1 to 2 hours.

[0188] In some embodiments, see Figure 4 Before the pre-ventilation treatment and mold opening and taking out the parts in step 7 (S700), the mold removal and transfer step (S650) is also included. After the vibration is completed, the front and rear templates of the clamping mechanism are opened, and the mold is taken out of the clamping mechanism.

[0189] After the mold is taken out, it switches to two operation paths:

[0190] The first operation path is to transfer the mold to the transfer platform and wait for the liquid colloid in the mold to dry before subsequent operations.

[0191] Another operation path is to put in another set of replica molds and enter the next cycle, that is, to start the rope placement step, and repeat it in sequence. In the reciprocating process, more replica molds need to be invested, and the specific number of molds depends on the production scale. Through the unique process control, the room temperature ultra-low pressure injection molding of rope tails is guaranteed to operate cyclically and effectively, and to achieve scale.

[0192] Through the coordination of two operation paths, multiple sets of replica molds can work in a cycle, solving the problem of long curing time of the rubber, improving production efficiency, and making the ultra-low pressure injection molding process more suitable for large-scale production.

[0193] In some embodiments, the mold is left to stand on the transfer platform for 30 to 60 minutes, the two half mold bodies are opened with a gap of 0.3 to 1 mm, and then left to stand for 1 to 2 hours to dry, and then the two half mold bodies of the mold are completely opened, and the dry-fixed rope tail is taken out. At this time, the rope tail is a semi-finished product. During the drying process, the two half mold bodies open a gap of 0.3 to 1 mm, and the gap generates air convection, which promotes the volatilization of the diluent in the liquid colloid in the cavity 101, shortens the drying time, and improves the cycle efficiency. According to experimental tests, the two half mold bodies are always in a closed state during the drying process. If the gap is not opened, the static drying time will be extended by 1 to 2 hours.

[0194] In order to verify the compounding effect of room temperature curing rubber under ultra-low pressure injection, see Table 1, the following orthogonal experiment was carried out.

[0195] Table 1

[0196]

[0197]

[0198] The present application provides a method for injection molding of a rope tail, which utilizes a room temperature curing rubber material within a specific viscosity range, and closely and organically cooperates with an ultra-low pressure injection molding process and an ultra-low pressure injection molding mold to achieve ultra-low pressure rope tail injection molding at room temperature. The design and manufacture of injection molding equipment and molds are simplified, the cost of equipment and molds is reduced, and the equipment and mold development cycle is shortened. It meets the market demand for rope tail products with a high degree of customization, diverse product shapes, frequent updates and high product quality requirements. Since heating and pressurization are not required, energy consumption in the production process of rope tails is reduced, and the cost of the production process is reduced.

[0199] The present application utilizes the close connection, interdependence, and synergy among room temperature curing rubber with specific viscosity, ultra-low pressure injection molding process, and injection mold to jointly solve the technical problem of "how to provide a rope pull tail manufacturing method with simple process, low production equipment cost, low energy consumption, customizable product shape and high product quality".

[0200] On the first hand, the applicant of the present application has found that when the injection mold provided by the present application is used for injection molding, the viscosity of the rubber and the injection pressure have different effects on the rope exposure defect rate, the glue deficiency defect rate, and the burr defect rate, and even have opposite effects on these three defects. For example, excessive viscosity will reduce the burr defect rate, but at the same time it will increase the rope exposure defect rate and the glue deficiency defect rate. If we only look at it from the perspective of viscosity or injection pressure, it is difficult to determine how to obtain a product with the required defect rate at room temperature. The present application utilizes a liquid rubber that cures at room temperature with a viscosity range of 5000 to 15000 cPs, which is different from 0.1 to 1 kg / cm 2 The ultra-low injection pressure between the two is matched. The room temperature curing liquid rubber in this viscosity range has fluidity so that when the injection molding operation is performed at ultra-low injection pressure, the liquid rubber can fully fill and flow in the cavity of the injection mold to avoid the product lacking glue; at the same time, the viscosity range is not too high to avoid the increase of the impact force on the rope in the injection mold, which may easily cause the rope to deviate from the center line of the cavity and cause the defect of rope exposure; due to the use of ultra-low pressure injection molding, the corresponding clamping pressure can also be reduced, and the viscosity range of the rubber is not too low, which avoids the rubber from easily seeping out from the mold parting surface and the problem of burrs on the parting line of the product after the rubber is dried, thereby improving the quality of the product. Figure 5 , Figure 6 and Figure 7 , which is a thermal diagram of cubic spline interpolation fitting of the embodiments and comparative examples in Table 1. Figure 8 and Fig. 9, which is a curve diagram of cubic spline interpolation fitting of the embodiment and comparative example in Table 1. It should be pointed out that, Figure 8 and Fig. 9 The curve is the result of the combined effect of viscosity and pressure. In order to intuitively and conveniently show the difference between the embodiment and the comparative example, it is shown from the perspective of viscosity and pressure separately. Figure 5 , Figure 6 and Figure 7 ,as well as Figure 8 and Fig. 9 The present application utilizes a liquid adhesive having a viscosity range of 5000 to 15000 cPs and curing at room temperature, and a viscosity range of 0.1 to 1 kg / cm 2 By matching the ultra-low injection pressure between the two, the injection mold provided by the present application is used for injection molding operation, and several defect indicators that influence each other or even contradict each other are well balanced, thereby improving the quality of the product.

[0201] On the second aspect, the injection mold provided by the present application is provided with a discharge port in the cavity, and a discharge cavity is provided. Since the cross-sectional area of ​​the gate is larger than the cross-sectional area of ​​the discharge port. When the first rubber injection is performed, more rubber is injected into the gate, and less rubber overflows the discharge port. The cavity is filled with the fluidity of the rubber. The pressure difference generated in the cavity can fill and compact the rubber in the cavity, and at the same time, the bubbles in the cavity are squeezed and discharged into the discharge cavity along with the overflow rubber. Different from high-temperature injection molding, in order to melt and compact the rubber, the injection molding equipment needs to be heated and pressurized, and the injection mold needs to be heat-resistant, heat-dissipating, and pressure-bearing. The present application realizes rubber filling, compaction, and bubble discharge under ultra-low injection pressure, which reduces the design cost and manufacturing cost of the injection molding equipment and molds. At the same time, no pressurization and heating are required during the production process, which reduces energy consumption and reduces the production process cost of the rope tail.

[0202] On the third aspect, the rubber will shrink to a certain extent during the curing period, resulting in glue shortage in the process. The injection mold provided in the present application is provided with a feeding cavity. The viscosity range of the rubber in the present application allows the rubber to maintain a certain fluidity even when the viscosity increases when it shrinks, and at the same time cooperates with the preset vibration mode to improve the fluidity of the rubber. By utilizing the pressure generated in the cavity when the colloid shrinks, and the pressure difference caused by the cross-sectional area of ​​the gate being larger than the cross-sectional area of ​​the discharge port, part of the liquid rubber in the feeding cavity is transferred into the cavity in conjunction with the preset vibration mode to make up for the glue shortage caused by the shrinkage of the colloid.

[0203] Fourthly, the ultra-low pressure injection molding process of the present application utilizes the setting of the discharge cavity. By detecting whether the discharged rubber in the discharge cavity reaches the first preset position, it can be conveniently determined whether the amount of rubber injected into the cavity meets the requirements. In the case where the injection mold is a steel film or a non-transparent plastic mold, the degree of automation of the injection molding process is improved, and the injection molding production efficiency is improved. Compared with the solution of using vents, overflow grooves, etc., which cannot detect the amount of overflow glue, the degree of overflow glue is quantified and the defect rate of the product is reduced.

[0204] At the same time, the discharge cavity can collect a part of the rubber during the first injection of the ultra-low pressure injection molding process, and use gravity to separate bubbles and rubber during the second injection of the ultra-low pressure injection molding process. During the period of colloid solidification and shrinkage, the main material in the cavity comes from the rubber in the feeding cavity, but the colloid at the discharge port will inevitably shrink to a certain extent. At this time, the rubber collected in the discharge cavity can make up for this part of the shrinkage, avoiding the lack of glue at the discharge port, thereby improving product quality and improving the yield rate of the product.

[0205] Fifthly, the present application uses a liquid rubber material with a viscosity range of 5000 to 15000 cPs that solidifies at room temperature. Although the ultra-low pressure injection molding process can be realized by using the injection mold provided by the present application, the curing time of the rubber material is correspondingly prolonged. In the ultra-low pressure injection molding process provided by the present application, after applying vibration to the injection mold, the injection mold is left to stand for a first preset period of time, that is, the rubber material in the cavity is initially solidified, and the cavity is ventilated before the two half molds are fully opened. Before the rubber material is completely dried and solidified, pre-ventilation can utilize air convection to promote the volatilization of the diluent in the liquid rubber material in the cavity, shorten the colloid drying time, improve the efficiency of the entire ultra-low pressure injection molding process, and make the ultra-low pressure injection molding process more suitable for large-scale production.

[0206] In the sixth aspect, the first half mold body and the second half mold body are combined to form a cavity, a feeding cavity, a discharge cavity and a fixed groove, that is, the room temperature ultra-low pressure injection mold is composed of two half mold bodies that match each other with a parting surface as a boundary. Due to the use of ultra-low pressure injection molding technology at room temperature, the entire process is completed at room temperature, and the mold does not need to be cooled or heated; injection molding is carried out under ultra-low pressure conditions, and the mold does not need to withstand high injection pressure impacts, nor does it need to withstand external large clamping force clamping. As a result, the design of the clamping mechanism of the injection molding equipment can be simplified, and the design of the mold itself can be simplified. The injection mold does not require an ejection system or a support system, and the pouring system and guide system can be simplified. At the same time, the performance requirements of the mold material are not high, and even plastic materials can be used to make the injection mold. The design cycle of the injection molding equipment and the injection mold is shortened, and the cost of designing and producing the injection molding equipment and molds is reduced.

[0207] To sum up the above, it can be seen that the realization of a new room temperature and ultra-low pressure injection molding process requires facing the following interrelated sub-topics: the impact of colloid fluidity on the rope, how to compact the colloid, how to discharge bubbles, how to reduce burrs, how to reduce and make up for the lack of glue caused by colloid shrinkage, how to detect the amount of glue overflow, how to shorten the drying time of the colloid, how to reduce costs, and how to save energy.

[0208] In order to solve a single technical problem, the usual design idea is to add new functional components, process flow, or improve the existing functional components and process flow. However, the purpose of this application is to solve the above problems and streamline the process flow, simplify the injection mold and injection molding equipment. Then how to design the coordinated relationship between the process flow, injection mold and injection molding equipment becomes the focus of this application.

[0209] The rope pull tail injection molding method provided in the present application, through the close connection, interdependence and synergy between the viscosity of the liquid rubber solidified at room temperature, the ultra-low injection pressure process flow, and the cleverly designed mold structure, jointly solves the problem of how to provide a rope pull tail manufacturing method with simple process, low production equipment cost, low energy consumption, customizable product shape and high product quality.

[0210] This application simplifies the design and manufacture of injection molding equipment and molds, reduces the cost of equipment and molds, and shortens the equipment and mold development cycle. It meets the market demand for rope and belt pull tail products with high customization, diverse product shapes, frequent updates, and high product quality requirements. Since heating and pressurization are not required, the energy consumption in the production process of rope and belt pull tails is reduced, and the production process cost is reduced.

[0211] In some embodiments, the section of the rope placed in the cavity is a buried section wrapped by colloid. Before placing the rope in step 1 (S100), the rope is cut according to the shape and size required by the design, and the buried section is processed with an anchoring colloid structure.

[0212] In some real-time methods, anchoring colloidal structures are processed on the buried section, including:

[0213] At least one of arranging a structure protruding from the rope surface in the buried section, arranging a structure recessed in the rope surface in the buried section, arranging a structure penetrating the rope in the buried section, and bending and shaping the buried section.

[0214] In some specific examples, the structure protruding from the surface of the rope includes at least one of a convex ring, a convex pattern, and a convex point; the structure recessed in the surface of the rope includes at least one of a groove, a concave point, and a concave pattern; the structure passing through the rope includes at least one of a through hole and a through groove; and the bending and shaping of the buried section includes at least one of a wave-shaped bending and a zigzag bending.

[0215] For example, the rope is cut according to the shape and size required by the design, and an anchoring colloid structure is set in the rope covering section to enhance the bonding strength between the rope and the tail. The anchoring colloid structure includes rings, holes, grooves, dots, patterns and other shape structures, preferably circular through holes, which can allow the rope tail colloid material to pass through the rope covering to form a bolt anchoring colloid structure.

[0216] For another example, the buried section of the rope may be hot-pressed by thermoforming to produce a smooth transition waveform bend similar to a sine wave, or a zigzag bend with a clear turning point similar to a triangular wave.

[0217] For another example, the anchoring colloid structure can be combined, and a circular through hole can be first made in the rope covering section, and then bent to shape.

[0218] Due to the elasticity of polymer materials, the buried section of the rope will come out of the tail colloid when subjected to a large pulling force. The anchoring colloid structure can generate mechanical interlocking force between the rope and the tail. The rope and the tail are bonded together by interface adhesion and mechanical interlocking force, which is more firm and can withstand greater external pulling force, thereby reducing the risk of separation between the rope and the tail. The rope is set with an anchoring colloid structure to enhance the tensile performance of the product.

[0219] In some embodiments, the processing of the anchoring colloid structure is achieved by laser, ultrasound, thermal forming and other methods, and the fibers at the cut of the rope can be prevented from rebounding, loosening or spreading during the manufacturing process.

[0220] In some embodiments, before adding the glue in step 3 ( S300 ), the process further includes preparing a room temperature curing liquid glue.

[0221] Among them, the room temperature curing liquid rubber is a two-component addition room temperature vulcanizing silicone composition; the two-component addition room temperature vulcanizing silicone composition includes the following components in parts by weight: 110 parts of two-component addition type room temperature curing silicone, 70-150 parts of diluent, and 5-20 parts of color paste.

[0222] The diluent can effectively improve the fluidity of the two-component addition room temperature curing silicone and adjust and control the viscosity of the liquid silicone composition. Petroleum ether is preferred. Petroleum ether has good volatility. After the room temperature and low pressure injection molding is completed, the product dries in a shorter time.

[0223] In some embodiments, the diluent is 70 to 150 parts, such as 70 parts, 80 parts, 90 parts, ..., 150 parts; or any one of 70 to 150 parts. The viscosity of the two-component addition room temperature curing silicone is adjusted to between 5000 and 15000 cPs in combination with other components.

[0224] Color paste is beneficial to pigment dispersion. It is mainly composed of silicone oil and pigment. It can provide various colors for room temperature low-pressure injection molding liquid silicone and ensure uniform color distribution of the final product.

[0225] In some embodiments, the color paste is 5 to 20 parts, such as one of 5 parts, 6 parts, 7 parts...20 parts; or any one of 5 to 20 parts.

[0226] In some specific embodiments, the two-component addition-type room temperature curing silicone comprises two raw materials, component A and component B, and component A and component B are mixed in a weight ratio of 10:1;

[0227] Component A contains the following components by weight:

[0228] 65-75 parts of a first base silica gel, preferably vinyl silicone oil;

[0229] 25-35 parts of reinforcing agent, preferably fumed silica;

[0230] 1 to 3 parts of a cross-linking agent, preferably methyl hydrogen silicone oil;

[0231] 0.01 to 0.1 parts of an inhibitor, preferably acetylene alcohol.

[0232] Component B contains the following components by weight:

[0233] 90-95 parts of a second base silica gel, preferably vinyl silicone oil;

[0234] 2 to 5 parts of a catalyst, preferably a chloroplatinic acid catalyst;

[0235] 1 to 5 parts of release agent, preferably methyl silicone oil.

[0236] In some embodiments, bubbles are usually mixed into the liquid silicone composition during the preparation process, and vacuuming is required after the preparation is completed to remove the bubbles.

[0237] The basic silicone provides basic physical and chemical properties, such as mechanical properties, temperature resistance, etc. As the main resin, it is combined with other components such as cross-linking agents, catalysts, etc. to form a silicone product with specific properties. The first basic silicone and the second basic silicone provided in the embodiment of the present application can be the same or different.

[0238] In some embodiments, the first base silica gel is 65-75 parts, such as one of 65 parts, 66 parts, 67 parts, ... 75 parts; or any one of 65-75 parts. The second base silica gel is 90-95 parts, such as one of 90 parts, 91 parts, 92 parts, ... 95 parts; or any one of 90-95 parts.

[0239] Reinforcing agents, such as white carbon black or silica powder, can enhance the mechanical properties of silicone and improve its tensile strength, elongation at break and tear strength.

[0240] In some embodiments, the color paste is 5 to 20 parts, such as one of 5 parts, 6 parts, 7 parts...20 parts; or any one of 5 to 20 parts.

[0241] Crosslinking agent: A crosslinking agent is a polysiloxane containing multiple Si-H bonds. It reacts with the vinyl groups in the base polymer in the addition-type silicone to form a three-dimensional network structure, thereby achieving the curing of the silicone.

[0242] In some embodiments, the cross-linking agent is 1 to 3 parts, such as one of 1 part, 1.5 parts, 2 parts, ..., 3 parts; or any one of 1 to 3 parts.

[0243] Inhibitors control the speed of the curing reaction and prevent the accumulation of heat and degradation of material properties caused by too fast a reaction. They slow down the reaction rate by competitively binding to the reactive centers of the catalyst.

[0244] In some embodiments, the inhibitor is 0.01 to 0.1 parts, such as one of 0.01 parts, 0.02 parts, 0.03 parts, ... 0.1 parts; or any one of 0.01 to 0.1 parts.

[0245] Catalysts are substances that promote the curing reaction of silicone rubber, usually platinum compounds or platinum complexes. In two-component addition room temperature curing silicone rubber, the presence of catalysts enables the reaction between the crosslinker and the base polymer to proceed, prompting the silicone rubber to transform from liquid to solid.

[0246] In some embodiments, the catalyst is 2-5, for example, one of 2 parts, 2.5 parts, 3 parts, ..., 5 parts; or any one of 2-5.

[0247] Release agent: The function of the release agent is to reduce the adhesion between the silicone and the mold, so that the cured silicone product can be more easily removed from the mold, thereby improving production efficiency and product appearance quality.

[0248] In some embodiments, the release agent is 1 to 5 parts, such as one of 1 part, 1.5 parts, 2 parts, ..., 5 parts; or any one of 1 to 5 parts.

[0249] In summary, the applicability of materials can be effectively improved through material optimization and combination, and the operation and control of room temperature ultra-low pressure injection molding can be better matched to achieve the best process effect.

[0250] In some embodiments, see Figure 4After the pre-ventilation treatment and mold opening and taking out the parts in step 7 (S700), the process also includes a tail surface treatment in step 8 (S800).

[0251] In some embodiments, after the pull tail is injection molded at room temperature and ultra-low pressure using liquid colloid materials such as acrylic resin, polyurethane resin, unsaturated polyester resin, epoxy resin, etc., the surface of the semi-finished rope pull tail only needs to be decorated with graphics and colors such as pad printing, silk screen printing, spraying, and painting, and no other special surface treatment is required.

[0252] In some embodiments, after the organic silicone is injected at room temperature and at ultra-low pressure, the surface of the semi-finished silicone rope tail is highly sticky and easily adheres to dirt such as dust and fluff, and needs to be subjected to special surface treatment, which includes photo-oxidation treatment using ultraviolet light with a wavelength of 365nm, and dipping treatment using matte silicone. After the surface treatment, the semi-finished product is converted into a finished product, and the surface of the finished product is dust-free and feels comfortable and soft.

[0253] An embodiment of the present application further provides a room temperature ultra-low pressure injection molding device, which includes an injection molding mechanism, a clamping mechanism, and a vibration mechanism.

[0254] In some embodiments, the injection molding mechanism includes an injection nozzle, a material cylinder, a plunger, and a power control system, which is vertically located above the mold clamping mechanism. The injection molding mechanism is used to apply ultra-low pressure to quantitatively inject liquid colloid into the mold cavity for molding at room temperature.

[0255] In some embodiments, the mold locking mechanism includes a front mold plate, a rear mold plate, and a power control system, which are integrally fixed to the vibration mechanism. The mold locking mechanism applies pressure to lock the two half mold bodies of the mold, further clamping the ropes to prevent them from loosening, and at the same time preventing the liquid colloid in the mold cavity from overflowing and seeping out on the parting surface, and avoiding the appearance of burrs on the tail parting line after drying, so that the applied mold locking pressure does not need to be very large.

[0256] In some embodiments, the vibration mechanism includes a vibration table and a vibration generating system. The vibration mechanism is used to generate vibration, driving the clamping mechanism and the room temperature ultra-low pressure injection mold to vibrate together. The mold vibration ensures that the liquid colloid in the mold cavity and the feeding cavity can flow and fill in a high viscosity state, and timely replenishes the shortage caused by the shrinkage of the glue. Taking the two-component addition room temperature curing silicone as an example to further illustrate: as the curing time of the two-component addition room temperature curing silicone increases, the liquid silicone composition in the mold continues to undergo hydrogen-silicon addition reaction, and the diluent continues to evaporate and decrease, gradually changing from liquid to solid, the viscosity of the liquid silicone composition gradually increases, and the fluidity of the liquid silicone composition deteriorates. The resistance to free flow by gravity in the mold cavity and the feeding cavity increases, and then the liquid silicone composition in the cavity cannot be replenished in time. The shrinkage caused by the curing shrinkage causes the shortage of glue, and the product after molding and curing has defects such as lack of glue and voids. The vibration mechanism drives the mold to vibrate, and the vibration force promotes the high viscosity flow of the colloid to make up for the defects of materials and processes.

[0257] In summary, through the specific functions and effects of the machine, the reliability and stability of the room temperature ultra-low pressure injection molding process of the rope tail is guaranteed, thereby realizing industrialization.

[0258] For a more convenient understanding of this application, see Figure 4 The present application provides a specific embodiment to illustrate the rope tail injection molding method provided by the present application. It should be pointed out that the specific embodiment does not constitute a limitation to the present application.

[0259] Step 1 (S100): Lay out the ropes.

[0260] The rope is placed in the fixed groove of the first half mold, with one end of the rope exposed outside the first half mold and the other end embedded in the cavity of the first half mold. The length of the rope embedded in the cavity of the half mold is slightly shorter than the length of the cavity, and the length difference is about 1.5mm.

[0261] Step 2 (S200): Locking the injection mold. This includes two sub-steps: preliminary mold closing (S210) and mold locking mechanism locking the mold (S220).

[0262] The mold is initially closed (S210). The first half mold body on which the rope is placed is initially closed with the second half mold body through the cooperation of the guide pin and the guide sleeve, and the rope is clamped and initially fixed on the center line of the mold cavity.

[0263] The clamping mechanism locks the mold (S220), inserts the preliminarily closed injection mold between the front mold plate and the rear mold plate of the clamping mechanism, and applies pressure to lock the mold. The rope is further clamped by the mold to prevent it from loosening, and at the same time prevents the liquid colloid from overflowing and seeping out on the mold parting surface.

[0264] Step 3 (S300): Adding rubber material.

[0265] Take a room temperature curing liquid rubber with a viscosity range of 10000 cPs, which is a two-component addition type room temperature curing silicone rubber, and put it into the material cylinder of the injection molding mechanism; wherein the room temperature is a temperature range of 25°C.

[0266] Step 4 (S400): First injection.

[0267] Carry out the first injection of the rubber compound, including the injection molding mechanism at 0.2kg / cm 2 The pressure between the gate and the discharge port is used to compact the liquid rubber and squeeze the bubbles in the cavity toward the discharge port, so that the bubbles and part of the liquid rubber are discharged from the cavity from the discharge port. The injection is stopped when it is detected that the discharge cavity is filled to about 2 / 3 of its volume.

[0268] Step 5 (S500): Second injection.

[0269] The second injection of the rubber material is carried out, including that the injection molding mechanism retreats until the nozzle reaches a position 6mm away from the gate in the feeding cavity, and the injection molding mechanism injects the liquid rubber material into the feeding cavity. When the liquid colloid fills 2 / 3 of the volume of the feeding cavity, the injection is stopped and the injection molding mechanism retreats and resets.

[0270] Step 6 (S600): Apply vibration to the injection mold.

[0271] Vibration is applied to the injection mold in a preset vibration mode, and the vibration promotes the transfer of part of the liquid rubber in the feeding cavity into the cavity under the pressure difference between the gate and the discharge port.

[0272] The preset vibration mode is to apply vibration once at an interval of 15 minutes, each vibration lasts for 20 seconds, and the vibration stops after 3 times.

[0273] The step of removing and transferring the mold (S650). After the vibration is completed, the front template and the rear template of the mold clamping mechanism are opened, and the mold is removed from the mold clamping mechanism.

[0274] After the mold is taken out, it switches to two operation paths:

[0275] The first operation path is to transfer the mold to the transfer platform and wait for the liquid colloid in the mold to dry before subsequent operations.

[0276] Another operation path is to put in another set of replica molds and enter the next cycle, that is, start the rope placement step (S100), and repeat the cycle in sequence. During the cycle, more replica molds need to be put in, and the specific number of molds depends on the production scale.

[0277] Step 7 (S700): Pre-ventilation treatment and mold opening and part removal.

[0278] After applying vibration to the injection mold, the injection mold is left to stand for 40 minutes. After the cavity is ventilated and left to stand for a preset 1.5 hours, the two half mold bodies are completely opened and the cured molded rope tail is taken out.

[0279] After the pre-ventilation treatment and mold opening and taking out the parts in step 7 (S700), the tail surface treatment is carried out in step 8 (S800). The surface treatment includes photo-oxidation treatment with ultraviolet light of wavelength 365nm, and dipping treatment with matte silicone. After the surface treatment, the semi-finished product is transformed into a finished product, and the surface of the finished product is dust-free and feels comfortable and soft.

[0280] It is understandable that those skilled in the art can, under the guidance of the above embodiments, combine various implementation methods in the above embodiments to obtain technical solutions of multiple implementation methods.

[0281] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A rope tail injection molding method, characterized in that: Provided is an injection mold, the injection mold comprising a first half mold body and a second half mold body; the first half mold body and the second half mold body comprise a cavity portion, a feeding cavity portion, a discharge cavity portion and a fixed groove portion corresponding to each other; the first half mold body and the second half mold body together form a cavity, a feeding cavity, a discharge cavity and a fixed groove; the cavity is provided with a gate, the gate is connected to the external space of the injection mold through the feeding cavity; the cavity is also provided with a discharge port, the discharge port is connected to the external space of the injection mold through the discharge cavity; the cross-sectional area of ​​the gate is greater than the cross-sectional area of ​​the discharge port; One end of the fixing groove is connected to the mold cavity, and the other end is connected to the outside of the injection mold; the rope tail injection molding method comprises the following steps: Step 1: placing a rope in the fixing groove of the first half mold body, with one end of the rope exposed outside the first half mold body and the other end embedded in the cavity of the first half mold body; Step 2: closing the first half mold body with the rope and the second half mold body, and applying pressure to the two half mold bodies to lock the injection mold; Step 3: Take a room temperature curable liquid rubber with a viscosity range of 5000 to 15000 cPs and put it into the material cylinder of the injection molding mechanism; wherein the room temperature is a temperature range of 25±5°C; Step 4: Perform the first injection of the rubber compound, including the injection molding mechanism at 0.1-1 kg / cm 2 The liquid rubber is injected from the gate into the cavity at a pressure between the gate and the cavity, and the injection is stopped when it is detected that the discharge cavity is overflowed and filled to a first preset position; Step 5: performing a second injection of the rubber material, including: the injection molding mechanism retreats until the nozzle reaches a second preset position in the feeding cavity, the injection molding mechanism injects the liquid rubber material into the feeding cavity, and when the liquid rubber material fills the feeding cavity to a third preset position, the injection is stopped; Step 6: applying vibration to the injection mold in a preset vibration mode; Step 7: After vibrating the injection mold, let the injection mold stand for a preset semi-curing time. After ventilating the cavity and letting it stand for a preset full-curing time, the two half mold bodies are fully opened to take out the cured molded rope tail.

2. The rope tail injection molding method according to claim 1, characterized in that: The section of the rope placed in the cavity is a buried section wrapped by colloid; before step 1, it also includes: The buried section is processed with an anchoring colloid structure.

3. The rope tail injection molding method according to claim 2, characterized in that: The buried section is processed with an anchoring colloid structure, including: At least one of providing a structure protruding from the surface of the rope in the buried section, providing a structure recessed in the surface of the rope in the buried section, providing a structure penetrating the rope in the buried section, and bending and shaping the buried section.

4. The rope tail injection molding method according to claim 3, characterized in that: The structure protruding from the surface of the rope belt includes at least one of a protruding ring, a convex pattern, and a convex point; The structure sunken in the surface of the rope belt includes at least one of a groove, a concave point, and a concave pattern; The structure penetrating the rope belt includes at least one of a through hole and a through groove; The bending and shaping of the buried section includes at least one of wave-shaped bending and zigzag bending.

5. The rope tail injection molding method according to claim 1, characterized in that: The guide system of the injection mold is composed of a guide pin arranged on one of the first mold half and the second mold half, and a guide sleeve arranged on the other; In step 2, the first half mold body and the second half mold body on which the rope is placed are closed, and pressure is applied to the two half mold bodies to lock the injection mold, including: Through the cooperation of the guide column and the guide sleeve, the first half mold body and the second half mold body on which the rope is placed are preliminarily closed; The preliminarily closed injection mold is installed between the front mold plate and the rear mold plate of the clamping mechanism, and pressure is applied to lock the mold.

6. The rope tail injection molding method according to claim 1, characterized in that: Before step 3, the method further includes preparing the room temperature curing liquid adhesive; Wherein, the room temperature curing liquid rubber is a two-component addition room temperature vulcanizing silicone composition; the two-component addition room temperature vulcanizing silicone composition comprises the following components in parts by weight: 110 parts of two-component addition-type room temperature curing silicone, 70-150 parts of diluent, and 5-20 parts of color paste.

7. The rope tail injection molding method according to claim 6, characterized in that: The two-component addition-type room temperature curing silicone comprises two raw materials, component A and component B, and the component A and the component B are mixed in a weight ratio of 10:1; The component A comprises the following components by weight: 65-75 parts of the first basic silica gel, 25-35 parts of a reinforcing agent, 1-3 parts of a cross-linking agent, and 0.01-0.1 parts of an inhibitor; wherein the first basic silica gel is vinyl silicone oil, the reinforcing agent is fumed silica, the cross-linking agent is methyl hydrogenated silicone oil, and the inhibitor is acetylene alcohol; The B component comprises the following components by weight: 90 to 95 parts of a second base silicone, 2 to 5 parts of a chloroplatinic acid catalyst, and 1 to 5 parts of a release agent; wherein the base silicone is vinyl silicone oil, the catalyst is chloroplatinic acid catalyst, and the release agent is methyl silicone oil.

8. The rope tail injection molding method according to claim 1, characterized in that: The first preset position is between the discharge port and the position where the discharge cavity is filled to 2 / 3.

9. The rope tail injection molding method according to claim 1, characterized in that: The preset vibration mode includes applying vibration once at a frequency of once every 10 to 20 minutes, each application of vibration lasting 15 to 60 seconds, and stopping the application of vibration after applying vibration 2 to 5 times.

10. The rope tail injection molding method according to claim 1, characterized in that: The preset semi-curing time is 30 to 60 minutes, and the cavity is ventilated and left to stand for the preset full curing time, including: Open the two half molds with a gap of 0.3 to 1 mm and let it stand for 1 to 2 hours.

Images