WO2020042516A1

WO2020042516A1 - Injection molding apparatus and injection molding method

Info

Publication number: WO2020042516A1
Application number: PCT/CN2019/000126
Authority: WO
Inventors: 邓俊钧; 罗力; 苏旭波; 项蔚翔; 沈明聪; 丁贵平
Original assignee: 宁波双马机械工业有限公司
Priority date: 2018-08-31
Filing date: 2019-06-17
Publication date: 2020-03-05

Abstract

An injection molding apparatus and an injection molding method. The injection molding apparatus comprises an injection mechanism (1), a mold assembly, a mold closing mechanism (2), and a rack (3). The mold assembly is provided on the rack (3) and has a cavity. The mold closing mechanism (2) is connected to the mold assembly and is used for opening or closing the cavity. The injection mechanism (1) has a material barrel (11) communicated with the cavity. The injection molding apparatus further comprises a heating device (5) for heating the mold assembly and a cooling device (4) for cooling a material in the cavity. The heating device (5) and the cooling device (4) are both provided in the rack (3). A heating member (12) is provided on the outer wall of the material barrel (11). The method can implement good product quality and high production efficiency.

Description

Injection pressure forming equipment and injection pressure forming method

Technical field

The invention relates to the technical field of molds, and in particular, to an injection molding device and an injection molding method.

Background technique

Ultra-high molecular weight polyethylene has many advantages such as excellent abrasion resistance, extremely high impact strength, excellent anti-adhesion, and good chemical stability not found in ordinary polyethylene. It has been widely used in industry and Civilian domain.

Because the ultra-high molecular weight polyethylene has an ultra-high molecular weight (viscosity average molecular weight is more than 1.5 million), the melt viscosity is as high as 108 Pa · s, and the melt index is almost zero, which makes the processing of ultra-high molecular weight polyethylene difficult. Generally, in the process of processing, the raw materials are usually put into a mold, and then placed in an oven with the mold for heating for several hours, and then the mold is taken out and placed on a press while cooling and molding, but the above-mentioned processing has the following aspects Problems: 1. The raw materials are heated unevenly in the mold, and there may be external melting and internal unmelting, which results in poor quality of the finished product; 2. The processing process is complicated and the degree of automation is not high. Generally, a product takes several hours. , The production efficiency is low, the labor intensity of workers is also large; 3, the energy consumption is relatively large.

Summary of the Invention

One of the main objectives of the present invention is to provide an injection molding device with better finished product quality and higher production efficiency.

In order to achieve the above objective, the technical solution adopted by the present invention is: an injection molding device, which includes an injection mechanism, a mold assembly, a mold clamping mechanism, and a frame, and the mold assembly is disposed in the frame, and The mold assembly has a cavity, the mold clamping mechanism is connected to the mold assembly and is used to open or close the mold cavity, and the injection mechanism has a material in communication with the mold cavity. Cylinder, said injection molding equipment further includes heating means for heating said mold assembly and cooling means for cooling materials in said cavity, said heating means and said cooling means Both are arranged in the frame, and heating elements are arranged on the outer side wall of the barrel.

The heating device includes an electromagnetic heater, and the electromagnetic heater is disposed in the rack. In this structure, the electromagnetic heater is a prior art, which can preheat the mold components and maintain a constant temperature, so that the materials can be fully melted.

The heating device includes an infrared heater, and the infrared heater is disposed in the rack. In this structure, the infrared heater is the existing technology, which has the advantages of rapid and uniform heating, high actual thermal efficiency, and simple use. It can preheat the mold components and maintain a constant temperature, so that the materials can be fully melted.

The cooling device includes a fan assembly, and the fan assembly is disposed in the rack. Due to the characteristics of ultra-high molecular weight polyethylene, fast cooling is not possible, and the setting of the fan assembly can reduce the temperature, and at the same time, the cooling speed will not be too fast.

The barrel has an extrusion cavity, and a screw is arranged in the extrusion cavity. The barrel is further provided with a hopper communicating with the extrusion cavity, and a lower portion of the barrel is provided with Cooling ring. In this structure, the setting of the screw plays the role of conveying the material, the hopper is easy to load, and the cooling ring is arranged at the lower part of the hopper, which can cool and cool the material, so that the material will not stick to the hopper.

The pitch of the screw is 0.6 to 0.9 times the screw diameter. The advantage is that it can increase the conveying capacity of the screw.

The injection mechanism further includes a power unit for moving the cartridge away from or close to the cavity. In this way, the contact between the screw and the cavity is achieved, and the purpose of injection is achieved. After the injection is completed, the screw can be retracted to prepare for the next injection.

The mold clamping mechanism includes a fixed template, a movable template, and a driving unit for driving the movable template close to or away from the fixed template. The fixed template is fixedly disposed in the frame. The fixed template is provided with an injection hole communicating with the barrel, the movable template is movably disposed in the frame, and the mold assembly is composed of a first mold and a second mold. The cavity is formed between the first mold and the second mold, and the first mold is located on the fixed template, and the second mold is located on the movable template. . In this structure, the movable mold plate brings the second mold closer to or away from the fixed mold plate, thereby achieving the opening or closing of the cavity.

The driving unit includes a mold-shifting cylinder and a mold-locking cylinder. The mold-shifting cylinder is disposed on one side of the fixed template. The piston rod of the mold-shifting cylinder passes through the fixed template and communicates with the fixed cylinder. The moving template is fixed, the mold-locking cylinder is disposed on the other side of the fixed template, and the piston rod of the mold-locking cylinder passes through the fixed template and is fixed to the moving template. In this structure, the mold-shifting oil cylinder and the mold-locking oil cylinder are used together to improve work efficiency.

The driving unit further includes an ejection cylinder disposed in the frame, the ejection plate is provided on the movable template, and a piston rod of the ejection cylinder is fixed to the ejection plate. In this structure, when the ejection cylinder is in motion, the ejection plate is driven to move, so that the product in the mold falls off, and the reclaiming is more rapid.

Compared with the prior art, the above solution has the advantage that the setting of the heating device can pre-heat and subsequently heat the mold component, so that the mold component can be maintained at a higher temperature before the material enters the cavity, and the material is fully melted. The purpose is to shorten the heating time and improve production efficiency; the setting of the cooling device can make the material cool to form; the setting of the heating element can heat the barrel, so that the temperature of the material is higher before it enters the cavity, which shortens the cavity. The internal heating time improves the production efficiency; at the same time, the device is fully automated without manual operation, which greatly improves the quality of the finished product; the quality of the finished product is better and the production efficiency is higher.

The other main purpose of the present invention is to provide an injection molding method with better finished product quality, higher production efficiency and lower energy consumption, which includes the steps of mold clamping, preheating, injection and mold opening, and also includes heating. And the cooling of the stamper, making the entire injection molding method as follows,

S1: The mold is closed, and the cavity in the mold assembly is closed;

S2: preheating, heating the barrel of the injection mechanism, so that the raw materials in the barrel are always maintained at a constant temperature value;

S3: heating, heating the mold components to a preset temperature value;

S4: injection, the injection mechanism injects the heated raw material into the cavity;

S5: The mold is cooled. The mold clamping mechanism maintains the pressure in the cavity to a preset pressure value. At the same time, the heating is stopped and the mold components are cooled. The cooling rate is 1 to 50 ° C / min, and the temperature is cooled to a preset temperature. After stopping cooling, the injection mechanism will prepare for the next injection;

S6: Open the mold, the cavity is opened, and the finished product is ejected.

In step S3, the preset temperature value is 50-280 ° C.

In step S4, a step of opening the mold cavity by a mold clamping mechanism is further included. In step S5, a step of closing the mold cavity gradually by the mold clamping mechanism is also included. The mold clamping mechanism opens the cavity for a gap to facilitate injection by the injection mechanism. The mold clamping mechanism gradually closes the cavity to maintain a certain pressure in the cavity, which is convenient for compression molding.

After step S4 and before step S5, the method further includes the step of heating the mold assembly again to maintain the mold assembly at a preset temperature value for a period of time. The advantage is to avoid the effect of cooling the mold component after injection, which affects the quality of the finished product.

The duration is 0 ~ 120min.

In step S5, the preset pressure value is 3 to 60 Mpa.

Compared with the prior art, the advantages of the above solution are: pre-heating the mold components and pre-heating the raw materials in the barrel before injection, thereby shortening the heating of the ultra-high molecular weight polyethylene in the mold components. Time to enable it to melt quickly and fully, and improve production efficiency: heating the mold components to prevent unmelted raw materials and improving the yield rate; during the cooling of the mold, the injection mechanism stores materials for the next time. Injection preparation. When the cycle is completed, the injection mechanism can directly perform the injection to shorten the preparation time. The cooling rate is 1 ～ 50 ℃ / min, which makes the cooling rate slower than the ordinary water cooling method, so that the product can be slowly cooled, which avoids affecting the quality of the finished product. After the heating is completed, the ultra-high molecular weight polyethylene is completely in a molten state. At this time, the mold components are slowly cooled, and finally a qualified finished product is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of the present invention.

detailed description

The present invention is described in further detail below with reference to the examples.

Embodiment 1: As shown in the figure, an injection molding apparatus includes an injection mechanism 1, a mold assembly, a mold clamping mechanism 2, and a frame 3, and the mold assembly is disposed in the frame 3, and the mold assembly has a cavity. The mold clamping mechanism 2 is connected to the mold assembly and is used to open or close the cavity. The injection mechanism 1 has a cylinder 11 communicating with the cavity. The injection molding device further includes a heating device 5 for heating the mold assembly and a heating device 5 for The cooling device 4, the heating device 5 and the cooling device 4 for material cooling in the cavity are all arranged in the frame 3, and the heating element 12 is arranged on the outer side wall of the barrel 11.

In this embodiment, the heating device 5 includes an electromagnetic heater, and the electromagnetic heater is disposed in the frame 3.

Embodiment 2: As shown in the figure, an injection molding apparatus includes an injection mechanism 1, a mold assembly, a mold clamping mechanism 2, and a frame 3, and the mold assembly is disposed in the frame 3, and the mold assembly has a cavity. The mold clamping mechanism 2 is connected to the mold assembly and is used to open or close the cavity. The injection mechanism 1 has a cylinder 11 communicating with the cavity. The injection molding device further includes a heating device 5 for heating the mold assembly and a heating device 5 for The cooling device 4, the heating device 5 and the cooling device 4 for material cooling in the cavity are all arranged in the frame 3, and the heating element 12 is arranged on the outer side wall of the barrel 11.

In this embodiment, the heating device 5 includes an infrared heater, and the infrared heater is disposed in the rack 3.

In this embodiment, the cooling device 4 includes a fan assembly, and the fan assembly is disposed in the rack 3.

In this embodiment, the barrel 11 has an extrusion cavity 13, and a screw 14 is arranged in the extrusion cavity 13. A barrel 15 is also provided on the barrel 11, which is in communication with the extrusion cavity 13, and a cooling ring is provided at the lower portion of the barrel 15. 16.

In this embodiment, a cooling mechanism is provided at the barrel 11 near the hopper 15 to further improve the cooling effect and prevent the materials from adhering at the blanking place.

In this embodiment, the pitch of the screw 14 is 0.6 to 0.9 times the diameter of the screw.

In this embodiment, the injection mechanism 1 further includes a power unit 17 for moving the cartridge 11 away from or close to the cavity.

In this embodiment, the mold clamping mechanism 2 includes a fixed template 21, a movable template 22, and a driving unit 23 for driving the movable template 22 closer to or far from the fixed template 21. The fixed template 21 is fixedly disposed in the frame 3, and the fixed template 21 An injection hole 24 communicating with the barrel 11 is provided. The movable mold plate 22 is movably disposed in the frame 3. The mold assembly is composed of a first mold and a second mold. A cavity is formed between the first mold and the second mold. The first mold is located on the fixed template 21 and the second mold is located on the movable template 22.

In this embodiment, the driving unit 23 includes a mold shifting cylinder 25 and a mold clamping cylinder 26. The mold shifting cylinder 25 is disposed on one side of the fixed platen 21, and the piston rod of the mold shifting cylinder 25 passes through the fixed platen 21 and is fixed to the movable platen 22 The mold clamping cylinder 26 is disposed on the other side of the fixed template 21, and the piston rod of the mold clamping cylinder 26 passes through the fixed template 21 and is fixed to the movable template 22.

In this embodiment, the driving unit 23 further includes an ejection cylinder 27 disposed in the frame 3, and a movable platen 22 is provided with an ejection plate 221, and a piston rod of the ejection cylinder 27 is fixed to the ejection plate 221.

Embodiment 3: As shown in the figure, an injection compression molding method includes the steps of mold clamping, preheating, injection, and mold opening, and further includes the steps of heating and cooling of the mold, so that the entire injection molding method is as follows.

S1: The mold is closed, and the cavity in the mold assembly is closed;

S3: heating, heating the mold components to a preset temperature value;

S6: Open the mold, the cavity is opened, and the finished product is ejected.

In this embodiment, in step S3, the preset temperature value is 50-280 ° C.

In this embodiment, step S4 further includes the step of the mold clamping mechanism to open the cavity by a gap. The cavity is opened with a gap by active opening or passive opening. The active opening uses the mold clamping mechanism to move the movable template back a certain distance ; Passive opening means that the injected material pushes the moving template back.

In step S5, a step of gradually closing the cavity by the mold clamping mechanism is further included.

In this embodiment, after step S4 and before step S5, the method further includes the step of heating the mold assembly again to maintain the mold assembly at a preset temperature value for a period of time.

In this embodiment, the duration is 0 to 120 minutes.

In this embodiment, in step S5, the preset pressure value is 3 to 60 MPa.

Claims

An injection molding apparatus includes an injection mechanism, a mold component, a mold clamping mechanism, and a frame. The mold component is disposed in the frame, and the mold component has a cavity. A mold mechanism is connected to the mold assembly and is used to open or close the cavity. The injection mechanism has a cylinder communicating with the cavity. The injection mechanism is characterized by the injection molding equipment. It also includes a heating device for heating the mold assembly and a cooling device for cooling the material in the cavity. The heating device and the cooling device are both arranged in the frame. A heating element is arranged on the outer wall of the barrel.
An injection molding apparatus according to claim 1, wherein said heating device comprises an electromagnetic heater, and said electromagnetic heater is disposed in said frame.
The injection molding apparatus according to claim 1, wherein the heating device comprises an infrared heater, and the infrared heater is arranged in the frame.
The injection molding apparatus according to claim 1, wherein the cooling device comprises a fan assembly, and the fan assembly is disposed in the rack.
The injection molding apparatus according to claim 1, wherein the barrel has an extrusion cavity, a screw is disposed in the extrusion cavity, and the barrel is further provided with a The hopper connected to the extrusion cavity is provided with a cooling ring at the lower part of the hopper.
The injection molding apparatus according to claim 5, wherein the pitch of the screw is 0.6 to 0.9 times the diameter of the screw.
The injection molding apparatus according to claim 5, wherein said injection mechanism further comprises a power unit for moving said cartridge away from or close to said cavity.
The injection molding apparatus according to claim 1, wherein the mold clamping mechanism comprises a fixed template, a movable template, and a driving unit for driving the movable template to approach or move away from the fixed template. The fixed template is fixedly disposed in the frame, the fixed template is provided with an injection hole communicating with the barrel, and the movable template is movably disposed in the frame. The mold assembly is composed of a first mold and a second mold, the cavity is formed between the first mold and the second mold, and the first mold is located in the mold. On the fixed template, the second mold is located on the movable template.
The injection molding apparatus according to claim 8, characterized in that: the driving unit comprises a mold shifting cylinder and a mold clamping cylinder, and the mold shifting cylinder is disposed on one side of the fixed template, so that The piston rod of the mold-shifting cylinder is fixed to the moving template after passing through the fixed template. The mold-locking cylinder is disposed on the other side of the fixed template, and the piston of the mold-locking cylinder. After the rod passes through the fixed template, it is fixed with the movable template.
The injection molding device according to claim 9, wherein the driving unit further comprises an ejection cylinder disposed in the frame, and an ejection plate is provided on the movable template, The piston rod of the ejection cylinder is fixed to the ejection plate.
An injection compression molding method using the injection compression molding equipment according to any one of claims 1 to 10, comprising the steps of mold clamping, preheating, injection and mold opening, characterized in that it further comprises heating and cooling of the mold Steps to make the entire injection molding method as follows,

S1: The mold is closed, and the cavity in the mold assembly is closed;

S2: preheating, heating the barrel of the injection mechanism, so that the raw materials in the barrel are always maintained at a constant temperature value;

S3: heating, heating the mold components to a preset temperature value;

S4: injection, the injection mechanism injects the heated raw material into the cavity;

S5: The mold is cooled. The mold clamping mechanism maintains the pressure in the cavity to a preset pressure value. At the same time, the heating is stopped and the mold components are cooled. The cooling rate is 1 to 50 ° C / min, and the temperature is cooled to a preset temperature After stopping cooling, the injection mechanism will prepare for the next injection;

S6: Open the mold, the cavity is opened, and the finished product is ejected.
The method of claim 11, wherein in step S3, the preset temperature value is 50˜280 ° C.
The injection molding method according to claim 11, characterized in that: in step S4, further comprising a step of opening the mold cavity by a mold clamping mechanism; in step S5, further comprising a mold clamping mechanism to mold the cavity Gradually closed steps.
The method of claim 11, wherein after step S4 and before step S5, the method further comprises the step of heating the mold component again to maintain the mold component at a preset temperature value for a period of time. .
The injection molding method according to claim 14, characterized in that the duration is 0 to 120 minutes.
The method of injection molding according to claim 11, characterized in that, in step S5, the preset pressure value is 3 to 60 Mpa.