Polydicyclopentadiene reaction injection molding mold and molding method

Abstract

A molding die and molding method for reactive injection of polydicyclopentadiene, the mold comprises N cavities, an intercavity channel is provided between two adjacent cavities, a feed port is arranged at the bottom of the first cavity, the feed port enters the first cavity through a microchannel, a jet spoiler block is also provided at the bottom of the first cavity, an exhaust port is arranged on the top of the cavity, the N cavities are separated by N-1 partitions, two cover plates are provided outside, each cavity has a sealing groove around it, a sealing ring is installed, and after closing with the cover plate, the upper ends of all cavities are communicated with the exhaust port, the partition plate and the cover plate are both equipped with a temperature-controlled U-shaped pipe, and the N is a positive integer greater than 2. The present invention can prepare multiple polydicyclopentadiene products at the same time, improve production efficiency, enhance product uniformity, and improve product performance.

Description

Technical Field

[0001] The invention relates to a molding die, in particular to a polydicyclopentadiene reaction injection molding die and a molding method.

[0002] Polydicyclopentadiene (PDCPD for short) engineering plastic is a new type of engineering material with excellent mechanical properties. It has high tensile and flexural modulus and good impact strength. It also has relatively high heat deformation temperature and thermal stability, and is acid and alkali resistant. Moreover, polydicyclopentadiene is a pure hydrocarbon. It does not produce harmful substances when burned. It is recyclable, energy-saving and environmentally friendly. It is a good environmentally friendly material and a high-tech encouraged by the state. Therefore, it has shown extremely broad application prospects in the automotive industry, engineering machinery manufacturing, medical and sports equipment, petrochemical pipelines, civil facilities and other fields.

[0003] The PDCPD material processed by RIM technology has excellent mechanical properties, thermal stability and anti-aging properties, and can be widely used in automotive parts, industrial equipment, medical devices, etc.

[0004] CN206484922U discloses a molding die for polydicyclopentadiene, which comprises a fixed die and a movable die, and a first temperature regulating system arranged in the fixed die; and a second temperature regulating system arranged in the movable die.

[0005] CN104250330A discloses a composite manhole cover of dicyclopentadiene (DCPD) and carbon fiber cloth and a manufacturing method thereof. Components A and B are mixed by a mixing head of an injection machine and injected into a manhole cover mold in which a surface-treated carbon fiber cloth is pre-placed and fixed. A polymerization reaction and molding process are carried out in the manhole cover mold to obtain a composite manhole cover of polydicyclopentadiene and carbon fiber cloth.

[0006] CN208343492U discloses a polydicyclopentadiene impact mixing system. The polydicyclopentadiene impact mixing system includes a first guide plate provided with an auxiliary material channel for the flow of auxiliary materials, a main material channel separated from the auxiliary material channel and for the flow of main materials, and a mixing channel separated from both the auxiliary material channel and the main material channel. The main material will not enter the auxiliary material injection head, thus preventing the auxiliary material injection head from being blocked, thereby making subsequent feeding smooth and extending the service life of the auxiliary material injection head. Summary of the invention

[0007] The object of the present invention is to provide a polydicyclopentadiene reaction injection molding die and a molding method. The molding die can prepare multiple polydicyclopentadiene products at the same time, enhance the uniformity of the products, and improve the product performance.

[0008] The technical solution of the present invention is as follows:

[0009] A molding die for reactive injection molding of polydicyclopentadiene, characterized in that the die comprises N cavities, which are sequentially the first cavity, the second cavity, the third cavity, ..., the Nth cavity, and an intercavity channel is provided between two adjacent cavities, the intercavity channel between the first cavity and the second cavity is arranged at the 1 / N position from bottom to top of the cavity, the intercavity channel between the second cavity and the third cavity is arranged at the 2 / N position of the cavity height, ..., the intercavity channel between the N-1th cavity and the Nth cavity is arranged at the (N-1) / N position of the cavity height. The feed port is arranged at the bottom of the first mold cavity, the feed port enters the first mold cavity through a microchannel, a jet spoiler block is also arranged at the lower part of the first mold cavity, the exhaust port is arranged on the top of the mold cavity, the N mold cavities are separated by N-1 partitions, and there are two cover plates on the outside, each mold cavity has a sealing groove around it, and a sealing ring is installed. After closing with the cover plate, the upper end of all the mold cavities is connected with the exhaust port; the partition plate and the cover plate are equipped with a temperature-controlled U-shaped pipe, and N is a positive integer greater than 2.

[0010] The process of reaction molding using the above mold includes the following steps:

[0011] 1) After the N mold cavities and the cover plate are closed, nitrogen is used for purging and replacement. Before feeding, the mold is preheated by heating the medium through the temperature-controlled U-shaped pipe on the partition and the cover plate. The preheating temperature is 30~50℃;

[0012] 2) The raw material contains dicyclopentadiene, catalyst, solvent and modification additive. The raw material is divided into two streams, A and B, which enter the microchannel through the feed port, are mixed in the microchannel and fed, and pass through the jet spoiler block to form a mixed flow in the first cavity to achieve a fully mixed effect;

[0013] 3) The raw material enters from the lower part of the first cavity. When the feed amount reaches 1 / N of the first cavity, it starts to enter the second cavity. When the raw material reaches 2 / N of the height of the first and second cavities, it starts to enter the third cavity, ..., when the raw material reaches (N-1) / N of the height of the first N-1 cavities, it starts to enter the N cavity. At this time, N cavities are fed at the same time. During the feeding process, the upper parts of the N cavities are connected and communicated with the exhaust port. The air is exhausted from the exhaust port on the top of the cavity. When all the cavities are full, the feeding is stopped and the feeding valve is closed.

[0014] 4) Raise the mold cavity temperature to 40℃~80℃ for 1~2h reaction to form, and then raise the temperature to 120℃~150℃ for post-treatment for 1~2h. After the reaction is completed, pass the cooling medium through the temperature-controlled U-shaped pipe, and demould after cooling.

[0015] The technical effects of the present invention are as follows:

[0016] 1. The molding die can prepare multiple pieces of polydicyclopentadiene products at the same time, which improves production efficiency, enhances product uniformity, and improves product performance.

[0017] 2. Each mold cavity is surrounded by a sealing groove, which is equipped with a sealing ring and can be completely sealed after closing with the cover plate.

[0018] 3. During the experiment, after the above four mold cavities and the cover plate were closed, nitrogen was used for purging and replacement, and feeding began. During the feeding process, the upper parts of the four mold cavities were connected, and there were exhaust ports to the outside, and the air was exhausted from the top of the mold cavity.

[0019] 4. In order to enhance the mixing effect, the molding die provided by the utility model has a jet spoiler block added to the connecting channel between the feed port and the mold cavity.

[0020] 5. Each mold cavity cover is equipped with pipelines to preheat before polymerization feeding and cool down in the later stage of reaction to accelerate the demoulding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a schematic diagram of the structure of a molding die for reactive injection molding of polydicyclopentadiene according to the present invention.

[0022] Figure 2 Figure 1. Upper cover plate DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with embodiments and drawings, but the protection scope of the present invention shall not be limited thereto.

[0024] Please refer to Figure 1 FIG1 is a structural principle diagram of an embodiment of a polydicyclopentadiene reaction injection molding die of the present invention. The embodiment is a 4-cavity polydicyclopentadiene reaction injection molding die, which can prepare four polydicyclopentadiene products at the same time. As can be seen from the figure, the polydicyclopentadiene reaction injection molding die of the present invention comprises a first cavity 1, a second cavity 2, a third cavity 3 and a fourth cavity 4. The first cavity 1 and the second cavity 2 are connected at the lower quarter by an inter-cavity channel 7, and the second cavity 2 and the third cavity 3 are connected at the half by an inter-cavity channel 7. The inter-cavity channel 7 is connected, the III cavity 3 and the IV cavity 4 are connected through the inter-cavity channel 7 at a quarter of the distance from the top, the feed port 11 is arranged at the lower part of the I cavity 1, the feed port 11 enters the I cavity 1 through the microchannel 9, a jet spoiler block 8 is arranged in the I cavity 1, the exhaust port 5 is arranged on the top of the cavity, the four cavities are separated by three partitions in the middle, and there are two cover plates on the outside, each cavity has a sealing groove around it, and a sealing ring is installed, which can be completely sealed after closing with the cover plate; the partition plate and the cover plate are both equipped with a temperature control U-shaped pipe 6.

[0025] The method of reaction molding using the above mold comprises the following steps:

[0026] 1) After the four mold cavities and the cover plate are closed, nitrogen is used for purging and replacement. Before feeding, the mold is preheated with hot water through the temperature-controlled U-shaped pipe 6 on the partition plate and the cover plate. The preheating temperature is 30~50℃;

[0027] 2) The raw material contains dicyclopentadiene, a catalyst, a solvent and a modifying additive. The raw material is divided into two streams, A and B, which enter the microchannel 9 through the feed port 10, are mixed in the microchannel and fed, and pass through the jet spoiler block 8 to form a mixed flow in the first cavity to achieve a sufficient mixing effect;

[0028] 3) The raw material enters from the lower part of the first mold cavity. When the feed amount reaches 1 / 4 of the first mold cavity, it starts to enter the second mold cavity. When the raw material reaches 1 / 2 of the height of the first and second mold cavities, it starts to enter the third mold cavity, ..., when the raw material reaches 3 / 4 of the height of the first three mold cavities, it starts to enter the fourth mold cavity. At this time, the four mold cavities are fed at the same time. During the feeding process, the upper parts of the four mold cavities are connected and communicated with the exhaust port 5. The air is exhausted from the exhaust port 5 at the top of the mold cavity. When the mold cavities are full, the feeding is stopped and the feeding valve is closed;

[0029] 4) Raise the mold cavity temperature to 60°C for 2 hours of reaction to form, and then raise the temperature to 120°C for 1 hour of post-treatment. After the reaction is completed, pass the cooling medium through the temperature-controlled U-shaped pipe, and demould after cooling.

[0030] Experiments show that the present invention can prepare multiple polydicyclopentadiene products at the same time, thereby improving production efficiency, enhancing product uniformity, and improving product performance.

Claims

1. A method for reaction injection molding using a molding mold for reaction injection of polydicyclopentadiene, characterized in that: The mold comprises N mold cavities, namely the first mold cavity, the second mold cavity, the third mold cavity, ..., the Nth mold cavity, and two adjacent mold cavities are connected by an inter-cavity channel (7). The inter-cavity channel between the first mold cavity (1) and the second mold cavity is arranged at the 1 / N position of the mold cavity height, the inter-cavity channel between the second mold cavity and the third mold cavity is arranged at the 2 / N position of the mold cavity height, ..., the inter-cavity channel between the N-1th mold cavity and the Nth mold cavity is arranged at the (N-1) / N position of the mold cavity height, and the feed port (10) is arranged at the bottom of the first mold cavity (1), and the feed port ( 10) entering the first mold cavity (1) through the microchannel (9), a jet spoiler block (8) is also provided at the lower part of the first mold cavity (1), an exhaust port (5) is arranged on the top of the mold cavity, N mold cavities are separated by N-1 partitions, two cover plates are arranged outside, each mold cavity has a sealing groove around it, and a sealing ring (11) is installed. After closing with the cover plate, the upper end of all the mold cavities is connected to the exhaust port, the partition plate and the cover plate are both equipped with a temperature control U-shaped pipe (6), and N is a positive integer greater than 2; the method comprises the following steps: 1) After the N mold cavities and the cover plate are closed, nitrogen is used for purging and replacement. Before feeding, the mold is preheated by heating the medium through the temperature-controlled U-shaped pipe on the partition and the cover plate. The preheating temperature is 30~50℃; 2) The raw material contains dicyclopentadiene, a catalyst, a solvent and a modifying additive. The raw material is divided into two streams, A and B, which enter the microchannel (9) through a feed port (10), are mixed and fed through the microchannel (9), and pass through a jet flow block (8) to form a mixed flow in the first mold cavity, thereby achieving a sufficient mixing effect; 3) The raw material enters from the lower part of the first mold cavity. When the feed amount reaches 1 / N of the height of the first mold cavity, it starts to enter the second mold cavity. When the raw material reaches 2 / N of the height of the first and second mold cavities, it starts to enter the third mold cavity, ..., when the raw material reaches (N-1) / N of the height of the first N-1 mold cavities, it starts to enter the Nth mold cavity. At this time, the N mold cavities are fed at the same time. During the feeding process, the upper ends of the N mold cavities are connected to the exhaust port (5), and the air is exhausted from the exhaust port (5) at the top of the mold cavity. When all the mold cavities are full, the feeding is stopped and the feeding valve is closed; 4) Raising the temperature of the mold cavity to 40°C to 80°C for 1 to 2 hours of reaction to form the mold, and then raising the temperature to 120°C to 150°C for post-treatment for 1 to 2 hours. After the reaction is completed, a cooling medium is passed through the temperature-controlled U-shaped pipe (6) to release the mold after cooling.

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