Process for manufacturing polyurethane double-color mold

Abstract

The technology comprises the following steps that firstly, a female die 1 and a female die 2 need to be manufactured, the female die 1 is provided with a corresponding product 1, the female die 2 is provided with a whole corresponding to the product 1 and the product 2, real-time machining is carried out through CNC according to the size specification and the shape standard of a 2D or 3D drawing, and then the product 1 and the product 2 are manufactured; according to a polyurethane product formed by two materials, only one bottom mold and two upper molds are manufactured by utilizing a silica gel mold copying process, the bottom mold and the upper mold 1 are firstly used for manufacturing a product 1, the product 1 does not need to be taken out, the upper mold 2 is directly replaced, and an adhesive and a release agent are not brushed, so that the production process is simple, and the production cost is low. The characteristic that the product 1 is just cured but not completely vulcanized is utilized, the material 2 is directly poured, and the finished product is taken out for vulcanization after the material 2 is cured, so that the two materials are crosslinked more tightly, the connection strength and the flash condition are obviously improved, and the mold manufacturing cost is effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane two-color mold processing, in particular to a process for manufacturing a polyurethane two-color mold. Background Art

[0002] Polyurethane is the abbreviation of polyurethane, which is a polymer material. Polyurethane is an emerging organic polymer material, known as the "fifth plastic". It is widely used in many fields of the national economy due to its excellent performance. For polyurethane products composed of two materials, they are divided into material 1 and material 2. The material 1 alone is called product 1, and the material 2 is called product 2. The original plan is generally to first make a metal mold 1 of one material, produce product 1, and then make another set of metal molds 2, brush adhesive on the contact surface of the two materials of product 1, brush release agent on the non-contact surface, put into mold 2 and cast the second material to obtain product 2.

[0003] At present, this method requires the separate production of two sets of metal molds, resulting in high mold manufacturing costs, a long mold manufacturing cycle, and greater difficulty in operation during production, which also leads to high labor costs. In addition, the finished products have serious flash and are extremely difficult to clean, which greatly increases labor hours and reduces the overall production efficiency and product quality. Summary of the invention

[0004] The purpose of the present invention is to provide a process for making a polyurethane two-color mold to solve the problem proposed in the above background technology that the current method requires two sets of metal molds to be made separately, resulting in high mold manufacturing costs, a long mold manufacturing cycle, and greater difficulty in operation during production, which also leads to high labor costs. In addition, the finished products have serious flash and are extremely difficult to clean, which greatly increases labor hours and reduces the overall production efficiency and product quality.

[0005] To achieve the above object, the present invention provides the following technical solution: a process for making a polyurethane two-color mold, characterized in that the process comprises the following steps:

[0006] S1. First, it is necessary to make a master mold 1 and a master mold 2, and the master mold 1 has the corresponding product 1 and the master mold 2 has the corresponding product 1 and 2 as a whole, and according to the size specifications and shape standards of the 2D or 3D drawings, real-time processing is performed by CNC, and then laser rapid prototyping is performed by SLA or a 3D printing device is used to produce a prototype of the master mold.

[0007] S2. Secondly, a silicone bottom mold and a silicone upper mold 1 need to be made. To make the silicone bottom mold and the silicone upper mold 1, a mold frame, a runner and an exhaust are required, as well as a fixed mother mold 1. The A and B materials are mixed in a ratio of 1:1 to prepare liquid silicone. After stirring evenly, vacuum degassing is performed, and then the silicone bottom mold and the silicone upper mold 1 are cast. After being kept at a certain room temperature for a period of time for curing, the molds are separated using a parting knife and a separation pliers.

[0008] S3. Then, the silicone upper mold 2 needs to be made, the mother mold 2 is placed into the silicone bottom mold, and the silicone bottom mold is coated with a mold release agent. Then, the A and B materials are mixed in a ratio of 1:1 to prepare liquid silicone, and after stirring evenly, vacuum degassing is performed, and the silicone upper mold 2 is poured. After being kept at a certain room temperature for a period of time to solidify, the mold is separated using a mold separation knife and separation pliers.

[0009] S4. Finally, product 1 and product 2 need to be manufactured. The prepared silicone bottom mold and silicone upper mold 1 are used for assembly. After assembly, they are fixed with high-temperature tape and placed in an oven and heated to a certain temperature. The polyurethane material 1 is poured and placed in an oven. After pouring, the polyurethane material 1 is poured and placed in an oven. After baking for a period of time, the polyurethane material 2 is cured. The silicone upper mold 1 is replaced with the silicone upper mold 2, which is placed in an oven and heated to a certain temperature. The polyurethane material 2 is poured and placed in an oven. After baking for a period of time, the polyurethane material 2 is cured and taken out. After taking out, the polyurethane material 2 needs to be vulcanized, that is, after taking out the finished product, a certain temperature is maintained for oven vulcanization for a period of time. After the vulcanization is completed, the product can be trimmed and polished to finally obtain a complete finished product.

[0010] Preferably, the casting silicone bottom mold, silicone upper mold and casting silicone upper mold need to be maintained at a room temperature of 25° C., and the curing process of the casting silicone bottom mold, silicone upper mold and casting silicone upper mold requires 3-4 hours.

[0011] Preferably, the temperature of the assembled silicone bottom mold and silicone upper mold 1 put into the oven for baking and the silicone upper mold 1 replacing the silicone upper mold 2 put into the oven for baking both need to be heated to 80°C-100°C, and the curing time of the poured polyurethane material 1 and the poured polyurethane material 2 both need to be 1 hour.

[0012] Preferably, the temperature of the finished product during oven vulcanization should be maintained at 80° C.-100° C., and the time for the finished product during oven vulcanization should be maintained at 12 hours.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: the scheme of the present invention can be used for polyurethane products composed of two materials, and only one bottom mold and two upper molds, namely, upper mold 1 and upper mold 2, are manufactured by utilizing the process of silicone mold replication. The bottom mold and upper mold 1 are used to manufacture product 1 first, and the upper mold 2 can be directly replaced without taking them out, and adhesive and release agent are not applied. By utilizing the characteristics that product 1 has just been cured and has not been completely vulcanized, material 2 can be directly poured, and the finished product can be taken out and vulcanized after it is cured, so that the two materials are more closely cross-linked to ensure their connection strength. In addition, due to the good fit of the silicone mold, the flash condition is significantly improved, which effectively reduces the cost of mold manufacturing, greatly simplifies the production process, and further reduces the cost of subsequent processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of the components of the silicone upper mold 1 of the present invention;

[0015] Figure 2 It is a schematic diagram of the structure of the components of the silicone upper mold 2 of the present invention.

[0016] In the figure: 1. Silicone bottom mold; 2. Bottom mold discharge channel; 3. Bottom mold feed channel; 4. Product 1; 5. Silicone upper mold 1; 6. Product 2; 7. Silicone upper mold 2 discharge channel; 8. Silicone upper mold 2 feed channel; 9. Silicone upper mold 2. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Embodiment 1:

[0019] The process of this embodiment includes the following steps:

[0020] S1. First, it is necessary to make a master mold 1 and a master mold 2, and the master mold 1 has the corresponding product 1 and the master mold 2 has the corresponding product 1 and 2 as a whole, and according to the size specifications and shape standards of the 2D or 3D drawings, real-time processing is performed by CNC, and then laser rapid prototyping is performed by SLA or a 3D printing device is used to produce a prototype of the master mold.

[0021] S2. Secondly, a silicone bottom mold and a silicone upper mold 1 need to be made. To make the silicone bottom mold and the silicone upper mold 1, a mold frame, a runner and an exhaust are required, as well as a fixed mother mold 1. The A and B materials are mixed in a ratio of 1:1 to prepare liquid silicone. After stirring evenly, vacuum degassing is performed, and then the silicone bottom mold and the silicone upper mold 1 are cast. After being kept at a certain room temperature for a period of time for curing, the molds are separated using a parting knife and a separation pliers.

[0022] S3. Then, the silicone upper mold 2 needs to be made, the mother mold 2 is placed into the silicone bottom mold, and the silicone bottom mold is coated with a mold release agent. Then, the A and B materials are mixed in a ratio of 1:1 to prepare liquid silicone, and after stirring evenly, vacuum degassing is performed, and the silicone upper mold 2 is poured. After being kept at a certain room temperature for a period of time to solidify, the mold is separated using a mold separation knife and separation pliers.

[0023] S4. Finally, product 1 and product 2 need to be manufactured. The prepared silicone bottom mold and silicone upper mold 1 are used for assembly. After assembly, they are fixed with high-temperature tape and placed in an oven to be heated to a certain temperature. The polyurethane material 1 is poured and placed in an oven after pouring. After baking for a period of time, the polyurethane material 1 is solidified. The product 1 is kept unchanged. The silicone upper mold 1 is replaced with the silicone upper mold 2, which is placed in an oven and heated to a certain temperature. The polyurethane material 2 is poured and placed in an oven after pouring. After baking for a period of time, the polyurethane material 2 is solidified and taken out. After taking out, the polyurethane material 2 needs to be vulcanized. That is, after taking out the finished product, a certain temperature is maintained for oven vulcanization for a period of time. After the vulcanization is completed, the product can be trimmed and polished to finally obtain a complete finished product. For polyurethane products composed of two materials, the silicone mold-replicating process can be used to make only one bottom mold and two upper molds, namely upper mold 1 and upper mold 2. First, use the bottom mold and upper mold 1 to make product 1, and there is no need to take them out. Just replace the upper mold 2 without brushing adhesive and release agent. Taking advantage of the fact that product 1 has just been cured and has not been completely vulcanized, directly pour material 2, and take out the finished product after it is cured for vulcanization, so that the two materials are cross-linked more closely to ensure their connection strength. In addition, due to the good fit of the silicone mold, the flash situation is significantly improved, which effectively reduces the cost of mold manufacturing.

[0024] In this embodiment, the casting silicone bottom mold, the silicone upper mold and the casting silicone upper mold need to be kept at a normal temperature of 25° C., and the curing process of the casting silicone bottom mold, the silicone upper mold and the casting silicone upper mold takes 3-4 hours.

[0025] In this embodiment, the temperature of the assembled silicone bottom mold and the silicone upper mold 1 and the silicone upper mold 2 being put into the oven for baking needs to be heated to 80°C-100°C, and the curing time of the poured polyurethane material 1 and the poured polyurethane material 2 both needs to be 1 hour, which can achieve a better baking effect and avoid insufficient temperature and time resulting in insufficient curing affecting the quality of the finished product.

[0026] In this embodiment, the temperature of the finished product for oven vulcanization should be maintained at 80°C-100°C, and the time of the finished product for oven vulcanization should be maintained at 12 hours, which can optimize the time and temperature of the vulcanization treatment and effectively improve the overall effect and efficiency of the vulcanization treatment.

[0027] Embodiment 2:

[0028] The difference from the first embodiment is that:

[0029] The process of this embodiment includes the following steps:

[0030] S1. First, it is necessary to make a master mold 1 and a master mold 2, and the master mold 1 has the corresponding product 1 and the master mold 2 has the corresponding product 1 and 2 as a whole, and according to the size specifications and shape standards of the 2D or 3D drawings, real-time processing is performed by CNC, and then laser rapid prototyping is performed by SLA or a 3D printing device is used to produce a prototype of the master mold.

[0031] S2. Secondly, a silicone bottom mold and a silicone upper mold 1 need to be made. To make the silicone bottom mold and the silicone upper mold 1, a mold frame, a runner and an exhaust are required, as well as a fixed mother mold 1. The A and B materials are mixed in a ratio of 1:1 to prepare liquid silicone. After stirring evenly, vacuum degassing is performed, and then the silicone bottom mold and the silicone upper mold 1 are cast. After being kept at a certain room temperature for a period of time for curing, the molds are separated using a parting knife and a separation pliers.

[0032] S3. Then, the silicone upper mold 2 needs to be made, the mother mold 2 is placed into the silicone bottom mold, and the silicone bottom mold is coated with a mold release agent. Then, the A and B materials are mixed in a ratio of 1:1 to prepare liquid silicone, and after stirring evenly, vacuum degassing is performed, and the silicone upper mold 2 is poured. After being kept at a certain room temperature for a period of time to solidify, the mold is separated using a mold separation knife and separation pliers.

[0033] S4. Finally, product 1 and product 2 need to be manufactured. The prepared silicone bottom mold and silicone upper mold 1 are used for assembly. After assembly, they are fixed with high-temperature tape and placed in an oven and heated to a certain temperature. The polyurethane material 1 is poured and placed in an oven. After pouring, the polyurethane material 1 is poured and placed in an oven. After baking for a period of time, the polyurethane material 2 is cured. The silicone upper mold 1 is replaced with the silicone upper mold 2, which is placed in an oven and heated to a certain temperature. The polyurethane material 2 is poured and placed in an oven. After baking for a period of time, the polyurethane material 2 is cured and taken out. After taking out, the polyurethane material 2 needs to be vulcanized, that is, after taking out the finished product, a certain temperature is maintained for oven vulcanization for a period of time. After the vulcanization is completed, the product can be trimmed and polished to finally obtain a complete finished product.

[0034] In this embodiment, the casting silicone bottom mold, the silicone upper mold and the casting silicone upper mold need to be kept at a normal temperature of 15° C., and the curing process of the casting silicone bottom mold, the silicone upper mold and the casting silicone upper mold takes 1-2 hours.

[0035] In this embodiment, the temperature of the assembled silicone bottom mold and the silicone upper mold 1 and the silicone upper mold 2 being put into the oven for baking needs to be heated to 40°C-70°C, and the curing time of the poured polyurethane material 1 and the poured polyurethane material 2 both needs 0.5 hours.

[0036] In this embodiment, the temperature of the finished product during oven vulcanization should be maintained at 40° C.-70° C., and the time of the finished product during oven vulcanization should be maintained at 8 hours.

[0037] Embodiment three:

[0038] The difference between the first embodiment and the second embodiment is that:

[0039] The process of this embodiment includes the following steps:

[0040] S1. First, it is necessary to make a master mold 1 and a master mold 2, and the master mold 1 has the corresponding product 1 and the master mold 2 has the corresponding product 1 and 2 as a whole, and according to the size specifications and shape standards of the 2D or 3D drawings, real-time processing is performed by CNC, and then laser rapid prototyping is performed by SLA or a 3D printing device is used to produce a prototype of the master mold.

[0041] S2. Secondly, a silicone bottom mold and a silicone upper mold 1 need to be made. To make the silicone bottom mold and the silicone upper mold 1, a mold frame, a runner and an exhaust are required, as well as a fixed mother mold 1. The A and B materials are mixed in a ratio of 1:1 to prepare liquid silicone. After stirring evenly, vacuum degassing is performed, and then the silicone bottom mold and the silicone upper mold 1 are cast. After being kept at a certain room temperature for a period of time for curing, the molds are separated using a parting knife and a separation pliers.

[0042] S3. Then, the silicone upper mold 2 needs to be made, the mother mold 2 is placed into the silicone bottom mold, and the silicone bottom mold is coated with a mold release agent. Then, the A and B materials are mixed in a ratio of 1:1 to prepare liquid silicone, and after stirring evenly, vacuum degassing is performed, and the silicone upper mold 2 is poured. After being kept at a certain room temperature for a period of time to solidify, the mold is separated using a mold separation knife and separation pliers.

[0043] S4. Finally, product 1 and product 2 need to be manufactured. The prepared silicone bottom mold and silicone upper mold 1 are used for assembly. After assembly, they are fixed with high-temperature tape and placed in an oven and heated to a certain temperature. The polyurethane material 1 is poured and placed in an oven. After pouring, the polyurethane material 1 is poured and placed in an oven. After baking for a period of time, the polyurethane material 2 is cured. The silicone upper mold 1 is replaced with the silicone upper mold 2, which is placed in an oven and heated to a certain temperature. The polyurethane material 2 is poured and placed in an oven. After baking for a period of time, the polyurethane material 2 is cured and taken out. After taking out, the polyurethane material 2 needs to be vulcanized, that is, after taking out the finished product, a certain temperature is maintained for oven vulcanization for a period of time. After the vulcanization is completed, the product can be trimmed and polished to finally obtain a complete finished product.

[0044] In this embodiment, the casting silicone bottom mold, the silicone upper mold and the casting silicone upper mold need to be kept at a normal temperature of 50°C, and the curing process of the casting silicone bottom mold, the silicone upper mold and the casting silicone upper mold takes 6-8 hours.

[0045] In this embodiment, the temperature of the assembled silicone bottom mold and the silicone upper mold 1 and the silicone upper mold 2 being put into the oven for baking needs to be heated to 110°C-150°C, and the curing time of the poured polyurethane material 1 and the poured polyurethane material 2 both needs to be 2 hours.

[0046] In this embodiment, the temperature of the finished product during oven vulcanization should be maintained at 110° C.-150° C., and the time of the finished product during oven vulcanization should be maintained at 15 hours.

[0047] In summary: the results of the present invention in Example 1 of the present invention show that, compared with the process results in Example 2 and Example 3, the present invention can be used for a polyurethane product composed of two materials, and only one bottom mold and two upper molds, namely upper mold 1 and upper mold 2, are made by using the process of silicone mold replication. The product 1 is first made with the bottom mold and the upper mold 1, and there is no need to take them out, and the upper mold 2 is directly replaced without brushing adhesive and release agent. The material 2 is directly poured by taking advantage of the fact that the product 1 has just been cured and has not been completely vulcanized. After it is cured, the finished product is taken out and vulcanized, so that the two materials are cross-linked more closely to ensure their connection strength. In addition, due to the good fit of the silicone mold, the flash situation is significantly improved, which effectively reduces the cost of mold manufacturing. Therefore, the effect of the present invention is better than that of Example 2 and Example 3.

[0048] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for making a polyurethane two-color mold, characterized in that: The process includes the following steps: S1. First, it is necessary to make a master mold 1 and a master mold 2. The master mold 1 has the corresponding product 1 and the master mold 2 has the corresponding product 1 and 2 as a whole. According to the size specifications and shape standards of the 2D or 3D drawings, the CNC is used for real-time processing, and then the SLA is used for laser rapid prototyping or the 3D printing equipment is used to produce the prototype of the master mold; S2. Secondly, a silicone bottom mold and a silicone upper mold 1 need to be made. To make the silicone bottom mold and the silicone upper mold 1, a mold frame, a runner and an exhaust are required, as well as a fixed mother mold 1. A and B materials are mixed in a ratio of 1:1 to prepare liquid silicone. After stirring evenly, vacuum degassing is performed, and then the silicone bottom mold and the silicone upper mold 1 are cast. After being placed under a certain normal temperature environment for a period of time for curing, the molds are separated using a mold separation knife and a separation pliers. S3. Then, the silicone upper mold 2 needs to be made, the mother mold 2 is placed in the silicone bottom mold, and the silicone bottom mold is rubbed with a mold release agent, and then the A and B materials are mixed in a ratio of 1:1 to prepare liquid silicone, and after stirring evenly, vacuum degassing is performed, and the silicone upper mold 2 is poured, and it needs to be placed under a certain room temperature environment for a period of time for curing, and then the mold is separated using a mold separation knife and a separation pliers; S4. Finally, product 1 and product 2 need to be manufactured. The prepared silicone bottom mold and silicone upper mold 1 are used for assembly. After assembly, they are fixed with high-temperature tape and placed in an oven and heated to a certain temperature. The polyurethane material 1 is poured and placed in an oven. After pouring, the polyurethane material 1 is poured and placed in an oven. After baking for a period of time, the polyurethane material 2 is cured. The silicone upper mold 1 is replaced with the silicone upper mold 2, which is placed in an oven and heated to a certain temperature. The polyurethane material 2 is poured and placed in an oven. After baking for a period of time, the polyurethane material 2 is cured and taken out. After taking out, the polyurethane material 2 needs to be vulcanized, that is, after taking out the finished product, a certain temperature is maintained for oven vulcanization for a period of time. After the vulcanization is completed, the product can be trimmed and polished to finally obtain a complete finished product.

2. A process for making a polyurethane two-color mold according to claim 1, characterized in that: The casting silicone bottom mold, silicone upper mold and casting silicone upper mold need to be kept at a normal temperature of 25° C., and the curing process of the casting silicone bottom mold, silicone upper mold and casting silicone upper mold requires 3-4 hours.

3. A process for making a polyurethane two-color mold according to claim 1, characterized in that: The temperature of the assembled silicone bottom mold and the silicone upper mold 1 put into the oven for baking and the silicone upper mold 1 replacing the silicone upper mold 2 put into the oven for baking both need to be heated to 80°C-100°C, and the curing time of the poured polyurethane material 1 and the poured polyurethane material 2 both need 1 hour.

4. A process for making a polyurethane two-color mold according to claim 1, characterized in that: The temperature of the finished product during oven vulcanization should be maintained at 80°C-100°C, and the time of the finished product during oven vulcanization should be maintained at 12 hours.

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