Epoxy resin mold, also known as resin mold, has a short manufacturing cycle, low cost, especially suitable for products with complex shapes and rapid product replacement in industrial fields; therefore, it has been widely used in foreign advanced countries, especially in the automotive manufacturing industry, toy manufacturing, home appliance manufacturing, hardware industry and plastic products and other industrial systems are used more popular. Epoxy resin mold according to the different structure and use, using a variety of properties of epoxy resin, curing agent, toughening agent and filler (iron powder, aluminum powder, silicon powder, barite powder, etc.) and other mold resin, while the glass fiber cloth and carbon fiber cloth for reinforcing materials and made.
Epoxy resin molds can be designed with different epoxy mold resin formula components according to different uses and technical requirements. From domestic and foreign epoxy resin mold practical application statistics, epoxy resin is suitable for making the following types of molds, in cold pressing molds: bending mold, drawing mold, drop hammer mold, casting mold, etc.; in hot pressing molds: plastic injection mold, wax injection mold, blow molding mold, suction molding mold, foam molding mold, leather molding mold, etc. The manufacturing characteristics of epoxy resin mold are simple, fast and low cost; for example, some metal molds with complicated shape and difficult to form can be made by epoxy resin, using casting method or low-pressure forming method, which can be formed in one time without large precision cutting machine tools and senior clampers. The cycle of some metal molds is several months to half a year, but the epoxy resin molds can be finished in 3-5 days, and the cost is only about 15-20% of steel molds, and the service life of resin molds is long, and it can be repaired quickly and continue to use. Therefore, the manufacture of epoxy resin mold is a new technology, new material and new process that breaks the traditional mechanical processing process. Epoxy resin mold, in foreign countries are large factories set up special development center manufacturing, and in the country only in the national defense industry unit developed some, general factory enterprises are lack of manufacturing technology and formula, so in our country ring resin mold application, popularization and development of the speed is very slow. In the future, with the development of new materials and new technology, the promotion of epoxy resin application technology, the comprehensive performance and manufacturing technology of epoxy resin mold is widely used and recognized, the improvement of the performance of epoxy resin composite material, the simplification of the production process and application process of resin mold, epoxy resin mold will certainly be developed by leaps and bounds, and become a new high-efficiency and low-cost advanced mold.
Types of epoxy resin molds
1) Epoxy resin cold pressing type molds
1) Bending mold, forming mold, stretching mold, notching mold, etc.
The composite material section of epoxy resin is mainly used to make concave and convex molds, which can be cast and formed or formed by low-pressure molding method, and it can be pressed or drawn for 0.8 mm steel plate of 2 mm or less aluminum plate, and the life span is more than 10,000 times without wear. For large drawing molds, such as automobile cab roof parts, making molds with epoxy resin shows greater superiority without large cutting machines. Notching dies are used to make large parts with complex structure, and steel strips are embedded in the edge of the concave and convex dies. The bending and forming molds made of epoxy resin are used for stamping other parts, such as the blades of ceiling fans, which have high requirements for the size of the blade surface, as it is related to the air volume and the use effect, etc. The epoxy resin molds are fixed on the 100-ton punching machine for stamping and forming, and the number of stampings has reached more than 300,000 times, and the resin molds are still in use.
2) Drop hammer die
Adopting epoxy resin drop hammer die, it can press 2.5mm thick aluminum plate and 1.5mm thick stainless-steel plate. The mold made of resin has good coordination performance, simple process and short manufacturing cycle, which can shorten 3/4 time than aluminum and zinc mold, and also can save a lot of non-ferrous metal and reduce cost.
3) Casting mold
Regarding cast molds such as models, core boxes, type plates, etc., the advantages of using epoxy resin to make cast molds are.
Short manufacturing cycle of resin molds, such as the manufacturing cycle of aluminum molds is about one month, while the making of resin molds only takes 3 to 5 days.
Long service life of resin mold, such as aluminum molds need to be overhauled for 2,000 times, but resin molds can be used for 20,000 times.
Resin mold is simple and convenient to repair.
resin mold light weight, high labor productivity.
Therefore, it is common and widely used in the country and abroad to make casting molds with epoxy resin. Structure form: there are resin package compound mold and all resin whole type mold.
In addition, epoxy resin can also make hammering mold, explosion forming mold, hydraulic forming mold, stretching mold, shifting mold, inspection mold, etc. Most of the above resin molds are used to make aircraft, automobile or rocket parts. Epoxy resin mold manufacturing speed, low cost, good coordination performance, can solve the general metal mold manufacturing in the technical difficulties.
Epoxy resin hot pressing type of mold
1) Wax injection mold
The mold used for pressing and injecting wax type is generally made of metal, and the plaster mold is also used for small batch and low requirement. The wax mold is first used to inject the wax pattern, and then the shell mold is made according to the wax pattern, and the metal is poured after the wax is dissolved. Resin wax injection mold, high strength, easy molding, high finish, good wear resistance, thermal conductivity is slightly worse, in the processing of molding sculpture type surface, the economic efficiency is higher.
2) Plastic injection mold
With the leap development of engineering plastics and the wide range of applications, plastic mold manufacturing, it is more obvious importance. Epoxy resin injection mold is a new technology that is trying to break through at home and abroad. According to the information, epoxy resin injection mold abroad as a simple, fast mold, because it is fast molding, precise shape, but the disadvantage is poor heat resistance, therefore, in the resin mold design should consider cooling water piping, to improve the number of injection. China also has several units in the development of this type of resin mold, and has achieved good application, the number of injection molding has reached more than 10,000 times, epoxy resin mold surface no change. In the resin mold formula design optimization and mold structure improvement, so that the resin mold thermal state strength, thermal conductivity have a high level. Therefore, if the product type surface is sculpted type surface, machine processing simply can not be processed, it is more obvious the superiority of epoxy resin mold.
3) Blow molding mold and blister mold
These molds all require the epoxy resin formula curing material to have good thermal state strength and thermal conductivity, its biggest advantage is the convenience of forming, these resin molds are in the development of applications.
Materials and properties for manufacturing epoxy resin molds
The base resins for manufacturing resin molds are phenolic resin, unsaturated polyester resin, epoxy resin and so on. Among these matrix resins, epoxy resin has the best mechanical and physical properties and good processability. So now all use epoxy resin to make moulds, such as the highest strength composite material, which is made of epoxy resin and boron fiber, carbon fiber, etc.
Matrix resin: commonly used epoxy resins are bisphenol A epoxy resin, such as; YD-128, E-51, E-44, etc.; linear phenolic epoxy resin F-44 and F-45; amino multifunctional group epoxy resin AFG-80, AFG-90; alicyclic epoxy resin R-122, etc. According to the mechanical strength requirements, heat resistance requirements and precision requirements of different resin molds, choose the type of base resin and then design the formula.
Curing agents: amine curing agents: aliphatic amines, condensed amines, aromatic amines, modified aromatic amines, etc.
Imidazole-type curing agent: 2-methylimidazole, modified imidazole, 2-ethyl-4-methylimidazole, etc.
Acid anhydride type curing agent: methyl tetrahydro phthalic anhydride, modified methyl tetrahydro phthalic anhydride, chloro-bridged anhydride, homothallic dianhydride, etc.
Toughening agent: LDY-050 active toughening agent, LDY-052 reactive toughening agent, LDY-055 island structure toughening agent, high polymerization polysulfide rubber, terminal carboxyl butadiene rubber, etc.
Fiber reinforced materials: glass fiber (cloth), carbon fiber (cloth), boron fiber (cloth), etc.
Fillers: silicon micronized powder, iron powder, aluminum powder, copper powder, alumina powder, barite powder, etc.
Epoxy resin mold composite material, is composed of matrix resin, curing agent, toughening agent, filler and fiber reinforcing material, etc., to start the curing reaction and achieve high performance mold resin. According to the different structure and technical requirements of different molds, design different formulations, the formulation is different, its forming process, curing process is also different.
Epoxy resin mold formula casting body typical mechanical and physical properties.
1) Compressive strength: 120～150MPa
2) Impact strength: 25～38KJ/m2
3) Flexural strength: 110～160MPa
4) Brinell hardness: 20～30MPa
5) Shrinkage during curing 0.2～0.5%
Process method of manufacturing epoxy resin mold
1) Pouring process manufacturing
Weighing and mixing according to the proportion of epoxy resin formula, then pouring into the model mold and curing at room temperature or high temperature according to the requirements of the formula process. Vibration casting process can also be adopted.
2) Made by lamination process
Glass fiber or carbon fiber reinforced epoxy resin mold, in the curing without pressure, in the model laminated fiber reinforced material and layer by layer coated with epoxy resin mixture, known as contact lamination process. Curing, such as under pressure, can increase the glass fiber content, called pressurized lamination process.
3) short glass fiber reinforced with resin mixture, able to be formed in a simple metal mold.
In short, different molds, according to the structure of the mold, the type of mold, the technical requirements of the mold to design different epoxy resin formula and manufacturing process, in order to create a good epoxy resin mold.
More information about epoxy resin applications in mold, please contact us via email: sales@yqxpolymer.com, or voice to us at: +86-28-8411-1861. Some pictures and texts are reproduced from the Internet, and the copyright belongs to the original author. If there is any infringement, please contact us to delete.
