How to select materials for plastic moulds
Today, with the rapid development of high-tech in the world, a variety of electronic products are overwhelming. And all kinds of electronic products can not be produced without plastic mold. Here we talk about how to choose the material of plastic mold.
Internal mold: mainly refers to mold core, slider, lifter, insert, etc. For plastic mold without any requirements, 45 # steel and 50 # steel materials are generally used; P20 pre hardening plastic die steel is generally selected for ordinary requirements; 718 super pre hardening plastic mould steel must be selected for the plastic mould inner parts with high requirements; For precision plastic molds with very strict requirements, 738 (4Cr2NiMnMo national standard) steel should be selected; If customers have a demand for polishing the plastic mold to mirror luster, most plastic mold factories will choose NAK80 mirror plastic mold steel; In the process of using plastic molds to produce plastic products, corrosive gases will sometimes be generated. At this time, we need to choose corrosion-resistant mold steel for production, such as M300 corrosion-resistant steel.
Mold base: generally, the minimum required mold base is also made of 45 # steel; The most commonly used mold base materials are 50 # steel; For plastic mold base with certain requirements, 55 # mold steel will be selected; GS638 (P20 American standard GS638 German standard 42CrMo national standard) die steel should be selected for the most exquisite plastic mold, which can meet the requirements for use.
Guide post: 1, 20 # (S20C) or 20Mn2B (SMn420), treatment: carburizing and quenching, hardness after treatment is greater than 55HRC 2, T8A, T10A, treatment: surface quenching, hardness after treatment is less than 55HRC 3, 45 # treatment: tempering, surface quenching, low temperature tempering, hardness after treatment is greater than 55HRC
Guide sleeve: Most plastic mold factories use H62 brass or bronze alloy to make guide sleeve.
Bushing: Most mold factories choose 45 #, 50 # and 55 # bushings. Treatment: surface quenching, hardness greater than 55HRC.
Push rod, thimble, draw bar: T8, T8A, T10, T10A Treatment: quenching, low temperature tempering, hardness greater than 55HRC 45 #, 50 #, 55 # Treatment: quenching, hardness greater than 45HRC.
All kinds of plate materials: General plastic mold factories choose to use 45 #, 50 #, 40Cr (quenched and tempered) and structural steel Q235~Q275. If large plates need to be produced, ductile iron can be used instead.
Selecting the right materials for plastic moulds is critical to ensuring the quality, durability, and longevity of the mould. There are several factors to consider when choosing materials for plastic moulds, including the type of plastic being used, the design of the mould, and the expected production volume. Here are some tips on how to select materials for plastic moulds:
- Determine the type of plastic: The type of plastic being used is a key factor in selecting the right materials for the mould. Different plastics have different properties, such as melting point, shrinkage rate, and viscosity, which will impact the mould design and material selection.
- Consider the mould design: The design of the mould is also important in selecting the right materials. The mould must be able to withstand the high temperatures and pressures of the injection molding process without deforming or warping. The design should also allow for easy removal of the finished product from the mould.
- Determine the expected production volume: The expected production volume is also an important factor in material selection. For high-volume production, materials that can withstand the wear and tear of constant use are needed, while for low-volume production, materials that are less durable but still effective may be sufficient.
- Consider the cost: The cost of the material is also a factor to consider. Materials that are more expensive may offer better performance, but they may not be cost-effective for lower volume production runs.
- Look for materials with high thermal conductivity: Materials with high thermal conductivity can help to reduce the cycle time and increase the production speed, making the manufacturing process more efficient.
- Consider the surface finish: The surface finish of the mould can impact the final product's quality. Choosing materials with the appropriate surface finish can help to reduce defects and improve the overall quality of the finished product.
In conclusion, selecting the right materials for plastic moulds is crucial to achieving high-quality and efficient production. By considering the type of plastic being used, the mould design, the expected production volume, cost, thermal conductivity, and surface finish, manufacturers can choose materials that will ensure the durability, longevity, and overall quality of the mould.
