塑料模具材料要求
塑料模具材料要求
Requirements for Plastic Mould Materials
塑料模具的工作條件與冷沖模不同,一般須在150°C-200°C下進行工作,除了受到一定壓力作用外,還要承受溫度影響?,F根據塑料成型模具使用條件、加工方法的不同將塑料模具用鋼的基本性能要求大致歸納如下:
The working condition of plastic die is different from that of cold punching die. Generally, it must work under 150 C - 200 C. Besides being subjected to certain pressure, it must also bear the influence of temperature. The basic performance requirements of steel for plastic moulds are summarized as follows according to the different working conditions and processing methods of plastic moulds.
1、足夠的表面硬度和耐磨性
1. Adequate surface hardness and wear resistance
塑料模的硬度通常在50-60HRC以下,經過熱處理的模具應有足夠的表面硬度,以保證模具有足夠的剛度。模具在工作中由于塑料的填充和流動要承受較大的壓應力和摩擦力,要求模具保持形狀的精度和尺寸精度的穩定性,保證模具有足夠的使用壽命。模具的耐磨性取決于鋼材的化學成分和熱處理硬度,因此提高模具的硬度有利于提高其耐磨性。
The hardness of plastic moulds is usually below 50-60 HRC. The heat treated moulds should have sufficient surface hardness to ensure that the moulds have sufficient stiffness. Because the filling and flowing of plastics must bear large compressive stress and frictional force in the work of the die, it is required to keep the shape accuracy and dimensional accuracy of the die stable, and ensure that the die has sufficient service life. The wear resistance of the die depends on the chemical composition of the steel and the hardness of heat treatment, so improving the hardness of the die is beneficial to improving its wear resistance.
2、優良的切削加工性
2. Excellent machinability
大多數塑料成型模具,除EMD加工外還需進行一定的切削加工和鉗工修配。為延長切削刀具的使用壽命,提高切削性能,減少表面粗糙度,塑料模具用鋼的硬度必須適當。
In most plastic moulds, besides EMD processing, certain cutting and fitter repairs are needed. In order to prolong the service life of cutting tools, improve cutting performance and reduce surface roughness, the hardness of steel for plastic die must be appropriate.
3、良好的拋光性能
3. Good polishing performance
高品質的塑料制品,要求型腔表面的粗糙度值小。例如,注塑模型腔表面粗糙度值要求小于Ra0.1~0.25的水平,光學面則要求Ra<0.01nm,型腔須進行拋光,減小表面粗糙度值。為此選用的鋼材要求材料雜質少、組織微細均一、無纖維方向性、拋光時不應出現麻點或桔皮狀缺陷。
For high quality plastic products, the surface roughness of the cavity is required to be small. For example, the surface roughness of injection mold cavity is required to be less than Ra 0.1-0.25 level, while the optical surface is required to be Ra < 0.01 nm. The cavity must be polished to reduce the surface roughness. For this reason, the selected steel requires less impurities, uniform microstructure, no fiber orientation, and no pitting or orange peel defects in polishing.