6. Mold material
Die support plate is usually made of non alloy tool steel (no.1.1730, DIN code c45w). For die support plate which needs to bear 170 ℃ - 210 ℃ high temperature in dry condition, considering impact resistance, it should be made of pre tempered steel (no.1.2312, dincode 40 crmn-m OS 8 6). For the die support plate with cavity, it shall be made of b-steel after nitriding or annealing heat treatment to ensure its high temperature resistance.

For LSR with high filling capacity, such as oil resistant LSR, it is recommended to use materials with higher hardness to make molds, such as bright chrome plated steel or powder metal specially developed for this purpose (no.1.2379, dincode x 155 crvmo121). In the design of high wear material mould, those parts which bear high friction should be designed to be replaceable, so that the whole mould does not need to be replaced.

The surface of die cavity has a great influence on the finish of products. The most obvious thing is that the finished product will completely match the cavity surface. Moulds for transparent products shall be made of polished steel. After surface treatment, Qin / Ni steel has very high wear resistance, while polytetrafluoroethylene (PTFE) / nickel can make demoulding easier.