Introduction of mold materials
The most important factors of mold materials are thermal strength and thermal stability. Common materials are mold materials: working temperature forming materials mold materials
<300 temperature zinc alloy Cr12, Cr12MoV, S-136, SLD, NAK80, GCr15, T8, T10.
300~500 degree aluminum alloy, copper alloy 5CrMnMo, 3Cr2W8, 9CrSi, W18Cr4V, 5CrNiMo, W6Mo5Cr4V2, M2.
500~800 temperature aluminum alloy, copper alloy, steel titanium GH130, GH33, GH37.
Titanium alloys, steels, stainless steels, nickel alloys K3, K5, K17, K19, GH99, IN100, C-6NX88, MAR-M200, TRW-NASA, WA at 800-1000 degrees C.
>1000 C nickel alloy Cu base alloy die and hard alloy die.
Classification of gating system
According to the difference of gating system, plastic moulds can be divided into three types.
(1) Large nozzle mold: runner and gate in the mold dividing line, together with the product in the mold opening demoulding, the design is the simplest, easy to process, low cost, so many people use large nozzle system operation. Plastic mold structure is divided into two parts: dynamic mold and fixed mold. With the moving part of the injection machine for the dynamic model (mostly for the ejection side), in the injection machine ejection end is generally inactive called fixed mold. Because the fixing part of the large nozzle mold is generally composed of two steel plates, it is also called the structure of the mold for two plates. The two plate die is the simplest structure in the big mouth mold.
(2) Fine nozzle mold: runner and gate are not on the parting line, generally directly on the product, so to design a more set of nozzle parting line, design is more complex, processing is more difficult, generally according to product requirements and choose fine nozzle system. The fixing part of the fine nozzle mold is generally composed of three steel plates, so it is also called "three plate mold" for this kind of mold. The three plate die is the simplest structure in the die.
(3) Hot runner mold: The structure of this kind of mold is roughly the same as that of fine nozzle. The biggest difference is that the runner is located in one or more hot runner plates with constant temperature and hot choke. There is no cold material demoulding, and the runner and gate are directly on the product. So the runner does not need demoulding. This system is also called nozzle-less system, which can save raw materials. It is applied to the situation that the raw materials are more expensive and the products are more demanding. The design and processing are difficult and the cost of the mould is high. Hot runner system, also known as hot runner system, mainly consists of hot runner sleeve, hot runner plate, temperature control box. Our common hot runner system has two forms: single point hot runner and multi point hot runner. Single-point hot gate is used to inject molten plastic directly into the cavity by a single hot gate sleeve, which is suitable for a single cavity and single gate plastic mold; multi-point hot gate is used to branch molten material into each heat-sharing gate sleeve by hot runner plate and then enter the cavity, which is suitable for single cavity multi-point feed or multi-cavity mold.