What is an injection mold? that’s many importeres are puzzled, they ask quotation for a plastic part, or a plastic injection mold. and Mold suppliers quote wildly different amounts for part or mold. today lets tale more detail on this topic. first lets understand, what is an injection mold. An injection mold is a device made of  metal, put it into Injection machine , the molten plastic been Injected into the mold, after cool down and formed products we need, to produce a plastic products faster with stable quality. Now the injection Molding is the most widely applied for different products.

what is an injection mold

Plastic Injection Mold Types

To be understand the injection mold type, we need figure out the plastic mold types first, plastic mold means use plastic material to produce products for us, this categery include many process,  here the firm you can find the common process in our current life. it use wildely, many of products in life are made by these Process.

Plastic mold TypeApplication
Injection MoldMost industry need injection mold.
Blow MoldPlastic table, boad and so on
Sheet Moulding Compound(SMC)Plastic dish
Rubber Moldsillicon product, Rubber Products
Rotary MoldToys

Lets talk back injection mold. through top table you can understand Injection molds are just one type of plastic molds, but injection molds also contain many subcategories; here let dig more detail.

According to the different flowing systems, molds can be divided into three types:

(1) Direct gate mold: the runner and gate are on the parting line, and they are ejected together with the product when the mold is opened. The design is the simplest, easy to process, and the cost is low, so many people use the Direct gate mold to operate.

(2) Point gate mold: The runner and gate are not on the parting line, and are generally directly on the product. Therefore, it is necessary to design an additional set of gate parting lines. The design is more complicated and the processing is more difficult. Generally, it is selected according to the product requirements.

(3) Hot runner mold: The structure of this kind of mold is roughly the same as that of the point gate mold. The biggest difference is that the runner is in one or more hot runner plates and hot Nozzle with constant temperature. There is no cold material demolding, runner and Gate is directly on the product, so the runner does not need to be demolded. This system is also called a gateless system, which can save raw materials. It is suitable for the situation where the raw materials are expensive and the product requirements are high. It is difficult to design and process, and the mold cost is high.

The hot runner system, also known as the manifold system, is mainly composed of a hot gate sleeve, a hot runner plate, and a temperature-controlled electric box. Our common hot runner system has two forms: single-point hot gate and multi-point hot gate. Single-point hot gate is to use a single hot gate sleeve to directly inject molten plastic into the cavity, it is suitable for a single cavity single gate plastic mold; multi-point hot gate is through the hot runner plate to branch the molten material into each Sub-heating gate sleeve and then enter the cavity, it is suitable for single cavity multi-point feeding or multi-cavity mold.