Classification of injection mold

(1) Injection mold with single parting surface

When opening the mold, the moving mold and the fixed mold are separated, so as to take out the plastic parts, which is called the single parting surface mold, also known as the double plate mold. It is the simplest and  basic form of injection mold. It can be designed into single cavity injection mold or multi cavity injection mold according to the needs. It is the  widely used injection mold. In mass production of plastic products, the manual labor in the process of opening and closing the mold and taking out the parts should be minimized,

Injection mold is the "tool" to produce plastic products. With injection mold, plastic products can be better produced. Injection mold also needs to keep pace with the times. Only the follow-up of the development of injection mold can produce ideal injection mold products. For injection mold, structure is of course important, which determines the success or failure of injection mold design. Practicability is the key element of injection mold product design, which means the value of the product designed. As far as the current injection mold products are concerned, the parting surface is required in the design process, which is also related to the position and form of the mold. In the design process, it is also necessary to master it better, so as to avoid the impact of the produced mold on the appearance and other aspects.

(2) Injection mould with double parting surface

The double parting surface injection mold has two parting surfaces. Compared with the single parting surface injection mold, the double parting surface injection mold adds a local movable middle plate (also known as the movable gate plate, which is equipped with gate, runner and other parts and components required by the fixed mold), so it is also called three plate (moving template, intermediate plate, fixed template) injection mold For injection mold with single or multiple cavities for point gate feeding, the intermediate plate is separated from the fixed template at a fixed distance on the guide pillar of the fixed mold, so as to take out the pouring system condensate between the two templates.

The injection mold with double parting surface has complex structure, high manufacturing cost and difficult parts processing, so it is generally not used for the molding of large or extra large plastic products. It will cause slight damage to the surface of the insert and affect the product quality. The allowable limits of quality should be confirmed in advance.

With the development of science and technology, plastic mold has already become an irreplaceable commodity in our life. In our real life, plastic products have  occupied every field. Whether it is the spare parts of airplane, automobile and ship, or some toothbrushes and cups which are commonly used in our daily life, there are plastic shadows. In fact, the commonly used plastic products around us are not produced one by one according to the drawings by the manufacturers, but are produced in batches through plastic molds.

(3) Injection mold with side parting and core pulling mechanism

When the plastic part has side hole or side concave, the core or slide block which can move laterally should be used. After injection molding, the moving mold first moves downward for a certain distance, and then the inclined section of the bending pin fixed on the fixed template forces the sliding block to move outwards. At the same time, the push rod of the demoulding mechanism pushes the push plate to make the plastic part take off from the core. Some surfaces have to be treated mathematically. The production of small batch mould is not mass production, in many cases, only one set is produced.

(4) Note with movable forming parts

In fact, both plastics and plastics refer to the same thing. There is no difference between them, but they are called differently. Because plastics are foreign products, they are often called plastics in China, while they are generally called plastics abroad. It is clear to insiders that both plastics and plastics refer to plastics. Electrical equipment can be seen in all aspects of our life, a complete set of electrical equipment injection mold, which contains about thousands of kinds of electrical accessories, but the general injection molding electrical parts and what kinds of.

Mold

Due to the special structure of the plastic parts, the injection mold is required to set movable molding parts, such as movable punch, movable female die, movable insert, movable thread core or ring, etc. when demoulding, the injection mold can be moved out of the mold together with the plastic part, and then separated from the plastic part. It will cause slight damage to the surface of the insert and affect the product quality. The allowable limits of quality should be confirmed in advance.

(4) Note with movable forming parts

High carbon and high alloy steels, such as Cr12MoV, W18Cr4V, etc., are widely used to make dies. However, there are some defects in these steels, such as segregation of components, uneven size of carbides, and uneven structure. Therefore, it is necessary to select reasonable casting technology to form the blank of module when using high carbon and high alloy steel to make mould. On the one hand, steel can reach the standard and standard of module blank On the one hand, it can improve the structure and function of the steel. Other high carbon and high alloy die steels have poor thermal conductivity, heating speed can not be too fast, and heating should be uniform. In the range of casting temperature, reasonable casting ratio should be selected.

(5) Injection mould with automatic thread removal

For the plastic parts with thread, when the automatic demoulding is required, the screw core or ring which can rotate can be set on the mold, and the mold opening action or the rotating mechanism of the injection molding machine, or the special transmission device can be set to drive the screw core or the thread type ring to rotate, so as to release the plastic parts. In modern production, reasonable processing technology, efficient equipment and advanced mould are essential and three important factors.

(4) Note with movable forming parts

When EDM technology is used to process dies, the current density in the discharge area is very high, and a lot of heat occurs. The temperature of the processing area of the mold is as high as 10000 ℃. Because of the high temperature, the metallographic structure of the heat affected zone will be changed. The surface layer of the mold will melt due to high temperature, then it will rapidly cool down and agglutinate quickly to form a reagglutination layer In order to extend the mold life, the following methods can be selected: adjust EDM parameters, grind the surface after EDM with electrolytic method or mechanical grinding method, remove the white bright layer in the abnormal layer, especially remove the micro cracks. After EDM, organize a low temperature tempering to stabilize the abnormal layer and prevent micro cracks The pattern is widened.

(5) Non runner injection mold

The non runner injection mold refers to the method of adiabatic heating in the convection channel to keep the plastic from the nozzle cavity of the injection molding machine in a molten state, so that there is no gating system condensate when the plastic parts are taken out. The former is called adiabatic runner injection mold, and the latter is called hot runner injection mold. First of all, from the mold injection molding. The defects of molded products are caused in the plasticizing and injection molding stages, but sometimes they are also related to improper mold design. The possible influencing factors include the number of cavities.

(6) Note with movable forming parts

The common holes in the processing of injection molding parts include through hole, blind hole, special-shaped hole (hole with complex shape) and threaded hole. These holes should be set at the place where it is not easy to weaken the strength of the plastic part. Sufficient distance should be left between the holes and between the hole and the side wall. For the relationship between the two holes of thermosetting injection molding parts and thermoplastic injection parts and between the hole and the side wall, please refer to the relevant industry tables. In general, there are several installation methods for the core used for forming through-hole. One end of the core is fixed. This method is simple, but there will be transverse flash which is not easy to trim, and it is easy to bend when the hole is deep or the hole diameter is small.

(7) Right angle injection mold

The right angle injection mold is only suitable for angle injection molding machine. Different from other injection molds, the feeding direction of this kind of mold is perpendicular to the opening and closing direction of the mold. The sprue is set on both sides of the parting surface of the moving and fixed mold, and its cross-sectional area is usually constant, which is different from other injection molding machines. In order to prevent the abrasion and deformation of the nozzle and the inlet end of the main channel, a replaceable runner insert can be set at the end of the main channel.

Several important parts of injection mold were tracked and detected, and the problems were solved immediately. Pay attention to the surface maintenance of injection mold, and do a good job of protection to prevent corrosion, so as to avoid affecting the service life of the mold. The injection mold structure is usually divided into two plate mold and three plate mold. The first difference is that the two plate mold is opened once, and the injection mold is separated by moving and fixed mold, while the three plate mold has an additional nozzle plate on the fixed mold, so it is twice opened, that is, the first is the separation between the dynamic and fixed mold, and then the nozzle plate of the fixed mold is separated from the fixed mold base plate. The upper part is two plate mold, and the lower part is three plate mold.

(8) Injection mould with demoulding mechanism on fixed mould

In most injection molds, the demoulding device is installed on the side of the moving mold, which is conducive to the work of the ejection device in the opening and closing system of the injection molding machine. The overall requirement of the mould is that it can produce the public owned products which meet the requirements of the use in the aspects of dimensional accuracy, appearance and physical properties.

In the actual production, due to the limitation of the shape of some plastic parts, it is better to leave the plastic parts on the side of the fixed mold, which makes the plastic parts come out of the mold, it is necessary to set up a demoulding mechanism on the side of the fixed mold. In order to reduce the heavy workload of mold design and manufacturing, most injection molds use standard mold base.

Preparation before mold forming of plastic daily necessities: in order to make injection molding production smoothly and ensure product quality, it needs to be carried out before production. Pretreatment of raw materials, appearance inspection of plastic raw materials, testing of plastic process performance when necessary, and sufficient drying of plastics easy to absorb moisture before forming. Clean or replace the barrel of the injection machine. Preheat the insert to reduce the temperature difference between the plastic melt and the metal insert. A series of preparation work, such as selecting mold release agent, preheating the mold, etc.

Injection molding_ What should be paid attention to in Shanghai plastic daily necessities mould? Progressive die refers to a set of mould which can automatically move the workpiece from one station to another and get the molding parts in the last station. Die processing technology includes: cutting die, blanking die, compound die, extrusion die, four slide die, progressive die, stamping die, die cutting die, etc.

Ordinary injection molding does not need to use special precision injection molding machine, and does not need special materials. Generally used thermoplastic can be used for production, so ordinary injection molding process is widely used in modern plastic industry. In injection molding, if the wall thickness of the injection molded parts is not uniform, it will lead to deformation or shrinkage of the product. To solve this problem, it is best to advise the customer to modify the product. If the product cannot be changed, the C angle or R angle can only be inverted at the transition point between the thick and thin parts. This will reduce the stress problem of the plastic in the flow, reduce the stress, and the product is not easy to deform However, this thick and thin place should not be more than 60%, otherwise it must be thinned or thickened.