Plastic Injection Molding

Why the venting is so important for a plastic injection mold?

The venting slot serves two purposes: 1. Expel air from the plastic injection mold during the injection process of the molten plastic material; 2. Get rid of the various gases produced during injection molding processing. The setup of venting slots is of great importance, especially for thin-walled products or the locations far away from the gate. In addition, close attention should also be paid to venting slots for the production of small-size or precision parts, because they are able […]

The reason and solution for surface roughness

Surface roughness means there is a lack of precision in the surface of a molded part, or an inconsistent level of precision all over the surface, e.g. some areas are glossier than the rest. The main reasons for surface roughness might lie in the injection molding machine, the mold, the process or the material.
(1)Injection Molding Machine
①Insufficient material supply;
②Material barrel is not thoroughly cleaned when changing material;
③Check for cold melt leakage at the nozzle;
①The gate is too small, or the runner […]

Key Links in Plastic Parts Processing

In addition to polymers, different plastic additives (such as stabilizers, plasticizers, colorants, lubricants and fillers) are usually added to the raw materials used in the processing of plastic parts in order to improve the moulding process and product performance or save the cost of products. Additives and polymers are mixed and evenly dispersed into powder, also known as dry mixtures. Sometimes the powder still needs to be processed into granules. This kind of powder and granular material is collectively […]

Introduce the test procedure of injection mould processing

In order to reduce the waste of time in mass production, it is necessary to adjust and control the processing conditions in time, find out the suitable temperature and pressure conditions, and formulate a standard test procedure for injection mould processing, which can be used to establish daily working methods.

Check whether the plastic material in the barrel is correct or not, and whether it is baked according to the regulations.


The cleaning of material pipes should be careful so as […]

Common failure of injection mold

1.1 Mold reset plate is not reset
After the mold is opened, the mold reset plate is not reset. The causes are: reset oil cylinder oil leakage, resulting in uneven force when the mold is reset. The mold reset is unbalanced.
The reset rod of the mold is strained, the cooperation between the reset rod and the guide sleeve is tightened, and the reset plate is not topped.
Solution: Check if the oil seal of the mold reset cylinder is worn out. If […]

Analysis of the Reasons for the Defects in the Processing of Plastic Parts

The reasons for the shortcomings in the processing of plastic parts are as follows:

Injection material. Material has impurities or supplies from different suppliers, different batches from the same manufacturer, and different batches of material processing technology is different.


Injection Moulding Machine. Check the function of each part of the injection molding machine is normal, and consider the influence of temperature, pressure, time and other reasons, control and adjust the injection molding machine.


Mold. Mould device should be appropriate, temperature should be […]

PMMA Plastic Injection Molding Process

PMMA, i.e. polymethyl methacrylate, also known as acrylic or organic glass, is a transparent thermoplastic with a relative density of 1.19, which is higher than that of water. With a high surface glossiness, the PMMA products are characterized by strength, rigidity and toughness.
The process features of PMMA: due to the high viscosity, PMMA has a poor fluidity. Therefore, a high material temperature and a high injection pressure must be applied during the injection molding process, among which the influence […]

Reasons for the Rising Price of Injection Molding Service

For the injection processing industry, the reasons for the rising cost of injection molding are as follows:

Increased labor costs

Although technicians’wages are higher than the basic wages, the wages of employees will rise after each increase. In addition, the difficulty of recruitment also forces the adjustment of salary structure, and the rising labor cost has become the basic phenomenon of injection molding industry.

Rising Prices of Raw Materials

Oil price fluctuation and raw material price fluctuation caused by plastic production problems also […]

Discoloration issue in plastic injection molding

Discoloration means the surface color of a molded part is not consistent with the required color. Discoloration may be caused by a variety of reasons, which may cover the several aspects of injection molding machine, mold, process and raw materials, etc.
(1) Injection Molding Machine
① Equipment is not clean and needs to be cleansed. Dusts or powders are deposited in the barrel, which contaminates and discolors the materials;
② Temperature control failure caused by malfunction of thermal couple, temperature controller or […]

What are the requirements for wall thickness of plastic parts

The wall thickness of plastic parts has a great influence on the quality. When the wall thickness is too small and the flow resistance is large, it is difficult for large and complex plastic parts to fill the cavity. The dimension of the processing wall thickness of plastic parts should meet the following requirements:

It has enough strength and stiffness.


It can withstand the impact and vibration of demoulding mechanism when demoulding.


Can withstand the fastening force when assembling.

The wall thickness value […]