Molds that can be used in injection plastic mold design can also be divided into two categories: male molds and female molds. You can use either one depending on your needs. The thermoplastic sheet is placed over the mold in male molds, while it is placed inside the mold in female molds. On the other hand, male molds have the thermoplastic sheet placed over the mold. In general, male molds are used when the inner dimension of the plastic part is more important than the part's outer dimensions, and female molds are used when the part's outer dimensions are more important than its inner dimensions.

A three-plate mold is comprised of the following components: movable side mounting, backing plate, support plate, spore splitter plate, fixed side mounting plate, positioning ring, runner, runner bushing, guide bushing, guidepost, return lever, and Ejector bottom plate.

• The gate is directly connected to the Thermoplastic component that melts into the cavity and serves as the cavity's lining

• As a result, the gate serves as the most important component of the gating system

• The form and dimensions of the gate have a significant impact on the characteristics of the Plastic Molding components

• When it comes to the channel system that regulates the flow of filling, the gate is typically the component that takes up the least amount of space

Injection molding relies heavily on gates because they act as a barrier between the part being molded and the scrap that is being produced. Therefore, their location, size, and shape play an important role in determining how everything should be constructed, from the product's structural integrity to its overall appearance on the outside. This applies to both the interior and the exterior of the finished product.


In this section, we will talk about the various defects that can occur when you are working with injection molding. This will be determined based on the reasons for the flaw as well as the appropriate corrective actions. The following is a list of some of the more common design flaws that can occur with injection molding.

Unsatisfactory Level of Filling

You need to keep an eye out for the design flaw known as insufficient filling when it comes to injection molding. It takes place when the resin does not reach the cavity's corners when the mold is being made. Inadequate filling can result in the following consequences:

Lack of fluidity in the resin as well as an inadequate internal pressure; increase the maximum injection pressure as well as the injection speed; raise both the temperature of the mold and the temperature of the resin.

Inadequate levels of plasticization

Raise the barrel's back pressure while also elevating the temperature at the back of the chamber.

Insufficient injection is caused by gas and air.

Insufficient exhaustion of the mold occurs, which is more likely to take place in a thinner part in which the thickness of the mold does not uniformly distribute itself. By reducing the rate at which the fuel is injected, it is possible to free up the flow of exhaust gas. In some cases, the exhaust failure can be solved by reducing the mold clamping ability. This eliminates the need for filling the mold.

A mold with a number of holes, only some of which are filled

Increase the speed of the shot so that it can fill up uniformly. In the event that the peak pressure was caused by an increase in speed, the pressure-holding position ought to be modified in order to prevent the peak pressure from occurring.

When there is insufficient filling of the molded product, there is good flow in the mold; the resin temperature, the mold temperature, the 2-1 underfill, and the burr are all present at the same time; however, there is insufficient filling of the molded product.

There are burrs in the area close to the runner and the gate, and the end portion of the molded article is not filled adequately to prevent it from unraveling.-

1. Configure the multi-segment injection, which will be formed by short shots, and adjust the speed at which the underfill and flashing will occur.

2. Raise the temperature of the mold as well as the temperature of the resin, improve the fluidity, and slow down the injection speed. In the event that the filling is still insufficient after the injection speed has been slowed down, the injection speed of this part will be increased.


The difference in volume shrinkage of the molded article causes the voids that are appearing inside the molded article to cause voids in the thickness portion of the molded article; the moisture and gas that are present in the resin become bubbles after being bubbled.

The traces of the resin flow are engraved on the surface of the molded product in the shape of a concentric circle, with the center of the circle centered on the direction of the gate.

Raise the temperature of the resin as well as the temperature of the mold, and adjust the injection speed if necessary.

If adjusting the injection speed does not allow you to eliminate the error, the mold needs to be inspected and possibly repaired.

When it comes to water ripples, the speed of the water ripple portion is increased. This is primarily due to the slow injection speed, cooling that occurs during the filling process, and wrinkles that appear as a result of the high viscosity of the material.