1). Plastic material for carrier tape

The complexity of plastic material properties determines the complexity of injection molding process. The properties of plastic materials vary greatly due to different varieties, brands, manufacturers and even batches. Different performance parameters may lead to completely different molding results.

2). Injection temperature for the embossed carrier tape

The melt flows into the cooled cavity and loses heat due to heat conduction. At the same time, the heat generated by shear may be more or less than that lost by heat conduction, which mainly depends on the injection molding conditions. The viscosity of the melt decreases with the increase of temperature. In this way, the higher the injection temperature, the lower the viscosity of the melt and the smaller the filling pressure required. At the same time, the injection temperature is also limited by thermal degradation temperature and decomposition temperature.

3). Mold temperature of the carrier belt

The lower the mold temperature, the faster the heat loss due to heat conduction, the lower the melt temperature and the worse the fluidity. This phenomenon is particularly evident when a lower injection rate is used.

4). Injection time

The influence of injection time on injection molding process is shown in three aspects:

(1) When the injection time is shortened, the shear strain rate in the melt will also increase, and the injection pressure required to fill the cavity will also increase.

(2) Shortening the injection time increases the shear strain rate in the melt. Due to the shear thinning characteristics of the plastic melt, the viscosity of the melt decreases, and the injection pressure required to fill the cavity also decreases.

(3) The shorter the injection time, the higher the shear strain rate in the melt, the greater the shear heating, and the less heat lost due to heat conduction. Therefore, the higher the temperature of the melt, the lower the viscosity, and the lower the injection pressure required to fill the cavity. As a result of the joint action of the above three cases, the curve of the injection pressure required to fill the cavity presents a “U” shape. That is, there is an injection time when the required injection pressure is the smallest.