Screw slip of plastic processing equipment often occurs in the plasticization stage

If the plastic processing equipment has spiral slip in the process of use, it will actually have a very adverse impact on the plasticizing effect of the equipment. If the processing of plastic products is unqualified due to spiral slip, it needs to be reworked, resulting in many losses, Therefore, it is necessary to solve the screw slip of plastic processing equipment in time. Generally speaking, the causes of screw slip of plastic processing equipment mostly occur in the plasticization stage.

Screw slippage of plastic processing equipment will cause material degradation, thus affecting the quality of products. What are the causes of screw slip? How to “grasp” the slipping screw? When the barrel screw slips, the materials will probably gather at the feeding port and cannot be normally transported to the end of the plastic processing equipment. When the screw rotates and retreats in the barrel to transport the material and prepare for the next injection, screw slip will occur in the plasticization stage.

At this time, the rotation of the screw of the plastic processing equipment is still inherited, but the axial activity of the screw will stop, that is, slipping. Screw slip often leads to degradation of materials before injection, reduction of product quality (such as lack of materials), and extension of molding cycle. There are many reasons for screw slip, which may be related to factors such as too high back pressure, overheating or supercooling at the end of the barrel, wear of the barrel or screw, too shallow thread in the feeding section, unfair hopper plan, blockage of the hopper, resin wetting, excessive resin lubrication, too fine material, unfair cutting of resin and recycled materials, etc.

Undercooling at the end of the barrel of plastic processing equipment is one of the main reasons for screw slip. The barrel of the plastic processing equipment is divided into three sections. At the end, that is, the feeding section, the granular material will form a layer of melt film and stick to the screw in the process of heating and compression. Without this film, the granular material is not easy to be transported to the front end.

The material in the feeding section of plastic processing equipment must be heated to the light critical temperature to form that critical melt film. However, generally, the residence time of materials in the feeding section is very short and can not reach the required temperature. This environment is generally produced on plastic processing equipment. Too short residence time will lead to incomplete melting of polymer and inclusion process, resulting in screw slip or stall.

According to all the above, do you have a deeper understanding of plastic processing equipment. If the content we share helps you, you are welcome to continue to pay attention to our website. We will continue to update the news information for you and strive to provide customers with better services.