Plastic automated extruder

The molds used in the production of plastic automated extruders have different combinations of core and sleeve according to different product and process requirements. Extrusion molding requires high accuracy in mold matching. If the performance of the extruded sheet is poor, it is due to the difference in the matching angle between the mold core and the mold sleeve that determines the size of the pressure, which affects the quality of the plastic layer and the extrusion yield; The dimensions of the mold core and sleeve also directly determine the geometric shape and surface quality of the extruded product. The aperture of the molded part of the sleeve must consider comprehensive factors such as "expansion" after pressure relief and shrinkage after cooling.

When using PVC cable materials, there may be phenomena such as porosity, rough surface, and brittleness. Let's discuss in detail the causes of these phenomena:

1、 Cable material porosity issue:

There are two main reasons for this problem, one is the problem of moisture, and the other is the problem of degradation.

1. The moisture content in the raw materials is relatively high. Raw materials that may have excessive moisture content include PVC resin, plasticizers, fillers, and stabilizers. Due to the large amount of additives, PVC resin and fillers should be the focus of inspection. This situation usually manifests during the kneading process and at the vacuum pumping point of the extruder.

2. The stability of the formula system is poor or the high-temperature residence time of the material is too long, which leads to the decomposition of the material and the appearance of pores. When this problem is severe, it is usually accompanied by a change in color.

2、 Rough surface of cable material:

There are two types of surface roughness, one is bumps and the other is pitting.

1. Knot phenomenon:

Mainly, it is formed in the cable material by encapsulating PVC material that cannot be plasticized during the extrusion process due to the uneven dispersion of powder aggregates during mixing.

The fish eyes of PVC resin and PVC resin particles that do not fully absorb plasticizers can also cause lumps, but they are generally relatively small.

Nowadays, the formula pursues finer and more fillers. If the surface of the fillers is not treated well, the mixing effect will be poor, and the probability of agglomeration will be relatively high. Just the degree of agglomeration and whether the performance in the cable material is severe? Has it become a problem?