PVC cable material is a polyvinyl chloride-based resin, added stabilizers, lubricants and inorganic fillers, etc., prepared by mixing kneading and extrusion of particles. Although its interface performance is general and environmentally friendly, its low price and simple process make PVC cable material one of the largest used cable materials.
When using PVC cable, air holes, rough surfaces, and brittleness may occur. We discuss in detail how these phenomena are caused:
one. Cable porosity problem
There are two main reasons for this problem. One is the problem of moisture and the other is the problem of degradation.
1. The raw material has high moisture content. The raw materials that may exceed the water content are PVC resin, plasticizers, fillers, and stabilizers. Due to the large amount of additives, PVC resins and fillers should be the focus of inspection. In this case, the kneading process and the evacuation of the extruder are generally performed.
2. The stability of the formulation system is poor or the high-temperature residence time of the material is too long, and the material decomposes to cause the appearance of pores. When this problem is serious, it is generally accompanied by changes in color.
two. Rough surface of cable material
The rough surface is divided into two types, one is smashing, and the other is sloping.
1. Phenomenon
The main reason is that: some powder aggregates that are dispersed unevenly during mixing cannot be plasticized during the extrusion process, and the plasticized PVC material is coated together and extruded from the die and formed in the cable material.
Fish eyes of PVC resin and PVC resin particles that do not fully absorb plasticizers can also cause blemishes, but they are generally small.
Today's formulas are pursuing more detailed fillers. If the filler surface is not handled well, the effect of mixing is poor, and the probability of agglomeration will be greater. Only the degree of agglomeration and the performance of cable materials are serious? Is it a problem?
2. Point problem
Pitches are relatively complex and are generally considered to be related to small molecules that run out of materials. These small molecules come from the resin itself, plasticizers, and lubricants.
Because vacuum extrusion is required for the extrusion granulation process, these small molecules should be extracted. However, why does this happen? Through analysis, it was found that in fact, these small molecular substances are generated after the vacuum is drawn in the material, and many of them come from lubricants that are not very large, and of course, plasticizers.
three. PVC cable insulation is not good
Because of the limitations of PVC materials and additives such as plasticizers, the insulation of PVC cable materials has a certain limit. For ordinary cable materials, if the insulation is significantly deviated, there are several main reasons:
1. More impurities
The incorporation of impurities will have an adverse effect on the cable material, and excessive impurities will cause insulation problems. These impurities may be derived from PVC resins and various additives, may also be derived from the mixing and feeding links.
2. Powdery particles are too thick
The powdery auxiliaries in the cable material are usually used after being ground. If the drawing is not convenient or some mechanical failure occurs, the powdery particles added will become too coarse, which will adversely affect the insulation of the cable material.
3. The colorant heavy metal problem
Many pigments are heavy metal salts, which increase the electrical conductivity of the cable and reduce its insulation. So the choice of cable pigment is very important.
four. Cable material moisture problem
Because there is a certain percentage of fillers in the cable material, some will have a certain percentage of low-grade plasticizers (or plasticizer substitutes). Cable materials that are not likely to produce moisture will occur in certain seasons.
The moisture content of the cable material has a lot to do with the packaging process and the packaging material. It should be strengthened and dried to a certain temperature and sealed again. In addition, the package should be improved to increase the moisture protection measures.
At the same time, attention should also be given to false moisture phenomena caused by potential degradation and surface adhesion.
Fives. Cable material brittle problem
The problem of brittleness of cable materials is generally related to the formulation components of PVC resins, plasticizers, lubricants, and fillers.
1. Choose a high model
If the PVC resin is used in a high-grade model, the performance of the cable material will be brittle due to the short molecular chain of PVC. The amount of plasticizer added is small, the cable material is too hard, and sometimes it has a brittle feel.
2. Too much filler added
What's more, because the amount of filler added is too large, the performance of the cable material is reduced and the strength is not good.
3. Lubricant
Lubricants are another important point. If the external lubrication is excessive, it will often cause poor plasticization (low temperature of plasticization is also another main reason for poor plasticization). At this time, the cable material will obviously have poor strength and brittleness.
HDPE Sheet
HDPE sheet, PE 500 sheet is used in a variety of applications and industries where excellent impact resistance, high tensile strength, low moisture absorption and chemical and corrosion resistance properties are required. And PE sheet has good insulation properties and is easy to weld. The operating temperature of HDPE is from -50°C to +90°C
