Due to the poor performance of PVC resin with limited processing range, and extremely harsh extrusion conditions, so different amounts of stabilizers, modifiers, lubricants, fillers, and other additives are added to the formulation. It can adapt its performance in processing to achieve the required mechanical and functions for custom PVC-U extrusion products.
The correct formula is the prerequisite for ensuring the PVC extrusion performance to obtain excellent quality.
The selection and content of various additives are not only related to the processing performance, physical and chemical properties but also have a very important influence on the appearance of the plastic product. For example,
1, Stabilizers can improve the thermal stability of PVC processing. If the amount used too small, it may cause thermal decomposition during PVC extrusion, resulting in a (light) yellow surface on the product.
2, The processing modifier in the formula promotes the plasticization and improves the processing fluidity. If the dosage is low, it will result in fluidity. The plasticization is prone to cause the surface to be rough and dull, which reduces the product feature of the brightness of the surface.
3, The selection and proportion of lubricant in the formula, especially the amount of external lubrication, has a more obvious effect on the appearance of the product. Due to its poor compatibility with PVC, too much amount will not only precipitate on the product surface. It makes the surface become roughness with streaks or moire. This effect is particularly obvious during high-speed extrusion production; If the amount is not enough, the fluidity becomes poor, which will also reduce the brightness of the surface of the product.
4, In addition, some manufacturers also add a small amount of fluorescent whitening agents in the formula to improve the brightness of the surface of the profile. However, due to the molecular structure of the fluorescent whitening agent, it generally accelerates the aging of the profile in the long time use. Therefore, we believe that it is not suitable for promotion.
In all, those influences of raw materials on the surface of PVC extrusion white corner edge parts cannot be ignored. Some defects will affect the surface brightness to varying degrees. If the moisture and volatile content of PVC exceeds the standard, it often causes too much gas during the process, which cannot be completely eliminated and generate bubbles. It affects the gloss of the surface.
Some complexity in the extrusion technology which affects the quality level from different extrusion manufacturer. We have gained highly sophisticated technical skills to void the bad surface on those extrude channel profiles and other custom request profile design.