Cause PVC edge strip discoloration

Many people think that to solve the problem of color inconsistency in PVC edge banding processing, as long as the yellowing profile production line to reduce the processing temperature, can reduce the color difference. But it is also believed that yellowing is the impact of PVC, CPE, stabilizer, different batches of PVC, CPE, stabilizer and other main auxiliary raw materials, processing there will be different color. In this case, even if the single addition of a certain amount of whitening agent, anti-photoaging agent, also play little role.

The main manifestation of heat, oxygen and light aging is yellowing of profiles. Some individual stabilizer manufacturers claim to use their products when promoting their products, it can reduce the number of parts and the cost, although the result can also produce the PVC profile with a relatively satisfactory appearance, but in the recycling of waste products, in the demanding process temperature requirements, because of its thermal stability efficiency is insufficient, the damage to the molecular structure of PVC is not visible to the naked eye, so the following conditions occur during production:

(1) the color and lustre of PVC edge banding strip are not uniform when it is processed (if the color and lustre have slight deviation is allowed) ;

(2) after heating deformation, the profile yellows obviously;

After heating the state is good, but the profile made of windows and doors for a short time to become gray. The profiles do not turn yellow in normal production, but turn yellow in later window-forming products. In the course of profile production, if the temperature of plasticizing section and homogenizing section is raised about 5 ° C when the basic conditions such as raw materials and dies are unchanged, the profiles will have yellowing tendency, it also shows that the heat stabilization efficiency is insufficient and the amount of heat stabilizer should be increased, especially when the fluorescent whitening agent is added in the formula, the heat stabilizer is insufficient for PVC, the whitening effect of PVC profile caused by discoloration is not obvious.