Reasons for the color change of pvc water pipes

PVC pipes will discolor due to various reasons during use. When consumers see the discoloration of PVC pipes, they will blame the quality of PVC pipes. In fact, the reason for the discoloration of PVC pipes is not only the quality of PVC pipes. Let's take a look at the reasons for the discoloration of PVC pipes.

1. PVC product quality

Because of the presence of tertiary chlorine and allyl chloride in the molecular structure of PVC, PVC pipes are prone to decompose during the production process and later in use, causing the pipes to begin to change color. The order of color change is: white, pink, yellow, red, black ( Carbonization), so the quality of PVC, the quality of stabilizer (to control decomposition) and the amount are very important.

2. Discoloration induced by unqualified titanium dioxide

There are generally two structural forms: anatase and rutile. Due to its different structure, use energy and aging resistance. It must be rutile type to be used as PVC pipe. However, due to production quality problems of some manufacturers or uneven surface coating, discoloration (greying) tends to occur under photocatalytic conditions.

3. Sulfur pollution and lead salt stabilizer, cadmium stabilizer

With the development of industry, the problems of acid rain and sulfide pollution are becoming more and more serious, and the profiles may come into contact with sulfide during storage and transportation, so the possibility of sulfide pollution is very high. The substance generated by the sulfur pollution reaction is black or red, which can cause the white substance to change color, so the lead salt stabilizer profile is prone to sulfur pollution. Cadmium stabilizers are toxic products. If used in pipelines, they will cause yellowing of pipelines in a sulfide environment, so cadmium stabilizers are rarely used.