Why Do PVC Hoses Turn White?

Categories:

NEWS

Author:

Papageno Group

Origin:

Original

Time of issue:

2023-12-11

Why does transparent PVC hoses turn white after soaking in water? PVC hoses are important in agriculture, gardening and household etc. However, PVC hose may exhibit a certain degree of whitening after exposure or bending and stretching. What are the reasons?

Why Do PVC Hoses Turn White?

1. Whitening due to water immersion: Many types of transparent PVC products, especially soft products, may develop a white, foggy appearance after prolonged exposure to water or steam. In such cases, even if the penetrating water evaporates, stabilizers cannot restore the original appearance. Transparency can be regained once the temperature rises, restoring the compatibility of the stabilizers.

2. Whitening due to exposure: When exposed outdoors, PVC hose may experience whitening effects. Organic tin stabilizers are less prone to whitening, with sulfur-containing organic tin being the best, followed by laurate and maleate. Adding light stabilizers, hypophosphite salts, liquid composite stabilizers, etc., can help avoid or reduce the whitening phenomenon caused by PVC.

3. Stress-induced whitening: Stress whitening occurs when certain areas of PVC pipes (such as bending creases and stretched areas) turn white under the action of mechanical external forces, such as bending or stretching. This may be due to external forces, the orientation of polymer molecular chains, variations in PVC density, and voids between certain molecules. This results in light scattering, giving PVC pipes and fittings a whitish appearance.

When buying PVC hoses, follow these guidelines: first, smell the hose to check for any odors; second, bend the PVC hose to assess its flexibility; third, expose it to sunlight for a day; fourth, store it in the refrigerator to see if it becomes stiff; and fifth, apply heat with fire. By following these criteria, you will be able to purchase the PVC hose that best suits your needs.