What Are The Anti-yellowing Solutions For Polyurethane Soft Foam Sponges?

Polyester foam and polyether foam are classified according to technology: hard foam, soft foam, and semi-hard foam. Regardless of the type, yellowing of polyurethane foam sponges is a problem that has been plaguing sponge manufacturers. Some high-end sponge production factories will try to improve the anti-yellowing properties of sponges by adding antioxidants and light stabilizers, but the results are not significant. Generally, the reasons for yellowing of polyurethane foam are as follows:
1. During the foaming production process, due to the need for high-temperature foaming, aging yellowing of the polymer material is caused, and core burning occurs when the interior is severe.
2. Yellowing caused by ultraviolet rays in the sun.
3. Gas smoke yellowing caused by exposure to nitrogen oxides in the workshop, especially BHT and amine additives, which accelerate sponge yellowing in the later stage.
So how to prevent it?
1. Add antioxidants: Adding antioxidants to polyurethane soft foam sponge can increase its antioxidant properties, thereby slowing down the rate of yellowing. Commonly used antioxidants include stearates, anilines, light stabilizers, etc. Through reasonable additive concentration, the antioxidant capacity of polyurethane soft foam sponge can be improved.
2. Use anti-UV coating: Apply the anti-UV coating on the surface of the polyurethane soft foam sponge.
It can form a protective film to prevent ultraviolet radiation. This coating can be an organic solvent-based coating or a water-based coating. Choosing the right coating can improve the UV resistance of polyurethane soft foam sponges.
3. Use anti-UV plastic coating: Processing a layer of anti-UV plastic coating on the surface of the polyurethane soft foam sponge can prevent UV rays from directly irradiating the polyurethane soft foam sponge. This coating layer can be polyethylene, polyvinyl chloride, etc. Choosing the appropriate coating material can improve the UV resistance of the polyurethane soft foam sponge.
4. Closed packaging: Closed packaging of polyurethane soft foam sponges can prevent oxygen and ultraviolet rays from contacting the polyurethane soft foam sponge, thereby reducing the chance of yellowing. Closed packaging can use plastic film packaging, vacuum packaging, etc.
5. Regular cleaning and maintenance: Regular cleaning and maintenance of polyurethane soft foam sponges to remove dust and dirt can reduce the possibility of yellowing of polyurethane soft foam sponges. For cleaning, you can use warm water and neutral detergent to wipe it gently. For maintenance, you can use appropriate care products, such as care solution, maintenance spray, etc.
In short, anti-yellowing solutions for polyurethane soft foam sponges include adding antioxidants, using anti-
UV coating or plastic cladding, closed packaging, and regular cleaning and maintenance. Through the comprehensive use of these solutions, the anti-yellowing performance of polyurethane soft foam sponge can be effectively improved and its service life can be extended.