Highly transparent TPU, is made out of transparent, why put a period of time after the start of opaque, it looks like the same as white rice.
TPU in the air will absorb moisture from the air and white or it is added during processing aids migrate out mainly opaque slip agent, yellowing is a feature of TPU. TPU is a yellowing resin, ISO in MDI will turn yellow under ultraviolet radiation, visible yellowing TPU is a property, so we have to delay the TPU yellowing of time. So how to prevent yellowing TPU it?
(1) avoid sunlight TPU. TPU storage area should be cool and airy, while the packet is placed in a plastic bag TPU available without sunlight.
(2) spraying resistant yellow paint. Spraying paint usually has two forms, one is mold spray, one is outside the mold spraying, spraying anti-yellowing paint will form a protective layer on the surface of the finished TPU, TPU avoid skin contact with the atmosphere pollution yellowing, this form has been widely used.
(3) Adding anti-yellowing agents. In order to strengthen the capacity of anti-yellowing TPU finished, often you want to add in the raw materials of a special anti-yellow anti-yellowing agents, anti-yellowing agents but expensive, we use anti-yellowing agents may also be a measure of its economic benefits, such as our Black type body is not susceptible to yellowing, so we can use cheaper anti-yellowing agents not add non-yellowing material, due to the anti-yellowing agent is a raw material additive, which adds to the A component, we request that when stirred ingredients For distribution, to achieve the anti-yellowing effect, there would be a partial yellowing phenomenon.
(4) Use a good mixture. I can make a good proportion of liquid and P liquid to achieve the fullest instead of a mixed reaction incomplete reaction section, and there is resistance to hydrolysis makes the finished product, anti-yellowing ability to greatly reduce these phenomena, in particular when the ratio of the ISO ones the finished product will accelerate yellowing.
(5) The procedure manual to avoid contamination. TPU has more refined in order to save the process or be contaminated and cause yellowing and organic solvents such as human sweat, etc., so pay special attention TPU products contact body clean, while minimizing finishing process.