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Homepage » News » Industry News » How to avoid the plastic hose (PU tube) turn yellow?
How to avoid the plastic hose (PU tube) turn yellow?

Careful users have found that a highly transparent TPU extrusion after molding PU hose is transparent, or even see the TPU tube shine, but allowed to stand for a period of time (the time period placed environment, damp, easily accessible to the light source The shorter the cycle) began opaque, somewhat similar to white rice.

Retrospective reason for this reaction TPU absorb air moisture in the air, which occurred in a color gradient, or add the main ingredient in the extrusion process as a slip agent migration TPU tube exposed to air. Look at PU, TPU characteristics: opaque, yellowing "Why? PU is a yellowing resin, ISO MDI will turn yellow under ultraviolet light, thus PU yellowing is an attribute, so we To delay the time PU yellowing. So how to prevent PU yellowing?

(1) should avoid exposure to the sun: the PU hose or high-pressure hose (TPU), PU gripper tube no exception. All PU tubes require cool, well ventilated storage areas, PU plastic hose available plastic bags or PU transparent hose packets placed in sunlight;

(2) spraying anti-yellowing paint: paint spraying usually have two forms, a mold spraying a mold outside spraying, anti-yellowing paint spraying will be in the the PU tube surface to form a protective layer, to avoid the increase in TPU fiber hose or other TPU pipe contact with the air pollution caused by the yellowing;

(3) Add anti-yellowing agents: in order to strengthen the ability of anti-yellowing PU tube, tend to be added in the raw material in a special anti-yellowing, anti-yellowing agents, but expensive anti-yellowing agents, anti-yellowing agents should also measure its economic benefits, such as the black body of yellowing is not sensitive, so we can use cheaper not add anti-yellowing agents, anti-yellowing raw materials, anti-yellowing agent is a raw material additives, add it to the A ingredient , Stir ingredients required to distribution, to achieve the effect of anti-yellowing, otherwise there will be local yellowing phenomenon.

(4) use the good mixing ratio: good proportion can make the buffer I and P liquid achieve sufficient mixing reaction without have not fully reflect part of these phenomena causes finished hydrolysis resistant, anti-yellowing capacity greatly lower ratio ISO ones will accelerate the yellowing of the finished product.

(5) to avoid contamination of the manual process: PU tube and high-pressure hose in the finishing process contamination yellowing, such as human sweat and organic solvents, PU products pay special attention to the contact body clean at the same time as much as possible Reduce finishing procedures. Division I PU gripper tube (fiber reinforced hose) extrusion, clean and then finishing looping, the next step is to wrap each roll of plastic film, this layer of film to protect the surface of the PU tube directly to avoid contact with other substances, which help users to extend the life cycle of the PU plastic hose retard discoloration yellowing cycle and to a large extent.