Precautions For TPU/PVC Coated Webbing In The Production Process

TPU/PVC coated webbing is a new webbing of webbing newly developed to replace traditional nylon webbing. Its main structure is a nylon or (polyester) webbing. It is mainly used for pet webbing and car handles. TPU/PVC coated webbing is fashionable, durable and easy to clean and stronger. It combines the physical properties of TPU/PVC to make the nylon webbing after covered the glue more and more widely used .

We should pay attention to those matters in the process of produce a high-quality TPU/PVC coated webbing. We will take care of various aspects of choice, preparation, molding, traction and packaging.

A few main  points of a high-quality TPU/PVC coated webbing:

1.TPU/PVC and the webbing have strong gluing fastness;

2.Wrapped webbing without streaks and bubbles；

3.After the webbing is coated, the webbing is in the middle position；

4.Dyed TPU / PVC surface will not fade;

5.For a long time, the TPU/PVC coated webbing has not turned white, fogged or turned yellow.

(1).Material choice: TPU / PVC material and webbing

What kind of TPU/PVC material is suitable for wrapping webbing, it must be extruded TPU/PVC  material, hardness is 80A~95A is the best, this can be based on the softness and hardness requirements of the product itself. TPU / PVC material hardness adjustment, generally select 85A material is more suitable;if the choice is too soft, the strength is not up, choose too hard TPU / PVC materials, the webbing is too hard, can not achieve a good hand feeling. The polyester material is also selected as the polyester material, which is selected according to the use of the product itself. If it is resistant to low temperature, hydrolysis, and has a good touch, polyester type TPU can be used; If it need good mechanical strength, heat resistance, stab resistance and other requirements, polyester TPU can be selected; In the process of TPU, the most important point to note is that there will be no phenomenon of seeping powder after a long time. This is the most common phenomenon of polyester TPU. This is especially important in selecting TPU materials;

Flame-retardant handle webbing must use flame-retardant TPU materials. Generally, ordinary grade TPU materials have no way to meet product requirements. Flame-retardant grades have V0 grade, V1 grade, and low-smoke and halogen-free environmental protection requirements, so If you choose some safety and environmental protection requirements, you must use imported flame retardant TPU materials, and require the material manufacturers to provide relevant certification certificates before they can be used.

(2).The choice of webbing can be used for coated webbing.

The selected webbing must be used for high temperature resistant webbing. What is high temperature resistance? Because the webbing passes through the oven during the production process, the temperature is generally 130℃, and the actual temperature reaches 160 ℃.So, the webbing must pass through high temperature.After treatment, the webbing  size is more stable; there will be no shrinkage during the coating process; in addition to passing through the oven, the webbing must pass through a high temperature die, and the temperature of the die will reach 200℃,If the webbing can't withstand high temperature, it will shrink when it meets high temperature. It will be unstable in the TPU/PVC coating process, and it will not reach the expected webbing effect.At the same time, the density of the webbing weave should be high, not too loose, to prevent the webbing from encountering high temperature shrinkage during the traction process. Webbing are generally made of nylon webbing or polyester webbing. 

Other notes: finishing of the webbing and adequate cooling of the TPU / PVC material

1.Finishing of webbing

Before wrapping the webbing, it is very important to finish the webbing that needs to be covered. The webbing is heat treated to prevent the webbing from shrinking during high temperatures during the coating process.Why is the finishing of the webbing an important point?When the webbing is in the process of traction, it is always in a constant speed. If the webbing is not finished, when there is distortion, there is no way to stop and adjust, it will continue in the direction of traction, and the twisted webbing can not pass through. Then the webbing must be cut  and re-inserted into the mold mouth. At this time, at the same time, TPU/PVC material will continue to discharge, will causing great waste and loss, so before coating , webbing finishing work is very necessary.

2.Adequate cooling of the TPU / PVC material 

When TPU/PVC is coated, it is melted by the host at a high temperature, and only be cooled and formed in the cooling water tank. If the cooling water does not reach the cooling effect, streaks or bubbles appear on the surface of the TPU/PVC after coating, TPU/PVC and Nylon webbing has insufficient coating fastness, which makes it easy to layer TPU/PVC and webbing, and can not achieve the coating effect; fully cooled TPU/PVC, the surface is fine and uniform, TPU/PVC and webbing coating effect is firm; especially TPU/PVC When it is just in contact with the cooling water, it must be cooled sufficiently. Place a few more cooling heads, when it enters the water,fully cool the coated webbing so that the webbing is flatter and will not be deformed.