PU is short of Polyurethane. Polyurethane combines the best properties of both plastic and rubber. It offers abrasion and tear resistance, high tensile and elongation values, and low compression set. Polyurethane is naturally flexible and exhibits virtually unlimited flexural abilities.
The two basic formulations of urethane, ester and ether, have some important differences. Water attacks ester-based urethane, causing a significant reduction in physical properties. Ether urethanes exhibit far superior hydrolytic stability, especially in humid environments. Ether-based materials also resist fungus growth better than ester-based materials.
When you buy PU air hose, do not consider price only. There is big quantity of bad tubes in the market. You will lose orders when you buy them. However, here are some advice to check air hose is good or bad.
The burst pressure of polyurethane tubing has a relation with operating temperature, that a inversely linear dependency exists. If the tube blow out at a relative low pressure as below chart, you need to be aware of this.
Flexibility and Elasticity
Polyurethane tube will stretch and flex but always return to its original shape.
When compared to other plastic and rubber tubing, polyurethane tubing offers improved flexibility at low temperatures, tear strength. When a bending happened, stretch and flex characteristics always make it return to its original shape.
Please try to pinch or bend the hose to see if it returns to original shapes quickly. It is like baby skin.
Good Flexibility and Elasticity is one strength of good tubes.
Usually a good performed PU air hose has a limited size tolerance.
As world standard, it always made below to satisfied different application.
For O.D. 3-8mm, +/-0.10mm
For O.D. 10-16mm, +/-0.15mm
To learn XHnotion air hose, please learn https://www.xpneumatic.com/Portfolio/pu-tubes