1, good adhesion, adhesion is not easy to fall off.
2, after curing, empty to fine, can not have large holes, otherwise it will leak.
3, the shrinkage should be small, not to pull the door, cracks, easy to leak
4, the foaming quantity is large, can save the cost.
5, after curing to have elasticity and hardness, the general quality of poor polyurethane foam is not elastic, as long as the force of a press will collapse.