ISUOCHEM PU BEADS Common Issues

⑴ Not scratch resistant：

a. The coating film is too hard: switch to elastic resin; increase the amount of "688", reduce the amount of "BF", and reduce the amount of curing agent.

b. The coating film is too soft: the amount of curing agent is not large, or the curing agent is not well stored or the main agent is volatilized, resulting in incomplete curing of the coating film; increase the amount of "BF" and reduce the amount of "688".

⑵ Dry and cracked:

a. There is less diluent to form a dry spray, which can be diluted to the required spray viscosity.

B. If the solvent volatilizes too fast, the amount of high-boiling solvent should be increased, such as the amount of ethylene glycol ethyl ether acetate or switch to propylene glycol ethyl ether acetate or increase the proportion of cyclohexanone in the release ratio.

C. After spraying, the surface should be dry before putting it into the oven

D. If the spray is too thick, the coating film should be controlled to be 30-40um after drying

E. The ratio of fluff powder to resin is too large, reduce the amount of fluff powder

⑶Rough surface：

A. The fluff powder is not completely dispersed. Increase the dispersion time and improve the dispersion method

b. Filter to remove a small amount of coarse and undispersed particles

c. If the amount of fluff powder is too large, adjust the amount.

D. Too little solvent will form a dry spray, which should be diluted to full 

viscosity

E. If the drying speed is too fast, the surface should be left to dry first and then placed in the oven or completely dried naturally.

⑷Surface blooming：

a, the fluff powder is seriously poorly dispersed

b. Uneven spraying

c. Insufficient viscosity, increase the amount of thickener

⑸No velvet feeling：

a. The ratio of fluff powder to resin is not enough, increase the amount of fluff powder

b. The coating film is too thick and the solvent volatilizes too slowly.

In addition, for different substrates, the spraying conditions must be changed accordingly. For example, the viscosity of the coating should be increased to prevent sagging if the surface of the non-absorbent plastic is sprayed, and the viscosity of the surface of the absorbent material such as cardboard can be adjusted to be thinner.