5. The fineness of raw and auxiliary materials varies greatly, resulting in uneven mixing or improper mixing time. Solution: crush and sift the raw and auxiliary materials so that their fineness can meet the quality requirement of this kind, and control the mixing time well.
6. Low concentration of adhesive or poor adhesion force due to the quality of adhesive, too much fine powder and adhesion. Solution: sift out fine powder with 40 purpose sieve mesh, make grain again, dry, whole grain, mix evenly all batch, press piece again.
7. Excessive humidity and humidity in the environment. Reduce environmental humidity.