reasons:

(1) heat sealing temperature is too high;

(2) excessive pressure;

(3) sealing time is too long;

(4) the upper part of sealing the edge of the too sharp or damage to the Teflon-coated;

(5) sealing the bottom of the silicone rubber excellent;

(6) in the composite and the curing process the part of the film adhesive into the internal. Substrate effects due to the infiltration of adhesive toughness (impact resistance) decreased increased brittleness;

(7) cooling and placed in plastic the heat seal strength has increased but also a tendency to become brittle.

Strategy:

(1) according to the material within the seal coat sealing properties select the appropriate processing temperature pressure and heat sealing time;

(2) to improve the state of the upper surface of sealing knife smooth the surface of the seal;

(3) coated with Teflon fabric intact;

(4) select the appropriate hardness of the silicone rubber pad