The heat sealing material thickness should be 60 ~ 80μm or more.

2, the heat sealing temperature on the heat sealing strength of the most direct.

Various materials of the melting temperature of the bump, the direct resolution of the composite bag minimum heat sealing temperature. In the production process, the heat sealing temperature is usually higher than the melting temperature of the heat sealing material due to the heat sealing pressure, the bag making speed and the thickness of the composite substrate. The smaller the heat sealing pressure, the higher the heat sealing temperature; the faster the machine speed, the thicker the surface layer of the composite film, the higher the heat sealing temperature. If the heat sealing temperature is lower than the softening point of the heat sealing material, it is impossible to seal the heat seal layer without any pressure or prolonging the heat sealing time. However, if the heat sealing temperature is too high, it is very simple damage to the welding edge of the heat sealing material melt extrusion, the occurrence of "root cutting" scene, greatly reduced sealing heat sealing strength and bag impact resistance.

3, to reach the aspirations of the heat sealing strength, must be essential pressure.

On the frivolous packaging bags, heat sealing pressure to reach at least 2kg / cm22, and with the composite film to add the total thickness of the corresponding progress. If the heat sealing pressure is lacking, it is difficult to reach the real fusion between the two layers of film, resulting in local heat sealing is not good, it may be difficult to catch the cracks in the middle of the weld, the formation of Weld; of course, heat sealing pressure is not bigger Well, should not damage the welding edge is appropriate, due to the higher heat sealing temperature, the welding edge of the heat sealing material has been in the semi-molten state, too much pressure to squeeze part of the heat seal material, so that the edge of the weld Semi-blocked state, the weld brittle, heat sealing strength decreased.

4, heat sealing time mainly by the speed of the bag machine resolution.

Heat sealing is also a key factor in the strength and appearance of weld seals. The same heat sealing temperature and pressure, heat sealing time is long, the heat sealing layer fusion more fully, more solid contact, but the heat sealing time is too long, the simple formation of weld wrinkling, affecting the appearance.

5, heat sealing after the weld if the poor is not good, not only will affect the appearance of the weld flatness, and heat sealing strength will have a certain impact.

The cooling process is carried out under certain pressure, with a lower temperature just after the heat sealing of the weld to shape, to eliminate the stress set the process. Therefore, the pressure is not, the cooling water circulation is not smooth, the amount of circulation can not, the water temperature is too high, or cooling is not timely will cause poor cooling, heat sealing edge Alice, heat sealing strength decreased.

6, the more the number of heat sealing, the higher the heat sealing strength.

The number of longitudinal heat sealing depends on the effective length of the longitudinal bar and the ratio of the length of the bag; the number of transverse heat sealing is determined by the number of sets of transverse heat sealing equipment. Outstanding heat sealing, the number of requests for heat sealing at least twice. The usual bag machine hot knife has two groups, and hot knife azimuth stacking degree is higher, the better the heat sealing effect.

7, the same structure and thickness of the composite film, the higher the peel strength between the composite layer, the greater the heat sealing strength.

On the low peel strength of the goods, weld damage is usually the weld at the first layer of the composite film between the stripping, resulting in the inner surface of the heat seal layer to accept the damage alone, and surface layer material to lose reinforcement effect, the weld heat sealing Strength is greatly reduced. If the composite peel strength is large, there will be no edge peeling between the edge, the measured heat sealing strength is much greater.