Packing bag heat sealing fault break one by one!

the lining of the bag for the heat sealing layer, the material and thickness of the heat sealing layer directly affect bag heat sealing effect, generally the commonly used thermal sealing compound packing materials have the CEP, LPPE, CPP, OPP, EVA hot melt adhesive resin and other ionic co-extrusion or blending modified membrane.

the thickness of the heat sealing material, generally in 20 - Floating between 80 microns. Special circumstances also has 100 - 200 microns, the same kind of heat sealing material, the heat sealing strength increases with the thickness of the heat sealing. Cooking bags, for example, the heat sealing strength of general requirements of 40 - 50 Newton, as a result, the thickness of heat sealing should be 60 - More than 80 microns.

heat sealing bag making the temperature in the process, the control of the temperature depends on the temperature meter to display them. In the process of heat sealing bag, as precise as possible to the requirement of thermometer, the error range and the best value is not more than + / - 5 ℃. Heat sealing temperature on the influence of heat sealing strength is the most direct, the melt temperature of various materials, determine the minimum heat sealing temperature.

in the actual production process, due to the heat sealing pressure, bag making machine speed and the thickness of the composite substrate aspects of influence, the actual use of the heat sealing temperature tend to be higher than the melting temperature of the heat sealing materials. Heat sealing pressure is smaller, for heat sealing temperature is higher, the faster machine speed, the surface of composite membrane material is thicker, the requirements of the heat sealing temperature is higher. If the heat sealing temperature is lower than the heat sealing material softening point, no matter how to increase the pressure or heat sealing time, all can't make real sealing heat sealing layer.

however, if the heat sealing temperature is too high, and easy to damage the welding place of heat sealing materials, melting extrusion 'root' phenomenon, greatly reduces the sealing heat sealing strength and impact resistance performance of composite bag. In the process of actual bag heat sealing, heat sealing tool can rotate spring to adjust pressure often USES

general tool adjustment process is composed of two springs, left and right sides, if the pressure affect the heat sealing strength, testing method is: in a compound bag look carefully stitch is processing, if the pressure evenly won't produce the phenomenon such as bubble; Another method is to use long 500 px, 75 px, 5000 px wide smooth bamboo piece of experiment, due to the pressure is insufficient, low intensity, tend to appear leakage phenomenon, so the uniform pressure and low temperature is to reduce strength, one of the basic stratification.

to achieve the ideal heat sealing strength, heat sealing pressure essential

for thin bags, heat sealing pressure to at least 2 kg/cm2, and as composite membrane increases with the increase of total thickness; Jorge sealing pressure is not enough, difficult to achieve real fusion between two layers of thin film, lead to local heat sealing is bad or difficult to eliminate the bubbles sandwiched between weld, virtual welding.

but heat sealing pressure is not the bigger the better, should not to damage it is advisable to weld edge, because the high heat sealing temperature, welding and heat sealing materials are already in a molten state, too much pressure to squeeze out some hot sealing material, the weld edge forming half cut off state. Weld crisp, heat sealing strength reduced. So the pressure regulation is critical.