The influence of compound bag heat sealing process elements

Composite bag heat sealing quality has always been a packaging produce manufacturer to control the quality of the products one of the most important factors. Today, the professional manufacturer of flexible packaging packaging is to analyze the composite bags under the influence of heat sealing process elements: 1, the heat sealing layer of material type, thickness and quality has a decisive influence on the intensity of heat sealing general commonly used heat sealing compound packing materials with CPE, CPP, EVA hot melt adhesive, resin and other ionic co-extrusion or blending modified membrane. The thickness of the heat sealing material in 20 ~ 80 & mu; M between, also has a special situations of 100 ~ 200 & mu; M. The same kind of heat sealing material, the heat sealing strength increases with the increase of the thickness of the heat sealing. Retort pouch heat sealing strength of the general requirements of 40 ~ 50 Newton, as a result, the heat sealing material thickness shall be in 60 ~ 80 & mu; M above. 2, the influence of the heat sealing temperature on heat sealing strength is the most direct melting temperature of various materials, concave and convex, directly decide the minimum heat sealing temperature compound bag. Produced in the process, because the heat sealing pressure, bag making speed and the thickness of the composite substrate aspects of influence, the actual selection of heat sealing temperature tend to be higher than the melting temperature of the heat sealing materials. The smaller the heat sealing pressure, require heat sealing temperature is higher; Machine speed faster, 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 the heat sealing layer are sealing. But jorge sealing temperature is too high, and easy to damage the solder side of heat sealing material melt extrusion, produce & other; Root cutting & throughout; Phenomenon, greatly reduced the sealing bag heat sealing strength and impact resistance of the function. 3, to achieve the ideal heat sealing strength, a certain amount of pressure is essential for thin bags, heat sealing pressure arrived at least 2 kg/cm22, composite membrane and follow the total thickness of the corresponding that add up. Lack of jorge sealing pressure, verily hard-to-reach fusion between two layers of thin film, to close part of the heat sealing is not good, or difficult to out air bubbles in the center of the weld, a virtual welding; Heat sealing pressure is not, of course, the bigger the better, it should be no damage to the welding edge advisable, because the high heat sealing temperature, welding and heat sealing materials are already in a molten condition, too much pressure to squeeze out some hot sealing material, make the weld edge constitute a half block status, weld crisp, heat sealing strength decreased. 4, heat sealing time is mainly determined by heat sealing bag making machine speed time is of the look of the welding seam sealing strength and an important factor. The same heat sealing temperature and pressure, heat sealing time is long, the heat sealing layer fusion more fully, combined with a more healthy and vigorous, but heat sealing time is too long, short weld wrinkling, affect the appearance. 5, if the weld cooling after hot sealing owe good, not only affect the appearance of weld seam smoothness, has certain influence and strength of heat sealing the cooling process is through under certain pressure, with low temperature on just after melting heat sealing weld shapes, eliminate stress concentration process. So the pressure is insufficient, cooling water circulation, circulation, the water temperature is too high, or not timely will cause poor cooling, cooling heat sealing edge case become warped, heat sealing strength decreased. 6, heat sealing, the more the higher the heat sealing strength of longitudinal heat sealing number depends on the useful longitudinal welding rod length and the ratio of the bag length; Lateral heat sealing number by the lateral heat sealing device on the number of group decision. Good heat sealing for heat sealing number at least more than two times. General hot knife of bag making machine has two groups, and hot knife position overlap degree is higher, the better heat sealing effect. 7, the same structure and thickness of the composite film, the higher the peel strength between composite layer, the greater the heat sealing strength also for low peel strength of composite products, weld damage often make seam composite membrane interlayer strip first, caused by the inside heat sealing layer independent accept damage, and the surface material lost, reinforcing effect of weld heat sealing strength reduced. If composite peel strength is larger, it does not produce welding strip between the upper layer, heat sealing strength is measured by the practice. After understanding, we think the packaging bag broken rate high reason is that the second group of heat sealing knife pressed parts not overlap, close to generate virtual welding heat sealing side, the CPP film thinning, part of the structure is damaged, in cooking in thin layer of CPP can't afford to pressure and broken bag.