Composite packaging bag broken rate is high, seven 'reason' finally found!
Can defeat bag, compound bag bag turned out to be caused by the seven largest source, professional manufacturer of flexible packaging packaging summarize seven reasons, power clothing, clothing, cosmetics, hardware electronics, food, etc. Will use composite bags enterprises better choose packaging products.
1, 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, practice 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 real sealing heat sealing layer.
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.
2, heat sealing material type, thickness and quality of the impact of heat sealing strength have chosen generally 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 have special cases of 100 ~ 200 & mu;
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;
3, to achieve the ideal heat sealing strength, the pressure must be necessary on frivolous bags, heat sealing pressure arrived at least 2 kg/cm2, and as composite film thickness increases with the increase of the total.
Jorge sealing pressure shortage, difficult to reach real fusion between two layers of thin film, to close part of the heat sealing owe good, may not out of 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 heat sealing materials, composing a half block of the weld edge weld crisp, heat sealing strength decreased.
4, if the weld cooling after hot sealing owe good, not only affect the appearance of weld seam smoothness, but is must for heat sealing strength is through the influence of the cooling process under the pressure of must, with a low temperature for just after melting heat sealing weld shapes, eliminating stress converged on the process.
Therefore, pressure, 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.
5, heat sealing time is mainly composed of bag making machine speed selection of heat sealing time is of the look of the welding seam sealing strength and a key 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.
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 chosen by the number of sets of machine horizontal heat sealing equipment.
Remarkable heat sealing for heat sealing number arrived in at least two more times.
General hot knife of bag making machine has two groups, and hot knife bearing stack 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 about low peel strength of composite products, weld damage is often welds of composite membrane interlayer strip first, caused by the inside heat sealing layer independent accept damage, reinforcing effect and surface material lost and 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.