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After Reading This Paper, Flexible Packaging Bag Heat Seal Fault Does Not Ask For Help!
Nov 25, 2016

Compound bag heat seal fault analysis:

Heat seal material type, thickness, and quality of materials is the most direct effect of heat seal strength.

General packaging commonly used heat sealing material for CEP and the LPPE, and CPP, OPP, EVA, hot melt adhesives, and other Ionic resins co-extruded blend films. Heat sealing layer thickness of the material, generally fluctuated between μ m 20-80. Special cases of 100-200 μ m, with a heat seal material, the heat seal strength-sealing thickness increases.

For example, cooking bag heat seal strength requirements of the 40-50 Newton, so the sealing thickness should be 60-80 μ m or more. Hot sealing bag making process involving temperature, temperature control depends on the temperature of the instrument display. In the process of sealing compound bags, require more precision thermometer, the better the range of error is best and set value is not greater than ± 5 ℃. Sealing temperature has a direct effect on the heat seal strength, the melting temperature of the material directly decided to bag the lowest heat seal temperature.

In the actual production process, due to heat stress, bag making machine speed and the thickness of the substrate, and many other effects, using heat seal temperatures tend to be higher than the melting temperature of sealing material. Heat sealing pressure is less, require higher heat seal temperature, faster speed, composite membrane surface in thicker materials requiring higher the sealing temperature. Heat seal temperature if below the softening point of sealing material, regardless of how to increase the pressure or extended heat sealing time, cannot make heat seal layer true seals. However, if the sealing temperature too high, and extremely easy to damage sealing material welding and melt "undercut" phenomenon, greatly reduced the seal of the seal strength and impact resistance of composite bags.

In practical bag sealing process, the pressure of heat seal cutter swivel spring is often used to adjust. Adjustment process general tool by two a spring composition, points left, and right on both sides, if pressure effect hot seal strength, detection method is is: take a only are processing of composite bags carefully observation sewing track, if pressure uniform is not produced bubble, phenomenon; another a method is, with long 500px, and wide 75px, and thick 5000px dedicated smooth bamboo block for test, due to pressure enough, strength low, often appeared leak broken phenomenon, so uniform of pressure and temperature is reduced strength low, and layered phenomenon of basic one of.