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Reduce the odor of packaging bags

For compliance with production control, the most important thing is to take measures to control the following odors that have the greatest impact: printing, solvent residues in compounding, resin decomposition and additive precipitation.Reason 1 for the peculiar smell of packaging bags: control of residual solvents① Printing substrate. Different printing substrates have different adsorption capacities for the solvents used in printing. The printing substrate selectively adsorbs the solvent,PPSuch materials have a large amount of toluene adsorption,PVDCEspecially adsorbs toluene,PAAdsorbed alcohols.PA,PETThe adsorption capacity for statistics is less thanPPkind.② product structure. For product structures with poor barrier properties, such asBOPP/PE, the residual solvent is heated in the drying room, slitting and rewinding and other processes. Especially the volatile ethyl alkyd. For product structures with good outer barrier properties, such asKBOPP/PE,VNPET/PEetc., the residual solvent is high. For products with a double-layer barrier structure, the residue is the most difficult to control, and it is also the most difficult after the fact, such asPET/VMPET/PE/Kcellophane/AI/PE,PET/VMCPPetc., the residual solvent trapped in the composite layer.③The control of the residual solvent of the peculiar smell of the packaging bag also includes: the printing screen, the release of the ink resin to the solvent, the purity of the solvent, and the solvent in the dry compounding.The second reason for the peculiar smell of packaging bags: resin decomposition in extrusion compoundingWhen extrusion compounding,TThe high temperature generation of the type touch head330℃, at such a high temperature, the resin is thermally decomposed and thermally oxidized with oxygen in the air, which will produce peculiar smell. In order to reduce the odor, when extruding, lower the resin temperature and shorten the die lip when possible. Different resins produce different odors.PPThe odor is slightly small,PEClass is larger,EVADue to poor thermal stability, odor is more likely to occur. There are also a large number of additives in the resin, such as: heat stabilizers, antioxidants, slip agents, etc., overflowing during molding is also an important cause of odor.Three reasons for the odor of packaging bags: other aspectsIt is necessary to have a good exhaust function on processing equipment such as extrusion and film blowing.When making packaging bags, there will also be peculiar smell due to heating. On the one hand, the heat sealing temperature should be reduced as much as possible, and on the other hand, good packaging bags should be placed for a while before wrapping.

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