Vacuum packing bag of the two methods of composite release date: 2020 -
08 vacuum bags there are two main types of two methods of composite dry after legal and coated after legal dry after legal dry after legal in all kinds of sheet or membrane material as base material, use the gravure roller in the substrate surface coating a layer of adhesive, after drying, drying and sticky, and then on the composite roller pressure compound.
This is the present domestic the most commonly used a composite film production method.
The characteristics of dry type composite is adaptation of wide and select the best bonding agent, can be any sheet or membrane material compound, such as PE film, PP film, PET film, PA film, etc.
Dry after legal composite high strength, composite speed, but the dry type composite cost is high, because the bonding agent dosage in 2.
5 ~ 5 (
Dry solid content)
, hence the solvent residues and environmental pollution problems.
Coating after legal coating after legal process is simpler, the more difficult to separate processed into film barrier property of the resin, such as PVA, PVDC coated composite can be used.
PVC melting temperature is 220 ~ 240 ℃, decomposition temperature 200 ℃.
To be processed into film need to add plasticizer and stabilizer, in order to improve the thermal decomposition temperature and reduce melting temperature.
Is water soluble PVA, in be used actually USES a mixture of water and ethanol as solvent, on the PE or PP film coated 4 ~ 6 & mu;
M the thickness of the PVA, due to the poor water resistance of PVA, crosslinking agent is added in the PVA solution can be used to improve its resistance to water, but also improve the adhesion of PVA with PE, PP, can save the bottom, in order to convenient bag.
PVA coated PE or PP membrane can be dry compound, with the rest of the film formed coating PVA/PE (
/ LDPE composite membrane structure, the membrane barrier performance is good, vacuum effect is better than a PA/LDPE, low cost.
Is used for coating of PVDC vinylidene chloride copolymer emulsion polymerization with acrylic ester monomer, coupled with the appropriate solvent and additives, coating in cellophane paper, BOPP, nylon and polyester, make it has good resistance wet gas blocking performance and heat sealing performance, the use of PVDC biggest problem lies in its safety and health, it is generally believed monomer content should be less than 1 & times;
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