Usually odorous nut bags, the main reason is the film together with organic solvents are volatile and soluble, and PET, PA, PE, PP, has curing polyurethane adhesive, already dry ink film are not volatile.
The odor problem analysis;
1, resin himself low molecular substances of all kinds of additives and their own;
2, film production and processing of peculiar smell;
3, flexible packaging in the production and processing of peculiar smell;
4, storage process of peculiar smell.
Steps to eliminate residual solvent problem are as follows: 1, the standard of the residual solvent testing methods, the interception of a small piece of composite material, cut up, preheating, extracting gas, into the gas chromatograph is used to detect the residual solvents;
2, the cutting part of the composite film, bag, filling the air, sealed mouth, in the electrical oven heated for a period of time, gas chromatograph of needle to extract certain amount of air from inside the bag, injected gas chromatograph in the detection of residual solvent.
Nut bags the influence of compound process: 1, the choice and that meet the needs of a two-component glue, ink solvent also needs to accord with the requirement of peculiar smell, do it after finished product without irritating smell.
2, to control the dosage of the glue must be strictly implemented, more usage of glue or glue line is too thick, can make less volatile solvent, lead to excessive residual solvents.
3, dry compound machine speed, matching of viscosity and adhesives to make adhesive is fully dissolved in the solvent, and be sure to guarantee the cleanliness of adhesive, there can be no impurities, uneven glue, otherwise affect the volatile solvent, inducing the layout with the problem of solvent evaporation.
4, set up dry compound machine oven paragraphs temperature, speed, temperature, set up paragraphs generally at about 70 ℃ ~ 90 ℃ advisable, attention should be paid to the exhaust air volume adjustment paragraphs oven at the same time, set the exhaust air of accurate, fully effectively remove odor in the film.
5, nut bags after the composite curing, curing time and temperature control, curing time is 24 - commonly
28 hours, at about 45 ℃ temperature, curing time is not enough or not complete, not only can produce peculiar smell, will seriously affect the peel strength of composite membrane.
At the same time, to ensure the curing chamber intake and exhaust flow, will smell the air discharge in a timely manner.