The composite process requirement of the water bag

Current water bag or commonly use dry after legally. 1. The gluing quantity on the selection criteria of glue quantity range: 2. 8 ~ 3. 2 GSM, excessive amount of glue on the peel strength is meaningless, but increases dry load. The compound equipment for drying ability is insufficient, but increases after boiling layer, the chance of broken bags. When testing the gluing quantity, it is important to pay special attention to the nylon membrane via bake, due to the change of water content before and after, affect the accuracy of the gluing quantity detection! When we in the production of water bag, can't just have a crush on resin content, but also focus on adhesive coating microstructure uniformity, network cable roller parameters will directly affect the adhesive coating microstructure uniformity. 2. Water requirements of GB/T3728 - ethyl acetate 2007 of the moisture content of ethyl acetate and ethanol content have specific requirements, the quality of the ethyl acetate is unqualified, Such as water content and alcohol levels) Often result in a composite membrane wrinkling quality accidents. Table 1 is a flexible packaging plant water content detection data, ethyl acetate in 20 batches of incoming goods inspection, there are four batches of more than 500 parts per million ( Classy article) , one of which is unqualified, and the number of buckets of ( Dealers partial shipments) Other batches for solvent, the solvent tank trucks. Most small soft packing enterprises buy bottled solvent, water content of ethyl acetate indicators may be beyond the requirements of the product. In alcohol content of the ethyl acetate often does not cause the attention of the most flexible packaging enterprises, the ethyl ester of flexible packaging enterprise test data ( Barrel solvent) Found that 14 batches of a classy article, only 2 grade a, and the overall quality is poorer, we should pay attention to the soft bag factory. 3. To ensure that the adhesive dry fully we usually focus on the compound glue quantity, actually insufficient drying is often caused by incomplete (adhesive curing Sub insufficient heat resistance) , packaging water layer, the phenomenon of wrinkling quality the most direct reason. With good adhesive solution exists in the small amount of water and alcohol impurities, good drying can make the moisture in the coated rubber impurities such as volatile as far as possible, reduce the consumption of proportion of curing agent in rubber. When dry process of composite in order to ensure the adhesive fully dry, want to note a few points: ( 1) The device itself dry performance, such as equipment into the exhaust air volume, the length of the oven. （ 2) The drying temperature setting. (1) set of drying temperature on the first block. The first area of drying medium the highest concentration of ethyl ester, so the first area drying temperature setting cannot be too high ( Generally not higher than 65 ℃) 。 Because temperature is too high, the surface of the rubber solvent volatilization quickly and skinning they inhibit the inner solvent in dry period of the escape of a few area. (2) the drying temperature gradient setting. Oven temperature should be set according to the increasing regularity of gradient, the purpose is to accelerate hardening area and eliminate peculiar smell area the spread of the rubber solvent volatilization, less solvent residue in the film. （ 3) In the adjustment of the exhaust air. (1) in the drying process of evaporation area into the exhaust air valve should be open to the maximum, and close the return air valve. (2) and in dry hardening area and eliminate peculiar smell area can be appropriately increased air flow back, part of the energy consumption can be saved. 4. The influence of environmental temperature and humidity in the summer of high temperature and high humidity season dry compound rubber is a two-component polyurethane adhesives do period of frequent occurrence of quality accidents, according to plant some adhesives, in the summer received 95% of the quality of the feedback related to rubber not stem. Under high temperature and high humidity environment, the air is very high in water content, easily by acetic acid consumption of volatile to glue plate curing agent, the adhesive of main agent and curing agent ratio imbalance, cause composite cured rubber crosslinking curing incomplete, delaminating wrinkling occurs when boiled. No conditions of temperature and humidity control workshop flexible packaging enterprises, high temperature and high humidity in summer season should be paid attention to the following: (1) by detecting the environment temperature and humidity and temperature at the top of the rubber plate, solvent drums, avoid & other; Dew point & throughout; Happens, once appear, & other; Dew point & throughout; Means that the moisture in the air a lot into the rubber plate, rubber not stem phenomenon appear easily. (2) water bag in the production of the arrangement as far as possible to avoid high humidity period for composite processing. (3) composite cycle with ethyl acetate barrels, glue barrel shall be affixed with the seal, such as adopting semi-closed injector can further reduce the influence of environmental humidity. 5. Curing process requirement general curing conditions: temperature 50 to 55 ℃, 48 hours. In addition, but also pay attention to the whole film uniformity of maturation: (1) according to the temperature and membrane (near the actual are consistent ( The actual temperature of roller up and down or so) ； (2) near the roller can realize effective air convection; (3) winding surface temperature effects of curing process of heat transfer to a certain extent, core winding composite membrane curing conditions whether meet the requirements. （ This may be caused by unstable quality of a major factor. ）