Application and Solution of Waterborne Glue Compound Technology (I)

With the development of social economy, the flexible packaging industry has been developing rapidly. The improvement of people’s living standards has increased concern for food safety and hygiene. Most of plastic packaging materials are used for food packaging, so the health, safety and environmental protection issues of plastic packaging are closely related to the health of consumers. At present, the food packaging composite film produced in China is basically compounded with a solvent-based adhesive, so that there is solvent evaporation and a small amount of solvent residue in the compound process towel. Food packaging with high residual solvent content can cause odors in the package and degrade the food. Solvent evaporation during compounding not only pollutes the environment, but also jeopardizes the physical health of field workers. Therefore, if the solvent evaporation and solvent residues in the compound food packaging process are reduced, and the quality of the product can be ensured, the cost can be reduced, and the efficiency of the enterprise can be improved. Therefore, it is necessary to find a way to meet the environmental protection of the food packaging and adapt to the company's own development approach. The goal of joint exploration by domestic food packaging companies.

After years of exploration, prolonged trials, and various attempts, Hangzhou Dingzhen Packing Materials Co., Ltd. finally found a new approach of hygienic and environmentally-friendly greedy product packaging—water-based adhesive compounding.

Compounding mechanism

Water-based glue refers to a compound cavity adhesive that uses water as the main solvent and can be used directly. The company chose a water-soluble acrylic adhesive.

Water-based adhesive is a cross-linked acrylic and polyurethane adhesive body, with good heat resistance and media properties, acrylic emulsion and most of the composite substrate has a good affinity, high molecular weight polymer to ensure high shear strength and initial peel strength. The film formation principle is shown in Figure 1.

experiment analysis

Waterborne adhesives are cheaper to use than solvent-based adhesives; they are especially solvent-free during compounding, and they have no solvent residue after compounding; they are safe, hygienic, and environmentally friendly; they require maturation after compounding, which saves energy; compound direct slitting shortens the production cycle. ,Reduce working space and increase production efficiency. See the composite adhesive performance comparison chart:

Water-based adhesive compounding conditions are as follows:

Substrate surface energy greater than 38 dyne/cm
180-200 online offset solid content: 40% -50%
Oven temperature: 75%, 80~C
Compound temperature: 85t
Working speed: 100-250m/min

(to be continued)