What Should Be Paid Attention To In The Applications Of Solventless Lamination

[YSmarines]

Determining the components of the solventless adhesive
The A component of the two-component solventless adhesive is easy to react with the water, affecting the adhesive ratio, thereby affecting the laminating quality of the product. So the requirements of the solventless lamination process for water vapor are particularly strict. The relative humidity of the workshop and the adhesive storage library are as low as possible. The drying and filtration of the gluing system must be thorough.

For the lamination of paper to aluminum and paper to plastic, a one-component solvent-free adhesive will be an economic choice. However, moisture is involved in the curing process for the application of a one-component solvent-free adhesive and moisture needs to be added to ensure the curing of the lamination. This laminating method is subject to certain restrictions in dry winter and should be paid attention to.

Sample test
Nowadays, each flexible packaging company has its own unique product and technical characteristics. The raw materials used in each company are not the same. The substrates, inks and solvents used in different products are also various. The molecular weight of the solvent-free adhesive is generally Low and it is easily affected by external factors. Therefore, each product is recommended to have a sample test before first adopting solventless lamination technology and then put into mass production after the test is passed.

Pay attention to the individual differences in special products
Due to the low molecular weight of the solvent-free adhesive and the extremely strong penetration, the problems of adopting solventless lamination for some products will occur, which requires special attention. For example, when the laminating substrate is thin and the flexible package products with the auxiliaries which contain a large amount of molecular weight, adopting solvent-free laminatingprocess, the adhesive will penetrate the substrate and In severe cases, it can accumulate on the thermal surface of the substrate, by secondary reactions, generating urea and other derivatives, which affects the heat-seal quality of the product. In addition, due to the high permeability of the solventless adhesive, the color of the product is different when using the solvent-free laminating process for some flexible packaging products which require printing. Moreover, the edge of the printing pattern for the lamination product will become larger and the stroke of the small text will be thicker.