It is mainly through the surface absorption of water to complete the drying or bonding. The raw solid starch in the adhesive gelatinizes and absorbs water on the paste line. The bonding time is a few seconds to a minute or so. The moisture is gradually absorbed by the surrounding air and paper fibers. This traditional adhesive is generally used in corrugated board production lines, which can immediately produce a strong bonding effect.
In order to achieve a satisfactory bonding effect, a slightly viscous suspoemulsion must be added to the starch and water emulsion, which contains pre-gelatinized starch. This suspoemulsion can suspend the raw starch in water and prevent its precipitation; increase the concentration to facilitate being carried by the glue roller and form a paste film of appropriate thickness on the roller; adjust the viscosity to make the paper fibers properly moisturized and initially adhered; to ensure the health There is a lot of water around the starch molecules so that the starch can expand to the maximum and gelatinize when heated; caustic soda must be added to adjust and control the gelatinization temperature of starch to the lowest point.
In order to achieve a satisfactory bonding effect, it is necessary to add borax to make the raw starch absorb all the water available for absorption when heated; to produce proper viscosity and toughness when the starch is gelatinized; to act as a buffer to prevent the caustic soda from being Under the lowest gelatinization temperature, a part of the raw starch swells.