Starch-based adhesives are used in paper bonding and paper products such as corrugated boxes, paper bags, wallpaper pastes, and bookbinding. Carbohydrates extracted from vegetable plants such as corn, rice, wheat and potatoes are natural polymeric products and are generally used for such applications. However, the natural tack of starch is too slow, and its viscosity too low to be effective as an adhesive. Borates in combination with caustic soda can dramatically change the properties of cooked starch, increasing its viscosity, tack property and cohesiveness.
Typically, borate powders such as borax or sodium metaborate are used in this application. Unfortunately, handling these powders creates dust in the work environment and the feeding of these powders can be very inconsistent due to the presence of caked lumps in the product. The powders will also need to dissolve into the starch solution. Borate liquids, as aqueous or amine-based solutions or suspensions, easily overcome these problems. They are easy to pump and meter and do not suffer from the dust problems.
If you would like to test the use of borate liquids in your starch adhesive production process, please speak to our technical team to select the most suitable borate liquid for your process and how to apply it.