How does water activated glue work?

Water-activated glue, also known as water-activated adhesive or gummed paper tape, is a type of adhesive that requires water to become sticky and bond surfaces together. Here is how it works:

1. Composition: Water-activated glue is typically made from a mixture of starch, dextrin, or other natural polymers. These materials are derived from plant sources and are usually combined with additives for better performance.

2. Activation: Water-activated glue remains in a dry and non-sticky state until it comes into contact with water. When water is applied to the glue, it activates the adhesive properties.

3. Hydration: Upon contact with water, the adhesive molecules in the glue absorb the water molecules. This process is called hydration, and it causes the glue to swell and become sticky.

4. Bonding: As the glue absorbs water and swells, it forms a gel-like substance. This sticky gel adheres to the surfaces it is applied to, creating a strong bond as it dries. The glue can bond to various materials such as paper, cardboard, wood, and fabric.

5. Drying: After the glue is applied and the surfaces are joined, the water in the glue begins to evaporate. As the water evaporates, the glue gradually hardens and solidifies, firmly bonding the surfaces together.

6. Strength and Durability: Water-activated glue forms a strong bond due to the hydration process. The adhesive properties are enhanced by the water molecules, providing an effective and long-lasting bond.

Water-activated glue is commonly used for sealing envelopes, packaging boxes, and in the art and craft industry. It is a versatile adhesive that offers a secure bond while being environmentally friendly, as it is often made from natural and renewable resources.