The adhesive on packaging tape is activated primarily through three different mechanisms depending on the type of tape:
1. Pressure-Sensitive Adhesive (PSA)
- The most common type of packaging tape uses pressure-sensitive adhesive.
- This adhesive is activated simply by applying pressure when the tape is pressed onto a surface.
- The pressure causes the adhesive to flow and conform to the surface irregularities, creating a secure bond at room temperature without needing heat or moisture.
- PSAs are made from a mixture of elastomers and tackifiers, providing stickiness and strength suitable for sealing cartons and boxes
2. Water-Activated Adhesive (WAA)
- Water-activated tape, also called kraft paper tape or gummed tape, has a starch-based adhesive that is dry until moistened.
- Activation occurs by applying water to the adhesive side, typically via a sponge or water dispenser.
- The water softens the starch adhesive, allowing it to penetrate and bond with the fibers of corrugated cardboard or paper packaging.
- Once dry, the adhesive forms a very strong, tamper-evident seal that is stronger than conventional pressure-sensitive tapes.
- This type is ideal for heavy-duty shipping and provides enhanced security because the tape cannot be removed without damaging the box
3. Heat-Activated Adhesive (HAA)
- Some packaging tapes use heat-activated adhesives.
- When exposed to heat, the adhesive undergoes chemical changes that increase bond strength.
- The process involves an initial bonding stage within seconds of heating, followed by a crystallization phase over several minutes that strengthens the bond.
- Heat-activated tapes are useful for bonding a variety of materials such as plastic, metal, and wood
Summary
Adhesive Type| Activation Method| Key Features
---|---|---
Pressure-Sensitive (PSA)| Applied pressure| Bonds at room temp, no moisture or
heat needed
Water-Activated (WAA)| Moistening with water| Strong, tamper-evident bond,
penetrates fibers
Heat-Activated (HAA)| Application of heat| Chemical bonding and
crystallization for strong adhesion
In most common packaging tapes used for cartons and boxes, the adhesive is activated by pressure (PSA) or water (WAA), with water-activated tapes providing superior strength and security for shipping applications
