Stick It – Adhesive Talk
When most people think about tape or labels, if it sticks it works. But there’s a lot more to the adhesives used in tapes and labels than just being sticky.
The adhesive that makes your label or tape stick can have varying levels of grip, shelf life, and longevity depending on the intended use. The adhesive can also be made from a variety of materials either man made or natural. In this post, we’ll look at Rubber, Silicone, and Acrylic.
Rubber – Natural or Synthetic
Natural rubber: used in the cheapest tapes on the market
- Has a higher tack (“stickyness when dry”)
- Limited UV resistance
- Dries out quickly (6 – 12 months)
Natural rubber adhesives are used in duct tapes and low-temperature masking tapes.
- Hot-melt – low-temp melting plastic, ages poorly, brittle, low UV resistance.
- Solvent-rubber – better temp and aging, poor UV resistance
- Butyl rubber – excellent UV and aging resistance, lower mechanical strength
Compared to acrylic and rubber adhesives, they are significantly more expensive, but due to their excellent high temperature performance they are very well suited to splicing tapes, masking tapes and Kapton tapes.
- High flexibility (low modulus) at sub-ambient temperature
- Consistent performance over wide temperature range
- Excellent aging and UV resistance
- High temperature resistance
- Good resistance to solvents
Acrylic adhesives can either be water-based or solvent-based and are generally divided into two subgroups: Pure and Modified
- Reasonable adhesion to a wide range of substrates (see modified acrylics below)
- Good aging and UV resistance
- Reasonable temperature resistance
- Lower tack and less adhesion on hard-to-bond plastics (high- and low-density polyethylene (HDPE & LDPE) and polypropylene (PP) ). Pure acrylic adhesives are mainly used on tapes whose applications are bonding, sealing or surface protection.
Modified acrylics have the same characteristics as pure acrylics, but have superior adhesion to the hard-to-bond-plastics mentioned above. Generally, these are more expensive than pure acrylics and are used for plastic bonding, lamination and splicing.
So there you have it. I hope some of this information sticks with you.