4.7.1 Pressure sensitive adhesives

General description:

  • High viskosity liquids (usually on a support material)
  • They do not harden or cure and consist of elastomers or thermoplastics

Physical properties of the adhesives

  • Viscous to paste-like liquids; usually on a support material

A wide range of PSAs are available and these can be categorised in a number of ways.

  • The adhesive applied to the support material can belong to any of the following groups of adhesives:
    • Solvent-containing PSAs
    • Dispersion PSAs
    • Hotmelt PSAs
    • Radiation curing PSAs
  • Regarding the chemistry, PSAs can be split up as follows:
    • Natural rubber PSAs
    • Acrylate PSAs
    • Silicone PSAs
    • Polyurethane PSAs
  • Regarding the joint properties, PSAs can be split up as follows:
    • Detachable PSAs
    • Permanent PSAs
  • Most PSAs are supplied to users/consumers as adhesive tapes. A distinction is made here between:
    • Single-sided adhesive tape
    • Double-sided adhesive tape
    • Transfer adhesive tape / free film

Structure of adhesive tapes

Processing properties:

  • Manual, semi-automated or fully automated processing
  • For preferred equipment contact the adhesive manufacturer
  • The contact pressure here has a decisive effect on the adhesion and strength of the resulting joint
  • Adhesive film thickness: depends on the product
  • There is no hardening; the adhesive remains as a viscous to paste-like liquid
  • The adhesion depends on the contact pressure and time, temperature and surface roughness
  • Sec‌uring/positioning often unnecessary
  • Take relevant measures for health and safety at work and environmental protection (General: see Section 7; Details: see safety data sheet)

Typical properties:

  • Immediate adhesion (“self-adhesive”), the adhesion increase further in the days after joining
  • Detachable systems: high initial strength, lower final strength
  • Non-detachable systems: low initial adhesion, higher final adhesion
  • Strength is very product and temperature dependent
  • Varying stability/resistance depending on the product

Points to heed:

  • Heed the temperature, contact pressure and surface roughness

If you have questions about the product then see the technical data sheet or contact the adhesive manufacturer