Pressure sensitive adhesive (PSA, self adhesive, self stick adhesive) is adhesive which forms a bond when pressure is applied to marry the adhesive with the adherent. No solvent, water, or heat is needed to activate the adhesive.As the name “pressure sensitive” indicates, the degree of bond is influenced by the amount of pressure which is used to apply the adhesive to the surface. Surface factors such as smoothness, surface energy, removal of contaminants, etc. are also important to proper bonding. PSAs are usually designed to form a bond and hold properly at room temperatures. PSAs typically reduce or lose their tack at cold temperatures and reduce their shear holding ability at high temperatures: Specialty adhesives are made to function at high or low temperatures. It is important to choose an adhesive formulation which is designed for its intended use conditions.

Applications

Pressure sensitive adhesives are designed for either permanent or removable applications. Examples of permanent applications include safety labels for power equipment, foil tape for HVAC duct work, automotive interior trim assembly, and sound/vibration damping films. Some high performance permanent PSAs exhibit high adhesion values and can support kilograms of weight per square centimeter of contact area, even at elevated temperature. Permanent PSAs may be initially removable (for example to recover mislabeled goods) and build adhesion to a permanent bond after several hours or days.

Removable adhesives are designed to form a temporary bond, and ideally can be removed after months or years without leaving residue on the adherent. Removable adhesives are used in applications such as surface protection films, masking tapes, bookmark and note papers, price marking labels, promotional graphics materials, and for skin contact (wound care dressings, EKG electrodes, athletic tape, analgesic and trans dermal drug patches, etc.). Some removable adhesives are designed to repeatedly stick and un-stick. They have low adhesion and generally can not support much weight.

Manufacture

Pressure sensitive adhesives are manufactured with either a liquid carrier or in 100% solid form. Articles such as tapes and labels are made from liquid PSAs by coating the adhesive on a support and evaporating the organic solvent or water carrier, usually in a hot air dryer. The dry adhesive may be further heated to initate a cross-linking reaction and increase molecular weight. 100% solid PSAs may be low viscosity polymers that are coated and then reacted with radiation to
increase molecular weight and form the adhesive (radiation cured PSA); or they may be high viscosity materials that are heated to reduce viscosity enough to allow coating, and then cooled to their final form (hot melt PSA).

 

Sample type of Adhesives

Rubber-Based

• 155 Performance Permanent
  Permanent,rubber-based adhesive used on corrugated, metal, glass, plastic, wood, and many other surfaces. Excellent on polyethylene films. The ultimate in quick-stick properties.
  
• 355 Cold Temperature Permanent
  Permanent rubber-based adhesive that adheres strongly to steel, fiber, and plastic drums. Ideal for chemical drum applications.
  
• 375 Broad Temperature Permanent
  Permanent, rubber-based adhesive with a wide temperature range.
  
• 655 Speciality Permanent
  Features a high degree of initial tack and ultimate removability from painted steel or high and low surface energy plastics.

Acrylic-Based

• 125 Economy Permanent Acrylic
  Permanent, all-purpose acrylic adhesive that adheres to a variety of surfaces, particularly corrugated and packaging films.
  
• 425 Performance Permanent Acrylic
  All-weather, acrylic emulsion adhesive that excels in flash freeze, frozen, and cold temperature applications. Adheres to many more shapes and surfaces than conventional adhesives. Extremely stable.
  
• 430 Standard Permanent Acrylic
  Permanent, acrylic-based adhesive that displays excellent adhesion to a variety of surfaces including corrugated, plastic, metal, and glass. Features a high degree of initial tack and long- term bond strength.
  
• 3000 Outdoor Permanent Acrylic
  High tack, acrylic adhesive used primarily for outdoor drum labeling applications. The best acrylic for quick-stick applications.
  

Specialty

• 500 Removable
  Durable adhesives which provide long-lasting bond strength, yet can be removed cleanly from a wide variety of surfaces—including glass, metal, wood, plastic, and corrugated.
  
• 600 Opaque
  Permanent, pressure-sensitive adhesives tinted black with strong initial tack to corrugated surfaces. Ideal for covering existing labels to block-out fixed information.
  
• 2000 Repositionable
  Unique acrylic adhesive developed so labels can be removed cleanly and re-adhered to virtually all smooth, flat surfaces while retaining superb bonding strength.
  
• Ultraplate Select and Plus
  High-performance, permanent acrylic adhesive that adheres well to aluminum, painted metal, steel, plastic, polypropylene, polyethylene, and polyvinyl chloride. Offers high degree of tack and ultimate bond strength; shows
  superior versatility for durable nameplate applications.