PSA TAPE DEFINED
Pressure sensitive adhesive (PSA) tape can be defined as a continuous flexible strip of cloth, paper, metal or plastic coated on one or both sides with a permanently tacky adhesive at room termperature which will adhere to a variety of surfaces with light pressure (finger pressure) with no phase change (liquid to solid) and usually on a roll.
PSAs can be blends of natural or synthetic rubber and resin, acrylic, silicone or other polymer systems, with or without additives.
An adhesive is applied to only one side of the backing. The backing composition may be paper, polymeric film, foil, nonwoven or high thread count woven cloth. The adhesive composition may be an acrylic, rubber or silicone.
Examples of single coated tapes are electrical, masking, carton sealing and medical.
An adhesive is applied to both sides of a backing. The release liners are commonly paper and coated on both sides of the paper with silicone release agents creating a differential release. The pressure sensitive adhesive is coated on both sides of the carrier which is typically a polymeric film such as 0.5 mil polyester. The adhesive on each side of the carrier may be the same or different chemistries and may have the same or different coating thicknesses.
Examples of double coated tapes include mounting, medical and membrane switch.
In addition to the backing and adhesive, these tapes include a reinforcement layer of woven or knitted cloth or glass strands parallel to the machine direction. Typical backings include polymeric films such as polyethylene and polyester. Rubber based adhesives are the most common but others can be used.
Examples of reinforced tapes are duct and filament.
Unsupported PSA tapes (adhesive transfer tapes) consist of release liners and adhesives. The release liners are commonly paper and coated on both sides of the paper with silicone release agents creating a differential release. Acrylic adhesives are commonly used in this application.
Examples of unsupported tapes are envelope sealing, graphic attachment and splicing.