Conformable film tapes

Conformable Film Tapes. For many applications the tape should conform to a rugged or profiled surface. There are two types of films, which differ in their tensile stress elongation curve. 

Conformable tape (for Eppendorf tube gaskets) is plastic film tape No. 471, from 3M Company and distributors. Other types of soft Teflon or polyvinyl film are equally suitable. 

Medical. Medical tapes often have cloth or cloth-like backings for comfort and breathability. Numerous synthetic breathable, conformable nonwovens (eg, spunlaced polyester such as Sontara, a trademark of DuPont creped polypropylene) have been developed for such purposes. In some instances, film tapes are preferred to provide a barrier for wound coverage or to increase hydration to speed transdermal drug delivery. Electrically conductive adhesives are used for electrode applications. 

Conformable films of type A are used as film-masking tapes and as thick films for corrosion protection tapes for underground transmission pipes. 

The use of coatings applied in the form of tape is also increasing. Polyethylene and polyvinyl chloride films, either self adhesive or else supporting films of butyl adhesive, petrolatum or butyl mastic are in use as materials applied cold at ambient temperatures. Woven glass fibre or nylon bandage is also used to support films of filled asphalt or coal tar and these are softened by propane gas torches and applied to the steel surface hot, cooling to form a thick conforming adherent layer. 

The flow of an anodic current oxidizes the conducting polymer and the film swells. At the polypyrrole/tape interface, electrochemically stimulated conformational changes in the polymer promote an expansion that... 

Silicone PSA products are used in a number of medical and industrial appKcations, ranging from a variety of PSA tapes and transfer films to automotive bonding. Advantages for the silicone PSA products include resistance to temperature extremes, chemical resistance, conformity to irregular surfaces, and electrical properties. They are also unique to most PSAs in their ability to adhere to difficult low-energy substrates, such as polytetrafluoroethylene and other silicones. 

Since the early 1980s, techniques for producing relatively coarse but very useful fibers or fiber-like tapes from films have been developed. Obviously, the first step in this operation is the production of a film. Films are manufactured in two conformations—sheet and blown films. Because the blown film operation is more complicated and because it produces a less fibrillatable film due to a more ordered crystalline structure and lateral orientation, it is not widely used and will not be discussed further. 

Thermally conductive adhesive tapes are double-sided, pressure-sensitive adhesive films filled with ceramic powder. The adhesive is typically supported either witii a carrier made from polyimide film or with aluminum foil to provide ease of handling and strength. If electrical isolation is required, polyimide is the carrier used. Acting in a fashion similar to elastomeric films, they require some initial mating pressure to conform to the surface irregularities. If the gap between the surfaces is too large, the adhesive tape is unable to fill it. Once a joint is formed with an adhesive tape, mechanical pressure is no longer required to maintain the mechanical or thermal performance of the joint [24]. 

Metal Foils. Most common is aluminum, less common are copper and lead. Snch tapes are quite conformable and are used to seal against moisture and water. Tapes with aluminum foils or aluminum-coated films can shield surfaces against thermal radiation. Copper and aluminum foils and vapor-coated films also can be used to shield against electromagnetic interference. 

Clear conformal, fast cure Standard conditions Immersion conditions Insulating Films and Tapes Low-density polyethylene film (40 pm thick)... 

Tape adhesives can be made thermally conductive by the dispersion of small articles of a conductive filler such as Saint-Gobain boron nitride (BN) PCTH3MHF and spherical aluminum oxide (AI2O3) available from Denka Corp. [42]. For example, 3M Corp offers pressure-sensitive adhesive (PSA) tapes filled with thermally conductive ceramic particles and flame retardant fillers. This product is designed with a thin polyester (PET) film and a soft acrylic polymer. It conforms to surfaces to which it adheres thus providing contact surface area for heat transfer [43]. 

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