I. Applications of Polytetrafluoroethylene (PTFE) Films
Polytetrafluoroethylene (PTFE) films are made from granular resins (skimmed films), aqueous dispersions (cast films), and fine powders (unsintered films). Each of these films has high service temperatures, excellent chemical resistance, non-stick and peel properties, and very good dielectric and barrier properties (in some cases).
01. Applications of Skived Polytetrafluoroethylene Skived PTFE films are available in thicknesses ranging from 0.0005 to 0.125 inches (0.0127 to 3.175 mm), with excellent flatness and the tightest tolerances in the industry for use on adhesive/bondable surfaces.
Due to their special properties, they are used in a wide range of applications:
Release: Release films in the production of high-temperature resistant flexible circuit materials; Release films in composite structure molding, such as vacuum bags; Release films and composite sheets in food baking and grilling.
Heat resistance: substrates (backings) for heat-resistant pressure-sensitive tapes, films, fabric-reinforced films, laminated films and composite sheets and tapes.
Chemical resistance: chemically resistant hose cores, spacers, covers and storage liners and diaphragms.
Dielectric properties: adhesive films in microwave circuit board production.
Low friction properties: low friction (anti-squeak properties) in the automotive industry.
Barrier properties: gas- and liquid-tight barriers in compensators, expansion joints and bellows.
Dielectric properties: fusible wraps in electrical/electronic cables; particularly suitable for wires and cables for high-temperature and sensitive equipment.
Conductive versions: these can be used in static dissipative applications, such as high-static coating hoses and static dissipative layers in static dissipative laminates.
02. Applications of cast PTFE films
Cast PTFE films are available as single-layer films or with pure PTFE films, as well as multilayer structures with layers of PFA or fluorinated ethylene propylene (FEP) and fluoropolymer blends. Individual layers can be clear, colored, or conductive. Multilayer films can be configured with different polymers or polymer blends and are inherently free of voids and pinholes and exhibit excellent dielectric properties, drape, and conformability. Multilayer films with outer layers of FEP and/or PFA/MFA are heat weldable and heat sealable. Bondable and pressure sensitive adhesive versions are available. Cast film is available in thicknesses ranging from 0.00025 to 0.005 inches (0.00635 to 0.127 mm).
Cast film is used in a wide range of applications due to its excellent properties:
Release: Release films in composite molding operations; release sheets and laminates in food processing and ceramic processing.
Dielectric properties: Films used for dielectric insulation and microwave circuit board production.
Barrier: Barrier films for spacer applications; barrier films for conductive films and laminates for protective clothing; and backings for pressure sensitive tapes.
Heat resistance: Substrates (backings) used for heat resistant pressure sensitive tapes.
Conductive types can be used for static dissipative applications such as static dissipative laminates.
Hydrophobicity: This property of PTFE film makes it suitable for surgical gowns, surgical towels, protective clothing and packaging materials for sterilization equipment.
03. Application of unsintered PTFE film Unsintered PTFE film is mainly used for electrical insulation, especially wire and cable applications [cable insulation, wire harness winding and dielectric medium in coaxial cable; in gaskets; expansion joints; valve seals, diaphragm applications; coil winding; zinc air batteries; metallized microwave antennas; flexible linings for transfer systems; substrates (backings) for pressure-sensitive tapes; pharmaceutical packaging/compounding; seal and gasket designs requiring low creep].
Other applications include battery/fuel cell components. The most common use of unsintered film is thread sealing tape for plumbers.
2. Application of fluorinated ethylene propylene (FEP) film
FEP film has excellent chemical resistance and release properties, and is easy to manufacture. Compared with PFA, FEP film has lower cost and temperature, lower dielectric constant and dissipation, and a continuous use temperature of 400°F (205℃), suitable for low and high temperature applications.
Environmental growth chambers and solar collectors, sample bags and containers, diaphragms, gaskets, protective linings, flexible printed circuit and flat cable applications, and electret condenser microphones are typical applications of FEP film.
3. Application of perfluoroalkoxy resin (PFA) film
This includes films made from copolymers of perfluoropropyl vinyl ether and tetrafluoroethylene (TFE) (commonly known as PFA fluoropolymers) and copolymers of perfluoromethyl vinyl ether and TFE (known as MFA fluoropolymers). Their properties are basically the same except for the melting temperature; the melting temperature of PFA fluoropolymers is 20℃ (36℉) higher than that of MFA polymers.
01. Application of Perfluoroalkoxy Resin Films These films offer a maximum continuous use temperature of 260°C (500°F), the highest of all melt-processable fluoropolymer film types. They provide many of the performance characteristics of PTFE film in a clear, transparent form.
Typically, PFA films offer a combination of these properties:
Excellent dielectric properties over a wide range of temperatures and frequencies;
The highest levels of chemical and stress crack resistance;
Excellent clarity and weather resistance.
Typical applications for PFA films include their use in circuit board manufacturing, flat cables, and electrical insulation applications. PFA's high temperature resistance and non-wetting surface make it an ideal material for high-temperature release films or bagging films for composite manufacturing.
02. Application of MFA Films MFA films offer an excellent combination of dielectric properties over a wide range of temperatures and frequencies; chemical and stress crack resistance similar to PFA, a continuous operating temperature of 230°C (446°F), and the highest clarity of all fluoropolymer films. Other properties of MFA film include excellent flex life, stress crack resistance, good anti-stick and very good weather resistance. MFA film is a clear, transparent product that can be heat sealed, thermoformed, welded, metallized or laminated to a variety of materials. Typical applications for MFA film are in the chemical processing industry (tank linings, roll covers); solar collectors; ultraviolet (UV) protective films; release films in composite manufacturing; in circuit boards and as electrical insulators.
It should be noted that the melting temperature of MFA resin is 20℃ (36℉) lower than that of PFA resin.
4. Application of ethylene and tetrafluoroethylene copolymer (PFA) film
Copolymers of ethylene and tetrafluoroethylene (ETFE) materials provide excellent performance of fluoropolymer films made from them in a temperature range from cryogenic to 165℃ (330℉). Chemical and weather resistance, low flammability and stress crack resistance make these films ideal for a variety of applications.
ETFE film has excellent mechanical properties and tear resistance. ETFE film's high light transmittance (>95%) combined with its very good mechanical and chemical properties provide excellent performance in architectural roofing designs and greenhouses. ETFE films are also a suitable choice for solar collector applications due to their excellent physical properties and high cover factor resulting from their low density. In addition, ETFE films have a low surface energy, making them ideal for release applications with process temperatures up to 350℉ (177℃). The low density of this material provides greater coverage per pound for laminating release film applications compared to FEP and PFA films. The low surface energy of ETFE film can also be used in applications such as wall coverings and anti-graffiti protection in high traffic areas.
ETFE films offer processors excellent dimensional stability for secondary operations such as thermoforming and welding. Products with surface treatment technologies improve bonding characteristics for metallization processes and adhesive coatings.
5. Application of Polychlorotrifluoroethylene (PCTFE) Film
Polychlorotrifluoroethylene (PCTFE) films are available in a variety of homopolymer and copolymer configurations, which allow them to be heat-sealed, thermoformed, laminated, sheeted, or die-cut. They offer the following properties:
Excellent permeation resistance
Excellent clarity
Excellent formability
Resistant to most chemicals and solvents
Flame retardant
Due to the above properties, they are used in the following applications:
Electroluminescent (EL) panel cover
Blister packaging
Durable labels
Electronic packaging and protection
The main application of PCTFE is specialty films for packaging, suitable for situations with high moisture protection requirements, such as pharmaceutical blister packaging and healthcare markets.
In EL lamps, PCTFE film is used to encapsulate phosphor coatings, which provide area light when electrically excited. The film acts as a water vapor barrier, protecting the phosphor chemicals that are sensitive to moisture. EL lamps are used in aircraft, military, aerospace, automotive, commercial equipment applications, and buildings.
Another use of PCTFE film is to package military and electronic components that are sensitive to corrosion. Due to their excellent electrical insulation properties, these films are used to protect sensitive electronic components that may be exposed to moisture or harsh environments. They can be thermoformed to fit any shape and detail. PCTFE films are also used to protect moisture-sensitive LCD panels for portable computers.
PCTFE films can be laminated to a variety of substrates such as PVC, polyethylene terephthalate, amorphous polyethylene terephthalate, or polypropylene. Metallized films are used for electronic dissipation and moisture barrier bags for sensitive electronic components, pharmaceutical packaging, and medical devices.
Other applications for PCTFE include pump components, transparent sight glasses, flow meters, linings for pipes and the chemical industry, and labware.
