ENGINEERING AND PERFORMANCE PLASTICS, 2005-2015, RAPRA, VIENNA 2005

Françoise Pardos, Pardos Marketing, February 2006

Main processes for engineering plastics, molded parts, films and sheet

Traditionally, the dominant process for engineering plastics has been, and still is, injection molding, with few exceptions, like films for PA, PET and PE, sheet for PC and PMMA.

Now, with growth and diversification, the other processes, particularly sheet and films, also pipes, are fast growing

High-performance films represent a niche market, accounting for about 10% of all commercial plastic films by volume. Compared to commodity plastics films, high-performance films feature greater tensile and impact strength, greater heat and moisture resistance, and improved gas barrier properties. Some also display special electrical or electronic properties.

With thicknesses generally less than 0.25 mm, high-performance films are made in relatively small quantities for specialized applications in packaging, mostly for food, electronics, photography, magnetic media, automotive, aerospace, signs and displays.

About 95% of high-performance films are made of polyesters, nylons and polyolefins. The rest are made of such materials as polycarbonates, fluoropolymers, polyimides, PEEK, PI, and other engineering resins.

Coating high-performance films with other polymers can improve their abrasion resistance, and their barrier, adhesion and antistatic properties. The films can also be metallized to alter their electrical characteristics or reduce their moisture permeability. The films may be used alone or as layers in laminated or coextruded structures.

High-performance fluoropolymer films include PTFE, PVF, PVDF, ETFE, and PCTFE. As a class, fluoropolymer films combine excellent chemical resistance and dielectric properties with heat resistance and moisture impermeability.

Fluoropolymer films are used in the chemical industry to line tanks and in the electronics industry in circuit board laminates and wire insulation. In plastics processing, fluoropolymer films perform well as release agents in the fabrication of industrial composites. Fluoropolymers are used in the packaging of medical and pharmaceutical products and as a barrier for protecting sensitive electronics, such as those found in sonar buoys.

Polycarbonate film is noted for its high clarity, heat resistance and dimensional stability. Its many applications include reverse screen printing, pressure sensitive nameplates and membrane switch panels.

The optical PC film business is booming for large-sized liquid crystal displays, LCD, and TV sets. Optical PC films will also be used for the overlay for Blue-ray optical storage discs.

Various electronic devices, including timers and filters, employ wound polycarbonate film capacitors, which have a very wide temperature range. In signs and other outdoor graphics applications, polycarbonate films offer exceptional resistance to moisture and sunlight.

Another use of polycarbonate film is for in-mold labels for cell phones and automobile components. Such labels are easy to customize to provide product differentiation.

Polyimide films, best known for their ability to withstand heat, retain their dielectric properties at temperatures as high as 240° C.

The films can be used to insulate the windings of large coils for motors. They allow wave soldering of flexible circuits without distortion. The films are also used in combination with inorganic insulating tapes to impart flame resistance to high-performance cables.

PEEK films display resistance to high temperatures, chemicals, solvents, wear, hydrolysis, fire and smoke. Usage temperatures for the films can be as high as 260° C. They have similar applications to polyimide films.

Polyetherimide, PEI, films have high heat resistance, inherent flame resistance, high dielectric strength, exceptional mechanical properties and dimensional stability. Applications of these products include flexible circuits, high-temperature labels, electrical insulation, automotive sensors, IC sockets and hot-melt adhesives.

Polyvinyl butyral, PVB, are used as an interlayer to provide impact resistance to glass laminates, in car glazing and in windows. Hurricane-resistant glazing is a prime outlet for these films.

Other high-performance films include ethylene vinyl alcohol, EVOH, used to impart barrier properties to food and beverage packaging, and polyvinyl alcohol, PVOH, employed in spiral wound tubes, coated paper and linerboard, and specialty water-soluble films. Ionomers are transparent, durable thermoplastics, widely used as heat-seal layers in composite flexible food packaging films.

Sheet and thermoforming

Flat products, sheet, have long been particularly important for polycarbonate, whether solid, thin wall or corrugated.

Now, GE Plastics has developed a range of new resins designed to encourage manufacturers of large parts to consider thermoforming as an option. Until now such manufacturers have preferred injection molding. GE expects to see rapid growth on the heavy-gauge thermoforming market over the next five years. The new resins for thermoforming include Geloy ASA resin with better weathering properties, Noryl PPX blend with superior surface finish, high gloss Lexan SLX for extreme temperatures, Lexan film for in-mold use. According to GE Plastics, these products are suitable for construction, automobile and marine applications. Thermoforming has cost advantages over injection molding, and thermoformed parts do not need painting. The resins will have to compete with acrylics which are already used in the paint-free large parts sector

One of the most promising future markets for PC sheet products is automotive glazing. Figures are staggering when applied to the total of cars produced ten years from now.

Solar panels should also really take off, and require sheet of high performances, another large market to come.

Long fiber composites

One of the fastest growing plastic industry sectors is long-fiber reinforced thermoplastics, LFT, both with better grades of commodity plastics, and engineering plastics.

Automotive applications account for over 95% of worldwide demand for LFT. The European long-fiber reinforced thermoplastic market is expanding the fastest in comparison with other markets, largely due to the automotive industry, where new applications include body parts, door panels and front-end modules.

And, finally, there is the nano story, and many others. But the other speakers will develop these exciting technical aspects definitely much better.

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