The development represents another milestone for Zyex Ltd., by far the world’s leading supplier of filaments and fibers in polyetheretherketone (PEEK) resin, whose list of applications continues to grow.

Located in Stonehouse, Gloucestershire, this privately owned UK company manufactures high performance Zyex-branded PEEK monofilament, multifilament and staple fiber for use in industrial applications where operating conditions are extremely demanding.

Zyex PEEK fibers are chosen for their thermal performance, chemical resistance, and flex and wear resistance. Essentially, any industrial process requiring fabrics to resist abrasion and chemical attack, while maintaining dimensional stability at elevated temperatures, is potentially an application for Zyex PEEK.

Zyex performs well at operating temperatures up to 250°C and even retains some properties at 300°C. Further, it has low flammability, is self-extinguishing and is emitting the lowest level of smoke and toxic gases of any high-tech fiber.

Applications Continue to Grow

Zyex is insoluble in common organic solvents and has excellent resistance to alkalis and acids. It has a very low moisture uptake and “outstanding” hydrolysis resistance, particularly in high temperature steam.

When used in rigorous running conditions, Zyex is tough yet flexible and has excellent impact/recovery characteristics, especially when compared with steel.

As well as outlasting most existing fibers, Zyex can often be recycled (a scheme has been in operation from the early 1990s). Fabrics woven with 100% Zyex qualify for recycling and up to 90% of the material can be efficiently reclaimed to first grade polymer.

Zyex monofilaments are currently being used in open mesh conveyor systems for paper drying, textile printing, fabric heat-setting, non-woven bonding and food processing. Zyex multifilaments are being used for aerospace components, thermoplastic composites and narrow weaving.

Combinations of Zyex monofilaments, multifilaments and staple fibers are being used for dry filtration and chemical separation as well as in the manufacture of sports strings, braids, brushes and cords.

One of the newest product areas is medical technology, where Zyex PEEK is being used in composites for bone implants and equipment filters as well as being proposed for reinforcement patches, braids for sutures and ligaments, and tubes for catheters and pneumatic devices. The fiber is available in special grades for long-term medical implant use.

Zyex can be twisted, woven, knitted, spun or needled into the full range of conventional textile structures. It has low shrinkage (typically 2% at 200°C) and can be heat set at temperatures up to 300°C.

Entrepreneur Buys Former ICI Unit

The company began in the mid-1980s as a business unit of ICI Fibres. Colin Bridgen, who had worked in the aerospace business and became convinced of the future of the fiber, acquired Zyex in 1994 prior to ICI Fibres’ acquisition by DuPont.

According to business manager Bruce McIntosh, monofilament yarns were developed in the early 1980s using ICI’s PEEK polymers. Initial target applications were woven conveyor fabrics used in high temperature dryers, especially papermakers’ felts.

These open-mesh products typically used unpigmented, circular monofilaments of 0.4-0.8 mm diameter. Customers quickly discovered that PEEK fibers also made the best material for making joins in conveyor-type situations.

Diversification has been considerable since the company’s early days. Zyex now produces a full range of PEEK monofilaments in diameters from 70 microns to 2 mm.

Use in Non-wovens Increases

Conveyor belts for non-wovens manufacture has been a growing business segment and Zyex PEEK fibers have achieved significant market penetration by replacing metal and polyester belts, Mr. McIntosh said.

Zyex PEEK monofilaments were later developed for use in tennis strings and braids where good recovery and low creep properties are important, such as in the aerospace and nuclear industries, for high-tech brushes, filter fabrics and acoustic dampening.

Zyex multifilament yarns and staple fibers were introduced to the market in the late 1980s and have been developed for a number of growing markets including high-temperature press felts, hot gas filtration fabrics and sewing threads.

Aromatic PEKK Copolymers

These new aromatic polyketone polymers were among the fiber innovations shown at Techtextil North America in Atlanta, USA, in March, according to Terry McKenna of Filtex Inc, North American agent for Zyex.

Although global production is difficult to quantify precisely (it is possibly around 50 tons a year), Zyex is believed to supply at least half the world’s requirements for fibers and filaments made from PEEK and other aromatic polyketone polymers.

The company’s business has grown globally; only 5% of sales are now from the UK. Europe (principally Switzerland, Germany, France and Italy) is the leading market, accounting for 40% to 50% of turnover. The remainder of output is shipped to the USA, Japan and other countries.

Specialized Technology

Zyex is a compact operation, currently operating on a three-shift basis, five days a week. The company uses small-scale melt-spinning technology based on machinery it has developed in-house over many years, and recently commissioned its latest multifilament machine.

Much of the specialty equipment is low in throughput and highly monitored, offering batch sizes in excess of 1,000 kg down to orders of just a few kilograms. Essentially, it operates from a low finished product stock, providing customized service.

The key to Zyex’ future will be finding niche requirements in many different industries, Mr. McIntosh said.

“We are now dealing with more than a dozen different major markets and constantly working with customers to establish new products in new areas,” he said. “We try to winkle out which industry will need fibers with the sort of properties we can offer and to look for niche opportunities.”

Not only does ZYEX outlast existing fibres but it can often be fully recycled. In fact more than half of all fabrics woven with ZYEX alone qualify for recycling and up to 90% of the material in these fabrics can be efficiently reclaimed to first grade polymer. This means that ZYEX offers substantial economic and environmental benefits.

ZYEX HAS A PROVEN TRACK RECORD

ZYEX Monofilaments are currently in use in open mesh conveyor systems for paper drying, textile printing, fabric heat setting, non-woven bonding and food processing... and the list is growing...

ZYEX Multifilaments are already being used for aerospace components, thermoplastic composites and narrow weaving... and the list is growing...

Combinations of ZYEX Monofilaments, Multifilaments and Staple fibres are being used for dry filtration and chemical separation as well as in the manufacture of sports strings, braids, brushes and cords... and the list is growing...