Space-Age Ertalyte Gives Needed Push

That fact caused a great deal of frustration for a producer of microwavable convenience meals. The part in question was a stainless steel piston used to push sandwich filling into the next step in the process. The filling consisted of several chunky food ingredients in a barbeque sauce.

Frustration stemmed from the piston’s regular failure and the continual expense of replacing it and the associated drive system. The piston alone weighed nearly 20 pounds and every time it failed, employees were idled and productivity was lost, adding to the cost.


Even when it worked, the piston was subject to corrosion from repeated exposures to the barbecue sauce and cleaning agents. To address these concerns, the stainless steel piston was replaced by one made of a thermoplastic polyester material known as Ertalyte®

What is Ertalyte®?

Ertalyte® is a type of plastic more commonly known as PET or PET-P, which is shorthand for Polyethelyne Terephthalate Copolymer. It is a lightweight and rigid material that offers a resilient moisture barrier that is not degraded by aggressive, clean-in-place sanitizing agents. It also resists staining, making it well suited to the regular contact with barbeque sauce and other acidic fluids.

In simple terms, Ertalyte® is a semi-crystalline, thermoplastic polyester that is manufactured from proprietary resins. It is FDA-compliant and available in natural or black. The natural material is also USDA-compliant and meets other regulatory standards both in the U.S. and abroad.

These characteristics have won the material many admirers in the food processing and food equipment industries. It is suited to dry as well as wet environments; offers high strength, rigidity and excellent dimensional stability; is ideal for close-tolerance parts applications; may be machined precisely on standard metal-working equipment; and features excellent wear resistance. It also withstands acids better than acetal—another type of plastic—and nylon.

Ertalyte or PET-P, is also well-suited to applications involving soft metal and plastic mating surfaces, including gears and bearings that do not require startup or running lubrication. Because it is more rigid and offers greater thermal performance than nylon and acetal, it machines somewhat differently.

Pistons machined from Ertalyte® rod hold extremely tight tolerances, assuring fill accuracy. The Ertalyte® piston eliminated the premature failure of the part and dramatically reduced costly maintenance and wasteful downtime.

Additional Benefits Discovered

After the Ertalyte® piston was installed, an unexpected benefit was realized by the food producer. The new part weighed only three pounds, which was significantly less than the metal piston’s nearly 20 pounds. This meant the engineering staff was able to redesign the drive system using smaller motors and gear boxes. These new components are less expensive to purchase, install and maintain. They are also more energy efficient and have permitted an increase in line speed, which has resulted in greater productivity.

Ertalyte®: A Solution for Many Industries

In addition to the roles it plays in the food processing and food equipment industries, engineers and designers have found many other uses for Ertalyte®. Depending on the situation, its characteristics are superior to aluminum, nylon, acetal and stainless steel. For example, process and test equipment manifolds machined from Ertalyte® offer better dimensional stability and superior stain and chemical resistance than those formed from aluminum or acetal. Other selections and uses include:

Metal selections include 90-degree angles, flats (bar), precision blanks, plates, rods and square stock with uses including highly machined parts such as valves, shafts, bolts, bushings, nuts, repairs to storage tanks, marine vessels and structural parts.

Rubber selections have been added in sheets and strips, both plain-backed and adhesive-backed with uses including gaskets, shock absorption, sound proofing, bumper pads and mud flaps.

Plastic selections have been added in pre-cut pieces available in sheets, rods, tubes, angles and u-channels. Uses include machine guards, conveyor systems, food processing, replacement windows, prototyping and high-wear applications. Felt selections have been added in sheets, strips, discs and cords, and are offered in both plain-backed and adhesive-backed. Uses include grease retainers, insulation, weather stripping, filters, gaskets, shock dampening and wicking.

Its rigidity and clean hygienic appearance— in addition to dimensional stability and resistance to dilute hydrochloric acid—make Ertalyte® the ideal choice for carousels; filter tracks; locating disks and rings; and other components found on pharmaceutical test equipment. Ertalyte® is offered in rod and sheet form and excels under both high-pressure and high-velocity conditions making it a good solution for use in a wide range of applications and industries.