Food & Belting

PTFE is a desired material for many applications because of near-perfect chemical resistance properties, severe temperature stability, and non-stick capability. PTFE, however, is generally weak and requires a reinforcement material. Fiberglass is a common reinforcement used with PTFE since it is a cost-effective material with high temperature capability. PTFE is usually applied to fiberglass using a dip-coating process. Dip-coated PTFE materials have been used for years in many different applications including food processing and conveyor belting.

With over 15 dip-coating towers of our own design, TCI is very skilled in the art of coating/impregnating fiberglass with PTFE.

PTFE coatings are inherently porous. Surface cracks in PTFE coatings permit harmful fluids to penetrate into the fiberglass substrates. Dip-coated PTFE/fiberglass materials often fail because the coatings are unable to provide an adequate barrier for the fiberglass. Unlike PTFE, fiberglass is easily attacked by light chemical exposure. Water is a very corrosive media to fiberglass. In a steam environment, failure will occur in weeks, if not days, for a PTFE-coated fiberglass material.

To improve the performance of dip-coated materials, PTFE films are laminated to PTFE dip-coated surfaces.

TCI is First in Film Technology with skilled PTFE film manufacturing for applications all over the world.

A PTFE film laminate consists of PTFE films that have been laminated to a PTFE coated fiberglass fabric. While some PTFE coated products can perform adequately in the demanding conditions, overwhelming evidence has shown that a PTFE film laminate provides the best long-term protection for the fiberglass reinforcement.

Surface cracks in PTFE coatings permit harmful fluids to penetrate into the fiberglass substrates. These cracks are totally unavoidable in any PTFE-coated fiberglass fabric. When a PTFE film is laminated to a PTFE-coated surface, the surface cracks remain sealed for the life of the product.

The overall porosity and permeation properties in PTFE film laminates will be lower than those found in PTFE coated fiberglass fabrics. Additionally, the laminated PTFE film ensures that the composite maintains a uniform PTFE thickness over the entire surface. The tough PTFE film barrier makes cleaning easier and eliminates any concern for the "thin coating areas" found in all PTFE-coated fiberglass fabrics.

Over time, many advancements have improved the performance of PTFE materials. Perhaps no advancement has been more significant than the development of a 100% PTFE Crossfilm material.

LFP Crossfilm materials have garnered numerous awards. As one judge from Chemical Processing’s Vaaler Award concluded, “This is the first major improvement in the fluoroplastic industry since its introduction some 40-odd years ago.”

LFP Crossfilm materials are tough; they resist tearing and possess incredible flexing traits. Because LFP Crossfilm materials are mechanically capable, no fiberglass reinforcement is needed. A 100% PTFE material like LFP Crossfilm has no concern for chemical attack, regardless of the chemical environment. In a steam application where the life of a fiberglass-reinforced material is short, the life of an LFP Crossfilm material is indefinite. Since 1993, LFP Crossfilm materials have been used in the some of the most challenging chemical environments in the world without one single instance of chemical degradation.

The durability and excellent flexing capability of LFP Crossfilm materials allow for significant improvement in conveyor belting, vibratory equipment, flexible ducting, and many other dynamic applications. In certain conveyor belting applications where the average life of a fiberglass-reinforced material is less than one week, a Crossfilm belt has lasted for months.

In release applications, a PTFE-coating eventually wears off a fiberglass surface. Often, failure can cause fiberglass contamination of the product and result in significant scrap.

An all-PTFE Crossfilm material has been proven to last much longer than fiberglass-reinforced materials in release applications because there is no fiberglass to serve as a binding site.

In a typical 10 mil (0.25 mm) thick PTFE-coated fiberglass material, 1/2 to 1 mil (0.013 to 0.026 mm) of PTFE coating may reside between the fiberglass and the media to serve as a release. In an LFP 2109 Crossfilm material (9 mils, 0.23 mm thick), there is no fiberglass; all 9 mils of PTFE provide release.

With unique manufacturing capabilities in PTFE processing, TCI is well situated to solve problems using advanced material technologies. Using conventional PTFE/fiberglass composite materials or state-of-the-art 100% PTFE Crossfilm materials, TCI can impart a vast array of material options and experience for challenging applications.

Photos: