Novel PPS material makes hard-wearing bearings

Edited by the Engineeringtalk editorial team Sep 20, 2004

Bushings made from Techtron HPV PPS material deliver reliable performance despite high loads, high temperatures and prolonged exposure to harsh chemicals.

An industrial process is only as efficient as the tools used to implement it.

Bearings used in extreme conditions, such as prolonged contact with aggressive chemicals or abrasion-sensitive components, or under heavy mechanical loads, can no longer be lubricated once they are installed and the process is in operation.

For De Smet Group, of Brussels, Quadrant Engineering Plastic Products (QEPP) provides a solution to this problem with its new Techtron HPV PPS material for bearings used in an extraction installation.

De Smet provides expanded systems and equipment offerings in oil extraction, protein meal production and refining to the global vegetable oil, protein meal, and protein isolate industries.

Continuous solvent extraction is used widely to process a wide range of products, including oil-bearing material.

It involves the washing of materials in solvent, which circulates in the direction opposite to the movement of the material bed.

De Smet plants employ this counter-current technique to form a miscella that drains from the meal through a wedge wire or V-screen.

The resulting solution is pumped to an evaporation system to recover solvent for re-use and to separate solvent free oil for subsequent refining.

The meal from which oil or sugar is extracted is transported by bushings, which serve as the rollers for the V-screen in continuous solvent extractors.

These bushings must withstand loads up to 90MPa, temperatures up to 80C, and prolonged exposure to grit and aggressive chemicals.

Also, it goes without saying that they must perform reliably and with minimal maintenance.

These stringent demands required careful selection of a reliable, high-performance material to form the extractor bushings.

De Smet found its solution in QEPP's Techtron HPV PPS material.

An ideal material for harsh processing environments, Techtron HPV PPS is used in applications where PA, POM, PET, PEI, and PSU fall short or where PBI, PI, Peek and PAI are over-engineered and a more economical solution is preferable.

A reinforced, internally lubricated polyphenylene sulphide grade, Techtron HPV PPS demonstrates an excellent combination of properties including wear resistance, load-bearing capabilities, and dimensional stability when exposed to chemicals and high-temperature environments.

It overcomes the disadvantages of virgin PPS caused by a high coefficient of friction and of glass-fibre reinforced PPS which can cause premature wear of the counterface in moving-part applications.

These features, in combination with its excellent mechanical strength, and chemical resistance and wear at high temperatures, make Techtron HPV PPS an attractive solution for a variety of food processing and handling applications such as filtering drums, meat and dairy forming equipment and industrial drying and food processing ovens.

Furthermore, Techtron HPV PPS now complies with food compatibility regulations for all plastic materials used in products that come into contact with foodstuffs.

It is in full compliance with both the European Union directive 90/128/EEC and the US Food and Drug Administration's 21 CFR (Code of Federal Regulations), denoting its safe application in products used to prepare, process and package food and beverage items.