|Tubing & Hose Buying Tips
#17: Alternate Materials
It can be challenging to make sure you’ve covered all the bases during the tubing and hose selection process. Have you considered all the elements involved with the application? Temperatures, chemicals, pressures, flexibility needs? In Tubing & Hose Buying Tips we’ll address common selection factors, one at a time, in each issue of extrusions.
Do not assume you're aware of every tubing and hose material out there. Research each need individually to make sure you're not over- or under-engineering your application. Advances in plastic and rubber development occur frequently, and you should keep yourself informed. Today's scientists and chemists are working on plastic materials that will harden and soften in response to electrical impulses, break down in seawater, transmit electricity, and are transparent yet nearly as strong as steel.
Some plastic materials have similar properties and can be substituted for each other, depending on the particular application. For instance, NewAge Industries' polypropylene tubing and fluoropolymer tubing (PTFE, FEP, PFA) have comparable performance characteristics including their tensile strength, excellent chemical resistance, and outstanding electrical properties. They're also all made with ingredients that meet FDA (Food and Drug Administration) standards for use with food contact surfaces. Polypropylene doesn't have fluoropolymer's wide temperature range, but it can often serve as a less-costly replacement.
Coextrusionstubing with one material on the interior that's permanently bonded to another on the exterior during the manufacturing processare another option. When an application requires different performance characteristics for the inside and outside of a tube or hose, coextrusions can often save costs. Hytrel®-lined PVC is one example of a coextrusion. Oil-resistant Hytrel makes up the interior while durable PVC protects the outside. It can be used in, for instance, a harsh environment application involving the transfer of oil where durability of PVC is needed for the exterior, and the oil resistance properties of Hytrel come into play on the interior contact surface.
Another example of coextruded tubing is polyethylene-lined EVA (ethylene vinyl acetate). Polyethylene tubing is typically a semi-rigid product. The addition of EVA gives it enhanced flexibility and allows its use with economical barb-style fittings. Like Hytrel-lined PVC, this tubing offers different performance characteristics for the inside and outside of the tubecleanliness inside, flexibility outside.
Keeping alternate tubing materials in mind or researching them for a project, whether it's a new one or a retrofit situation, can help hold down costs. Using a material that does more than you need isn't always the best choice.
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#16: Abrasion & Corrosion Resistance
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