Thermoplastics offer many advantages over thermoset rubber materials. Thermoplastic polymers become pliable or moldable above specific temperatures and return to a solid state upon cooling. Read below to learn how this can benefit your application when it comes to hose or tubing. For temperatures up to 500°F, see the Fluoropolymer section.
The manufacturing process of thermoplastic hose allows for long continuous lengths due to the material being "cured" on the line and a self-supporting core tube. Rubber hoses require a secondary curing process and a mandrel to hold the core tube dimensions. Parflex and Polyflex have made continuous lengths of 3200m in the past - important for off shore oil applications (umbilicals). For hose assembly locations, the long lengths mean less scrap and fewer reel changeovers during production.
Because thermoplastic hose/tube manufacturing does not require a mandrel for support of the core tube, thermoplastic hoses can be made to extremely small inner diameters such as 1.3mm (.051"). Since rubber hoses require a mandrel, the inner diameter of rubber hoses typically stops at 4.8mm (3/16"). This is important in applications where only a small amount of fluid needs to be transferred.
The inherent strength of the thermoplastic materials used to make thermoplastic hose allows the use of less material when compared to rubber hoses. The outer diameter of thermoplastic hose from Parflex and Polyflex can be 20% smaller than outer diameters on comparable rubber hose. This feature is very important on equipment where space is limited and many hoses must fit into a small area.
Thermoplastic hoses, due to the material and construction, are almost always lighter than comparable rubber hoses. With Parflex and Polyflex XDT products, low pressure rubber lines can be replaced with thermoplastic tubing that is 70% lighter.
From abrasion resistance and cleanliness to a longer shelf life and reduced noise, thermoplastic hose offer significant performance advantages over traditional rubber hoses.
Many thermoplastic materials are inherently abrasion resistant. In fact, most rubber hose manufacturers add thermoplastic to hose covers to increase abrasion resistance of their hoses. Parflex and Polyflex hoses with polyurethane covers have proven, through testing, that it takes 3 times the cycles to rub through .001 inches of cover when compared to competitive rubber hose that is touted as abrasion resistant.
The above pictures compare the contamination levels, after manufacturing, of a thermoplastic hose and a rubber hose. As seen in the pictures, the manufacturing of thermoplastic hose produces far less contamination than rubber equivalents. In many cases, the assembly of rubber hose will require cleaning of the hose prior to production use.
Through the use of various hose reinforcement methods, Polyflex manufactures hoses that can endure 4000 bar (58,000 psi) working pressures. Most rubber hose manufacturers stop at 700 bar (10,000 psi).
Through the use of various thermoplastic polymers the permeation resistance (ingression and egression) can be far greater than rubber. As seen in the illustration, thermoplastic products have superior permeation resistance against gases like CO2, Oxygen, and Nitrogen in comparison to rubber.
Under optimal storage conditions, fluoropolymer-based thermoplastic hose and tubing products should have unlimited storage life prior to initial usage. However, optimal conditions are required (contact Parflex or Polyflex Technical Services for more information on optimal conditions). Per SAE J517, Rubber Hose is acceptable for 10 years if stored under optimal conditions.
Fiber reinforced hoses with specific reinforcement have been shown to reduce noise on machines. This is important to operator comfort and environmental noise pollution. Please contact Parflex or Polyflex for more information or download the whitepaper, "Reducing Noise In Hydraulic Systems."
Thermoplastic hoses offer a wide variety of added value and can be thermally formed into specific shapes. The hose cover can be made from various colors, laylines can be modified for specific customer requirements, and hoses are available as a twin line hose or a bonded hose with multiline "ribbons" up to 10 hoses wide. The formulation can be changed to make the hose more conductive or nonconductive.