Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
  • D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
  • D06M15/37—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D06M15/55—Epoxy resins

Definitions

• This invention relates to a method of producing coated sleeving in particular coated electrical sleeving.
• Sleeving for example for use as electrical insulation, has hitherto been produced from braided material, for example, glass fibre, which is then coated with an elastomeric composition.
• elastomers employed include silicone rubbers and acrylic latices, both of which are applied from solvent based systems.
• the elastomer solution is applied to the braiding and, before curing of the elatomer can take place, the solvent must be removed. This entails a relatively long residence time within an oven or other heating zone firstly to remove the solvent, and then to effect curing of the elastomer. In order to keep the heating zone down to a reasonable size, it is therefore necessary to ensure that the sleeving passes through the heating zone at a relatively slow rate, typically in the order of 1 meter per minute.
• the invention seeks to provide a method of producing sleeving, suitable for use as electrical insulation, which is very much faster than known methods.
• the invention provides a method of coating a fibrous material tube which comprises applying to the tube a solventless epoxy resin system and curing the resin, the interstices in the tube being sufficiently small that they do not allow full impregnation of the resin through to the inside of the tube before curing.
• the tube may be braided from fibrous materials but is preferably, according to the invention, a knitted tube produced on a circular knitting machine.
• the fibrous materials employed may in general comprise any textile fibre, but for the properties of heat resistance required for electrical insulation.it is preferred that textile fibres having high resistance to heat are employed or, preferably, that glass fibres are employed.
• the invention also provides a process in which a tube is knitted from a glass fibre yarn on a circular knitting machine, a solvent free resin system is applied to the knitted tube, and the resin cured.
• the knitted tube presented to the coating zone should be of close mesh construction to prevent impregnation through to the inside of the tube. This will to some extent depend on the viscosity of the resin system used.
• knitted tubes may be produced both quickly and continuously in indefinite lengths.
• long runs of tube may be coated and cured at the high speed possible with the resin system employed.
• Short runs are, in general, not economical since the handling between runs, which is labour intensive, is increased, and the resin system is itself more expensive than the conventional solution based systems.
• the particular combination of the preferred form of the invention employing long runs of knitted tube coated at high speed with an epoxy resin, enables a superior product to be obtained extremely economically.
• the resin system employed in accordance with the invention is an epoxy resin, preferably a long chain epoxy resin with an acid polyester hardner.
• Such systems are solventless and are usually two-pack, but need not be so.
• a fibrous material tube was produced by knitting on a circular knitting machine in a continuous manner a glass fibre yarn.
• the bore of the tube knitted was 10 mm. arid the average size of the interstices in the knitted structure was 0.1 x 0.2 mm.
• the product so produced was found to be evenly coated, flexible, and with no strike through of the resin into the bore of the tube.
• Other properties of the product were as follows: The product was produced continuously in long runs and thereafter cut into lengths and wound on standard reels.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Insulating Bodies (AREA)
• Reinforced Plastic Materials (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10534333

Family Applications (1)

Country Status (3)

Citations (4)

• 1983
  • 1983-10-25 ZA ZA837913A patent/ZA837913B/xx unknown
  • 1983-11-04 EP EP83306716A patent/EP0109794A1/de not_active Withdrawn
  • 1983-11-07 AU AU21033/83A patent/AU2103383A/en not_active Abandoned

Patent Citations (4)

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