Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L11/00—Hoses, i.e. flexible pipes
  • F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
  • F16L11/08—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall
  • F16L11/085—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall comprising one or more braided layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60H—ARRANGEMENTS OF HEATING, COOLING, VENTILATING OR OTHER AIR-TREATING DEVICES SPECIALLY ADAPTED FOR PASSENGER OR GOODS SPACES OF VEHICLES
  • B60H1/00—Heating, cooling or ventilating [HVAC] devices
  • B60H1/00507—Details, e.g. mounting arrangements, desaeration devices
  • B60H1/00557—Details of ducts or cables
  • B60H1/00571—Details of ducts or cables of liquid ducts, e.g. for coolant liquids or refrigerants

Definitions

• This invention relates to hoses for transporting or otherwise handling refrigerants. More specifically, this invention relates to improved inner tubes and outer covers for these hoses.
• Prior hoses of this type comprise an inner tube and an outer cover, the inner tube being made up of a polymeric inner wall and a rubbery outer peripheral wall.
• Certain polymeric materials are known which render the hose highly resistant to refrigeration gases. These materials include polyamides such as nylon-6, nylon-6/66, nylon-1 1 , nylon-12 and the like. Many nylons, however, produce inner walls which are very stiff and not very flexible. Flexibility is highly desirable, particularly in automotive applications for ease of routing and damping of noise transmission. Attempts to modify the nylons through the use of traditional plasticizers such as oils or excess monomer to provide more flexible inner walls have resulted in hoses with higher gas permeability. In addition, normal A/C system use can cause these plasticizers to be extracted from the nylon, stiffening the hose and potentially contaminating the refrigeration system. Normal A/C systems often see temperatures in excess of 200°F. DISCLOSURE OF THE INVENTION
• the hose has an inner tube with improved flexibility while maintaining low gas permeability without the use of extractable plasticizers.
• the inner tube includes a resinous inner peripheral wall and a rubbery outer peripheral wall, wherein the resinous inner peripheral wall consisting essentially of nylon and a non-extractable elastomeric plasticizer, and wherein the rubbery outer peripheral wall is a butyl rubber or a halogenated butyl rubber.
• the non-extractable elastomer plasticized inner wall has numerous positive attributes over traditional plasticized nylons, however, permeability is essentially equivalent.
• a hose with improved permeation resistance is achieved effectively obtaining all desirable properties in a single hose.
• the hose also has a reinforcing layer laminated over the outer peripheral wall, and an outer cover laminated over the reinforcing layer.
• the outer cover is a halogenated butyl rubber.
• the resinous inner wall has an increased nylon content relative to the elastomeric plasticizer content.
• the discharge hoses have a smaller diameter than hoses on the low pressure, suction side.
• the resulting hoses in both embodiments are more flexible with lower gas impermeability.
• the hoses also have better refrigerant oil resistance, favorable inner wall characteristics, high temperature resistance and maintain their flexibility after prolonged use.
• Traditional walls have negative swell; i.e., they shrink or decrease in size. Shrinking may contribute to leakage.
• Our development provides a positive swell and actually creates a tighter, more leak proof seal.
• Fig. 1 is a perspective view, partly cut away, illustrating a hose according to our invention.
• Hose 10 is a multi-layered structure which comprises inner tube 20, outer cover 40 and reinforcing layer 30 disposed therebetween.
• Inner tube 20 includes resinous inner peripheral wall 21 and rubbery outer peripheral wall 22.
• Inner wall 21 of inner tube 20 is made of the combination of nylon and a non-extractable elastomeric plasticizer, preferably grafted ethylene-propylene-diene rubber (EPDM).
• the nylon can vary widely and comes from the family of polyamide polymers characterized by the amide radical: -CONH. By far, the most common nylons are nylon 66 and nylon 6.
• Nylon 66 is a condensation product of adipic acid and hexamethylenediamine.
• Nylon 6 is a polymer of caprolactam.
• Nylon 4 is based on butyl-rolactam (2-pyrrolidone).
• Nylon 1 1 is the self-condensation product of aminoundecanoic acid and nylon 12 is made from butadiene.
• inner wall 21 is made from a mix of nylon 66 and grafted EPDM.
• rubbery outer wall 22 of inner tube 20 is made of butyl rubber or halogenated butyl rubber.
• the butyl rubbers can vary widely. Generally, they are a copolymer of isobutylene and small amounts of a diolefin.
• a typical butyl rubber is made from isobutylene and isoprene (II R). Typically, the II R copolymer contains 3% isoprene.
• a typical halogenated butyl rubber is chlorinated butyl rubber (Cl-ll R). In the preferred embodiment of this invention, we use butyl rubber (II R).
• the resinous inner peripheral wall consisting essentially of 24 to 80 percent by weight nylon and 10 to 60 percent by weight elastomeric plasticizer. Materials for the inner wall are described in U.S. Patent No. 5,091 ,478 which is herein incorporated by reference.
• the preferred halogenated butyl rubber for outer cover 40 is chlorinated butyl rubber.
• hose according to the invention may be fabricated by any suitable known methods.
• One such method involves passing a release-treated mandrel through an extruder equipped with heads from which resins are extruded peripherally on the mandrel and thus form an inner wall.
• the mandrel is allowed to successively enter a rubber extruder at which time an outer wall of rubbery material is laminated over the plastic wall.
• a layer of reinforcement is laminated by braiding suitable textile yarns over the outer rubbery wall of the inner tube.
• An outer cover is disposed outwardly about the braided layer by extrusion of the rubbery material.
• Braided layer 30 may be made from any number if fibers including glass fibers, polyester fibers, nylon, graphite, rayon and polyamide fibers (Kevlar). We prefer that braided layer 30 be made of polyester fibers.
• the hoses we tested had an inside diameter, typically 8 to 16 mm.
• the inner tube was made of 60 to 80 percent by weight nylon
• the reinforcing layer was braided polyester and the outer cover was chlorinated butyl rubber.
• the hoses we tested are Type E hoses under SAE J2064.
• the refrigerant we used was Refrigerant 134A.
• the gas permeations we measured under SAE J2064 ranged from 0.25 to 0.75 lbs/ft 2 /yr.
• the material of the inner wall of the hoses of this Example have a flex modulus under ASTM D 790-86 of less than, 100,000 psi.
• unplasticized nylon typically has a flex modulus ranging from 50,000 psi to 100,000 psi.
• unplasticized nylon is very stiff and has a flex modulus of 250,000 psi.
• Conventional oil plasticized nylon 66 have a stiffness of 100,000 to 125,000 psi. Oil, however, extracts from the conventional oil plasticized nylons at usual operating temperature in excess of 200°F.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Rigid Pipes And Flexible Pipes (AREA)
• Laminated Bodies (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=21816618

Family Applications (1)

Country Status (7)

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Citations (3)

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• 1993
  • 1993-12-03 JP JP6518941A patent/JPH08507351A/ja active Pending
  • 1993-12-03 BR BR9307818A patent/BR9307818A/pt not_active Application Discontinuation
  • 1993-12-03 AU AU56855/94A patent/AU5685594A/en not_active Abandoned
  • 1993-12-03 WO PCT/US1993/011772 patent/WO1994019638A1/en not_active Application Discontinuation
  • 1993-12-03 EP EP94902501A patent/EP0694140A4/en not_active Withdrawn
• 1994
  • 1994-02-09 MX MX9401026A patent/MX9401026A/es unknown
  • 1994-02-24 CN CN 94102160 patent/CN1098772A/zh active Pending

Patent Citations (3)

Non-Patent Citations (1)

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