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CN-122029027-A - Spiral wound pipe insulation

CN122029027ACN 122029027 ACN122029027 ACN 122029027ACN-122029027-A

Abstract

A pipe insulation is formed from a plurality of discrete sheets of glass fibers wetted with a binder composition. The sheets are spirally wound around a mandrel in a partially overlapping manner. The rolled sheet is further processed to join it to one another and form a unitary elongate cylinder. The adhesive in the elongated cylinder is then cured to form the pipe insulation.

Inventors

  • M. D. Gavrila
  • M. E. Mantonia
  • P.E. shocr Ross
  • CLEMENTS CHRISTOPHER J.
  • B. T. Padgett

Assignees

  • 欧文斯科宁知识产权资产有限公司

Dates

Publication Date
20260512
Application Date
20241018
Priority Date
20231027

Claims (20)

  1. 1. A method of forming a pipe insulation, the method comprising: providing a plurality of sheets of insulation material, each sheet comprising a binder and a plurality of glass fibers; compressing each sheet of insulating material to have a thickness in the range of about 1.5mm to about 6.5 mm; Drying each sheet of insulating material to remove a substantial portion of the water therefrom; Directing each sheet of insulating material toward the mandrel at an angle α, where α+.90 degrees, and Spirally winding each sheet about the mandrel in a partially overlapping manner to form an elongated hollow cylinder of the insulating material, the elongated hollow cylinder having a wall thickness in the range of about 10mm to about 55 mm; wherein each sheet of insulating material has a width in the range of about 35mm to 80 mm; Wherein each sheet of insulation material has a Fiber Area Weight (FAW) in the range of about 195g/m 2 to about 410g/m 2 ; wherein each sheet of insulation material has a fiber basis weight variation within a range of about FAW+ -50%, and Wherein the adhesive of each insulating sheet is substantially uncured as the sheet is spirally wound on the mandrel.
  2. 2. The method of claim 1, wherein each sheet of insulating material has a first scrim bonded to a top surface of the sheet and a second scrim bonded to a bottom surface of the sheet, and Wherein the first scrim and the second scrim are removed from the sheet after drying the sheet and before spirally winding the sheet.
  3. 3. The method of claim 1, further comprising hydrating each sheet of insulation on the mandrel by applying about 1 wt% to about 5wt% water to the sheet based on the weight of the sheet.
  4. 4. The method of claim 1, further comprising kneading the sheet of insulation material on the mandrel to redistribute a portion of the adhesive located at an overlapping portion of the sheet.
  5. 5. The method of claim 1, further comprising cauterizing an innermost sheet and an outermost sheet of insulation material on the mandrel.
  6. 6. The method of claim 5, wherein the cauterizing comprises applying heat to the innermost sheet and the outermost sheet in the range of about 750°f (398.89 ℃) to about 900°f (482.22 ℃) for about 1/8 seconds to about 1 second.
  7. 7. The method of claim 1, further comprising curing the adhesive of the elongated hollow cylinder on the mandrel.
  8. 8. The method of claim 7, wherein the curing comprises applying heat to the sheet in a range of about 475°f (246.11 ℃) to about 650°f (343.33 ℃) for at least about 5 seconds.
  9. 9. The method of claim 1, further comprising cutting the elongated hollow cylinder to a desired length as the elongated hollow cylinder exits the mandrel.
  10. 10. The method of claim 9, further comprising cutting a longitudinal slit in the length of the elongated hollow cylinder.
  11. 11. The method of claim 10, further comprising applying an outer jacket material to the length of the elongated hollow cylinder.
  12. 12. The method of claim 1, wherein the spiral winding is effective to produce about twenty-four 3 foot (0.9144 meter) segments of the pipe insulation per minute.
  13. 13. The method of claim 1, wherein the lumen of the elongated hollow cylinder has a diameter of less than 67 mm.
  14. 14. The method of claim 1, wherein the fibers in each sheet have an average fiber diameter in the range of about 6 μιη to about 9 μιη.
  15. 15. The method of claim 1 wherein each sheet has the adhesive from about 5% LOI to about 8% LOI.
  16. 16. The method of claim 1, wherein the pipe insulation has a density in the range of about 56,000g/m 3 to about 88,000g/m 3 .
  17. 17. The method of claim 1, wherein the uncured binder is substantially free of formaldehyde.
  18. 18. The method of claim 1, wherein the binder comprises polyacrylic acid and sorbitol.
  19. 19. The method of claim 1, wherein the sheet is spirally wound along the mandrel using at least one ribbon.
  20. 20. The method of claim 1, wherein between 2 and 32 sheets are used to form the pipe insulation.

Description

Spiral wound pipe insulation Cross Reference to Related Applications The present application claims priority and any benefit from U.S. provisional application No. 63/593,557 filed on 10/27, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field The present general inventive concept relates to fiber pipe insulation and, more particularly, to spiral wound pipe insulation. Background It is known to surround the pipe with, for example, fibrous insulation to improve energy efficiency. A conventional process for forming fibrous conduit insulation is a continuous molded Conduit (CMP) process. CMP processes are commonly used to form smaller diameter pipe insulation, such as pipe insulation having an inner diameter of 6 inches (15.24 cm) or less. In a CMP process, a raw material ("batch") can include recovered glass particles that are melted at high temperatures (e.g., greater than 2000°f (1,093.33 ℃)) to produce molten glass. The molten glass is then used to form solid fibers, which are deposited on a conveyor to form a fiber "pack" having a desired thickness. The pack is cut to specific lengths and/or widths, each length and/or width forming a "rawhide (pelt)" having that thickness. The width of the pelt corresponds approximately to the circumference of the pipe insulation produced. The pelt is then fed into the mould and folded around a fixed hollow mandrel centred in the mould. The mold itself is a hollow tube, at least a portion of which is perforated, so that heated air can be forced into and out of the mold. The rawhide is cured in the mold and on the mandrel to form the pipe insulation segments as tubular bodies. In particular, the dimensions of the mandrel define the inner diameter of the tube. Also, the die defines an outer diameter of the tube, wherein a distance between the die and the mandrel limits a wall thickness of the tube. Curing may be accomplished by using multiple heat sources, such as an induction heater for curing the outer surface of the tube (at the beginning of the mold), and applying heated air into both the mold and the through holes formed in the mandrel. Thus, the outside of the tube is rigid, while the inside has a softer core that can be compressed to form surrounding fittings and other complex pipe shapes. The pipe insulation segments are pulled through the mold using a woven fiberglass scrim that separates from the pipe insulation as the pipe insulation segments exit the mold. As the pipe insulation segments leave the die, longitudinal seams are cut completely through the top of the pipe insulation segments and a partial longitudinal back cut is made along the bottom of the pipe insulation. These cutouts facilitate subsequent installation of the pipe insulation around the pipe. The pipe insulation segments exiting the die are cut transversely to the pipe insulation of the desired length (e.g., up to 36 inches (91.44 cm)). In some embodiments, the jacket is applied (e.g., adhered) to the outer surface of the pipe insulation. Fig. 1 illustrates (in cross-section) an exemplary pipe insulation 100 produced by CMP or other conventional mandrel-based processes. The pipe insulation 100 is formed from a fibrous insulation material 102 (e.g., fiberglass) into an elongated hollow cylinder having a wall thickness 104 and an interior cavity 106. The inner cavity 106 defines an inner diameter 108 of the pipe insulation body 100. The inner diameter 108 of the pipe insulation 100 is selected to match the outer diameter of the pipe or pipe-like member to be insulated. An optional outer jacket 110 wraps around the insulation 102 and, in particular, serves as a vapor barrier for the pipe insulation 100. The outer jacket 110 may also serve as an aesthetic cover for the insulation 102. Slits 112 are formed through the insulation 102 to facilitate placement of the pipe insulation 100 around the pipe. To further facilitate installation of the pipe insulation 100, a partial slit 114 may also be formed, typically on the side of the insulation 102 opposite the slit 112. The partial slit 114 typically does not extend through the entire thickness 104 of the insulation 102 (and does not damage the outer jacket 110). After the pipe insulation 100 is assembled around the pipe, a portion of the outer jacket 110 forms a cover 116 that extends over (and seals) the slit 112. A disadvantage of conventional molding processes, as well as other fiber pipe insulation production processes, is that they often involve relatively slow production times, which significantly limit the amount of material that can be produced in a given period of time. For example, a conventional molding process may only produce approximately twelve 3 foot (0.9144 meter) segments of pipe insulation per minute. Accordingly, there is an unmet need for a faster, more efficient process for producing fiber pipe insulation that produces fiber pipe insulation comparable to the slower conventional process. In