This invention relates generally to pipe insulation and more particularly to pipe insulation having two semi-cylindrical pieces of insulating material adhesively secured to an outer jacket or cover which acts as a hinge when the pieces of insulating material are pulled apart for installation on a pipe.
An object of the invention is to provide pipe insulation of such a type having improved means for adhesively securing the cover flap to the cover to form a seam.
Other objects and advantages will become apparent when the following specification is considered along with the accompanying drawing wherein:
FIG. 1 is a perspective view of a piece of pipe insulation constructed in accordance with the invention, two portions thereof being pulled apart for installation on a pipe and protective covering on self-sealing adhesive material being partially peeled off;
FIG. 2 is a perspective view of the piece of pipe insulation of FIG. 1 installed on a pipe, the protective covering on the self-sealing adhesive material being removed but the cover flap still being unsealed;
FIG. 3 is a perspective view similar to FIG. 2, but with the cover flap sealed; and
FIG. 4 is an end view of the installed insulation of FIG. 3.
With respect to the drawing, a length of pipe insulation 10 constructed in accordance with the invention is shown. The insulation 10 includes two semi-cylindrical pieces of insulating material 12 and 13 adhesively secured at their outer peripheries to a flexible jacket or cover strip 14 having an overlapping flap 14a forming one edge portion thereof and adapted to overlap an opposite edge portion thereof. The cover strip 14 is preferably a laminate of paper, fibrous glass scrim reinforcement, and an aluminum foil vapor barrier. One strip 16 of adhesive material or tape with self-sealing adhesive on both sides is adhesively secured on one side to the inner side of the flap 14a and another strip 17 of adhesive material or tape with self-sealing adhesive on both sides is adhesively secured on one side to the outer side of the opposite edge portion of the cover strip 14. The strips 16 and 17 are respectively covered on their other sides during storage and shipment with protective silicone coated paper strips 18 and 19 (FIG. 1) removably adhered thereto.
In FIG. 1 the pieces of insulating material 12 and 13 are spread apart as they would be prior to being placed around a pipe, the cover strip 14 acting as a hinge at a point generally diagonally opposite the flap 14a, and the strips 18 and 19, called release paper, are partially peeled off the strips 16 and 17 of adhesive material. In FIG. 2, the pieces of insulating material 12 and 13 are disposed around a pipe 20 and the strips 18 and 19 of FIG. 1 have been completely removed. In FIGS. 3 and 4, the flap 14a is sealed to the opposite edge portion of the cover strip 14 by the strips 16 and 17 of adhesive material, which have been pressed together after the strips 18 and 19 of release paper have been removed. Normally the strips 18 and 19 are not removed until the insulation is on a pipe.
The pieces of insulating material 12 and 13 may be molded fibrous glass wool, plastic foam, or any other kind of insulation. The strips 16 and 17 of adhesive material or tape are about from one to two inches wide and are shown for ease of illustration with exaggerated thickness. The strips 16 and 17 are tissue paper impregnated with an adhesive, preferably an adhesive having a neoprene or acrylic base, a narrow edge portion of the tissue paper on the side with the release strips 18 and 19 being adhesive free for easy removal of the release strips.
Prior to this invention, pipe insulation was provided with only one strip of self-sealing adhesive material, such as the strip 16 on the flap 14a. A pressing tool had to be used, and in cold weather it was difficult to get the self-sealing adhesive on the flap 14a to flow into the paper at the opposite edge portion of the cover strip 14. In accordance with this invention, a second strip of self-sealing adhesive material, such as the strip 17, is provided on the opposite edge portion of the cover strip 14 from the flap 14a for cooperative engagement with the first strip of self-sealing adhesive material. A much stronger seal results from the joining of the adhesive material directly to adhesive material, and the insulation can be installed by hand pressing of the sealing strips together without the use of a pressing tool.
The cover strip 14 is secured to the pieces of insulating material 12 and 13 by adhesive extruded onto the cover strip 14 in a controlled pattern while the cover strip is flat. The pieces of insulating material 12 and 13 are rolled up in the cover strip 14 with beads of adhesive extruded thereon, as indicated in FIG. 1. Four beads 21 of a heat meltable adhesive such as amorphous polypropylene are provided on the cover strip 14 along with four beads 22 of a water based or water emulsion adhesive. The beads 21 of the heat meltable or "hot melt" adhesive are disposed on the cover strip 14 so as to be on the outer periphery of the pieces 12 and 13 and respectively adjacent the flat surfaces such as the surfaces 12a and 12b of the piece 12, defining circumferentially opposite ends of the semi-cylindrical pieces when the pieces of insulation 12 and 13 are rolled up in the cover strip. The beads 22 of water based adhesive are disposed on the cover strip 14 so as to be spaced further inwardly respectively from circumferentially opposite ends of the semi-cylindrical pieces 12 and 13 than the beads 21 of heat meltable adhesive. The hot melt adhesive 21 sets up quickly, and the water based adhesive 22 maintains the cover strip 14 properly in place when the pipe insulation encounters temperatures in shipment high enough to remelt the hot melt adhesive temporarily. Each of the beads 21 and 22 extends longitudinally of the pieces of insulation 12 and 13 for the full length of the cover strip 14, but for clarity only one bead 21 and one bead 22 are shown full length in broken lines in FIG. 1.
It is within the scope of the invention to provide three pieces of insulation, each of arcuate length of one hundred twenty degrees, secured to a cover strip 14 in a similar manner, for pipes of larger diameter.
Preferably some lightly sealing adhesive 24, shown as two drops in FIG. 1, is placed on the flap 14a on top of the release paper 18 for the strip 16 of adhesive material, to temporarily hold the flap 14a in a closed position during shipment of the insulation 10.
Various modifications may be made in the structure shown and described without departing from the spirit and scope of the invention.