Stock material or miscellaneous articles – Layer or component removable to expose adhesive
Reexamination Certificate
2003-01-23
2004-08-31
Ahmad, Nasser (Department: 1772)
Stock material or miscellaneous articles
Layer or component removable to expose adhesive
C138S149000, C138S151000, C138S152000, C428S036900, C428S036910, C428S042200, C428S192000, C428S194000
Reexamination Certificate
active
06783830
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to adhesive tape structures, and more particularly to adhesive tape structures which are used in conjunction with insulation for fluid conduits.
BACKGROUND OF THE INVENTION
Most heating and air conditioning units in dwellings, commercial buildings and industrial plants include cylindrical pipes which carry heated or cooled air or water or steam. In addition, in industrial applications, pipes may be used to carry these and other fluids. In most instances, particularly in more severe climates, these pipes must be insulated to prevent freezing, and/or to maintain the temperature of the fluid within the pipes, especially where the pipes are disposed on the exterior of the building structure.
Insulation segments may be used to insulate such pipes. These segments typically are cylindrical in shape and include an inner insulating layer surrounded by a jacket. In the center of the segments is a cylindrical passageway extending axially or longitudinally along the segment and having a diameter roughly equal to the outside diameter of the pipe to be insulated. A longitudinal slit is provided extending from one end of the segment to the other. This slit may be opened to allow insertion of the pipe therethrough and into the central passageway. A flap is provided for covering the slit and for sealing the pipe within the segment. Such segments typically extend along a pipe in an end to end, abutting relationship to fully insulate and seal the pipe.
The inner insulating layer in each segment typically is formed of a fiberglass or mineral wool, a foamed cellular fiberglass or a rigid foam. The jacket which covers the insulating layer typically is formed of a metal or metalized foil, and/or a layer of kraft paper or the like. A preferred jacket material is an All Service Jacket (ASJ), which has layers that include paper, scrim, and aluminum foil and/or metalized polyester. Often, the metal or metalized layers and/or paper layers are laminated together to provide a weather-tight structure with a suitable tear and tensile strength. Typically the flap which covers the slit is merely an extension of the jacket and is formed of the same materials.
Often, the flap and/or the outer surface of the insulation jacket adjacent the slit is provided with a strip of adhesive or adhesive tape to bond the flap to the outer surface of the jacket to cover and seal the slit. The actual sealing of the flap to the jacket typically occurs at the job site when the insulation is installed. It is desirable, if not necessary, to keep the bonding surfaces of the flap and the confronting, outer surface of the jacket free from dirt and moisture to permit a tight seal. If the seal is not satisfactory, “fish mouthing” can occur either as a result of the breakdown of the bond between the adhesive strip and the flap, or the bond between the adhesive strip and the outer surface of the jacket. This breakdown can produce delamination or disintegration of the jacket or the flap which can occur over a period of a few weeks in a very damp environment, or over a period of many months in less damp environments. If such “fish mouthing” occurs, the insulation segments must be removed and replaced if the desired level of protection is to be maintained “Fish mouthing” is a particular problem on jobs for the United States Government, since such “fish mouthing” does not meet its specifications and the contractor may be required to return to the job site and repair the damage at his or her own cost.
Moreover, hot melt adhesives typically are used to bond the jacket to the inner insulating layer. The insulation segments typically are still hot, and the adhesive is still soft and not yet cured, when the insulation segments are placed in containers for shipment. This quick placement in containers is necessary to expedite the manufacturing and shipping process. The containers into which the segments are placed tend to act as insulators and retain the heat within the container maintaining the hot melt adhesive in a softened condition for a prolonged period of time after placement in the containers. As a result, the jacket can separate from the inner insulating layer prior to cooling and curing, and prior to arrival of the segment at the job site. Such separated segments are not acceptable, and must either be discarded or reattached. Obviously, this repair or replacement is very costly. To overcome this problem, harder, more quickly curing adhesives have been used to bond the jacket to the inner insulating layer. However, since these harder adhesives do not permit movement of the jacket with respect to the inner insulating layer with time and under charging temperature and moisture conditions, unacceptable dimpling of the jacket often occurs with such adhesives.
One solution to the foregoing problems is to use soft, hot melt adhesives or two component urethane adhesives and to temporarily seal the flap to the outer surface of the insulation jacket at the-factory prior to shipping. This solution protects the surfaces to be adhered to one another to minimize any “fish mouthing” effects. This solution also wraps the jacket tightly about the inner insulating layer, and prevents separation of the structure during shipment because of the soft or uncured condition of the hot melt adhesive. This solution also avoids most dimpling effects. One existing structure that provides such a solution is found in U.S. Pat. No. 4,157,410. In this structure, tape is provided having either two or four layers of pressure sensitive adhesive separated by release liners. When applied to the insulation jacket and flap at the factory, the outer two release liners are removed, exposing a layer of pressure sensitive adhesive on either side of the structure which then temporarily bonds the flap to the outer surface of the insulation jacket. When it is desired to install the insulation segment at the job site, the flap is separated from the outer surface of the jacket by prying apart the structure along a central release liner in the structure that separates two adhesive layers. The central release liner is then removed, and the two adhesive layers are bonded together to permanently seal the flap to the outer surface of the insulation jacket.
Another solution is that disclosed in U.S. Pat. No. 5,104,701 assigned to the assignee of the present application. In the closure system of this '701 patent, a tape contains a layer of a low tack, pressure sensitive adhesive which bonds the tape on one side to a strip either on the outer surface of the jacket on one side of the slit or on the flap. The opposite side of the tape has a release liner to which a high tack adhesive layer on the other of the flap or the outer surface of the jacket is bonded to temporarily bond the flap to the outer surface of the jacket. The tape structure can be opened at the job site by peeling the adhesive layer on the tape away from the strip. Once the flap is opened, the release liner is removed and the high tack adhesive layer on the flap or jacket may be permanently bonded respectively to the outer surface of the jacket or the flap to provide a permanent seal.
Another structure is found in U.S. Pat. No. 5,964,252, in which an abridged release liner is provided to allow partial exposure of the adhesive layer to achieve a temporary bond. This temporary bond may be severed and the release liner may be subsequently removed to achieve a permanent bond.
Another existing prior art structure in which an adhesive layer is disposed on one of the flap and the outer surface of the jacket is disclosed in U.S. Pat. No. 5,104,701. In one embodiment of this prior art structure, an adhesive tape is provided which can be bonded to the underside of the flap or to the outer surface of the jacket, either at the job site or at the factory. This tape typically includes a substrate having a layer of a pressure sensitive adhesive disposed on both sides thereof. The adhesive layer on one side of the substrate is bonded to the inside surface of the flap or to the jacket,
Cohen Lewis S.
Litman Gary
Ahmad Nasser
Venture Tape Corp
Wolf Greenfield & Sacks P.C.
LandOfFree
Adhesive tape structure for use with insulation jackets does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Adhesive tape structure for use with insulation jackets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adhesive tape structure for use with insulation jackets will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3279067