WO1998005725A1

WO1998005725A1 - Method of adhering sheet goods to a work surface

Info

Publication number: WO1998005725A1
Application number: PCT/US1997/013648
Authority: WO
Inventors: David L. Remerowski; Duane C. Shomler; Anthony T. Racca; David J. Lococo
Original assignee: Senco Products, Inc.
Priority date: 1996-08-05
Filing date: 1997-08-05
Publication date: 1998-02-12
Also published as: TW438663B; AU3906197A

Abstract

A clean, neat and effective method for adhering sheet goods to a work surface entails placing adjacent to the surfaces to be joined a device which comprises: a target element contiguous with a heat activatable adhesive material, said target element being absorbent of electromagnetic waves which are convertible to heat energy to activate said adhesive material, holding said surfaces together, and exposing said device to electromagnetic waves to produce heat sufficient to activate the adhesive material to effect a bonded relationship between the sheet goods and the work surface.

Description

METHOD OF ADHERING SHEET GOODS TO A WORK SURFACE

CROSS REFERENCE TO A RE ATED APPLICATION This application relates to U.S. Patent Application Serial No. filed on even date

herewith and entitled "Adhesive Device" by Shomler et al. Said application and its

disclosure are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

This disclosure relates to the installation of sheet goods by adhesive attachment.

"Sheet goods" is the term used in the construction industry to describe panels, plastic

counter laminates, gypsum board drywall, plywood, oriented strand board (OSB), particle

board, asphaltic shingles, insulation board and exterior siding panels. These sheet goods

are generally employed to construct subfloors, roof sheathing, walls sheathing, sheer

walls, roof and wall shingle, insulate walls and floor underlayment. On the job, sheet

goods are attached to conventional structural framing material which is usually wood or

steel. The sheeting is also frequently attached to itself and to steel framing members of

various gauges and strengths. It is envisioned that the practice of the disclosed method

would occur both at in-plant and construction sites.

Sheet goods are usually attached to a structural work surface which, as mentioned

above, is usually a 2x or 4x material of wood, composite material or a steel framing

member. It is also important to note that sheet goods may also be attached to another piece of sheet goods which, in that case, would also be a work surface. The attachment of

sheet goods to the work surface is typically effected by employing mechanical fastening

devices such as nails, staples, tacks and brads. However, these power or hand driven

fastening devices are labor intensive and are rapidly falling into disfavor as new

adhesives are developed which are safer to work with and produce attachments that are

actually more secure than the traditional fastening methods. However, the use of new

adhesives alone is not the final answer. Adhesives are messy and difficult to apply to

"hidden" or inaccessible places. It is apparent, then, that inventions are waiting to be

made which address the placement of adhesive material in a neat, clean, safe and

effective manner that can be used beneficially in manufacturing and construction, and

especially with regard to the placement or sheet goods to a work surface.

Not surprisingly then, others have experimented with alternatives to traditional

fastening devices for attaching sheet goods to a work surface.

DESCRIPTION OF THE PRIOR ART

United States Patent 4,038, 120 to Russell describes the use of an energized

heating element or wire to heat a hot melt glue resulting in adhesion between

contiguously assembled panels. The reference method involves heating a glue-coated

wire to liquefy the glue producing a cohesive state and facilitating the assembly of panels.

This method is particularly useful for introducing a cohesive material (glue) to an area of

limited accessibility (groove), but the heating element (wire) requires the direct

application of energy (electricity) to provide the heat to melt glue.

United States Patent 3,574,031 to Heller et al. describes a method and material for welding thermoplastic bodies by using a susceptor between the bodies to be joined. The

susceptor sealant is characterized by having particles, heatable by induction, dielectric or

radiant energy, dispersed in a thermoplastic carrier compatible with the thermoplastic

sheets to be welded. The welding of the thermoplastic sheets is effected by exposing the

susceptor sealant to heat energy, softening the carrier material and joining all

thermoplastic materials.

United States Patent 3,996,402 to Sindt relates to the assembly of sheet materials

by the use of a fastening device utilizing an apertured sheet of eddy current-conducting

material sandwiched between coatings of hot-melt glue. An induction heating system is

activated causing eddy current heating in the EC-conducting material with consequent

melting of the hot-melt glue thus resulting in fusion and, ultimately, bonding of the sheet

materials in accordance with the desired construction.

SUMMARY OF THE INVENTION

The presently disclosed method of adhering sheet goods to a work surface is

distinguished from, and improves upon, the prior art by utilizing a device to be placed

adjacent to the surfaces to be joined which comprises a target element contiguous with a

heat activatable adhesive material said target element being absorbent of electromagnetic waves which are convertible to heat energy for activating the adhesive material, holding

said surfaces together, and exposing said device to electromagnetic waves to produce heat

sufficient to activate the adhesive material to effect an adhesive bond between the sheet

goods and the work surface. DESCRIPTION OF THE PREFERRED EMBODIMENT

Sheet goods comprising, for example, gypsum board drywall, plywood, insulation

board, plastic or metal laminates, oriented strand board, particle board, asphaltic shingles

and exterior siding panels can be adhesively joined effectively and efficiently to a work

surface such as ajoist, stud, plate, header, truss or rafter typically fashioned from a 2x or

4x wood, steel or composite material by employing the method herein described.

A typical procedure for the attachment of sheet goods to a work surface would

entail little more than placing the devices disclosed herein in such a manner that when

activated they would adhesively join a piece of sheet goods material to the intended work

surface.

At the risk of stating the obvious by describing the ease of performing the disclosed method, consider the simplicity of installing a subflooring or a roof sheathing

using four feet by eight feet plywood panels. The method entails little more than simply

placing, or perhaps securing, units of the disclosed device on the edge surfaces of the

rafters, wall studs or floor joists where the plywood panel is to be attached, putting the

panel in place and then activating the adhesive device with electromagnetic waves to

adhesively join the panel to its work surface.

In the case of asphaltic shingles, the roof and wall sheeting materials would, in

turn, be the work surface for the next layer of sheeting material, viz., the asphaltic

shingle. Shingles are particularly well suited for installation according to the disclosed

method. Shingles are widely used as roof coverings and frequently for siding as well.

Shingles are applied in overlapping courses or rows, and the degree of overlapping is determined by the pitch of the roof or aesthetic concerns. In either case, one shingle will

be the work or attaching surface of the overlapping shingle. In these cases, almost the

entire construction of the dwelling or edifice would be effected by adhering one sheeting

material to another and to a third layer, all using the adhesive device of the disclosed

method.

Looking at the adhesive device employed in the disclosed method in greater

detail, we see that the target element must, for the most part, be fashioned from materials

or substances that are not transparent to electromagnetic waves. Indeed, the target

element will necessarily be constructed of a composition that ill absorb electromagnetic

waves. Once absorbed by the target element, these waves will produce magnetic

hysteresis and eddy currents resulting in heat energy which will melt or activate the contiguous adhesive material.

Typically, the target element will be fashioned from metallic materials such as

steel, aluminum, copper, nickel or amalgams thereof which have proven utility and are

readily available; although, some semi-metallic materials such as carbon and silicon are

also known to be suitable for the absorption of electromagnetic waves.

The target element can assume any form or shape consistent with the overall

configuration of the adhesive device. Frequently, the target element will be presented as

a metallic foil, mesh or strip, and, in some instances, it will be more effective to present

the target element in the form of a fiber, chip or flake of an electromagnetic absorbable

material. The point to be made is that the target element need only be fashioned from a

material reasonably impervious to, and absorptive of, electromagnetic waves. In use, the adhesive device needs to be situated adjacent to the sheet goods and the

work surface. Typically, the sheet goods will be wood, fiber board, insulation board,

plastic or any of a variety of composite materials. As a practical matter, of course, the

sheet goods need to be transparent to electromagnetic waves. Some materials will be

more transparent than others, and empirical adjustments can and will be made to modulate the quantity and intensity of electromagnetic wave energy needed to optimally

activate the adhesive material.

In many instances, it will be sufficient for the adhesive device simply to be

placed adjacent to the sheet goods and the work surface. In other construction or

assembly situations, it will be necessary to make some arrangements or take additional

steps to make sure the adhesive device remains in place prior to activation. Such an

additional step need be little more than introducing an additional attachment element such

as a small pressure sensitive adhesive area on the surface of the device . Simpler means

for positioning the device prior to activation might entail clamping, tacking, stapling or

spiking to make sure the adhesive device is situated and activated in the most effective

and, therefore, most desirable location. But these measures, of course, would be optional

procedures and in no way essential to the performance of the device in its broadest typical

and routine applications

When desirably situated adjacent to the sheeting materials and the work surface,

the adhesive device is ready to be exposed to electromagnetic waves, produced by and emanating from a generator powered by a source of alternating electric current. The

generator can be held in a fixed position for assembly-line production or designed to be manipulated so as to quickly and easily pass over, around or near the strategically

"hidden" device while emitting electromagnetic waves which will penetrate the

"transparent" sheet goods, be absorbed by the target element, be converted to heat energy,

activate the adhesive material resulting in a bonded relationship between the sheet goods

and the work surface.

To elaborate, somewhat, heat is produced in the conductive target element by two

mechanisms: eddy current resistive heating and magnetic hysteresis. Eddy current

resistive heating applies to all conductive materials and is produced in the target element

by the electromagnetic waves emanating from the generator. The heat resulting from

magnetic hysteresis is observed only in magnetic materials. As the electromagnetic field

produced by the generator reverses polarity, the magnetized atoms or molecules in the

target element also reverse. There is an energy loss in this reversal which is analogous to

friction: This energy loss is magnetic hysteresis. The "lost" energy is quickly converted to heat and conducted by the target material to the contiguous, and frequently enveloping,

heat-activatable adhesive material to initiate adhesion.

When heated to the necessary temperature, the adhesive material will liquefy or

become heat-activated, attach itself to the work surface and, on cooling, create an

adhesive relationship between the sheet goods and the work surface.

Two adhesion mechanisms, hot-melt and heat-activated cure, are proposed for use

with the disclosed device. Both mechanisms are initiated by heat emanating from the target element. Hot-melt adhesives are solid at ambient temperatures, but melt or liquefy

when the temperature is elevated by, for instance, heat accumulating in the target element. The melted adhesive "wets" the adherends and, in the case of porous or fibrous

adherends, penetrates the surface of the pieces to be bonded. As the adhesive cools, the

adherends and adhesive are bonded by the electrostatic attraction of polar molecular

groups. In the case of porous or fibrous adherends, mechanical interlocking can

contribute to bond strength. Note that for the hot-melt mechanism, the bonding is

reversible. Thus by repeating the induction heating procedure, the bond can be undone

and the adherends separated. The ability to reverse the adhesion and separate fixed

mill work is not a trivial attribute. In addition to the obvious advantage of being able to

reassemble or repair misaligned sheet goods, it may also desirable to be able to

disassemble affixed sheeting material to facilitate serviceability and repair.

Heat-activated curing adhesives are also solid and easy to manipulate at ambient

temperatures, but when the adhesive temperature is elevated by, for example, the heat

emanating from the target element, a chemical reaction is initiated. This reaction

involves a cure or crosslinked bonding either within the adhesive or between the

adherends. Such bonds are typically irreversible. Frequently, a heat-activated curing

adhesive bond will demonstrate an electrostatic attraction between the adhesive and the

adherends and a crosslinked bond within itself.

While the foregoing is a complete description of the disclosed method, numerous

variations and modifications may also be employed to implement the purpose of the

invention. And, therefore, the elaboration provided should not be assumed to limit the

scope of the invention which is intended to be defined by the appended claims.

Claims

What is claimed is:

1. A method of adhering sheet goods to a work surface which comprises placing

adjacent to the surfaces to be joined a device which comprises: a target element

contiguous with a heat activatable adhesive material, said target material being absorbent

of electromagnetic waves which are convertible to heat energy to activate said adhesive

material, holding said surfaces together, and exposing said device to electromagnetic

waves to produce heat sufficient to activate the adhesive material to effect a bonded

relationship between the sheet goods and a work surface.

2. An article of sheet goods including an adhesive device which comprises: a

target element contiguous with a heat activatable adhesive material, said target material

being absorbent of electromagnetic waves which are convertible to heat energy to activate

said adhesive material.