WO1998005724A1

WO1998005724A1 - Method of adhering decorative masonry to a work surface

Info

Publication number: WO1998005724A1
Application number: PCT/US1997/013646
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: AU3825997A

Abstract

A clean, neat and effective method for adhering decorative masonry 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 heats sufficient to activate the adhesive material to effect a bonded relationship between the decorative masonry and the work surface.

Description

METHOD OF ADHERING DECORATIVE MASONRY TO A WORK SURFACE

CROSS REFERENCE TO A RELATED 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

This disclosure relates to the installation of decorative masonry by adhesive

attachment. Decorative masonry is a term used to describe brick veneers and ceramic

floor and wall tiles. It is also used to describe roofing tiles, interior and exterior brick,

false and natural stone and marble.

Interior masonry is attached to a work surface by a variety of glues, mastics,

cementatious mortar mixtures and the like. Roof masonry like clay tiles and slate are

applied with nails, staples, mortar or specialty fasteners. Mortar mixtures are long lasting

and fireproof but not flexible and slow to dry and cure. Many mortars require mixing

several ingredients for the best and most effective results. Mortars are also difficult to

level and usually require an elevated degree of skill to spread properly.

Not surprisingly then, others have experimented with alternatives to traditional

fastening devices for attaching construction materials 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 decorative masonry to a work surface

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

between the attaching surface of the decorative masonry and the work surface 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 decorative masonry and the work surface.

DESCRIPTION OF THE PREFERRED EMBODIMENT

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 will 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 absorbtion 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 between the decorative masonry

and the work surface. Typically, the decorative masonry will be brick, ceramic, clay

tile, natural stone or slate or any of a variety of composite materials. The work surface

for decorative masonry include particle board, OSB and plywood, waterproof cement

boards, waterproof dry walls and masonry.

As a practical matter, of course, the decorative masonry needs 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 between the decorative masonry 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,

spiking or even snap-fitting by slotting the decorative masonry and grooving the work

surface 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 between the decorative masonry 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" decorative masonry, be absorbed by the target element, be converted to heat

energy, activate the adhesive material resulting in a bonded relationship between the

decorative masonry 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 decorative masonry 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

decorative masonry is not a trivial attribute. In addition to the obvious advantage of

being able to reassemble or repair misaligned decorative masonry, it may also be

desirable to be able to disassemble affixed decorative masonry 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 decorative masonry to a work surface which comprises

placing between 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 decorative masonry and a work surface.

2. An article of decorative masonry 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.