IES80889B2 - Apparatus and method for applying adhesive onto a substrate - Google Patents

Abstract

The present invention relates to an apparatus and a method for applying a substantially zigzag line of adhesive onto a substrate. The apparatus (10, 110) includes means (12, 112) for spraying an adhesive (14, 114). The apparatus (10, 110) also includes means (18, 118) for rectilinearly moving a substrate (16, 116) in a first direction (20, 120) under the spray means (12, 112). The apparatus (10, 110) further includes means (22, 122) for reciprocatably moving the spray means (12, 112) in a second direction (24, 124), the second direction (24, 124) being substantially perpendicular to the first direction (20, 120). .

Description

Apparatus and Method for Applying Adhesive onto a Substrate The present invention relates to an apparatus and a 5 method for applying adhesive onto a substrate.

According to a first aspect of the invention there is provided an apparatus for applying a substantially zigzag line of adhesive onto a substrate, the apparatus comprising means for spraying an adhesive; means for rectilinearly moving the substrate in a first direction under the spray means; and means for reciprocatably moving the spray means in a second direction, the second direction being substantially perpendicular to the first direction.

Preferably, the substrate is a metal sheet.

More preferably, the moving means is arranged to move the substrate under the spray means at a substantially constant velocity.

In a second aspect, the invention also provides a method for applying a substantially zigzag line of adhesive onto a substrate, the method comprising rectilinearly moving the substrate in a first direction under a spray means whilst reciprocatably moving the spray means in a second direction, the second direction being substantially perpendicular to the first direction.

Preferably, the substrate is a metal sheet.

The invention will be understood in greater detail from the following description of a preferred embodiment thereof by way of example only and with reference to the accompanying drawings in which:Figure 1 is a sectional view of a first embodiment of an apparatus according to the present invention,· Figure 2 is a schematic side view of two first embodiments of an apparatus according to the present invention for applying a substantially zigzag line of adhesive onto metal sheets; Figure 3 is a side view of a second embodiment of an apparatus according to the present invention; and Figures 4-6 are side views of apparatus used to form a structural panel.

In the drawings, similar numerals have been used to indicate like parts.

Referring to Figure 1 of the accompanying drawings, there is illustrated a sectional view of a first embodiment of an apparatus according to the present invention, generally indicated as 10.

The apparatus 10 according to the present invention includes means 12 for spraying an adhesive 14 onto a substrate 16.

The apparatus 10 according to the present invention also includes means 18 (not shown in Figure 1) for rectilinearly moving the substrate 16 in a first direction 20, which, as illustrated in Figure 1, would be at right angles to the plane of the drawing itself and which direction 20 is indicated in Figure 2.

The apparatus 10 according to the present invention also includes reciprocatable moving means 22 for moving the spray means 12 in a second direction 24 which is substantially perpendicular to the first direction 20. It is preferred that the adhesive 14 be a single component moisture cure polyurethane adhesive with a relatively fast cure time. Suitable adhesives include XP1207WB from Chemique Adhesives and Sealants Ltd, which adhesive develops tack between one-five minutes after spraying. Another suitable adhesive is XP1672 from Chemique Adhesives and Sealants Ltd. XP1672 is a single component moisture cure polyurethane having a curing time of less than two minutes at 60°C.

It is preferred that the adhesive 14 be a single component moisture cure polyurethane adhesive with a cure time of approximately 2½ minutes at 60°C.

It will be appreciated that the adhesive 14 need not be a single component adhesive and, in that event, it will be necessary to employ two or more spray means 12 as is required by the number of components of the adhesive in question.

If the adhesive is a moisture cure adhesive, as is preferred, the apparatus 10 according to the present invention also includes a second spray means 40, to provide the required humidity for the adhesive 14. The second spray means 40 is operatively associated with the spray means 12 so that the second spray means 40 is only actuated when the spray means 12 is actuated. It is desired that a humidity of 70-90% is achieved, in order to optimise curing of a suitable moisture cure adhesive.

For example, the second spray means 40 may be a Lechler Humidity Air Atomised system comprising two off units each projecting diagonally across the spray of adhesive 14. The second spray means 40 is in liquid communication with a water reservoir 42 and a water filter flow regulator 44 may be provided in-line, intermediate the water reservoir 42 and the second spray means 40.

Referring now to Figure 2 of the accompanying drawings, there is schematically illustrated two apparatus 10a, 10b according to the present invention, each apparatus 10a, 10b being operatively associated with a respective substrate 16, depicted as 16a and 16b.

The apparatus 10 according to the present invention has particular application in the manufacture of polystyrene panels, comprising a structure means 28 faced, on each side, by a metal layer or substrate 16a, 16b. The schematic side view of Figure 2 illustrates a preferred application of the apparatus 10 according to the present invention in the manufacture of such polystyrene panels.

It will, of course, be appreciated that the apparatus 10 according to the present invention is by no means limited to the manufacture of such polystyrene panels which are manufactured in the following manner.

Metal sheets 16a and 16b are respectively unrolled from metal coils 17a, 17b. Each of the apparatus 10a, 10b according to the present invention then applies a substantially zigzag line of adhesive 14 onto an inner surface of the respective metal sheets 16a, 16b.

Whilst the metal sheets 16a, 16b can be of any width, each reciprocatable moving means 22 is dimensioned so that the spray means 12 moves in the second direction 24 over a distance which is slightly shorter than the width of the substrate 16. Thus, when the substrate 16 has a width of 1.25m, the reciprocatable moving means 22 is adapted to move a distance of 1.22m in the second direction 24.

Each apparatus 10 according to the present invention is housed within an enclosure 50a, 50b. Each such enclosure 50a, 50b comprises a warm air flash off unit, in the form of a steel housing vented to atmosphere, to disperse solvents and air borne particles. A hot air blower (not shown) with a thermostatic control (not shown) provides the source of heat to the respective enclosures 50a, 50b.

The respective moving means 18a, 18b comprise a pair of mechanically driven rollers and the structure means 28, which comprises a sheet of polystyrene or the like, is fed through the rollers 18a, 18b at 2 metres per minute.

To further improve the adhesive bond using single component moisture cured polyurethanes, it is desirable to hold the substrate 16 in contact with the structure means 28 for the entire curing period. This may be achieved by providing a series of pressure means in the form of a pair of rollers 52a, 52b in a heated enclosure 54. The pressure rollers 52a, 52b are adapted to apply 5-10psi to the respective substrates 16a, 16b and the structure means 28. The enclosure 54 is heated to 60°C by the recirculation of hot air.

The panel is then cut to a desired length by two traversing blades (not shown), one on top of the panel and the other underneath the panel.

Referring now to Figures 3-6 of the accompanying drawings, there is illustrated a second embodiment of an apparatus according to the present invention, generally indicated as 110.

The apparatus 110 includes means 112 (not visible in Figure 3) for spraying an adhesive 114 (not visible in Figure 3) onto a substrate 116. The apparatus 110 also includes means 118 for rectilinearly moving the substrate 116 in a first direction 120, which direction 120 is indicated in Figure 3. Apparatus 110 further includes reciprocatable moving means 122 (not visible in Figure 3) for the moving spray means 112 in a second direction 124 which, as illustrated in Figure 3, would be at right angles to the plane of the drawing itself.

The spray means 112 and the reciprocatable moving means 122 are housed in the enclosure 150, which is vented by means of a fume duct 148.

It is preferred that the adhesive 114 be a double component adhesive. A suitable double component adhesive is XP1875 from Chemique Adhesives and Sealants Ltd, in which first and second components are mixed in a ratio of 1.19 to 1.

The substrate 116 is coated with the adhesives at a density of 300 g/m2, the adhesive 114 being applied in a substantially zigzag line on the substrate 116.

Referring to Figure 4 of the accompanying drawings, there is illustrated an apparatus for expanding a structure means 128, generally indicated at 160. In use, the structure means 128 is placed into the apparatus 160 and the structure means 128 is then expanded to the required width. It is preferred that the structure means be an expanded, substantially hexagonal core.

Referring now to Figure 5 of the accompanying drawings, there is illustrated an apparatus for pressing the substrates 116a, 116b to the structure means 128, generally indicated as 170. In use, the substrates 116a, 116b and the structure means 128 are assembled and are braced laterally to prevent any distortion of the panel whilst it is in the apparatus 170.

Referring now to Figure 6 of the accompanying drawings, there is illustrated an apparatus for curing the panel, generally indicated as 180. In use, the structural panel is transferred from the apparatus 170 to the apparatus 180 and is cured under a total force of 35 Te in an apparatus comprising a plurality of hydraulic rams 182, in order to achieve a desired peel strength. After curing, the panel is then removed from the curing apparatus 180 and is stored for despatch.

The apparatus 110 has particular application for the 10 manufacture of structural panels for use as the walls and ceiling of a clean room.

It will be appreciated that the apparatus and method of the present invention for applying a substantially zigzag line of adhesive onto a substrate, facilitates controlled application of adhesive 14,114 onto the substrate 16,116, thereby reducing wastage of adhesive 14,114. In addition, the apparatus 10,110 permits a rapid through-flow of substrate 16,116 having a substantially zigzag line of adhesive 14,114 thereon which, in turn, permits the rapid adhesion of such substrates 16a, 16b; 116a,116b onto each face of a structure means 28,128, thereby allowing rapid automated manufacture of the panels.

Claims (5)

1. An apparatus for applying a substantially zigzag line of adhesive onto a substrate, the apparatus comprising means for spraying an adhesive; means for rectilinearly moving the substrate in a first direction under the spray means; and means for reciprocatably moving the spray means in a second direction, the second direction being substantially perpendicular to the first direction.

2. An apparatus according to Claim 1, in which the substrate is a metal sheet.

3. An apparatus according to Claim 1 or 2, in which the moving means is arranged to move the substrate under the spray means at a substantially constant velocity.

4. A method for applying a substantially zigzag line of adhesive onto a substrate, the method comprising rectilinearly moving the substrate in a first direction under a spray means whilst reciprocatably moving the spray means in a second direction, the second direction being substantially perpendicular to the first direction.

5. A method according to Claim 4, in which the substrate is a metal sheet.