IES80143B2 - 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) includes means (12) for spraying an adhesive (14). The apparatus (10) also includes means (18) for rectilinearly moving a substrate (16) in a first direction (20) under the spray means (12). The apparatus (10) further includes means (22) for reciprocatably moving the spray means (12) in a second direction (24), the second direction (24) being substantially perpendicular to the first direction (20).

Description

Apparatus and Method for Applying Adhesive onto a Substrate.

The present invention relates to an apparatus and a 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 an apparatus according to the present invention; and Figure 2 is a schematic side view of two apparatus according to the present invention for applying a substantially zigzag line of adhesive onto metal sheets.

Referring to Figure 1 of the accompanying drawings, there is illustrated a sectional view 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.

The reciprocatable moving means 22 comprises, in the present embodiment, an Origa double cylinder on a high speed guidance system with electronic digital control. It will be appreciated, however, that any means for reciprocatably moving the spray means 12 falls within the scope of the present invention. The speed of reciprocatable movement of the moving means 22 is controlled by a pneumatic regulator (not shown).

The reciprocatable moving means 22 is provided with a pair of high speed dampers 26.

The spray means 12, which is in operative association with the reciprocatable moving means 22, is in liquid communication with a reservoir 30 of adhesive 14. It is preferred that the spray means 12 apply 80g adhesive 14 to each m2 of substrate 16. It is also preferred that the spray means 12 apply adhesive 14 in a spray pattern of about 200mm width and at a rate of 1.2 feet per minute.

The spray means 12 may be, for example, an AGG-510 automatic spray gun from De VILBISS. The AGG-510 gun is triggered by compressed air to a single acting cylinder by a remotely positioned three-way valve.

The adhesive reservoir 30 is in liquid communication with an adhesive pump means 32, which pumps adhesive in a dry air system to the, or each, spray means 12. The adhesive pump means 32 is, for example, an ARO 4:1 pump means to be used with a three-way tap system, if the pump means 32 is to pump adhesive 14 to spray means 12b, in addition to spray means 12a.

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

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