WO2014004383A1

WO2014004383A1 - Method of forming an aperture masking article component

Info

Publication number: WO2014004383A1
Application number: PCT/US2013/047338
Authority: WO
Inventors: Dyfrig E. Clement; Kin-Chau CHAN; Clive Bew; Martyn V. Hagedorn; Gareth M. Jones
Original assignee: 3M Innovative Properties Company
Priority date: 2012-06-25
Filing date: 2013-06-24
Publication date: 2014-01-03
Also published as: GB201211334D0

Abstract

Disclosed is a method of forming an aperture masking article (1a, 1b), the method comprising the steps of extruding a polymer material through a die (14) in an extrusion direction (A) to form a extruded blank (15) having a first side (16) and an opposing second side (17), the die(14) having a profile, parallel to the extrusion direction, corresponding to the cross-section of at least one aperture masking article (1a, 1b); and recovering at least one aperture masking article (1a, 1b, from the extruded blank (15), comprising a backing having first surface and an opposing second surface, and a gap filler, the gap filler being integral with the backing at the second surface. Alternatively, the method may be used to produce a component of an aperture masking article (1a, 1b).

Description

METHOD OF FORMING AN APERTURE MASKING ARTICLE COMPONENT

The present invention is related to a method of forming an aperture masking article component, in particular, a method comprising the steps of providing a polymer material blank, treating the polymer material blank to form a shaped foam article; and processing the shaped polymer article to recover an aperture masking article component

The outer body of a vehicle has parts which move relative to each other, for example, static door posts and movable door frames. There exists a visible gap, which is usually curved, created between the fixed and movable parts. The width and depth of the gap varies depending on the model of the vehicle and the relative position of the static and movable part. Similarly, a gap may exist created between two static parts, or between two moving parts, or may be formed within a single part. When the vehicle is spray painted, there is flow of paint into the gap formed by the two parts or substrates. This overspray is undesirable and requires rectification.

Various methods and devices have been developed and adopted to overcome the flow of paint into such gaps. One method is to adhere a strip of foam-like material to an interior surface of the static or movable part of the vehicle. The material prevents paint flow further into the gap, but a build up of paint between the foam-like material and a surface of the static or movable part results in an unwanted rough paint edge when the material is removed which is apparent both to touch and visually.

Another technique adopted involves folding, lengthwise, a portion of a strip of masking tape, applying the adhesive section of the masking tape to an interior surface of a static part of the vehicle such that a non-adhesive section of the tape protrudes outwardly, and then applying a strip of foam-based material to the masking tape before closing the moving part and spray painting the vehicle. The non- adhesive portion of the folded tape prevents the masking tape from contacting paint sprayed on the static part. This technique often results in a smoother paint line, but is only suitable for particular geometries of gaps. For some vehicles, the foam-based material is compressed by the movable part to an extent that, from within the gap, it protrudes outwardly. This causes paint to 'bridge' between a surface of the movable part and the foam. Such a build up of paint therefore results in a rough paint edge when the foam and tape are removed. Furthermore, this technique is time consuming and requires considerable skill to position the tape and foam correctly. An additional drawback of using folded masking tape is that, due to the curvature of the gap, there is a tendency for the tape to lift away from the vehicle part, which often results in excessive paint build up. One solution to this is to use an aperture masking article such as that described in PCT/US201 1/066781. In this an article comprising a backing, a gap filler and a spacing means are used to create a smooth paint edge on a static vehicle part and a moving vehicle part, such as around a door aperture. Such an article is pre-formed, and effectively fills the gap between the door and surrounding frame, preventing ingress of paint into the gap.

Such an aperture masking article offers improved results in terms of paint finish when compared to other products known in the art. However, to guarantee the reliability of such improved results, it is necessary to ensure that the aperture masking article itself is made using repeatable and consistent manufacturing processes.

The present invention aims to address this need by providing a method of forming an aperture masking article, the method comprising the steps of: extruding a polymer material through a die in an extrusion direction to form a extruded blank having a first side and an opposing second side, the die having a profile, parallel to the extrusion direction, corresponding to the cross-section of at least one aperture masking article; and recovering at least one aperture masking article, from the extruded blank, comprising a backing having first surface and an opposing second surface, and a gap filler, the gap filler being integral with the backing at the second surface. Preferably, the method further comprises the step of applying an adhesive to a region of the first side of the extruded blank, such that the backing of the recovered aperture masking article has adhesive on at least a portion of the first surface. Preferably, the method also further comprises the step of laminating a release liner onto at least a portion of the adhesive. When a release liner is laminated on a portion of the adhesive to leave a portion of the adhesive exposed, a step of laminating a spacing means onto said exposed portion may also be carried out.

Preferably, the method also comprises laminating a spacing means onto the first surface of the extruded blank. The die may have a profile corresponding to the profile of a first and the profile of a second aperture masking article, such that the step of recovering comprises recovering a first aperture masking article and a second aperture masking article. Preferably, the profile of the second aperture masking article is a reflection of the profile of the first aperture masking article along an axis parallel to the extrusion direction, the axis being disposed centrally with respect to the profile of a first and the profile of a second aperture masking article, such that the step of recovering comprises recovering a first aperture masking article and a second aperture masking article. In this case, the method may also comprise the step of separating the first aperture masking article from the second masking article by slitting the extruded blank.

The step of recovering may comprise winding at least a first aperture masking article onto a reel.

The polymer material may comprises a thermoplastic elastomer material. Preferably, the thermoplastic elastomer material is a styrene butadiene styrene or styrene ethylene butylene styrene material. The extrusion die may have a profile in which a spacing means is included in the cross-section of an aperture masking article.

Preferably, the recovered aperture masking article further comprises a spacing means integral with the first surface of the backing.

In a further aspect, the present invention also provides a method of forming an aperture masking article comprising a backing and a gap filler, the method comprising the steps of: extruding a polymer material through a die in an extrusion direction to form a extruded blank having a first side and an opposing second side, the die having a profile, parallel to the extrusion direction, corresponding to the cross-section of at least one aperture masking article component; and recovering at least one aperture masking article component from the extruded blank, the component forming a backing of an aperture masking article, the backing having a first portion and a second portion, the first portion having a first side and an opposing second side, and the second portion being shaped to receive a gap filler; and applying a gap filler to the second portion.

Preferably, the method further comprises the step of coating the second portion with an adhesive before applying a gap filler, such that the gap filler is bonded to the second portion.

Preferably, the die has a profile corresponding to the profile of a first and the profile of a second aperture masking article component.

The profile of the second aperture masking article component may be a reflection of the profile of the first aperture masking article component along an axis parallel to the extrusion direction, the axis being disposed centrally with respect to the profile of a first and the profile of a second aperture masking article component. Preferably, the method further comprises after the step of applying a gap filler, the step of separating the first aperture masking article from the second masking article by slitting the extruded blank.

Preferably the polymer material comprises a thermoplastic elastomer material. Preferably the thermoplastic elastomer material is a styrene butadiene styrene or styrene ethylene butylene styrene material.

Preferably the gap filler is a conformable foam material, more preferably, the gap filler is an open cell polyurethane foam material.

The present invention will now be described by way of example only, and with reference to the accompanying drawings, in which:

Figure 1 is a cross-section of an aperture masking article;

Figure 2 is a schematic side view of an extrusion line for carrying out a first preferred embodiment of the present invention;

Figure 3A is a cross-section of an extruded blank before slitting;

Figure 3B is a cross-section of an extruded blank after slitting;

Figure 4A is a cross-section of a first aperture masking article made using a method in accordance with the first preferred embodiment of the present invention;

Figure 4B is a cross-section of a second aperture masking article made using a method in accordance with the first preferred embodiment of the present invention;

Figure 4C is a cross-section of a third aperture masking article made using a method in accordance with the first preferred embodiment of the present invention;

Figure 4D is a cross-section of a fourth aperture masking article made using a method in accordance with the first preferred embodiment of the present invention;

Figure 4E is a cross-section of a fifth aperture masking article made using a method in accordance with the first preferred embodiment of the present invention;

Figure 5 is a schematic side view of an extrusion line for carrying out a second preferred embodiment of the present invention;

Figure 6A is a cross-section of a first aperture masking article made using a method in accordance with the second preferred embodiment of the present invention;

Figure 6B is a cross-section of a second aperture masking article made using a method in accordance with the second preferred embodiment of the present invention;

Figure 7 is a cross-section of an aperture masking article made using a method in accordance with the third preferred embodiment of the present invention; Figure 8 is a cross-section of an extruded blank used to form the aperture masking article of Figure 7 in accordance with the third preferred embodiment of the present invention;

Figure 9 is a cross-section of the extruded blank of Figure 8 with a precursor gap filler in place; and Figure 10 is a schematic side view of an extrusion line for carrying out a third preferred embodiment of the present invention.

In the present invention it has been appreciated that an extrusion process can be used to form an aperture masking article in a repeatable and reliable manner, thus ensuring a high quality paint edge on a vehicle when the resulting aperture masking article is put to use. The preferred embodiments of the present invention involve extruding a polymer material through a die in an extrusion direction to form an extruded blank. The extruded blank has a first side and an opposing second side, with the die having a profile, parallel to the extrusion direction, corresponding to the cross-section of at least one aperture masking article. Subsequent to this, at least one aperture masking article is recovered from the extruded blank. The recovered aperture masking article comprises a backing having first surface and a second surface, opposite the first and a gap filler, the gap filler being integral with the backing at the second surface.

Figure 1 is a cross-section of an aperture masking article. This illustrates the general design of an aperture masking article, the individual features of which are discussed in more detail in relation to the preferred embodiments of the present invention below. A typical aperture masking article 1 that may be made using the preferred embodiments of the present invention comprises a backing 2, the backing having a first surface 3 and an opposing second surface 4, and a gap filler 5, the gap filler being integral with the backing 2 at the second surface 4. The backing 2 is generally elongate in cross-section, with the gap filler 5 being provided adjacent a proximal edge of the backing 2. The aperture masking article 1 may also be provided with a spacing means 6 on the first surface 3 of the backing 2, in this example, in the form of a spacer 7 that projects outwards from first surface 3. The spacing means 6 is provided adjacent the distal edge of the backing 2. The spacing means 6 may be integral with the first surface 3 of the backing 2, or may be laminated to the first surface 3 of the backing 2. In order to adhere the aperture masking article 1 to a vehicle during use the first surface of the backing 2 is provided with an adhesive 8 that extends across a portion of the first surface 3 of the backing 2. This is typically covered by a release liner 9 to protect the surface of the adhesive 8 in storage. Where a release liner 9 is laminated on a portion of the adhesive 8 to leave a portion of the adhesive 8 exposed, the spacing means 6 may be laminated onto said exposed portion. The spacing means 6 may also optionally be provided with an absorbent layer 10, which may aid the formation of a smooth paint line by wicking paint or lacquer away from the distal edge of the aperture masking article. Finally, as a further option, the aperture masking article 1 may be provided with a scrim 1 1 or other reinforcing means for strengthening the backing 2, placed either on the first surface 3 of the backing 2 or the second surface 4 and bonded to the backing 2 by means of an adhesive. If provided on the first surface 3 of the backing 2, as opposed to the second surface 4 as shown in Figure 1 , it may be desirable to provide the scrim 11 between the first surface 3 of the backing 2 and the adhesive 8 and spacing means 6, respectively.

In use, the aperture masking article 1 is positioned in a gap between a static vehicle part, for example, a door post, and a moving vehicle part, such as a door. When adhered to an inner surface of this gap, the gap filler 5 has minimal or glancing contact with the underside of the moving vehicle part, and the spacing means 6 is positioned approximately level with the outer surface of the static vehicle part. When sprayed with a fluid paint or other coating material, the gap filler 5 prevents the ingress of fluid into the gap, and promotes the creation of a smooth paint edge on the moving vehicle part. The spacing means 6 is in minimal or glancing contact with the inner surface of the gap adjacent the outer surface of the static vehicle part, but creates a space between the inner surface of the gap, spacing means 6 and the backing 2. This results in a smooth paint edge on the static vehicle part. A smooth paint edge is classified as one that feels smooth to touch.

Figure 2 is a schematic side view of an extrusion line for carrying out a first preferred embodiment of the present invention. In this example two aperture masking articles are recovered from the extrusion line, although at least one, such as one, three or more may be recovered depending on the configuration of the extrusion die used. Such an extrusion line can be used to form an aperture masking article having the same general construction as described with respect to Figure 1. The extrusion line 12 comprises a single screw extruder 13 having a die 14 having a profile, parallel to an extrusion direction A, corresponding to the cross-section of at least one aperture masking article 1. In this example, the extrusion die 14 has a profile corresponding to a first aperture masking article la and a second aperture masking article lb. The profile of the second aperture masking article lb is a reflection of the profile of the first aperture masking article 1 a along an axis parallel to the extrusion direction A, the axis being disposed centrally with respect to the profile of the first 1 a and the profile of the second lb aperture masking articles. The extrusion die 14 may also have a profile in which a spacer means is included in the cross-section of an aperture masking article. Polymer material is extruded through the die in an extrusion direction A to form an extruded blank 15 having a first side 16 and an opposing second side 17. The extruded blank 15 travels along a conveyor 18 to an adhesive station 19. This step of applying an adhesive 8 to a region of the first side 16 of the extruded blank 15, results in the backing 2 of the recovered aperture masking article 1 having adhesive 8 on at least a portion of the first side 16. In this example, adhesive 8 is applied to the first side 16 of the extruded blank 15, covering at least the portion of the extruded blank 15 that will form the first surface 3 of the backing 2 of the first aperture masking article 1 a and the first surface 3 of the backing 2 of the second aperture masking article lb. Suitable adhesives include styrene isoprene styrene block polymer-based PSAs (pressure sensitive adhesive) and hydrocarbon resin blend PSAs, as well as acrylic-based and UV-curable resins.

Once the adhesive 8 has been applied the extruded blank 15 travels to a release liner lamination station 20, where a release liner 9 is applied to at least a portion of the adhesive 8, covering the first side 16 of the extruded blank 15 to the extent necessary to provide a release liner 9 on each of the first aperture masking article la and the second aperture masking article lb when recovered at the end of the extrusion line 12. Any suitable release liner may be used, but typically a single-sided siliconised release liner is used. Once the extruded blank 15 has passed through the release liner lamination station 20 it passes through a slitting station 21. At this point the first aperture masking article 1 a is separated from the second masking article by slitting the extruded blank. The slitting is carried out using a knife arrangement. Such steps lead to a recovered aperture masking article 1 wherein the gap filler 5 is integral with the second surface 4 and the spacer means 6 is integral with the first surface 3 of the backing 2.

Once the extruded blank 15 has been slit, at least one aperture masking article 1, in this example, the first aperture masking article la and the second aperture masking article lb, is recovered from the extruded blank 15. Each of the first la and second lb aperture masking articles comprises a backing 2 having first surface 3 and an opposing second surface 4, and a gap filler 5, the gap filler 5 being integral with the backing 2 at the second surface 4. As shown in Figure 2, the step of recovering the aperture masking articles la, lb, comprises winding each of the aperture masking articles la, lb onto a reel - the first aperture masking article la is wound onto a first master roll winder 22a, and the second aperture masking article lb is wound onto a second master roll winder 22b. As an alternative to a single-screw extruder, it may be desirable to use a twin-screw extruder.

Figure 3A is a cross-section of an extruded blank before slitting and Figure 3B is a cross-section of an extruded blank after slitting. As described above the extrusion die 14 has a profile corresponding to a first aperture masking article la and a second aperture masking article lb. The profile of the second aperture masking article lb is a reflection of the profile of the first aperture masking article la along an axis parallel to the extrusion direction A, the axis being disposed centrally with respect to the profile of the first la and the profile of the second lb aperture masking articles. The first side 16 of the extruded blank 15 carries the adhesive 8 and the release liner for both the first aperture masking article la and the second aperture masking article lb. The backing 2 of the aperture masking articles la, lb is formed by the upper section 23 of the extruded blank 15, creating the first surface 3 of the backing 2. The lower section 24 of the extruded blank 15 forms a gap filler 5 once the extruded blank 15 is slit into two forming the first la and second lb aperture masking articles.

Figures 4A to 4E are cross-sections of first to fifth aperture masking articles made using a method in accordance with the first preferred embodiment of the present invention. Figure 4A is a cross-section of a first aperture masking article made using a method in accordance with the first preferred embodiment of the present invention. This aperture masking article 25 comprises a backing 26, the backing having a first surface 27 and an opposing second surface 28, and a gap filler 29, the gap filler being integral with the backing 26 at the second surface 28. The backing 26 is generally elongate in cross-section, with the gap filler 29 being provided at the proximal edge of the backing 26. The aperture masking article 25 is provided with a spacing means 30 on the first surface 27 of the backing 26, formed by creating a kink in the backing 26 such that the spacing means 30 extends beyond the plane of the backing 26. The gap filler 29 extends from the backing 26 at the proximal edge at an angle a to the plane of the backing 26.

Figure 4B is a cross-section of a second aperture masking article made using a method in accordance with the first preferred embodiment of the present invention. This aperture masking article 31 comprises a backing 32, the backing having a first surface 33 and an opposing second surface 34, and a gap filler 35, the gap filler being integral with the backing 32 at the second surface 34. The backing 32 is generally elongate in cross-section, with the gap filler 35 being provided at the proximal edge of the backing 32. The aperture masking article 31 is provided with a spacing means 36 on the first surface 33 of the backing 32, formed by creating a step 37 in the backing 32 such that the spacing means 36 extends beyond the plane of the backing 32. The gap filler 35 extends from the backing 32 at the proximal edge at an angle a to the plane of the backing 32.

Figure 4C is a cross-section of a third aperture masking article made using a method in accordance with the first preferred embodiment of the present invention. This aperture masking article 38 comprises a backing 39, the backing having a first surface 40 and an opposing second surface 41, and a gap filler 42, the gap filler being integral with the backing 39 at the second surface 41. The backing 39 is generally elongate in cross-section, with the gap filler 42 being provided at the proximal edge of the backing 39. The aperture masking article 38 is provided with a spacing means 43 on the first surface 40 of the backing 39, formed by creating a kink in the backing 39 such that the spacing means 43 is created by extending the distal edge of the backing 39 beyond the plane of the backing 39 towards the gap filler 42, inclined at an angle β to the plane of the backing 39. The gap filler 42 extends from the backing 39 at the proximal edge at an angle a to the plane of the backing 39. Figure 4D is a cross-section of a fourth aperture masking article made using a method in accordance with the first preferred embodiment of the present invention. This aperture masking article 44 comprises a backing 45, the backing having a first surface 46 and an opposing second surface 47 and a gap filler 48, the gap filler being integral with the backing 45 at the second surface 47. The backing 45 is generally elongate in cross-section, with the gap filler 48 being provided at the proximal edge of the backing 45. The aperture masking article 44 is provided with a spacing means 49 on the first surface 46 of the backing 45, formed by creating a kink in the backing 45 such that the spacing means 49 is created by extending the distal edge of the backing 45 beyond the plane of the backing 45 towards the gap filler 48, inclined at an angle β to the plane of the backing 45. The gap filler 48 extends from the backing 45 a distance d away from the proximal edge and towards the distal edge at an angle a to the plane of the backing 45.

Figure 4E is a cross-section of a fifth aperture masking article made using a method in accordance with the first preferred embodiment of the present invention. This aperture masking article 50 comprises a backing 51, the backing having a first surface 52 and an opposing second surface 53, and a gap filler 54, the gap filler 54 being integral with the backing 51 at the second surface 53. The backing 51 is generally elongate in cross-section, with the gap filler 54 being provided at the proximal edge of the backing 51. The aperture masking article 50 is provided with a spacing means 55 on the first surface 52 of the backing 51, formed by creating a tapered surface 56 in the backing 51 at the distal edge. This reduces the calliper of the backing 51 to a sharp edge thus giving a smooth paint edge on a static vehicle part in use. The tapered surface 56 therefore acts as the spacing means by preventing the backing 51 from contacting, either completely or merely allowing a minimal or glancing contact, the surface of the static vehicle part in use, thus preventing paint build up along and adjacent the distal edge of the backing 51. The gap filler 54 extends from the backing 51 at the proximal edge at an angle a to the plane of the backing 51.

With reference to Figure 4D, typical dimensions for the resulting aperture masking article 44 are as follows, and are given nominally and should therefore be understood to include minor variances according to the tolerances of the extrusion process and apparatus being used. The calliper of the aperture masking article is preferably in the range of 0.2 to 1.5mm, preferably 0.5mm. However, different callipers may be included within the extrusion die 14, resulting in a variation of calliper in the aperture masking article 44 as desired. The length of the gap filler 48 is chosen to ensure that a smooth paint edge is generated on any moving part being sprayed or painted, and is typically in the range of 5 to 20mm, and preferably 15mm. The gap filler 48 is positioned at a distance d from the proximal edge of the backing 45, typically in the range of 0 to 3mm from this edge, with the angle a at which the gap filler 48 extends from the backing 45 typically in the range of 50° to 75°, and preferably approximately 65°, with all angles measured from the plane of the backing 45. The total length of the backing 45 is in the range 6mm to 10mm, and preferably 8 mm. The length of the backing 45 between the proximal edge and the kink is typically in the range of 4mm to 6mm, and preferably 5mm, with the angle β being in the range of greater than 0° to 20°, and preferably 10°. The backing 45 extends for a distance typically in the range of 2 to 5mm, and preferably 3mm from the kink to the distal edge of the backing 45.

The selection of polymer material chosen to form the extruded blank 15 and therefore the aperture masking article 1, 25, 31, 38, 44, 50 is governed by the requirements of the end application (for example, the size, profile and complexity of shape of the aperture between the moving vehicle part and static vehicle part being sprayed). This comprises considering the required combination of elasticity, Young's modulus (the measure of the material's stiffness) and drape (the ease with which the article lies on a surface and conforms to the profile of the aperture between the static vehicle part and the moving vehicle part). The surface texture or finish of the aperture masking article 1, 25, 31, 38, 44, 50 is also an influencing factor in the choice of polymer material, as this affects the apparent surface friction felt by a user applying the aperture masking article 1, 25, 31, 38, 44, 50 to a vehicle as well as the general handling characteristics of the aperture masking article 1, 25, 31, 38, 44, 50. Suitable polymer materials include those comprising a thermoplastic elastomer material, for example a styrene butadiene styrene or styrene ethylene butadiene styrene material. As an example, AlphaGary 948 and AlphaGary 3784, available from AlphaGary Corporation, 170 Pioneer Drive, Leominster, MA 01453 USA exhibit the desired qualities for the final aperture masking article 1, 25, 31, 38, 44, 50, with the aperture masking article 31 shown in Figure 4A made successfully using AlphaGary 948. Evoprene 094 and GC087, also available from AlphaGary may also be used. A single screw extruder was used with a die having a cross-section corresponding to the profiles of two of the aperture masking articles 31 shown in Figure 4B to form first and second aperture masking articles 31. Such an extruder is preferably fitted with high volume, low shear transfer screws. The length to diameter ratio (L/D) should be in the range 20/1 to 24/1, and the compression ratio (C/R) in the range 2.5 to 3.5. Breaker plates and screens are recommended to help build shear, with a pressure die having a short land of approximately 5mm being ideal to produce the aperture masking article 31. The processing temperature was held between 160°C and 185°C, with cooling provided using a water bath, with no pre-drying. Other designs of article such as shown in Figures 4A and C - 4Emay also be made in such a duplex configuration.

Other suitable polymer materials may include elastic polyolefins such as those in the Vistamaxx range available from ExxonMobil, Corporate Headquarters, 5959 Las Colinas Boulevard, Irving, Texas 75039-2298 USA. These materials may be used alone or in combination with other polyolefins and/or thermoplastic elastomer materials. The entire aperture masking article 1, 25, 31, 38, 44, 50 may be formed from a single polymer material (which itself may be a single or blend of multiple polymer materials) or the various components may be formed from different polymer materials giving different physical properties to the backing 2, 26, 32, 39, 45, 53 or gap filler 5, 29, 35, 42, 48, 54.

Figure 5 is a schematic side view of an extrusion line for carrying out a second preferred embodiment of the present invention. The embodiment is essentially the same as that described above with respect to Figure 2, with like parts being described by like references. However, in addition to the stations shown in Figure 2, in the second preferred embodiment of the present invention an absorbent material lamination station 57 is included, immediately after the extruded blank 15 exits the extrusion die 14. In this embodiment, fibre-containing material (not shown) is used as the absorbent material and laminated to the first side 15 of the extruded blank 15. The purpose of the paper is two-fold: firstly, the fibre-containing material may act as the spacing means 6, creating a gap between the aperture masking article 1 and the surface of the static part being sprayed in use, and secondly acts to absorb or wick away surplus sprayed material from the distal edge of the aperture masking article 1 and consequently the paint edge formed on the static part being sprayed. This aids in creating a smooth paint edge. Suitable fibre-containing materials include those containing natural, cellulose or synthetic fibres, and may be one of paper, tissue, woven material or non-woven material.

Figure 6A is a cross-section of a first aperture masking article made using a method in accordance with the second preferred embodiment of the present invention. This aperture masking article 58 comprises a backing 59, the backing having a first surface 60 and an opposing second surface 61, and a gap filler 62, the gap filler 62 being integral with the backing 59 at the second surface 61. The backing 59 is generally elongate in cross-section, with the gap filler 62 being provided at the proximal edge of the backing 59. The aperture masking article 58 is provided with a spacing means 63 on the first surface 60 of the backing 59, formed by creating a tapered surface 64 in the backing 59 at the distal edge. This reduces the calliper of the backing 59 to a sharp edge thus giving a smooth paint edge on a moving vehicle part in use. A strip of paper 65 is laminated to the tapered surface 64. In this example, raw 39 gsm GP paper, available from Neenah Gessner GmbH, Otto-von- Steinbeisstrasse 14b, 83052 Bruckmuhl, Germany. The gap filler 62 extends from the backing 59 at the proximal edge at an angle a to the plane of the backing 59.

A further variation on the aperture masking article that may be made in accordance with the second embodiment of the present invention is illustrated in Figure 6B. Figure 6B is a cross-section of a second aperture masking article made using a method in accordance with the second preferred embodiment of the present invention. This aperture masking article 66 comprises a backing 67, the backing having a first surface 68 and an opposing second surface 69, and a gap filler 70, the gap filler being integral with the backing 67 at the second surface 69. The backing 67 is generally elongate in cross-section, with the gap filler 70 being provided at the proximal edge of the backing 67. The aperture masking article 66 is provided with a spacing means 71 on the first surface 68 of the backing 67, formed by creating a kink in the backing 67 such that the spacing means 71 is created by extending the distal edge of the backing 67 beyond the plane of the backing 67 towards the gap filler 70, inclined at an angle β to the plane of the backing 67. The gap filler 70 extends from the backing 67 a distance d away from the proximal edge and towards the distal edge at an angle a to the plane of the backing 67.

In order to alter the feel of the aperture masking article 66 to the user such that the user perceives the aperture masking article 66 to be easier to use, the surface texture of the second surface is altered by the addition of a surfacing layer (not shown). When in use, the aperture masking article 66 is typically applied to a vehicle by a user who runs their thumb over the second surface 69 to provide the force to adhere the backing 67 to the static vehicle part via an adhesive (not shown). If the second surface 69 has a surface texture that feels "rough" or "grippy" to the user who perceives the friction caused by running their thumb over the second surface 69 to be uncomfortable, it may be difficult to apply the aperture masking article 66 accurately, with a consequent risk of delamination from the static vehicle part and/or the creation of a rough paint edge. Suitable surfacing layers include tape, such as self-adhesive or pressure sensitive adhesive tapes (for example, masking tape or Scotch™ tape, available in the United Kingdom from 3M United Kingdom pic, 3M Centre, Cain Road, Bracknell, Berkshire, RG12 8HT), a fabric-backed tape (such as 3M™ Duct Tape, available as before), paper (such as the Neenah-Gessner product discussed above) or plastic release tapes may be used. In this situation the fibre-containing material lamination station 57 may be converted to apply the surfacing layer rather than the fibre-containing material, or a second lamination station may be included in the extrusion line 12.

It may also be desirable to include a scrim material 1 1 as a strengthening means in the construction of the aperture masking article 1, as shown in Figure 1. This strengthening means acts to increase the tensile strength of the aperture masking article 1, which in turn may offer more flexibility in the choice of polymer materials used to form the aperture masking article 1. A suitable strengthening means is a lightweight polyester scrim, comprising 18/7 warp/fill threads at 150/70 denier, available from Milliken and Company, PO Box 1926, Spartanburg, SC 29304, USA. Although in the preferred embodiments described above a single screw extruder is used, other suitable extrusion devices may be employed to carry out the method of the present invention. Similarly, it may be desirable to extrude only a component of the aperture masking article 1, 25, 31, 38, 44, 50, 58, 66, rather than the entire article, and to use such components along with components made using other techniques in a further assembly process to create a final aperture masking article 1, 25, 31, 38, 44, 50, 58, 66. Although in the preferred embodiments described above a knife arrangement is used to slit the extruded blank 15, other cutting or slitting arrangements suitable for use in an in-line process may be used instead. Other adhesives known in the art as being suitable for use with aperture masking articles such as those having appropriate holding power and heat resistance coupled with clean removability after the painting/spraying process is complete are suitable for use in place of the PSAs described above. Alternative release liners include double-sided release liners, filmic or paper release liners, with or without perforations for easy tearing.

As mentioned above, it may also be desirable to extrude only an aperture masking article component, such as the backing, and add other components, such as a gap filler, separately. This is the approach taken in the following third preferred embodiment of the present invention.

Figure 7 is a cross-section of an aperture masking article made using a method in accordance with the third preferred embodiment of the present invention. The aperture masking article 101 comprises a backing 102, the backing having a first portion 103 and a second portion 104, the first portion being provided with a first surface 105 and an opposing second surface 106. The second portion 104 is adapted to receive a gap filler 107. The first 103 and second portion 104 form a "V"-shape when viewed from the side/in cross-section, with the second portion 104 shorter in length than the first portion 103. The first 103 and second 104 portions are separated by an angle γ, where γ is approximately 65°, but may be in the range of approximately 50° to 80°. The second portion 104 is also provided with a first surface 108 and a second surface 109, where the first surface 108 is adjacent the second surface 106 of the backing 102. The backing 102 is generally elongate in cross-section, with the gap filler 107 being provided at the proximal edge 1 10 of the backing 102. The gap filler 107 may be adhered to either the first surface 108 of the second portion 104 or the second surface 109 of the second portion (the latter as illustrated in Figure 7). The backing 102 is provided with a kink 1 1 1 approximately half the distance between the proximal edge 1 10 of the backing 102 and the distal edge 1 12 of the backing, such that the portion of the backing 102 closest to the distal edge 1 12 is positioned at an angle δ to the plane of the backing, δ is approximately 10°, but may preferably be in the range of 5° to 15°. The gap filler 107 is applied to the second surface 109 of the second portion 104 by bonding with a layer of adhesive 113 positioned on the second surface 109. A layer of adhesive 1 14 is provided on the first surface 105 of the backing 102, which may be covered by an optional release liner (not shown), and is intended to be used to affix the aperture masking article 101 to the interior surface. To fit most vehicles, the length of the first portion 103 of the backing 102 is approximately 8mm, with the length of the kinked region being approximately 3mm and the length of the remainder of the backing 102 being approximately 5mm. The length of the second potion 104 of the backing 102 is approximately 3mm. However, it is possible to vary these dimensions making the various portions longer or shorter, for example +/- 1 - 3mm depending on the portion chosen. Ideally the thickness of the backing is approximately 0.5mm, although again this may be varied if desired.

Figure 8 is a cross-section of an extruded blank used to form the aperture masking article of Figure 7 in accordance with the third preferred embodiment of the present invention. The extruded blank 1 15 forms a first aperture masking article component 101a and a second aperture masking article component 101b, joined at the apex of the "V"-shape 1 16 between the first 103a, 103b and second 104a, 104b portions of the component 101a, 101b. The second surface 109a of the second portion 104a of the first aperture masking article component 101a forms a second "V"-shape 1 16 with the second surface 109b of the second portion 104b of the second aperture masking article component 101b. In the present embodiment where the gap filler 107 is applied to the second surface 109 of the second portion 104 of the backing 102, a layer of adhesive 1 13a, 1 13b is positioned in the "V"-shape 1 16 to receive the gap filler 107 when applied. Figure 9 is a cross-section of the extruded blank of Figure 8 with a precursor gap filler in place. The precursor gap filler 1 167 is formed from a flexible and conformable foam material. In this embodiment, the foam has a calliper of 3mm, and the overall length of the precursor gap filler 1 17 is 30 mm, which results in the gap filler 107 in the final aperture masking article 101 having a length of 15mm. By positioning the precursor gap filler 1 17 centrally and entirely within the "V"-shape 1 16 of the extruded blank 1 15, the gap filler 107 in the aperture masking article 101a, 101b extends from the first portion 103 a, 103b of the backing 102a, 102b, and is adhered to each aperture masking article 101a, 101b by means of the adhesive 1 13a, 1 13b provided on the second portion 104a, 104b. To recover two aperture masking articles 101a, 101b both the extruded blank 1 15 and the precursor gap filler 1 17 are slit centrally, lengthwise.

The aperture masking article 101, 101a, 101b in accordance with this embodiment of the present invention is preferably made on a line essentially identical to either that shown in Figure 2 or Figure 5, as discussed above, with the addition of an adhesive application station and a foam lamination station. This is shown schematically in Figure 10. Figure 10 is a schematic side view of an extrusion line for carrying out a third preferred embodiment of the present invention. In this example two aperture masking articles are recovered from the extrusion line, although at least one, such as one, three or more may be recovered depending on the configuration of the extrusion die used. Such an extrusion line can be used to form an aperture masking article having the same general construction as described with respect to Figure 7. The extrusion line 12 comprises a single screw extruder 13 having a die 14 having a profile, parallel to an extrusion direction A, corresponding to the cross-section of at least one aperture masking article 101. In this example, the extrusion die 14 has a profile corresponding to a first aperture masking article 101a and a second aperture masking article 101b. The profile of the second aperture masking article 101b is a reflection of the profile of the first aperture masking article 101a along an axis parallel to the extrusion direction A, the axis being disposed centrally with respect to the profile of the first 101a and the profile of the second 101b aperture masking articles. The extrusion die 14 may also have a profile in which a spacer means is included in the cross-section of an aperture masking article. Polymer material is extruded through the die in an extrusion direction A to form an extruded blank 1 15 having a first side 118 and an opposing second side 1 19. In addition to the steps shown in Figures 2 and 5 above, the extruded blank 115 travels through an adhesive application station 120, where the adhesive 1 13 is applied into the "V"- shape 1 16 of the extruded blank 1 15. Consequently, with regard to the aperture masking article 101, 101a, 101b, there is a step of coating the second portion with an adhesive before applying a gap filler, such that the gap filler is bonded to the second portion. The next step is for the extruded blank 1 15 to travel to a foam lamination station 121, where the precursor gap filler 1 17 is laminated to the adhesive 1 13 in the "V"-shape 1 16, on the second side 1 19 of the extruded blank 1 15, with foam fed from a roller 122. Suitable adhesives include hot melt pressure sensitive adhesives such as 3M Type 22 adhesive, available from 3M United Kingdom pic, 3M Centre, Cain Road, Bracknell, RG12 8HT, although other adhesive materials such as water or solvent-based adhesives or double coated tape adhesives may be used if desired. Suitable foam materials for the precursor gap filler 1 17 include conformable foam materials, such as open or closed cell polyurethane foams, for example, X4200 available from Caligen Foam Ltd, Broad Oak, Accrington, Lancashire, BB5 2BS. The width of the foam strip used is typically of the order of 20 to 40 mm. However, other foams, including closed-cell foams, may also be suitable. At this point, as in Figures 2 and 5 above, the extruded blank 1 15 then travels along a conveyor 18 to an adhesive station 19. This step of applying an adhesive 1 14 to a region of the first side 1 18 of the extruded blank 1 15, results in the backing 102 of the recovered aperture masking article 101 having adhesive 1 14 on at least a portion of the first portion 103. In this example, adhesive 1 14 is applied to the first side 1 18 of the extruded blank 1 15, covering at least the portion of the extruded blank 1 15 that will form the first portion 103a of the backing 102a of the first aperture masking article 101a and the first portion 103b of the backing 102b of the second aperture masking article 101b. Suitable adhesives include styrene isoprene styrene block polymer-based PSAs (pressure sensitive adhesive) and hydrocarbon resin blend PSAs.

Once the adhesive 1 14 has been applied the extruded blank 1 15 travels to a release liner lamination station 20, where a release liner 9 is applied to at least a portion of the adhesive 1 14, covering the first side 1 18 of the extruded blank 1 15 to the extent necessary to provide a release liner 9 on each of the first aperture masking article 101a and the second aperture masking article 101b when recovered at the end of the extrusion line 12. Any suitable release liner may be used, but typically a single-sided siliconised release liner is used. Once the extruded blank 1 15 has passed through the release liner lamination station 20 it passes through a slitting station 21. At this point the first aperture masking article 101a is separated from the second masking article 101b by slitting the extruded blank. The slitting is carried out using a knife arrangement. .

Once the extruded blank 1 15 has been slit, at least one aperture masking article 101, in this example, the first aperture masking article 101a and the second aperture masking article 101b, is recovered from the extruded blank 1 15. Each of the first 101a and second 101b aperture masking articles comprises a backing 102 having first portion 103 and a second portion 104, and a gap filler 107. As shown in Figure 7, the step of recovering the aperture masking articles 101a, 101b, comprises winding each of the aperture masking articles 101a, 101b onto a reel - the first aperture masking article 101a is wound onto a first master roll winder 22a, and the second aperture masking article 101b is wound onto a second master roll winder 22b. As above, suitable materials for forming the extruded blank 1 15 are polymer materials, in particular thermoplastic polymer materials, such as styrene butadiene styrene or styrene ethylene butylene styrene materials. The die used preferably has a profile corresponding to the profile of a first 101a and the profile of a second 101b aperture masking article component, creating the extruded blank 1 15. Preferably, the profile of the second aperture masking article 101b component is a reflection of the profile of the first aperture masking article component 101a along an axis parallel to the extrusion direction, the axis being disposed centrally with respect to the profile of a first 101a and the profile of a second 101b aperture masking article component.

Claims

1. A method of forming an aperture masking article, the method comprising the steps of:

extruding a polymer material through a die in an extrusion direction to form a extruded blank having a first side and an opposing second side, the die having a profile, parallel to the extrusion direction, corresponding to the cross-section of at least one aperture masking article; and

recovering at least one aperture masking article, from the extruded blank, comprising a backing having first surface and an opposing second surface, and a gap filler, the gap filler being integral with the backing at the second surface.

2. Method as claimed in claim 1, further comprising the step of:

applying an adhesive to a region of the first side of the extruded blank, such that the backing of the recovered aperture masking article has adhesive on at least a portion of the first surface.

3. Method as claimed in claim 2, further comprising the step of:

laminating a release liner onto at least a portion of the adhesive.

4. Method as claimed in claim 3, further comprising the step of:

when a release liner is laminated on a portion of the adhesive to leave a portion of the adhesive exposed, laminating a spacing means onto said exposed portion.

5. Method as claimed in any of claims 1 to 3, further comprising laminating a spacing means onto the first surface of the extruded blank.

6. Method as claimed in any preceding claim, wherein the die has a profile corresponding to the profile of a first and the profile of a second aperture masking article, such that the step of recovering comprises recovering a first aperture masking article and a second aperture masking article.

7. Method as claimed in claim 6, wherein the profile of the second aperture masking article is a reflection of the profile of the first aperture masking article along an axis parallel to the extrusion direction, the axis being disposed centrally with respect to the profile of a first and the profile of a second aperture masking article, such that the step of recovering comprises recovering a first aperture masking article and a second aperture masking article.

8. Method as claimed in claim 6 or 7, further comprising the step of:

separating the first aperture masking article from the second masking article by slitting the extruded blank.

9. Method as claimed in any preceding claim, wherein the step of recovering comprises winding at least a first aperture masking article onto a reel.

10. Method as claimed in any preceding claim, wherein the polymer material comprises a thermoplastic elastomer material.

1 1. Method as claimed in claim 10, wherein the thermoplastic elastomer material is a styrene butadiene styrene or styrene ethylene butylene styrene material.

12. Method as claimed in any preceding claim, wherein the extrusion die has a profile in which a spacing means is included in the cross-section of an aperture masking article.

13. Method as claimed in claim 1, wherein the recovered aperture masking also comprises a spacing means integral with the first surface of the backing.

14. A method of forming an aperture masking article comprising a backing and a gap filler, the method comprising the steps of:

extruding a polymer material through a die in an extrusion direction to form a extruded blank having a first side and an opposing second side, the die having a profile, parallel to the extrusion direction, corresponding to the cross-section of at least one aperture masking article component; and recovering at least one aperture masking article component from the extruded blank, the component forming a backing of an aperture masking article, the backing having a first portion and a second portion, the first portion having a first side and an opposing second side, and the second portion being shaped to receive a gap filler; and

applying a gap filler to the second portion.

15. Method as claimed in claim 14, further comprising the step of coating the second portion with an adhesive before applying a gap filler, such that the gap filler is bonded to the second portion.

16. Method as claimed in claim 14 or 15, wherein the die has a profile corresponding to the profile of a first and the profile of a second aperture masking article component.

17. Method as claimed in claim 16, wherein the profile of the second aperture masking article component is a reflection of the profile of the first aperture masking article component along an axis parallel to the extrusion direction, the axis being disposed centrally with respect to the profile of a first and the profile of a second aperture masking article component.

18. Method as claimed in claim 16 or 17, further comprising after the step of applying a gap filler, the step of:

19. Method as claimed in any of claims 14 to 18, wherein the polymer material comprises a thermoplastic elastomer material.

20. Method as claimed in claim 19, wherein the thermoplastic elastomer material is a styrene butadiene styrene or styrene ethylene butylene styrene material.

21. Method as claimed in any of claims 14 to 20, wherein the gap filler is a conformable foam material.

22. Method as claimed in any of claims 14 to 21, wherein the gap filler is an open cell polyurethane foam material.