CN1292732A - Masking materials and method of use - Google Patents

Abstract

A masking material comprises an elongate strip (8) at least partially coated with a layer of a pressure-sensitive adhesive (4), the strip having a curved surface which is convex when the strip is viewed in cross section and is positioned such that when the strip is adhered to a substrate (12) by the layer of pressure-sensitive adhesive a portion of the curved surface overhangs the substrate. The masking material comprises a removable edge portion (10) comprising said portion of the curved surface detachably secured to a remainder of the strip and which may be removed to expose a second curved surface on the remainder of the strip which is convex when viewed in cross section and which is positioned to overhang the substrate. The removable portion and remainder of the strip have different dimensions. Methods for making such masking material are also described.

Description

Masking material for coating and method of use thereof

Background of the invention

technical field

The present invention relates to masking materials and the use of these materials when applying two or more coating materials to a surface. In particular, the invention relates to such masking material which has a curved edge strip which can be removed from the remainder of the masking material.

Description of the technology

There is a known foam masking tape which includes a foam backing with a layer of pressure sensitive adhesive on a portion of the backing surface. A preferred cross-section of the tape has a curved surface, such as a circle or oval, which is preferred because the masking tape obtains a "feathered edge" ( feathered edge) or "soft edge". The masking tape is positioned so that the curved surface overhangs the surface to be painted so that when the paint is sprayed, only paint projected at an angle can pass under the overhang of the masking tape and the thickness of the paint will be relatively The thin, overhanging edge below the surface allows a smooth transition into the adjacent painted area. The use of foam absorbs paint impinging on the foam tape to prevent the paint from flowing away from the masking material and damaging the treated surface. Such masking material is commercially available from 3M in the UK under the trade name Soft Edge Masking Foam Tape.

A cold weld is formed by pressing a predetermined portion of a foam web with a blunt-tipped rotary knife, such that the opposite surfaces of the web are secured to each other at the cold weld, thereby forming a curved surface, whereby soft edge masking is produced Foam Tape (SEMFT). Passing a foam web through a plurality of parallel blunt rotary knives compresses and welds the foam along parallel lines to form an array of adjacent and easily separable circular or oval foam strips. The processing of such foam strips is disclosed in EP-B-0384626. Other cold welded foam masking materials are disclosed in GB-2254811 and GB-2288137.

SEMFT is commonly used to mask the inside of door openings to prevent contamination of the vehicle interior when paint or primer is sprayed. After spraying the primer onto the fascia of the car, it is desirable to spray the paint with the paint over the primer to ensure that the primer is fully covered and not showing. In this case, the SEMFT was removed and repositioned after the primer spray. Alternatively, gently push the SEMFT to displace it away from the edge of the primer. But since this is labor intensive (higher labor intensity) and cannot be used if the primer is still wet, neither technique is suitable.

The present invention starts at this point exactly.

Summary of the invention

According to one aspect of the present invention, there is provided a masking material comprising an elongated strip at least a portion of which is coated with a pressure sensitive adhesive. The strip has a curved surface that is convex when viewed in cross-section, and the strip is positioned such that a portion of the curved surface is suspended when the tape is adhered to a substrate by a layer of pressure-sensitive adhesive. on top of the substrate. The masking material includes a removable edge portion including a curved surface portion releasably secured to the remainder of the belt, this portion being removable to expose the first strip on the remainder of the belt. A second curved surface, the second curved surface being convex in cross-section, and the portion of the curved surface positioned to overhang the substrate. The size of the removable part and the rest of the belt are different.

According to a second aspect of the present invention there is provided a method of coating a sub-area of a substrate surface with a first and a second coating material. The method comprises the steps of:

(i) Providing a masking material comprising an elongated or endless strip at least a portion of which is coated with a layer of pressure sensitive adhesive. The tape has a curved surface that is convex in cross-section and when the tape is adhered to a substrate by the pressure sensitive adhesive layer, a portion of the curved surface overhangs the substrate. The masking material includes a removable edge portion including a curved surface portion that is releasably secured to the remainder of the belt and is removable to expose a second curved surface on the remainder of the belt. , the second curved surface is convex when viewed in cross-section, and the portion of the curved surface is suspended above the substrate. The size of the removable part and the rest of the belt are different.

(ii) Applying the masking material to the substrate such that the curved surface is adjacent to the edge of the area to be coated.

(iii) Applying the first coating material over the surface area up to the masking material.

(iv) Detaching and removing the removable portion of the masking material.

(v) Applying the second coating material over the first coating material until the remainder of the masking material.

The masking material of the present invention is simple and effective to use. The strip is applied to the surface by conventional means so that the curved surface is adjacent to the edge of the area of the surface to be coated. After application of a first coating material such as a primer, the curved surface can be easily removed to expose a second curved surface extending slightly over the area to be coated, allowing the second coating to completely cover the first coating layer while making sure to get a feathery edge. In this way, it is not necessary to reposition the masking material between successive coating operations.

The masking material is preferably made of foam and can be conveniently produced by cold welding foam webs using the technique disclosed in EP-0384626. Polyurethane foam is preferred in cold welded embodiments of the present invention. The density of the foam is preferably about 26 kg/m ³ . A preferred cold weldable foam is available from Caligen Foam, Inc. under the trade designation "Grade 4273A".

The removable edge of the masking material can be obtained in a number of ways.

In one embodiment, the elongated strip may be circular or oval in cross-section, and a layer of foam or similar material releasably secured to and along the contour of the curved surface extends as a strip along the length of the masking material to form a removable edge. The removable strap is secured by pressure sensitive adhesive, welding, or a combination thereof.

This masking material can be made by a method which includes the following steps:

(a) providing a first cold-weldable foam banner;

(b) applying at least two parallel runs of pressure-sensitive adhesive to one surface of the foam web;

(c) applying a second cold-weldable foam web of thinner thickness than the first web to the first web such that the second web overlaps but does not completely cover adjacent parallel strips of pressure sensitive adhesive ;

(d) compressing the first and second cold-weldable webs between adjacent strips of pressure-sensitive adhesive with a blunt-tipped rotary knife to form a cold weld, securing the two webs to each other at the weld region, thereby forming a curved surface; and

(e) compressing the first web with a blunt-tipped rotary knife to form a cold weld, securing the opposing surfaces of the web to each other at the weld area, thereby forming a curved surface, compressing the said web along at least three parallel lines The banner or banners are formed to form at least two cords of circular or oval cross-section.

The elongated strip may include removable edge portions in the form of foam layers that follow the contour of the curved surface and extend along the length of the strip. This masking material is made by a method comprising the following steps:

(a) providing a first cold-weldable foam banner;

(b) providing at least two second cold-weldable foam panels having a thickness and width smaller than the first cold-weldable foam panel;

(c) adhering the second banner to a surface of the first banner with a pressure sensitive adhesive to form parallel bands of the second banner;

(d) compressing said first and second cold-weldable webs with a blunt-tipped rotary knife to form a cold weld which holds the first and second webs together at the weld region thereby forming a bend a surface that compresses said web along at least two parallel lines along the longitudinal axis of the second web to form at least one strand that is circular or oval in cross-section;

(e) Applying a pressure sensitive adhesive to the surface of the first web in the area between the second webs before cold welding or to the cord between the second webs after cold welding on the face of the first banner of the strip.

In another embodiment, the masking material comprises a primary cord with a circular or oval cross-section coated with a strip of pressure-sensitive adhesive and a secondary cord parallel to and releasably secured to the primary cord. cable. A foam web is cold welded to conveniently form the secondary strand at the same time as the primary strand.

This masking material can be made by a method comprising the following steps:

(a) Provide a cold-weldable foam banner;

(b) compressing the foam web with at least one blunt-tipped rotary knife to form a cold weld that secures the opposing surfaces of the web to each other at the weld region, thereby forming a curved surface along at least three parallel The wire compresses the web to form at least two strands having a pair of longitudinal welds and a circular or oval cross-section, the two strands being releasably secured together by a common weld, the two strands The dimensions of the cords are different; and

(c) Apply a strip of pressure sensitive adhesive to the web in the region of the larger sized cord before cold welding or to the larger sized cord after cold welding.

In another embodiment of the invention, the masking material is in the form of an endless strip, such as a closed curved strip, such as a circular or oval or other shape such as a square, hexagonal, etc. closed curved strip . Concentric arrays of strips can be formed, for example, by compressing and cold welding the foam, with tearing of the welds separating adjacent strips from each other. GB-2254811 discloses an example of such an array. In use, the user removes enough strips to form a hole in the area of the surface to be coated, applying the masking material to the surface. After applying the first coating layer, such as a primer, the inner tape is removed and a second coating layer is superimposed on the first coating layer.

Brief description of the drawings

Describe the present invention below in conjunction with accompanying drawing, in the accompanying drawing:

Figures 1a and b illustrate the processing of a masking material according to an embodiment of the present invention;

Figures 2a and b illustrate the use of the masking material of Figure 1;

Figure 3a and b show the processing of the masking material according to the second embodiment of the present invention;

Figures 4a and 4b illustrate the use of the masking material of Figure 3;

Figures 5a and b illustrate the processing of another masking material according to the present invention;

Figure 6 shows the masking material used in the present invention.

Description of the preferred embodiment

Figures 1a and b show a production process of a masking material according to an embodiment of the present invention. FIG. 1 a shows in section a part of a foam web ( 2 ) on which a strip of pressure-sensitive adhesive ( 4 ) is applied. The foam web passes through a multi-slitter equipped with pressurized blades (6). Three pressing blades (6) are shown, spaced at a suitable distance to form a primary cable (8) and a secondary cable (10). By repeating this pressurized blade across the width of the web, multiple strips of masking cord can be produced.

The pressurized blade compresses the foam web and forms a cold press weld, which gives the foam the curved shape shown in Figure 1b. The primary cable (8) with the pressure sensitive adhesive strip (4) is connected to the primary cable (10) by cold welding. It is easy to separate the secondary cable bar (10) from the main cable bar (8) by tearing it apart along the weld.

Figures 2a and b illustrate the use of masking material. The masking material is secured to a surface to be coated (12) by means of a strip of pressure-sensitive adhesive (4). The masking material is positioned such that the secondary cord (10) contacts the surface (12) adjacent the area to be coated. A first coating layer (14) is applied (thickness shown exaggerated). The first coating layer (14) is generally a primer. Note that the coating (14) extends under the curved surface of the secondary cord (10) such that the coating (14) forms a tapered or feathered edge.

Remove the lower cable (10) along the cold weld tear, leaving the main cable (8) in place. A second coating layer (16) is applied over the first coating layer (14) (the thickness shown is exaggerated). The second coating layer (16) extends to the edge of the coating layer (14) and extends under the suspended curved surface of the main cable (8), thereby ensuring that the coating layer (14) is not exposed, and The coating layer (16) is provided with a feathered edge. Thereafter, remove the main cable (8).

The dimensions of the primary and secondary cables are varied by the thickness of the foam coating chosen and the spacing of the press blades. A suitable masking material can be produced from a foam web with a thickness of about 15 mm, and a substantially cylindrical main cable with a diameter of about 13 mm. Secondary strands of about 3, 6 and 7 mm attached to the primary strands can be formed with appropriately spaced pressurized blades.

Figures 3a and b show the processing of a masking material according to a second embodiment of the invention. A foam banner (20) is coated with two pressure-sensitive adhesives (22, 24), a second thinner foam banner (25), for example a foam banner with a thickness of 2 to 5 mm, overlapping but not completely covering Hold the adhesive strips (22, 24). This composite web is fed into a multi-head shear equipped with pressurized blades whose positions are indicated by (26). The pressurized blade compresses the foam web to form a cold weld, thereby machining two separate masking strips (28). Each masking strip (28) includes a substantially cylindrical portion (30) formed by a foam web (20), an adhesive strip (22, 24) and a removable strip formed by the foam web (25). The edge portion (32) is fixed to the cylindrical portion (30) by adhesive strips (22, 24) and cold welding. The shape of the removable edge (32) matches the cylindrical contour of the core (30).

Figures 4a and b illustrate the use of masking material (28). The masking material is located on a surface to be coated (12) and is secured by a strip of pressure sensitive adhesive (22 or 24, not shown). The masking material is positioned such that the removable edge (32) is adjacent the edge of the area to be coated. When applying the first coating material (14), eg as a backing, a portion thereof extends below the overhanging bend of the removable edge (32) to provide a feathery edge for coating. Thereafter, the removable edge (32) is peeled off the core (30) without moving the core (30), thereby exposing the curved surface of the core near the edge of the area to be coated. Next, a second coating layer (16) is applied on top of the first coating layer. The second coating (16) completely covers the first coating and extends below the overhanging curved surface of the core (30), thereby providing a feathery edge to the second coating. Finally, remove the masking material.

Figures 5a and b show the processing of a masking material similar to that shown in Figures 3 and 4, but with two removable edges. The masking material is formed from a foam web (31) onto which two thin foam strips (33) are bonded with a pressure sensitive adhesive or double sided pressure sensitive adhesive tape (not shown). A gap (34) is separated between the two foam strips (33), and a strip of pressure-sensitive adhesive is applied to the gap (34) before or after cold welding. The composite web is fed into a multi-head shearer equipped with pressurized blades (36) that compress the foam and form a cold weld. Figure 5b shows the resulting masking material comprising an array of masking material each comprising a central core (38) and a pair of removable edges (40). Adjacent masking strips are cold welded to each other, but they are easily separated. Each masking strip can be used in conjunction with the method described in Figures 4a and b.

Figure 6 of the accompanying drawings shows a variable-sized painted mask produced by stamping a foam web, for example, 5 mm thick, in such a way that the die steel does not completely punch through the foam, but the foam A series of concentric cold welds are welded on. The total masking material may be in an area of one square meter and include a plurality of concentric cold welds (50a to 50d) to form annular segments (52a to 52d). In use, one or more segments of the mask large enough to fully expose the painted area are removed, such as segment (52a), the mask applied to the surface and covered with a layer of glue (not shown). ) remain in place. The first coating material is applied first, and the shield forms a feathery edge due to the curvature caused by the cold weld. The cold weld is then torn off to remove the inner section of the shield eg (52b), thereby exposing another curved surface. A second coating layer is then applied over the first coating layer, leaving the curvature of the masking material to create a feathery effect at the edge of the top layer. It is to be pointed out that many other shapes than round can be used for the varnished mask with variable dimensions.

Claims (19)

1. A masking material comprising an elongated strip coated at least in part with a layer of pressure-sensitive adhesive, the strip having a curved surface that is convex when viewed in cross-section, in such a position that the strip is positioned : When the tape is adhered to a substrate by a layer of pressure-sensitive adhesive, a portion of the curved surface overhangs the substrate, wherein the masking material includes a removable edge portion including a said curved surface portion of the remainder, the edge portion being removable to expose a second curved surface on the remainder of the belt, which is convex in cross-section and overhangs the substrate, so The dimensions of the removable portion and the rest of the strap are different. 2. 3. The masking material of claim 1, wherein the strip is formed from a cold weldable foam web having at least one cold weld along its longitudinal length to maintain the shape of the curved surface. 3. 3. Masking material as claimed in claim 1 or 2, characterized in that the strip comprises a pair of cold welds having a substantially oval or circular cross-section. 4. A masking material as claimed in any one of the preceding claims, wherein the removable edge portion comprises a foam cord of substantially oval or circular cross-section, detachably secured to the elongate strip. 5. 4. The masking material of claim 4, wherein the foam cord and the strip are joined together by a cold weld. 6. 3. Masking material as claimed in any one of claims 1 to 3, wherein the removable edge portion comprises a strip of foam releasably secured to the curved surface of the elongated strip. 7. 6. The masking material of claim 6, wherein the foam strip is detachably secured by pressure sensitive adhesive. 8. 6. Masking material as claimed in claim 6 or 7, characterized in that the edge portion is detachably secured to the remainder of the strip by a cold weld. 9. 8. Masking material as claimed in any one of claims 6 to 8, including a plurality of removable edge portions. 10. 8. An array comprising a plurality of adjacent strips of masking material as claimed in any one of the preceding claims, wherein adjacent strips are detachably connected to each other by longitudinal welded seams. 11. A method of coating a region of a substrate surface with first and second layers of coating material, the method comprising the steps of: (i) providing a masking material comprising an elongated or endless strip coated at least in part with a layer of pressure sensitive adhesive, having a curved surface which is convex when viewed in cross-section, The tape is positioned such that a portion of the curved surface overhangs the substrate when the tape is adhered to a substrate by the pressure sensitive adhesive layer, wherein the masking material includes a removable edge portion that includes a removable A portion of said curved surface releasably secured to the remainder of the belt which is removable to expose a second curved surface on the remainder of the belt which is convex in cross-section and which the curved surface overhangs the substrate, the removable portion and the rest of the strip are of different dimensions; (ii) applying the masking material to the substrate such that the curved surface is adjacent to the edge of the area to be coated; (iii) applying a first coating material over said region of the surface up to said masking material. (iv) separating and removing said removable portion of masking material; and (v) Applying the second coating material over the first coating material until the remaining surface of the masking material is masked. 12. A method as claimed in claim 11 wherein the masking material is as claimed in any one of claims 1 to 9. 13. 12. A method as claimed in claim 11 or 12, characterized in that the first coating material is a primer and the second coating material is a paint. 14. A method as claimed in any one of claims 11 to 13 wherein the surface comprises an automotive surface. 15. A method of manufacturing the masking material as claimed in claim 5, comprising the steps of: (a) Provide a cold-weldable foam banner; (b) compressing said foam web with at least one blunt rotary cutter to form a cold weld such that opposite surfaces of the web are secured to each other at the weld region thereby forming a curved surface along At least three parallel wires press the web to form at least two strands having a pair of longitudinal welds and circular or oval cross-section, the two strands being releasably secured by a common weld Together, the dimensions of the two cords are different; and (c) Apply a strip of pressure sensitive adhesive to the web in the region of the larger sized cord before cold welding or to the larger sized cord after cold welding. 16. A method of manufacturing the masking material as claimed in claim 6, the method comprising the steps of: (a) providing a first cold-weldable foam banner; (b) applying at least two parallel runs of pressure-sensitive adhesive to one surface of the foam banner; (c) applying a second cold-weldable foam web of thinner thickness than the first web to the first web such that the second web overlaps but does not completely cover adjacent parallel strips of pressure sensitive adhesive; (d) compressing the first and second cold-weldable webs intermediate adjacent strips of pressure-sensitive adhesive with a blunt-tipped rotary knife to form a cold weld such that the two webs are secured to each other at the weld region, thereby forming a curved surface; and (e) compressing the first web with a blunt-tipped rotary knife to form a cold weld so as to secure the opposing surfaces of the web to each other in the area of the weld, thereby forming a curved surface, compressing all the webs along at least three parallel lines; Said banner, to form at least two cables with circular or elliptical cross-sections. 17. A method of manufacturing the masking material as claimed in claim 9, the method comprising the steps of: (a) providing a first cold-weldable foam banner; (b) providing at least two second cold-weldable foam panels having a thickness and width smaller than the first cold-weldable foam panel; (c) adhering the second banner to a surface of the first banner with a pressure sensitive adhesive to form parallel bands of the second banner; (d) compressing said first and second cold-weldable webs with a blunt-tipped rotary knife to form a cold weld such that the first and second webs are held together at the weld region thereby forming a bend a surface that compresses said web along at least two parallel lines along the longitudinal axis of the second web to form at least one strand that is circular or elliptical in cross-section; (e) Applying a pressure sensitive adhesive to the surface of the first web in the area between the second webs before cold welding or to the cord between the second webs after cold welding on the face of the first banner of the strip. 18. 3. The masking material of claim 1 wherein said strip is endless. 19. The masking material of claim 18, formed from a cold weldable foam, the masking material comprising a plurality of concentric cold welds to form a plurality of concentric endless strips, each strip passed through a cold weld The seam is detachably secured to an adjacent belt.

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