GB2408486A - Elongate embossing assembly with plurality of embossing elements - Google Patents

Abstract

The assembly has a cylindrical embossing surface defined by the elements 25a, b which are detachably secured to a core element 12. Each embossing element 25a, b is a disc with a concentric or eccentric aperture with one or more outward recesses for engagement with one or more keyways mounted in an axial recess in the core element 12. A plurality of embossing element recesses enables adjacent elements 25a, b to be mutually displaced circumferentially to provide different patterns of formations on the elements. The embossing elements 25a, b are retained on the core element 12 under axial pressure by compression spacers 19, securing nuts 18 and locking nuts 16 at each end of the core element. The assembly is used for embossing a pattern in a plastics film and underlying adhesive layer of a bituminous sheet roof coating material, as well as for paper, packaging, flooring material, kitchen towels and leather.

Description

i. 1 Improvements in and relating to embossing .

. 3 The present invention relates to the field of embossing. ë

:4 In particular, the invention in one of its aspects relates to an improved embossing tool, and its method of 6 use. In another of its aspects, the invention relates to 7 a method of forming a coating material.

9 Embossing is a process of moulding or carving a decoration or design onto a surface, in order to form a 11 pattern raised above the surface in low relief.

12 Embossing techniques are used in a variety of 13 applications, such as the manufacture of paper, flooring, 14 coating materials (e.g. for roofing structures), leather, sheet packaging materials etc. Embossing may be used to 16 create a decorative effect, or may be used to create a 17 textured surface necessary or desirable for the embossed 18 material to function.

2 Embossing involves the application of a die to the 3 surface of the material, the die having a textured 4 surface that is the inverse of the pattern to be provided on the material to be embossed. The exact form of the 6 die will depend on the type of material to be embossed, 7 and the desired pattern. However, the dies are purpose 8 built for the material and/or pattern.

For many applications, it is desirable to emboss a 11 continuous roll of sheet material with a regularly 12 repeating pattern. Typically, the die used will be in ë ï3 the form of an embossing roller, applied to the material I. ....14 at an appropriate point on a production line. The embossing roller die will typically be a steel cylinder, .e 16 formed from a single piece of steel. The surface of the ë 17 cylinder is textured in a manner appropriate to the depth 18 of relief and surface pattern required. For applications I. 19 to, for example, leather, flooring or roofing materials, .

the surface of the cylinder may be textured by milling 21 channels parallel to the axis of rotation and/or turning 22 channels circumferentially around the cylinder.

23 Alternatively, the roller may be drilled in order to form 24 a series of indentations in the roller surface.

26 These machining techniques are limited in their ability 27 to form a variety of patterns and shapes. More 28 complicated and sophisticated patterns could be formed by 29 engraving or etching techniques, but these are relatively expensive and time consuming.

32 Furthermore, each embossing roller is limited to one 33 particular embossing pattern. This means that a 1 manufacturer will need to obtain an embossing roller for 2 each pattern that he wishes to apply to a material, 3 thereby increasing capital expense. Even if a 4 manufacturer wants to achieve a subtle change in embossed pattern, a different embossing roller must be produced.

7 In addition, embossed rollers, particularly those with 8 significant protrusions, are susceptible to damage during 9 use, storage, fitting or carriage. This can be partially attributed to brittleness having a correlation with the 11 desirable hardness of the roller material. ..

ï3 It would therefore be desirable to provide an embossing ...

.i4 tool that obviates or at least mitigates one or more of the drawbacks associated with the prior art apparatus. ë .

17 It is one aim of the invention to provide an embossing a.. 18 tool with increased flexibility of application.

ace. 19 It is a second aim of the invention to provide a 21 configurable embossing tool and a method of 22 configuration.

24 It is a further aim of the invention to provide an embossing tool that is more easily and economically 26 maintained.

28 Further aims and objects of the invention will become

29 apparent from the following description.

31 According to a first aspect of the invention there is 32 provided embossing apparatus comprising an elongate 33 assembly defining an embossing surface, wherein the 1 elongate assembly comprises a plurality of embossing 2 elements which partially define the embossing surface and 3 are adapted to enable attachment to the elongate 4 assembly.

6 Preferably, the embossing elements are adapted to enable 7 attachment to and detachment from the elongate assembly.

9 Preferably, the elongate assembly defines a substantially cylindrical embossing surface.

12 Preferably, the assembly comprises an elongate core ë 13 element, and the plurality of embossing elements are me ....14 disposed along the length of the elongate core element.

i6 Each embossing element may have an internal aperture .

17 adapted to be received on the elongate core element. : 18 I.-

I. 19 The assembly may be provided with means for preventing rotation of the embossing element relative to the 21 elongate core element.

23 The internal aperture may have a substantially circular 24 cross-section provided with at least one detent for engaging a corresponding part of the elongate core 26 element.

28 Preferably, the internal aperture is provided with a 29 plurality of detents for engaging a corresponding part of the outer surface of the elongate element.

32 The internal aperture may be provided with a plurality of 33 detents disposed regularly around the internal aperture.

2 Four detents may be provided, the detents being disposed 3 at angular intervals of 90 degrees.

Alternatively, eight detents may be provided, disposed 6 regularly at angular intervals of 45 degrees.

8 Preferably, the detents are rectangular recesses 9 extending outwardly from an edge defining the internal aperture.

12 A detent may engage directly with a formation on the .

:. .13 elongate core element. I.-

..,.14 Preferably, a detent may engage with a formation on the 16 elongate core element via a locking member. ..

18 More preferably, the locking member is a keyway received I. . 9 in a channel formed in the elongate core element.

21 At least some of the embossing elements may be circular 22 in cross-section.

24 At least some of the embossing elements may be substantially circular in cross-section with one or more 26 discontinuities disposed on an outer edge.

28 The internal aperture of one or more embossing elements 29 may be concentric with the elongate core element.

31 Alternatively, the internal aperture of one or more 32 embossing elements may be eccentric with the elongate 33 core element.

2 The assembly may comprise a plurality of identical 3 embossing elements.

The identical embossing elements may be arranged on the 6 assembly such that they are rotationally displaced with 7 respect to one another.

9 Optionally, the assembly comprises a plurality of sets of embossing elements, each set of embossing elements having 11 a distinct shape. ..

.'.13 The embossing elements may be arranged in a repeating ..

.i4 pattern along the length of the elongate core element. . 15

16 The embossing elements may be arranged in a repeating :.

17 pattern of identical embossing elements rotated with .

18 respect to one another.

. 59 The embossing elements may be arranged in a repeating 21 pattern of embossing elements of distinct shape.

23 The embossing elements may be arranged in a repeating 24 pattern of identical embossing elements rotated with respect to one another in combination with embossing 26 elements of distinct shape.

28 Preferably, the embossing elements are discs.

More preferably, the embossing elements comprise steel.

32 The embossing elements may be formed by a laser cutting 33 process.

2 According to a second aspect of the invention, there is 3 provided an embossing element for an embossing apparatus 4 having an elongate assembly defining an embossing surface, wherein the embossing element partially defines 6 an embossing surface of the elongate assembly, and is 7 adapted to enable attachment to the elongate assembly.

9 The embossing element is preferably adapted to enable detachment from the elongate assembly.

12 Preferably, the embossing element is a disc. ..

:.: .13 .e.

....i4 More preferably, the embossing element comprises steel. .

16 The embossing element may be formed by a laser cutting ..

17 process. : 18 a.

. t9 Preferably, the embossing element comprises an internal .

aperture adapted to be received on an elongate core 21 element of the elongate assembly.

23 The embossing element preferably comprising means for 24 preventing rotation of the embossing element relative to the elongate core element.

27 The internal aperture may have a substantially circular 28 cross-section provided with at least one detent for 29 engaging a corresponding part of the elongate core element.

32 According to a third aspect of the invention, there is 33 provided a method of configuring an embossing apparatus 1 having an elongate assembly defining an embossing 2 surface, the method comprising the step of attaching a 3 plurality of embossing elements to the elongate assembly, 4 the embossing elements partially defining the embossing surface.

7 The plurality of embossing elements may be removably 8 attached to the elongate assembly.

The method may comprise the additional step of axially 11 compressing the embossing elements on the elongate 12 assembly and securing the elongate elements in a state of ë :. .13 compression. I.

....q4 According to a fourth aspect of the invention, there is 16 provided a method of embossing a sheet material using ..

17 apparatus the first or second aspects of the invention. q8

- ..

. t9 According to a fifth aspect of the invention, there is provided a method of forming a bituminous sheet coating 21 material comprising the steps of providing an adhesive 22 layer, providing a plastic film over the adhesive layer, 23 and forming an embossed pattern in the adhesive layer by 24 embossing the plastic film and the adhesive layer simultaneously.

27 Preferably, the step of embossing the plastic film and 28 adhesive layer at least partially tensions the plastic 29 film.

31 The embossed pattern preferably comprises a plurality of 32 longitudinal grooves.

1 The step of embossing preferably uses the apparatus of 2 the first or second aspects of the invention 3 According to a sixth aspect of the invention, there is 4 provided an embossed material made by the method of the fourth or fifth aspects of the invention.

7 According to a seventh aspect of the invention, there is 8 provided an embossed bituminous coating sheet material 9 made by the method of the fourth or fifth aspects of the invention.

12 There will now be described, by way of example only, with 613 reference to the following drawings of which: I. 14 . 15 Figure 1 is a plan view of an embossing apparatus in .e 16 accordance with an embodiment of the invention; ë 18 Figure 2 is plan view of a detail of a part of the ë ,..9 embossing apparatus of Figure li 21 Figure 3a is a plan view of an arbor of the 22 embodiment of Figures 1 and 2; 24 Figure 3b is a longitudinal view of the arbor of the embodiment of Figures 1 and 2i 27 Figure 3c is a detail of the arbor of the embodiment 28 of Figures 1 and 2; Figure 4a and 4b are respectively cross-sectional 31 and side views of an embossing element used with the 32 embodiment of Figures 1 and 2; 1 Figures 5a and 5b are respectively cross-sectional 2 and side views of another embossing element used 3 with the embodiment of Figures 1 and 2; Figures 6a and 6b are respectively side and cross 6 sectional views of a compression spacer used with 7 the embodiment of Figures 1 and 2; 9 Figures 7a and 7b are respectively cross-sectional and side views of an alternative embossing element; 12 Figures 8a and 8b are respectively cross-sectional 13 and side views of a further alternative embossing 14 element; .15 ë .16 Figures 9a and 9b are respectively cross-sectional 17 and side views of a further embossing element; - : 18 ..19 Figures 10 to 19 are perspective views of parts of various examples of embossing surfaces created used 21 apparatus according to embodiments of the invention.

23 Referring firstly to Figures 1 and 2, there is shown in 24 plan view an embossing apparatus according to an example embodiment of the invention. The apparatus, generally 26 depicted at 10, comprises an elongate assembly 11 and a 27 pair of mounting assemblies 20. The elongate assembly 11 28 comprises an elongate core element in the form of arbor 29 12, and a plurality of embossing elements 25 which together form an embossing surface 14 of the apparatus.

31 The assembly comprises a plurality of embossing elements 32 25 located along the length of the arbor 12, as most 1 clearly shown in Figure 2. The assembly is rotatable 2 about the longitudinal axis of the arbor 12.

4 In this example, the embossing elements 25 are substantially circular at cross-section, and therefore 6 partially define a substantially cylindrical embossing 7 roller rotating about its longitudinal axis.

9 The tool further comprises a pair of compression spacers 19, disposed on the arbor at either side of the plurality 11 of embossing elements 25. Located longitudinally 12 outwardly of the compression spacers 19 are securing nuts .

ï3 18. Outwardly of the securing nuts are located a pair of .e ^.14 locking nuts 16. The outermost embossing elements 25, the compression spacer 19, the securing nuts 18 and the .

16 locking nuts 16 are in abutment and function to prevent : 17 longitudinal movement of the components on the arbor is (which is transverse movement in the sense of motion of . a9 the material to be embossed).

21 The mounting assembly 20 includes a mounting bracket 21 22 secured to a frame or support by means of fasteners, such 23 bolts (not shown). The mounting bracket 21 has a 24 circular bore extending therethrough for receiving the end of the arbor 12. A bearing 22 is positioned between 26 the arbor and the mounting bracket.

28 Figure 2 shows a detail of the right-hand side of the 29 tool, including mounting assembly 20, arbor 12, compression spacer 19, securing nut 18 and locking nut 31 16. Figure 2 also shows the embossing elements 25a and 32 25b with greater clarity. Embossing element 25a has a 33 radius greater than that of element 25b. Elements 25a 1 and 25b are alternately disposed on the elongate assembly 2 to form a repeating surface pattern. In this example, 3 elements 25a and 25b are circular in cross-section, and 4 the surface formed by the combination of embossing elements is a cylinder having a plurality of grooves 6 formed therein. During use, the edges of the embossing 7 elements 25a will form a plurality of grooves in the 8 surface of the embossed material.

Figure 3a shows the arbor 12 of the embodiment of Figures 11 1 and 2. Figure 3c shows a detail of the right-hand side 12 of the arbor 12. The arbor 12 is elongate, and has ë 3 portions of different cross-section along its length. I.

i4 The two longitudinally outermost portions 33 of the arbor are of circular cross-section and are adapted to be - i6 received within the bearings 22 of the mounting assembly ë- 17 20. is

I. 19 Inwardly of the arbor are threaded portions 31, which - have a circular cross-section at an increased outer 21 diameter relative to the end portions 33. The threaded 22 portion 31 functions to co-operate with a thread provided 23 on the securing nuts 18.

The arbor is also provided with main portion 34 extending 26 over the majority of the length of the arbor. The main 27 portion is partially cylindrical, although it is provided 28 with two inwardly formed rectangular recesses 35 located 29 at diametrically opposed sides of the arbor (most clearly shown in Figure 3b). This recess extends along the 31 majority of the length of the main portion 34 to form a 32 longitudinal channel 35 of rectangular profile. The 1 longitudinal channel functions to receive a locking 2 member in the form of a keyway (not shown).

4 Figures 4a and 4b show the detail of the embossing element 25a of Figures 1 and 2. The embossing element 6 25a is a disc of circular cross-section. The disc is 7 provided with an internal aperture 27 concentric with the 8 disc. The internal aperture is part-circular, with a 9 pair of outwardly cut rectangular recesses 28 disposed at diametrically opposed edges of the internal aperture.

12 The rectangular recesses 28 function as detents, and me :.: J3 engage with the keyway located in the longitudinal A. ...4 channel 35 of the arbor. The embossing element 25a is l5 thereby engaged with the arbor via the keyway, to prevent I6 relative rotation of the arbor and embossing element. 17

:18 In this example, disc 25a is formed from stainless steel - .e .39 of lmm thickness by a laser cutting process. The outer - diameter of the disc is 150mm, and the internal diameter 21 of the aperture is 70mm. The inwardly cut recesses 28 22 are 14mm wide, and formed to a depth of 7mm. The keyway 23 is a steel member of square cross-section of 14mm edge.

Figures 5a and 5b show embossing element 25b in cross 26 section. Embossing element 25b is similar to embossing 27 element 25a although the outer diameter of element 25b is 28 reduced, in this example to 140mm. In addition, the 29 thickness of the disk 25b is approximately half of the thickness of disk 25a, and in this example is 0.5mm.

32 The apparatus is assembled by locating a pair of keyways 33 in the channels 35, and locating the embossing elements 1 on the arbor such that the recesses 28 are aligned with 2 the keyways. Subsequently, when all of the embossing 3 elements 25 are located, compression spacers 19 are 4 located on the arbor to abut the outermost embossing elements 25.

7 Figures 6a and 6b show the compression spacer 19 in 8 detail. The compression spacers 19 are provided with a 9 longitudinal bore 29 extending therethrough for location on the arbor. Two rectangular channels 26 are formed 11 outwardly from the internal bore, and correspond to the 12 locations of the keyways. The compression spacers 19 3 span the distance from the keyways to the location of the c ...14 securing nuts 18, and transfer thrust to the embossing elements to prevent longitudinal movement thereof. i6

17 Securing nuts 18 are provided with internally threaded :18 bores, and are screwed on to the cooperating threaded

I

I. 19 portions 31 of the arbor into abutment with the compression spacers 19. The securing nuts 18 are 21 provided with thrust bearings 24 that allow control of 22 the axial force applied to the compression spacers.

24 Longitudinally outward of the securing nuts 18 are locking nuts 16. The locking nuts 18 comprise threaded 26 bores that correspond with the threaded portions 31 of 27 the arbor. The locking nuts are screwed into abutment 28 with the securing nuts 18.

Together, the locking nuts, securing nuts, thrust 31 bearings and compression spacers function to retain the 32 embossing elements 25 on the arbor in a compressed state.

1 The embossing surface defined by the apparatus is made up 2 of a number of embossing elements, each extending 3 longitudinally over a part length of the assembly. By 4 selecting and arranging embossing elements in different manners, different embossing surfaces can be created.

7 In the example shown in Figures 1 and 2, the embossing 8 elements are used to create a regular alternating pattern 9 of grooves around the cylindrical surface. However, the same elements could be arranged to form a multitude of 11 different embossing surfaces. For example, patterns or 12 grooves and ridges of varying widths could be created by :.;,13 placing identical circular embossing elements next to one -...

^.4 another.

.16 Alternatively, embossing elements of differing width 17 could be used. q8

t9 Furthermore, by using alternative embossing elements, elaborate embossing patterns can be created. Figures 7a 21 and 7b show an example of an alternative embossing 22 element 40. As with the examples of Figure 4 and 5, the 23 embossing element 40 is a disc laser cut from sheet 24 stainless steel. The embossing element is substantially circular in cross-section, but is provided with a 26 discontinuity 42 at its outer edge. The discontinuity 42 27 is in the form of an inwardly extending recess or notch 28 in the outer edge. The recess is substantially 29 rectangular in cross-section, although the internal and external corners of the recess are rounded.

32 In use, the embossing element 40 would form a groove of 33 low relief, except for at locations on the embossed 1 material corresponding to the recess. A longitudinal 2 groove would be formed having breaks at regular intervals 3 corresponding to the circumference of the disc.

Figures 8a and 8b show an alternative embossing element 6 50. In this example, the embossing element 50 is 7 substantially circular in cross-section, with a first 8 outer diameter and is provided with a discontinuity in 9 the form of an outwardly extending portion 52 of increased outer diameter. In use, the outwardly 11 extending portion creates an indentation in the embossed 12 material. ë

ees.13 tare Id The embossing elements 40 and 50 have four detents 48, 58 .15 located at 90 degree angular intervals around the ë 16 internal aperture. The embossing elements thus have four 17 different angular locating positions on the arbor and .

a. 18 keyways, each providing the discontinuity in a different .9 position. Identical embossing elements can thus be used on the same assembly in different rotational positions.

22 In the examples of Figures 7 and 8, the embossing 23 elements have a maximum outer diameter of 150mm, and a 24 minimum outer diameter of 140mm. Used in conjunction with the embossing elements 25a, 25b, a variety of 26 embossing patterns can be built up.

28 More elaborately shaped embossing elements having a 29 number of protrusions or recesses located around the outer edge can be used to construct a wide range of 31 surface patterns.

1 Figures 9a and 9b show an alternative example of an 2 embossing element 60. In this example, the embossing 3 element is circular in cross-section, and has an internal 4 aperture 67 formed eccentrically with respect to the outer edge of the embossing element. In use, the arbor 6 and the embossing element are rotated causing the outer 7 diameter of the embossing element to undulate 8 sinusoidally between a minimum and a maximum value. This 9 creates a corresponding undulation in the embossed material.

12 The embossing element 60 comprises eight detents 68 ë .13 located around the internal aperture at regular angular I. ....14 intervals of 45 degrees. Accordingly, the embossing element can be located in any one of eight angular ..

16 positions. Identical embossing elements 60 could be ë 17 located on the tool rotated with respect to one another 8 to provide a pattern of offset undulations. I. n9 .

Figures 10 to 19 show a number of examples of embossing 21 surfaces that may be created with the apparatus of the 22 present invention.

24 Figure 10 is a perspective view of a part of an embossing surface, comprising a repeating pattern of square-based 26 pyramids 102 and rectangular-based peaked protrusion 103.

27 The square-based pyramids 102 and the rectangular-based 28 peaked protrusions 103 alternate in a direction parallel 29 to the axis of rotation, and in circumferential direction of the cylinder. The embossed material will be provided 31 with a longitudinal and transverse pattern of alternating 32 pyramid-like and rectangular-based indentation. The 1 pyramid and rectangular-based troughs are constructed 2 from appropriately cut embossing elements.

4 Figure 11 is a perspective view of a part of an embossing surface, comprising a repeating pattern of ridges 112 and 6 bars 113. The resulting embossed material will consist 7 of a pattern of 0.9mm width continuous longitudinal 8 grooves at a pitch of 11.5mm with ridges broken by 9 grooves at repeats of 26mm.

11 Figure 12 is a perspective view of a part of an embossing 12 surface, comprising a repeating pattern ridges of 122 and ë 13 bars 123. This example is similar to that of Figure 11, *14 although the ridges are broken at repeats of 52mm. ë

6 It is possible to construct the patterns shown in Figures 17 11 and 12 using embossing elements of different widths.

.18 That is, one set of discs could be used with a width ë ., 19 corresponding to the internal separation of the ridges, interposed with intermediate discs of smaller width and 21 larger diameter to form the ridges. However, the same 22 pattern could equally be formed from an arrangement of 23 embossing elements of smaller width, with a sequence of 24 identical, aligned discs to form the area of the pattern between the ridges.

27 Figure 13 is a perspective view of a part of an embossing 28 surface, comprising a repeating pattern of ridges 132 and 29 arrows 133. The resulting embossed material will consist of a pattern of 0.9mm width continuous longitudinal 31 grooves at a pitch of 11.5mm with ridges broken by 32 grooves at repeats of 26mm.

1 The arrows are formed from a series of identical 2 embossing elements, with adjacent elements being 3 rotationally offset. After a predetermined number of 4 embossing elements, the direction of offset is reversed, thereby creating the arrow pattern.

7 Figure 14 is a perspective view of a part of an embossing 8 surface, similar to that of Figure 13, although the 9 rotational offset of the elements is reversed in order to form arrows over a greater width with a larger pitch.

12 Figure 15 is a perspective view of a part of an embossing ë :.: .13 surface, having a checkerboard pattern of alternating .e ....q4 raised squares 152 and recessed squares 153. In this example, the squares are formed to a size of 26mm by . \6 26mm. A series of aligned identical elements make up one 17 band of squares, with an adjacent series of aligned : 18 elements being offset.

- ..

. .19 .

Figure 16 is a perspective view of a part of an embossing 21 surface, having a checkerboard pattern of alternating 22 raised and recessed rectangles. In this example, the 23 pattern is similar to that of Figure 15, although 24 rectangles are formed to a size of 12mm by 13mm.

26 Figure 17 is a perspective view of a part of an embossing 27 surface, having a pattern of hollow squares 172 formed 28 from square, raised perimeters 173.

Figure 18 is a perspective view of a part of an embossing 31 surface, having eccentric embossing elements. Adjacent 32 sets of eccentric embossing elements, at a pitch of 4.5mm 33 are rotated 180 degrees with respect to one another. The 1 eccentric sets of embossing elements are provided with 2 opposing 0.5mm recesses and protrusions to provide ridges 3 and channels at the peaks and troughs of the undulations 4 formed in the embossed material.

6 Figure 19 is a perspective view a part of an embossing 7 surface, having a pattern of raised crosses 192. The 8 raised crosses have a pitch of 12.5mm, and are 9 rotationally offset with respect to one another.

11 The present invention allows a multitude of surface 12 patterns to be created from various arrangements of ..

.3 embossing elements. In some cases, different patterns -e ....14 can be created from arranging the same sets of embossing elements in a different manner. For example, the . 16 patterns shown in Figures 17 and 19 can be formed from .

17 different arrangements of the same embossing elements.

: 18 ...

I. :19 The present invention allows patterns to be produced that would otherwise be difficult and impractical to produce.

21 By configuring an embossing pattern from a plurality of 22 embossing elements, a user may create a pattern that 23 meets a particular set of criteria. The criteria may be 24 a consequence of a function of the embossed material. For example, a flooring material may require an embossed 26 pattern on its

lower surface to prevent slipping, or a 27 kitchen towel may be provided with increased surface area 28 to improve absorption.

Alternatively, the patterning requirements may be based 31 on aesthetic criteria, such as creating a finish on paper 32 or packaging.

1 Often, the criteria will be based on functional and 2 aesthetic considerations, as the user seeks to provide a 3 technical effect while patterning a material in a manner 4 that is distinctive, allowing aesthetic differentiation from competitors' products.

7 The present invention offers apparatus with high 8 flexibility, allowing a user to arrive at an embossing 9 pattern that meets his selection criteria.

11 Furthermore, should the user's requirements change, the 12 apparatus of at least one embodiment may be dissembled ..

:.: ,13 and reconfigured to create a different embossing pattern.

14 This detachable arrangement also allows convenient replacement or repair of damaged embossing elements, 16 without the need for welding and machining an embossing e.

17 die. .18 ..e

. 19 One application of the above-described apparatus is to .

the embossing of bituminous coating sheet or web 21 materials, of the type used for covering roofing 22 structures. The coating material typically comprises a 23 length of bituminous felt with an adhesive layer that is 24 activated by applying a gas burner or flow of heated gas during installation. A plastic film of, for example, 26 oriented polypropylene is provided over the adhesive 27 layer to prevent the material from adhering to itself or 28 to other surfaces. The underside of the material is 29 textured for various reasons, such as improving the heat transfer to the material by increasing surface area, 31 aiding removal of the plastic film during installation, 32 and pressure equalization.

1 The described apparatus can be used to form a wide range 2 of patterns in bituminous coating sheet or web materials.

3 In a preferred embodiment, the bituminous coating sheet 4 material is provided with an adhesive layer comprising bitumen, over which is formed a plastic film. A textured 6 pattern is then formed in the adhesive layer and plastic 7 film by simultaneously embossing the adhesive layer and 8 the plastic film.

By embossing the plastic film and adhesive layer 11 simultaneously, a coating material is formed that is 12 surprisingly easy to install. The embossing process .13 tensions, or partially tensions the plastic film at areas an..

....14 of discontinuity. When heated, the plastic film decomposes more effectively because of the tension in the 16 film. This increases the speed at which the coating 17 material may be applied to a roofing structure. 8 - -

:19 The tensioning effect of the tool can be enhanced by ë maximising discontinuities in the embossing surface. The 21 configurable nature of the apparatus allows the depth and 22 pattern of the embossing surface in order to adjust the 23 tension imparted to the plastic film. The tensioning 24 effects can therefore be optimised for the particular type of plastic film, film thickness, embossed material, 26 and/or conditions under which film removal will take 27 place.

29 Various modifications and improvements can be made to the described apparatus and methods within the scope of the 31 invention. In particular, the apparatus is not limited 32 to any particular shape, form or dimension of embossing 33 elements or embossing patterns.

2 The described embodiments include embossing elements of 3 thickness of 0.5mm, 0.9mm, and lmm, but it should be 4 appreciated that any thickness of embossing element could be used. However, the thickness of the embossing element 6 corresponds with the amount the embossing element extends 7 over the length of the assembly. There is a correlation 8 between the degree of flexibility of the apparatus and 9 the thickness of the embossing elements used, and as such embossing elements with a thickness of O.lmm to 3mm are 11 preferred.

:.:.13 In addition, the thickness and material of the embossing A..

.,..14 elements has consequences for the available techniques is for forming the shapes of the embossing elements. The 6 embossing elements are described as being made of sheet 17 stainless steel, and being formed by a laser cutting : 18 process, but it will be appreciated that other materials ...

. 19 and cutting techniques may be suitable. Indeed, the ë material chosen for the embossing elements will depend on 21 the characteristics of the material to be embossed.

23 Additional flexibility may be achieved by providing in 24 excess of eight detents, allowing additional rotational mounting positions for the embossing elements and offsets 26 of smaller increments. Alternatively, or in addition, 27 the embossing elements can be asymmetric, with 28 discontinuities located at unequal angular displacements 29 from the detents. The embossing elements can be "flipped" over (that is, placed on the elongate element 31 right-handed or left-handed) such that the 32 discontinuities to provide a mirror image and thus a 33 number of different angular positions for the 1 discontinuities. - -e A. A. ë .. : . ... ë -

Claims (1)

1 Claims 3 1. Embossing apparatus comprising an elongate assembly 4

defining an embossing surface, wherein the elongate assembly comprises a plurality of embossing elements 6 which partially define the embossing surface and are 7 adapted to enable attachment to the elongate 8 assembly.

2. Apparatus as claimed in Claim 1 wherein the 11 embossing elements are adapted to enable attachment 12 to and detachment from the elongate assembly. 13 I..

....14 3. Apparatus as claimed in Claim 1 wherein the elongate assembly defines a substantially cylindrical 16 embossing surface. ..

]8 4. Apparatus as claimed in any of Claims 1 to 3 wherein ...

I. 9 the assembly comprises an elongate core element, and ë the plurality of embossing elements are disposed 21 along the length of the elongate core element.

23 5. Apparatus as claimed in Claim 4 wherein each 24 embossing element has an internal aperture adapted to be received on the elongate core element.

27 6. Apparatus as claimed in Claim 4 or Claim 5 wherein 28 the assembly is provided with means for preventing 29 rotation of the embossing element relative to the elongate core element.

32 7. Apparatus as claimed in Claim 5 or Claim 6 wherein 33 the internal aperture has a substantially circular 1 cross-section provided with at least one detent for 2 engaging a corresponding part of the elongate core 3 element.

8. Apparatus as claimed in any of Claims 5 to 7 wherein 6 the internal aperture is provided with a plurality 7 of detents for engaging a corresponding part of the 8 outer surface of the elongate element.

9. Apparatus as claimed in Claim 8 wherein the internal 11 aperture is provided with a plurality of detents 12 disposed regularly around the internal aperture.

:.: ,13 14 10. Apparatus as claimed in Claim 9 wherein four detents are provided, the detents being disposed at angular 16 intervals of 90 degrees. ..

q8 11. Apparatus as claimed in Claim 9 wherein eight . ace. 19 detents are provided, disposed regularly at angular ë intervals of 45 degrees.

22 12. Apparatus as claimed in any of Claims 7 to 11 23 wherein the detents are rectangular recesses 24 extending outwardly from an edge defining the internal aperture.

27 13. Apparatus as claimed in any of Claims 7 to 12 28 wherein a detent engages directly with a formation 29 on the elongate core element.

31 14. Apparatus as claimed in any of Claims 7 to 12 32 wherein a detent engages with a formation on the 33 elongate core element via a locking member.

2 15. Apparatus as claimed in Claim 14 wherein the locking 3 member is a keyway received in a channel formed in 4 the elongate core element.

6 16. Apparatus as claimed in any preceding Claim wherein 7 at least some of the embossing elements are circular 8 in cross-section.

17. Apparatus as claimed in any preceding Claim wherein 11 at least some of the embossing elements are 12 substantially circular in cross-section with one or .

.13 more discontinuities disposed on an outer edge. ë ..14

18. Apparatus as claimed in any preceding Claim wherein i6 the internal aperture of one or more embossing ..

17 elements is concentric with the elongate core 18 element. . 9 ë

19. Apparatus as claimed in any preceding Claim wherein 21 the internal aperture of one or more embossing 22 elements is eccentric with the elongate core 23 element.

20. Apparatus as claimed in any preceding Claim wherein 26 the assembly comprises a plurality of identical 27 embossing elements.

29 21. Apparatus as claimed in Claim 20 wherein at least some of the identical embossing elements are 31 arranged on the assembly such that they are 32 rotationally displaced with respect to one another.

1 22. Apparatus as claimed in any preceding Claim wherein 2 the assembly comprises a plurality of sets of 3 embossing elements, each set of embossing elements 4 having a distinct shape.

6 23. Apparatus as claimed in any preceding Claim wherein 7 the embossing elements are arranged in a repeating 8 pattern along the length of the elongate core 9 element.

11 24. Apparatus as claimed in Claim 23 wherein the 12 embossing elements are arranged in a repeating .

:.:.13 pattern of identical embossing elements rotated with A. ., 14 respect to one another.

\6 25. Apparatus as claimed in Claim 23 wherein the .

17 embossing elements are arranged in a repeating 18 pattern of embossing elements of distinct shape. --e I. 19 .

26. Apparatus as claimed in Claim 23 wherein the 21 embossing elements are arranged in a repeating 22 pattern of identical embossing elements rotated with 23 respect to one another in combination with embossing 24 elements of distinct shape.

26 27. Apparatus as claimed in any preceding Claim wherein 27 the embossing elements are discs.

29 28. Apparatus as claimed in any preceding Claim wherein the embossing elements comprise steel.

1 29. Apparatus as claimed in any preceding Claim wherein 2 the embossing elements are formed by a laser cutting 3 process.

30. An embossing element for an embossing apparatus 6 having an elongate assembly defining an embossing 7 surface, wherein the embossing element partially 8 defines an embossing surface of the elongate 9 assembly, and is adapted to enable attachment to the elongate assembly.

12 31. The embossing element as claimed in Claim 30 wherein 13 the embossing element is adapted to enable . 14 detachment from the elongate assembly. :5

6 32. The embossing element as claimed in Claim 30 or 17 Claim 31 wherein the embossing element is a disc. : 8 .e

. 9 33. The embossing element as claimed in any of Claims 30 to 32 wherein the embossing element comprises steel.

22 34. The embossing element as claimed in any of Claims 30 23 to 33 formed by a laser cutting process.

35. The embossing element as claimed in any of Claims 30 26 to 34 further comprising an internal aperture 27 adapted to be received on an elongate core element 28 of the elongate assembly.

36. The embossing element as claimed in Claim 35 31 further comprising means for preventing rotation of 32 the embossing element relative to the elongate core 33 element.

2 37. The embossing element as claimed in Claim 35 or 3 Claim 36 wherein the internal aperture has a 4 substantially circular cross-section provided with at least one detent for engaging a corresponding 6 part of the elongate core element.

8 38. A method of configuring an embossing apparatus 9 having an elongate assembly defining an embossing surface, the method comprising the step of attaching 11 a plurality of embossing elements to the elongate 12 assembly, the embossing elements partially defining

-

613 the embossing surface. - 14

I. 15 39. The method as claimed in Claim 38 wherein the .

16 plurality of embossing elements are removably 17 attached to the elongate assembly. .

..19 40. The method as claimed in Claim 38 or Claim 39 comprising the additional step of axially 21 compressing the embossing elements on the elongate 22 assembly and securing the elongate elements in a 23 state of compression.

41. A method of embossing a sheet material using 26 apparatus according to any of Claims 1 to 37.

28 42. A method of forming a bituminous sheet coating 29 material comprising the steps of providing an adhesive layer, providing a plastic film over the 31 adhesive layer, and forming an embossed pattern in 32 the adhesive layer by embossing the plastic film and 33 the adhesive layer simultaneously, wherein the step 1 of embossing utilises the apparatus of any of Claims 2 1 to 37.

4 43. An embossed material made by the method of any of Claims 38 to 40.

7 44. An embossed bituminous coating sheet material made 8 by the method of claim 42.

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