Patent Publication Number: US-2004058129-A1

Title: Patterned polymer articles

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001] This application claims priority to Great Britain Application Nos. GB 0216373.1, filed Jul. 13, 2002 and GB 0315433.3, filed Jul. 2, 2003.  
       FIELD  
       [0002] This invention concerns improvements in or relating to polymer articles. More especially, the invention relates to polymeric foam articles and a method of manufacturing polymeric foam articles with a surface pattern applied to an area of the article. The invention has particular, but not exclusive, application to such foam articles for use as masking materials when painting a vehicle.  
       SUMMARY  
       [0003] According to a first aspect of the present invention there is provided a polymer article provided with a surface pattern applied to an area of the article that has been formed to a desired shape by deforming the area under pressure so that, when the pressure is removed, the desired shape is produced in the deformed area.  
       [0004] The shaping process may be applied to an open or closed cell polymer material to compress and fuse the cells together. The shaping process may result in complete or partial compression and fusing of the cells together. The shaping process may result in the compression and fusing of the cells being permanent so as to retain and maintain the desired shape of the article. Alternatively, the compression and fusing of the cells may be semi-permanent so that the desired shape of the article is retained and maintained for a period of time after which the article reverts to its original or substantially original shape. For example, we may use a semi-permanent shape to indicate the useable life of an article.  
       [0005] Depending on the material of the article and the pressure applied, the deformation of the material may be sufficient to cause the material to retain the desired shape without any additional energy input during the shaping process. In some case, however, the shaping process may be enhanced by providing an additional input of energy to assist in retaining the desired shape of the article when the pressure is removed. This may be achieved in a variety of ways. For example by increasing the pressure applied to deform the material, or by the application of heat to the material or by other means such as electromagnetic radiation or ultrasonics.  
       [0006] The surface pattern may be functional to provide the article with desired properties or decorative to enhance the aesthetics of the article or a combination of both.  
       [0007] In one embodiment, the surface pattern may modify the physical properties of the area to which it is applied. For example, the surface pattern may include formations such as ribs arranged to provide stress relief or alter the stiffness, strength or flexibility of the shaped area.  
       [0008] In another embodiment, the surface pattern may provide or include a visual display of information. For example the information may be in the form of indicia such as letters, numerals, symbols or pictures applied to the shaped area. Such information may identify the article and/or the manufacturer providing the end user with information identifying genuine articles. Alternatively or additionally, the information may provide instructions for use of the article.  
       [0009] Advantageously, the surface pattern is applied during the shaping process. For example, formers such as shaping dies and/or cutting blades may be provided with a contact surface adapted to provide the desired surface pattern in the compressed polymeric material. By applying the surface pattern in this way, the pattern cannot be easily removed, defaced or altered without such changes being visibly obvious. Alternatively, the surface pattern may be applied before or after the shaping process, for example by laser cutting or other suitable forming/shaping technique.  
       [0010] The surface pattern may be provided on one or both sides of the shaped area. Where the surface pattern is applied to one side during the shaping process, the reverse of the surface pattern is formed on the opposite side. Thus, we may shape an area of the article in the nip between a pair of rollers having a surface pattern applied to the surface of one or both rollers, for example etched in the surface of the roller.  
       [0011] We may apply a surface pattern to each side during the shaping process and offset the patterns so that the reverse pattern does not interfere with the pattern applied to the opposite side. Alternatively, we may apply surface patterns to both sides so that the reverse pattern overlaps with the pattern applied to the opposite side.  
       [0012] Where we apply surface patterns to both sides that are offset so as not to interfere with each other, the patterns may be the same or different and may be offset in the longitudinal direction of the article. For example we may apply a decorative pattern to one side and information to the other side.  
       [0013] Where we apply surface patterns to both sides that overlap, the patterns may co-operate to produce a combined surface pattern on both sides that may be decorative and/or provide information.  
       [0014] Where the surface pattern is applied separately from the shaping process, for example by laser cutting, the pattern may be applied to one side only. Alternatively, patterns may be applied to both sides. The patterns so formed may be the same or different and may be aligned or offset.  
       [0015] The surface pattern may have the same surface finish, for example colour, texture, as the adjacent polymeric material. Alternatively, the surface pattern may have a different surface finish. For example, the surface pattern may be of a contrasting colour or texture. In this way, the visibility of the surface pattern can be enhanced. This may be especially useful where the surface pattern is employed to provide information to the end user.  
       [0016] In one arrangement, the part of the contact surface forming the surface pattern may be provided with colouring material that is transferred to the polymer material where the surface pattern is formed. Alternatively or additionally, it may be provided with a different surface finish (texture) that is imparted to the polymer material where the surface pattern is formed.  
       [0017] Preferably, the article is made of polymeric foam material, for example an open or closed cell polymeric foam that is resiliently compressible and can be formed to a desired shape under pressure. Foams having a density in the range of from 20 to 30 Kg.m 3  are typically found to be suitable and include polyurethane, polyolefin, polyester or like foam materials.  
       [0018] In one embodiment, the shaped area is of reduced thickness relative to an adjacent area of the article. Where the article is in the form of an elongate strip for use as a masking material, the shaped area may extend along the length of the strip and may be continuous or discontinuous.  
       [0019] The shaped area may provide the article with desired properties for the intended application of the article. Thus, the shaped area may form a hinge portion extending along the length of an elongate strip to be used as a masking material such that an adjacent portion of the strip can hinge relative to the shaped area.  
       [0020] Alternatively or additionally, the shaped area may provide a tab by means of which the article can be gripped to assist handling the article in use. Where the article is in the form of an elongate strip for use as a masking material, the tab may be continuous along the length of the strip or a series of tabs may be provided spaced apart along the length of the strip.  
       [0021] The shaped area may include a seam formed by completely compressing and fusing the cells together. The seam may be continuous or discontinuous along the length of the article. The seam provides a line of weakness that may be of linear, curved or other suitable configuration to allow adjoining areas either side of the seam to be separated along the seam. For example, two or more articles may be formed together and releasably secured to each other by a seam allowing the articles to be separated from each other. Alternatively, where a tab is provided this may be connected to the article by a seam allowing the tab to removed after the article has been secured in place.  
       [0022] The polymer material may be a natural or synthetic polymer. Synthetic polymers may include polyesters, polyurethanes and polyolefins. Natural polymers may include polyoses such as cellulose. Preferred polymer materials are foams but other materials including elastomers, thermoplastics and non-woven materials capable of being shaped under pressure may be used. The polymer material may be a combination of two or more polymer materials.  
       [0023] According to a second aspect of the present invention, there is provided a method of marking an article of polymer material comprising shaping an area of the article by applying pressure to the polymer material and applying a surface pattern to the shaped area.  
       [0024] Preferably, the surface pattern is formed during the shaping process to compress the polymer material. The surface pattern may be inset below the adjacent surface of the shaped area. Alternatively, the surface pattern is raised above the adjacent surface of the shaped area. For example a shaping die forming the shaped area may be provided with a contact surface in which the surface pattern is raised above or inset below the contact surface.  
       [0025] According to a third aspect of the present invention, there is provided apparatus for manufacturing an article of polymer material comprising means for compressing a portion of the article to form an area of reduced thickness, and means for applying a surface pattern to the area so formed.  
       [0026] The compression means may comprise a former such as a shaping die or blade having a contact surface for forming the area of reduced thickness by compressing the polymer material. The surface pattern applying means may comprise a portion of the contact surface in which the surface pattern is provided. In this way, the surface pattern is formed as an integral part of the compressed area.  
       [0027] According to a fourth aspect of the invention, there is provided an elongate foam strip for use as a masking material to mask a gap between two relatively movable parts, the foam strip having an adhesive stripe for releasably securing the foam strip to one of the parts to close temporarily the gap, and a surface pattern provided in an area that has been formed to a desired shape under pressure.  
       [0028] These and other features, benefits and advantages of the invention will be more fully understood from the description hereinafter of exemplary embodiments of articles according to the invention and methods and apparatus for making such articles. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0029]FIG. 1 shows a diagrammatic cross-section of a foam article for use as a masking material disclosed in our co-pending UK patent application No.0216373.1;  
     [0030]FIG. 2 shows a method and apparatus for making the foam article shown in FIG. 1;  
     [0031]FIG. 3 shows an adhesive delivery system for use with the method and apparatus of FIG. 2;  
     [0032]FIG. 4 shows application of the foam article of FIG. 1 as a masking material for masking a gap between two parts of a vehicle;  
     [0033] FIGS.  5  to  14  show alternative patterned contact surfaces for applying surface patterns to the connecting web of the foam article shown in FIG. 1 using the method and apparatus of FIG. 2, wherein the contact surfaces in FIGS.  8  to  14  are of enlarged scale compared to the contact surfaces in FIGS.  5  to  7 ;  
     [0034]FIG. 15 shows a diagrammatic perspective view of another foam article for use as a masking material according to the present invention;  
     [0035]FIG. 16 is a section on the line  16 - 16  of FIG. 15;  
     [0036]FIG. 17 is a section on the line  17 - 17  of FIG. 15;  
     [0037]FIG. 18 shows a diagrammatic perspective view of yet another foam article for use as a masking material according to the present invention;  
     [0038]FIG. 19 is an end view of the foam article shown in FIG. 18;  
     [0039]FIG. 20 is an end view of the foam article shown in FIG. 18 with the cord and tab separated;  
     [0040]FIG. 21 shows a diagrammatic perspective view of a still further foam article for use as a masking material according to the present invention;  
     [0041]FIG. 22 is a section on the line  22 - 22  of FIG. 21;  
     [0042]FIG. 23 is a section on the line  23 - 23  of FIG. 21;  
     [0043]FIG. 24 shows a diagrammatic perspective view of a foam article for use as a packing material according to the present invention;  
     [0044]FIG. 25 is a section on the line  25 - 25  of FIG. 24;  
     [0045]FIG. 26 is a section on the line  26 - 26  of FIG. 24; and  
     [0046]FIG. 27 shows a diagrammatic perspective view of a foam article for use as adhesive backed tape according to the present invention. 
    
    
     DETAILED DESCRIPTION  
     [0047] There is shown in FIGS.  1  to  3  a foam article  10  and apparatus for making the foam article  10  as disclosed in our co-pending UK patent application No.0216373.1. The article  10  is for use as a masking material between two parts of a vehicle when the vehicle is spray painted as shown in FIG. 4.  
     [0048] As shown in FIG. 1, the foam article  10  comprises an elongate foam strip  11  having two lobes  12 ,  13  of elliptical cross-section connected by an integral web  14 . Each lobe  12 ,  13  has a major axis transverse to the length of the foam strip  11  and the connecting web  14  is aligned with the major axis of each lobe  12 ,  13 .  
     [0049] In this embodiment the lobes  12 ,  13  are of different cross-section and the thickness of the web  14  transverse to the length of the foam strip  11  is less than the thickness of both lobes  12 ,  13  transverse to the length of the foam strip  11 . It will be understood, however, that this is not essential and that the lobes  12 ,  13  and connecting web  14  can be of different shapes as disclosed in our aforementioned co-pending UK patent application.  
     [0050] Suitable dimensions for the foam article  10  are given in Table 1 for masking gaps of varying size and shape commonly found in automotive vehicles, especially cars, in different locations, for example between a front or rear door, or hood or trunk or tailgate and the adjacent vehicle body.  
                                   TABLE 1                       A   B   C   C’   D   E       (Thickness)   (Width)   (Width)   (Thickness)   (Width)   (Thickness)                  4.5 mm   4.5 mm   3.5 mm   1 mm   13.5 mm   12 mm                  
 
     [0051] It will be understood these dimensions are given by way of non-limiting example only and any dimension may be altered according to the particular requirement for any given application of the foam strip  11 .  
     [0052] The foam strip  11  may be made from any suitable polymeric foam material. Preferred foam materials are polyesters or polyurethanes or polyolefins but it will be appreciated that other foam materials may be used as will be familiar to those skilled in the art.  
     [0053] In this embodiment, the foam strip  11  is a polyester or polyurethane foam. A suitable foam is available from Caligen Foam Limited under the trade designation “X4200AM” although it will be understood that other foam materials may be used.  
     [0054] The foam strip  11  is provided with a longitudinally extending adhesive stripe  15  on one side of the web  14  by means of which the foam strip  11  can be releasably secured in position. In other embodiments (not shown), the adhesive stripe may extend onto part or all of the lobe  13 . The adhesive stripe  15  may be a pressure sensitive adhesive such as a hot melt rubber adhesive applied by any suitable means, for example die coating.  
     [0055] In this embodiment, the adhesive stripe  15  is applied across the full width of the web  14  but it will be appreciated that this is not essential and the adhesive stripe  15  may be applied across part of the width of the web  14 . The adhesive stripe  15  may also be continuous or discontinuous in the longitudinal direction provided that the foam strip  11  is effectively anchored in position to permit the lobes  12 , 13  to move independently without motion of one lobe causing motion of the other lobe.  
     [0056] The method and apparatus for forming the foam article  10  of FIG. 1 will now be described with reference to FIGS. 2 and 3 starting from a flat sheet  16  of foam.  
     [0057] As shown in FIG. 2, the foam sheet  16  is provided with a plurality of uniformly spaced, parallel, seams  18  extending longitudinally of the foam sheet  16  by the application of pressure via a plurality of laterally spaced blades  17 . The blades  17  have blunt ends approximately 0.5 mm wide that compress the foam so that the upper and lower surfaces fuse together along the seams  18  and prevent the foam returning to its original shape on removal of the pressure.  
     [0058] The foam sheet  16  is also compressed between the seams  18  to form the webs  14  by the application of pressure via a plurality of flat blades  19 . One blade  19  is provided between each pair of blades  17  and is offset towards one of the blades  17 . The ends of the blades  19  are wider than the blades  17  and they only partially compress an area of the foam sheet  16  between the seams  18  so that the foam material is prevented from returning to its original shape on removal of the pressure.  
     [0059] In this way, the desired shape of the foam article  10  having two elliptical lobes  12 ,  13  of different transverse cross-section connected by the flat web  14  is produced. The foam sheet  16  is separable along the seams  18  to form individual foam strips  11 .  
     [0060] The stripe  15  of pressure sensitive adhesive can be applied to the web  14  before or after separating the foam strips  11  along the seams  18  by a suitable adhesive delivery system such as that shown diagrammatically in FIG. 3. The system comprises a plurality of separate, individual dies  20  positioned above the connecting webs  14  of the foam strips  11 . The dies  20  are supplied with adhesive from a remote source (not shown) via separate flow channels  21  and apply the adhesive stripes  15  to the connecting webs  14  of the foam strips  11 .  
     [0061] The foam strips  11  can be stored and supplied in rolls of pre-determined length wound on itself or a core (not shown) from which the end user can unwind and separate a required length. More than one foam strip  11  may be wound on a common core either separately or joined together by the seams  18  and manually separated by the end user when unwinding a desired length of the foam strip  11 .  
     [0062] As will be appreciated, the relative size of the lobes  12 ,  13  is determined by the offset of the flat blades  19  between the blades  17  and can be varied to provide any desired shape of foam article  10 . The spacing of the lobes  12 ,  13  can also be altered by changing the width of the flat blades  19 .  
     [0063] In the above method, the foam sheet  16  is compressed by the blades  17 ,  19  while the foam sheet  16  is stationary and the foam sheet  16  is formed to the required shape in a series of steps by advancing the sheet  16  between forming operations to present a new area of the sheet  16  to be shaped. In another method (not shown), the blades  17 ,  19  are replaced by rotatable discs and the foam sheet  16  is formed to the required shape in a continuous manner by feeding the sheet  16  past the discs.  
     [0064] Referring now to FIG. 4, the foam strip  11  is shown masking the gap  3  between the door  1  and post  2  of a vehicle when the vehicle is spray painted. The foam strip  111  is secured to the base face of the post  2  by means of the adhesive stripe  15  so that an adhesive free surface of the smaller lobe  12  contacts the side face of the post  2  at point Y.  
     [0065] The larger lobe  13  is folded upwards by contact with the base face of the post  2  so that an adhesive free surface of the lobe  13  contacts the inside face of the door  1  at point X when the door  1  is closed. In this way, the gap  3  is closed to prevent paint passing through the gap  3  when the vehicle is spray painted.  
     [0066] As will be understood, the web  14  permits the lobes  12 ,  13  to move independently of each other so that forces applied to the lobe  13  by the door  1  are not transferred to the lobe  12 .  
     [0067] In this way, the adhesive free contact between the lobe  12  and the side face of the post  2  is unaffected by compression of the lobe  13  and the adhesive stripe  15  is concealed preventing formation of a hard edge when the vehicle is spray painted.  
     [0068] Furthermore, the foam strip  11  can adapt to close gaps  3  of different size and/or shape by hinging movement of the lobe  13  about the web  14  and this movement does not cause the position of the lobe  12  to change.  
     [0069] Accordingly, there is no tendency for the lobe  12  to lift off the side face of the post  2  to expose the adhesive stripe  15  when the door  1  is closed.  
     [0070] In this way, a soft edge is formed at the interface between the unmasked surface of the post  2  and the adhesive free surface extending lengthwise of the strip where the edge of the lobe  12  contacts the side face of the post  2  at point Y.  
     [0071] A soft edge is also formed at the interface between the unmasked surface of the door  1  and the adhesive free surface extending lengthwise of the strip where the edge of the lobe  13  contacts the inner face of the door  1  at point X.  
     [0072] As will be understood, the function of filling the gap  3  to prevent paint passing through the gap  3  is performed by engagement of the lobes  12 ,  13  with faces of the post  2  and door  1 .  
     [0073] Moreover, the foam strip  11  can adapt to fill gaps  3  of different size and shape independently of the edge forming function performed by each lobe  12 ,  13  where it contacts the face of the post  2  and door  1 .  
     [0074] As a result, soft edges can be formed between painted and masked areas on both the post  2  and door  1 .  
     [0075] In this embodiment, the lobe  12  provides an adhesive free region that extend lengthwise of the strip on one side of the adhesive stripe  15  and has a transverse width of 4.5 mm (Table 1).  
     [0076] We have found that the adhesive free region can be of narrower width without exposing the adhesive stripe  15  and, in general, a width of 2 mm may be sufficient to maintain contact between an adhesive free surface of the lobe  12  and the part to which the strip is anchored by the adhesive strip.  
     [0077] The connecting web  14  may have a flat surface formed by compressing the foam material with blades  19  having a smooth contact surface. More preferably, in accordance with the present invention, the connecting web  14  has a surface pattern formed by compressing the foam material with blades having a patterned contact surface. In this way, the surface pattern applied to the connecting web  14  is formed integrally from the foam material during the shaping process. As a result, the surface pattern cannot be removed or altered without defacing the article so as to be readily apparent to a user of the article.  
     [0078] The surface pattern may be decorative. For example, the surface pattern may provide the connecting web  14  with a visually distinctive appearance so as to enhance the aesthetics of the article  11 . Alternatively or additionally, the surface pattern may be functional. For example, the surface pattern may modify the physical properties or characteristics of the connecting web  14  to adapt the article  11  for a particular application. Alternatively, the surface pattern may provide a visual indication of information identifying the article or its source or its use. For example the surface pattern may comprise indicia applied to the connecting web  14 . The indicia may be letters, numerals, symbols or pictures in the form of text or graphics.  
     [0079] The surface pattern may be inset (recessed) into the surface of the connecting web  14  by providing a raised (elevated) pattern on the contact surface of the blades  19 . Alternatively, the surface pattern may be raised (elevated) above the surface of the connecting web  14  by providing an inset (recessed) pattern in the contact surface of the blades  19 .  
     [0080] The contact surface of the blades  19  may be provided with colouring material that is transferred to the foam of the connecting web  14  so that the surface pattern on the web  14  has a contrasting colour to that of the remainder of the web  14 . In this way, the visual appearance of the surface pattern is enhanced.  
     [0081] Alternatively or additionally, the visual appearance of the surface pattern may be enhanced by providing the contact surface of the blades  19  that forms the surface pattern with a different surface finish such that the resulting surface pattern has a different surface finish, for example texture, relative to the surface finish of the adjacent surface of the web  14 .  
     [0082] Referring now to FIGS.  5  to  14 , these show examples of the contact surfaces of blades  19  that can be employed to apply a surface pattern having a decorative and/or functional nature to the connecting web  14 .  
     [0083]FIG. 5 shows a blade  19  having a contact surface  19   a  with an array of recessed notches  23  that form a plurality of raised parallel ribs extending in the longitudinal direction of the foam strip  11  that increase bending of the web  14  in this direction.  
     [0084]FIG. 6 shows a blade  19  having a contact surface  19   b  with an array of recessed notches  24  that form a plurality of raised parallel ribs extending transversely to the longitudinal direction of the foam strip  11  that increase stiffness of the web  14  against bending in this direction.  
     [0085]FIG. 7 shows a blade  19  having a contact surface  19   c  with an array of recessed notches  25  that form a plurality of raised parallel ribs extending at an angle of between 0° and 90° to the longitudinal direction of the foam strip  11  that modify the bending and stiffness properties of the connecting web  14 .  
     [0086]FIG. 8 shows a blade  19  having a contact surface  19   d  with an array of recessed notches  26  that form a plurality of raised chevrons that extend in the longitudinal direction of the foam strip  11  that modify the bending and stiffness properties of the connecting web  14 .  
     [0087]FIG. 9 shows a blade  19  having a contact surface  19   e  with an array of recessed notches  27  that form a plurality of raised wavy ribs extending in the longitudinal direction of the foam strip  11  that modify the bending and stiffness properties of the connecting web  14 .  
     [0088]FIG. 10 shows a blade  19  having a contact surface  19   f  with an array of recessed notches  28  that form a plurality of raised wavy ribs extending transversely to the longitudinal direction of the foam strip.  11  that modify the bending and stiffness properties of the connecting web  14 .  
     [0089] As will be appreciated, each of the contact surfaces  19   a  to  19   f  provide the connecting web  14  with a surface pattern that modifies the physical properties of the web  14  i.e. is functional and that can also provide the connecting web  14  with an aesthetically pleasing appearance i.e. is decorative.  
     [0090] The blades  19  may be arranged so that the surface pattern provided by each of the contact surfaces  19   a  to  19   f  is substantially continuous in the longitudinal direction of the strip  11 . Alternatively, the blades  19  may have contact surfaces  19   a  to  19   f  arranged so that the surface pattern is discontinuous in the longitudinal direction with breaks or gaps in the surface pattern in the longitudinal direction being provided at regular or irregular intervals. The breaks or gaps may be provided with an alternative form of marking as described below.  
     [0091] It will also be understood that the surface patterns produced by the contact surfaces  19   a  to  19   f  are exemplary only of the invention and that blades  19  having other shapes and configurations of recessed notches in the contact surface may be employed to provide any desired surface pattern on the connecting web  14 . For example, FIG. 11 shows a blade  19  with a contact surface  19   g  having an array of recessed notches  29  that form a decorative surface pattern of raised circular ribs that is repeated in the longitudinal direction of the foam strip  11 .  
     [0092] Referring now to FIGS.  12  to  14 , these show examples of the contact surfaces of blades  19  that can be employed to apply a surface pattern to the connecting web  14  in the form of indicia so as to provide the user with information relating to the article. For example to identify the article or its source or its use.  
     [0093]FIG. 12 shows a blade  19  having a contact surface  19   h  provided with recessed notches  30 ,  31  that form the raised numeral “3” and the raised letter “M” arranged to apply the marking “3M” to the connecting web  14  to identify the manufacturer of the strip  11 .  
     [0094] The marking “3M” is repeated at spaced intervals in the longitudinal direction of the strip  11  and the surface area of the connecting web  14  between such markings may be plain or provided with a surface pattern such as any of the patterns shown in FIGS.  5  to  11 . FIG. 13 shows a blade  19  having a contact surface  19   i  combining the recessed notches  24  of FIG. 6 with the recessed notches  30 , 31  shown in FIG. 12 to provide the connecting web with the marking “3M” alternating with transverse ribs in the longitudinal direction of the foam strip.  
     [0095] It will be understood that any combination of letters and/or numbers may be employed to identify the article, for example a product code and/or the source, for example manufacturer. It will also be understood that the marking may consist of letters and/or numbers arranged to provide instructions for the use of the article.  
     [0096]FIG. 14 shows a blade  19  having a contact surface  19   j  provided with recessed notches  32  that form a symbol or picture on the connecting web  14  that is repeated at spaced intervals in the longitudinal direction of the strip  11 . Again the symbol or picture may be combined with any of the other forms of surface pattern described herein.  
     [0097] Each of the contact surfaces  19   a  to  19   j  of the blades  19  shown in FIGS.  5  to  14  applies a surface pattern to one side of the compressed area and the reverse of the surface pattern is formed simultaneously on the opposite side. We may arrange for surface patterns to be applied to both sides of the compressed area and to offset the surface patterns so that the reverse patterns so formed do not interfere with the surface patterns. This may be desirable where the surface pattern includes information in the form of letters and/or numerals. Offset surface patterns applied to both sides of the compressed area may be the same or different.  
     [0098] In another embodiment (not shown), we may arrange for surface patterns applied to both sides of the compressed area to overlap so that the patterns co-operate to produce a desired combined pattern on both sides.  
     [0099] Referring now to FIGS.  15  to  17  there is a second embodiment of a foam article  100  according to the present invention.  
     [0100] The foam article  100  comprises two elongate cords  101 , 101 ′ of generally circular cross-section joined together by a series of compressed areas  102  of approximately diamond shape. The compressed areas  102  are arranged so that adjacent areas  102  in the longitudinal direction contact each other at the apices  102   a ,  102   b . As shown, each of the compressed areas  102  is provided with marking “3M” to identify the manufacturer of the article  100 . It will be understood that the compressed areas  102  may be provided with any other form of surface marking as described previously.  
     [0101] The article  100  may be produced by compressing a flat sheet of foam with a rotating blade (not shown) having a peripheral surface formed with diamond shaped formations joined at the apices in the circumferential direction with recesses corresponding to the indicia to be applied to the article  100  provided in the diamond shaped formations.  
     [0102] The article  100  may be provided with a seam  103  (shown in outline in FIG. 15) by means of which the cords  101 ,  101 ′ may be separated so that the compressed areas  102  are split in half and form a respective series of triangular shaped compressed areas  102 ,  102 ′ in the longitudinal direction of each cord  101 ,  101 ′. Alternatively, the cords  101 ,  101 ′ may be separated with scissors.  
     [0103] The cords  101 ,  101 ′ may be used as masking materials to mask a gap between two parts of a vehicle when the vehicle is being spray painted. The cords  101 ,  101 ′ are secured in place by means of a longitudinal adhesive strip (not shown) applied to each cord  101 ,  101 ′ and the compressed areas  102 ,  102 ′ provide tabs for the user to hold the cords  101 ,  101 ′ to assist positioning and securing the cords  101 ,  101 ′ accurately.  
     [0104] With reference now to FIGS.  18  to  20 , there is shown a third embodiment of a foam article  200  according to the present invention.  
     [0105] The foam article  200  comprises a cord  201  of generally circular cross-section for use as a masking material to mask a gap between two parts of a vehicle when the vehicle is being spray painted. The cord  201  is provided with a longitudinal flange  202  formed by compressing the foam material and with a longitudinal adhesive stripe (not shown) for securing the cord  201  in use. The flange  202  provides a tab to assist the user position and secure the cord  201  in use and is connected to the cord  201  by a seam  203  so as to be separable from the cord  201  when the cord  201  is secured in position (FIG. 20). Alternatively, the flange  202  may be left in place to assist masking the gap.  
     [0106] As shown, the flange  202  is provided with a series of markings “3M” spaced apart along the length of the cord  201  to identify the manufacturer of the article  200 . It will be understood that the compressed areas  202  may be provided with any other form of surface pattern as described previously.  
     [0107] Referring now to FIGS.  21  to  23  there is shown a fourth embodiment of a foam article  300  according to the present invention.  
     [0108] The foam article  300  comprises two elongate cords  301 , 301 ′ of generally circular cross-section joined together by a series of compressed areas or webs  302 . The compressed areas  302  are spaced apart in the longitudinal direction by cut out areas  303  formed during the shaping process. As shown, each of the compressed areas  302  is provided with marking “3M” to identify the manufacturer of the article  300 . It will be understood that the compressed areas  302  may be provided with any other form of surface marking as described previously.  
     [0109] The article  300  may be produced by compressing a flat sheet of foam with a rotating blade (not shown) having a peripheral surface shaped to form the compressed areas  302  and cut-out areas  303 .  
     [0110] The cords  301 ,  301 ′ may be separated by cutting through the compressed areas  302  to leave each cord  301 ,  301 ′ with a series of tabs that can be used to assist positioning the cords  301 ,  301 ′ when used as masking materials to mask a gap between two parts of a vehicle during spray painting as described previously. For such application the cords  301 ,  301 ′ are provided with a longitudinal adhesive stripe (not shown) to secure the cords  301 ,  301 ′ in position.  
     [0111] As will now be appreciated, the present invention provides articles of compressible polymer material with a surface pattern applied to an area of the material that has been shaped under pressure so as to retain a desired shape when the pressure is removed. The pattern can be decorative and/or functional and may be formed simultaneously with the shaping process by appropriate construction of the contact surface of the former employed to compress the polymer material.  
     [0112] Alternatively, the pattern may be applied to the area in a separate operation, for example by laser cutting or any suitable technique before or after the shaping operation. A separate forming operation may be used to apply the surface pattern to one or both sides of the shaped area. Where the pattern is applied to one side, the other side may be plain. Where the pattern is applied to both sides, the patterns may be the same or different and may be aligned or offset.  
     [0113] Although the invention has been described with particular reference to articles made of polymeric foam suitable for use as masking materials when spray painting a vehicle, it will be understood that the invention is not limited to such application and that the invention can be applied to other articles made of polymeric foam that can be shaped under pressure so as to retain a desired shape when the pressure is removed.  
     [0114] For example, with reference to FIGS.  24  to  26 , there is shown application of the invention to an article  400  suitable for use as packaging for eggs or similar fragile items (not shown). As shown a sheet of foam is compressed to provide a plurality of areas  401  of generally star shape aligned in two mutually perpendicular directions to produce a convoluted surface in which each compressed area  401  forms a recess or pocket  402  in the foam sheet to receive an egg.  
     [0115] The areas  401  are produced by compressing the foam sheet with formers (not shown) having contact surfaces corresponding to the star shape of the areas  401 . In this embodiment, the contact surfaces are formed with recessed notches that provide the areas with a surface pattern in the form of raised parallel ribs  403 . It will be understood, however, that the areas  401  can be provided with any other surface pattern of decorative and/or functional nature as described herein. The article  400  is also suitable for other uses such as a sound proofing or sound deadening material in a variety of applications.  
     [0116] Referring now to FIG. 27, there is shown application of the invention to an article  500  comprising a foam backed pressure sensitive adhesive tape  501  provided along one side edge with a flange  502  to which a surface pattern comprising the marking “3M” is applied as previously described herein. The flange  502  is formed by compressing an area of foam so as to retain the desired shape of the flange  502  when the pressure is removed. It will be understood that any other surface pattern of a decorative and/or functional nature as described herein may be applied to the flange  502 . The flange  502  may be attached via a seam that allows the flange  502  to be separated from the tape  501  if desired.  
     [0117] In the above-described embodiments, an area of the article is deformed under pressure so as to retain a desired shape when the pressure applied to the area is removed. Depending on the material of the article and the pressure applied, the deformation of the material may be sufficient to cause the material to retain the desired shape without any additional energy input. For example, the applied pressure to deform the material may set the material and prevent it returning to its original shape. In some case, however, it may be desirable or necessary to provide an additional input of energy to assist in retaining the desired shape of the article when the pressure is removed. This may be achieved in a variety of ways to enhance or optimise the shaping process. For example by applying a higher pressure to the material than is required to deform it, or by the application of heat to the material or by other means such as electromagnetic radiation or ultrasonics. Heat may be applied by changing the ambient temperature or by heating the formers used to shape the material or in any other suitable manner. Any one or more of these means for inputting additional energy may be employed separately or in combination.  
     [0118] It will be understood that the above-described examples are intended to illustrate the diverse range and application of the invention and that features of the embodiments may be used separately or in combination with any other feature of the same or different embodiments to produce an article with a surface pattern applied to an area of the article that has been compressed so as to retain a desired shape when the pressure is removed.  
     [0119] Thus, it will be appreciated that the invention has general application to any article made of compressible polymer material, especially foam articles, to which a decorative and/or functional surface pattern may be applied to a compressed area for any desired purpose. For example, the invention may be applied to headliners for cars, carpet underlay and other articles to which a surface pattern can be usefully applied.  
     [0120] Moreover, while the specific materials and/or configuration of the articles described and illustrated are believed to represent the best means currently known to the applicant for producing articles having a surface pattern applied to an area that has been compressed so as to retain a desired shape when the pressure is removed, it will be appreciated that the invention is not limited thereto and that various modifications and improvements can be made within the spirit and scope of the claims.