Abstract: A wood grain finish to a pultruded part is obtained by applying to a surface of the part before entering the die a strip carrying male projections shaped in differential depths and spacing across the width of the part to form a simulated wood grain pattern. The strip is then removed after the part is set leaving recesses in the outside surface which provide a simulated wood grain finish which can be differentially stained.

Abstract: An embossed metal foil laminate is prepared by laminating a metal foil to a paper web, utilizing an extrusion coated resin interlayer therebetween, by passing the layered structure between a nip roll and an engraved chill roll. The metal foil quickly conducts heat energy from the molten resin layer to the chill roll, allowing the process to be run at a high speed. The engraved chill roll impresses a pattern into the metal foil during the lamination operation.

Abstract: A method for making an absorbent article having a transverse partition including the following steps: a) providing a first web of barrier leg cuff material having a generally uniform width in a machine direction; b) providing a second webs of barrier leg cuff material in a machine direction generally parallel to the first web of barrier leg cuff material; c) activating at least a portion of said first webs so as to provide an activated region which is extensible in at least said lateral direction; d) providing a transverse partition having a proximal edge and a distal edge; e) joining at least a portion of the transverse partition adjacent the distal edge to the first webs of barrier leg cuff material adjacent to the activated region of the first web of barrier leg cuff material; f) providing a third web of topsheet material; g) joining at least a portion of each of the first and second webs of leg cuff material to the third web of topsheet material; h) providing a fourth web including an absorbent material d

Abstract: A laminate having two or more plies. The plies are embossed, and adhesively joined together. The adhesive forms an essentially continuous network. The essentially continuous network increases the strength of adhesive, increases the strength of the laminate, and is disposed within the X-Y plane of the laminate coincident the embossments.

Abstract: Embossed metallic flakelets have high damage resistance and can be produced readily. A method for production is also provided. The embossed metallic flakelets are produced by dip-coating an organic-inorganic composite layer 12 on upper and lower sides of a carrier layer made of a PVA film or the like by a sol-gel process, and pressing an original embossed pattern 14 having an embossed pattern against the organic-inorganic composite layer 12 under pressure to transfer the embossed pattern onto the organic-inorganic composite layer 12. A sample having the transferred embossed pattern is sintered, to form a metallic film 10 on the organic-inorganic composite layer 12 by deposition or the like.

Abstract: An embosser can emboss two webs of sheet material with either nested or foot-to-foot embossments. The embosser includes two steel embossing rolls which are engraved with the same embossing pattern. When foot-to-foot embossments are desired, the embossing rolls are positioned so that the corresponding embossments on the two rolls are aligned. When nested embossed are desired, one of the embossing rolls is moved either axially or circumferentially, or both, relative to the other embossing roll so that embossments on the two rolls nest.

Abstract: The present invention provides a selectively-activatible sheet material for delivering a substance to a target surface. The sheet material comprises a three-dimensional sheet of material having a first side and a second side. The first side has a plurality of hollow protrusions extending outwardly therefrom and separated from one another by valleys, while the second side has a plurality of depressions corresponding with the hollow protrusions. A substance adheres to and partially fills a location protected from external contact comprising the valleys and/or depressions. The sheet material may be selectively activated by deforming the hollow protrusions to deliver the substance to a target surface. The three-dimensional structure includes hollow protrusions which are adapted to progressively activate in multiple discrete stages to effect multistage progressive delivery of the substance to the target surface.

Abstract: Apparatus for coating metal sheets with plastic film, consisting of a sequential arrangement of metal sheet feed (1), oven (3), film feeding unit (4), corona stations (9), laminating rolls (10), texturing or smoothing rolls (7) and printing mechanism (8).

Abstract: A method for making multilayer polymer films with involves the use of preferably embossed rollers which oscillate oppositely with respect to each along their respective rotational axis. Multilayer film is made by passing two or more molten thermoplastic films through the nip of these rollers, thereby laminating the individual films together. The method is particularly useful for improving the adhesion between film layers, and/or when at least one of the layer is a liquid crystalline polymer. Such films are useful in packaging, multilayer containers and for circuit boards.

Abstract: Polymer structures having a laminated surface and enhanced physical properties that can be used for packaging, athletic gear (e.g., padding, water sport equipment), gaskets, and protective garments are described. The structures include a core of a relatively high density material and one or more layers laminated to the surfaces of the core material of relatively low density polymer foam. The structures can be stiff or flexible. The foam layers improve the softness of the surfaces of the core material.

Abstract: An embossing and laminating machine comprising a first embossing cylinder with a surface provided with a first set of protuberances, a second embossing cylinder with a surface provided with a second set of protuberances, said two embossing cylinders forming a nip, and a first and a second pressure roller interacting with said first and second embossing cylinders respectively; and in which said sets of protuberances are made in such a way that in said nip some of said first set of protuberances coincide with some of said second set of protuberances, while other protuberances of said first set are out of phase with corresponding protuberances of said second set, wherein said embossing cylinders are mechanically connected by a transmission which does not keep the cylinders in phase and which causes slight relative slippage between said embossing cylinders.

Abstract: An embossing and laminating machine is provided comprising a first embossing cylinder with a surface provided with a first set of protuberances and a second embossing cylinder with a surface provided with a second set of protuberances. The two embossing cylinders forming a nip. First and second pressure rollers interact with the first and the second embossing cylinders respectively. The protuberances are constructed in such a way that in the nip some of the protuberances of the first set coincide with some protuberances of the second set while other protuberances of the first set are out of phase with corresponding protuberances of the second set.

Abstract: A process for high pressure embossing a single ply of paper and the paper produced thereby. The embossing process requires two rolls, a pattern roll 30 and an anvil roll 32. The rolls are loaded together at a pressure of at least 1000 psi at the nip. A single ply of paper is embossed in the nip. The embossments of the paper do not extend outwardly beyond the thickness of the paper to have any out-of-plane deformation. The embossments are typically glassined. The resulting paper has an aesthetically pleasing appearance, without undue loss of tensile strength from the embossing process.

Abstract: A backing film for incorporation as a backing layer in a resilient floor covering or a floor tile having at least two laminae and a method for making such a backing layer whereby wastage is reduced when the color of the upper lamina is changed. Where there are two backing films having two or three laminae making up the backing layer the intermediately colored film resulting from a change in the color of the upper lamina can be utilized without further processing on the second backing film where color is not essential. Where there are three laminae making up a backing film the desired color is introduced and established in the bottom lamina before the supply of the original color to the upper lamina is stopped. The film can then be turned over for use with the former bottom lamina becoming the upper lamina.

Abstract: An embossed substrate comprising a substrate of a plastic material and having a surface and an embossed surface carried by the surface of the substrate. The embossed surface is characterized by having a pattern with an average roughness of between 100 nanometers and 300 nanometers with the roughness being distributed substantially uniformly over the surface, the pattern has ridges and valleys with the horizontal distance between adjacent ridges and/or valleys being greater than the depth between the ridges and the valleys. The peaks and the valleys are randomly disposed without periodicity to cause diffusion of light impinging thereon to minimize or eliminate interference effects when the embossed surface overcoated with thin planar organic layers is exposed to light.

Abstract: The present invention is generally directed to single ply scrim-like wiping products having great softness and strength. The wiping products are made from a paper web containing softwood fibers in combination with bicomponent fibers. Once formed, the paper web is treated on each side with a bonding agent in a preselected pattern. Both sides of the paper web are also creped. In order to create a wiping product with a scrim-like appearance, a reticular pattern is then embossed into the paper web. Specifically, the pattern is permanently imprinted into the product by compressing and fusing together the bicomponent fibers contained within the lines of the pattern.

Abstract: After laminating together the first sheets crepe-processed at a high crepe ratio and the second sheet crepe-processed at a crepe ratio lower than that of the first sheet or not crepe-processed, the sheets are bonded together at bonding parts at a given pitch in rows. When the resulting bonded sheets are impregnated with a liquid, expansions are generated between the rows of bonding parts due to the difference in ratios of the elongation of the two sheets. The expansions take on the shape of large wrinkle according to the pitch of the bonding parts. At the production process of the sheet, the sheet is crepe-processed containing water at a preset ratio, whereby small wrinkles as residual crepe wrinkles are formed on the sheet surface. The large wrinkles and the small wrinkles can enhance the wiping effect.

Abstract: Laminae suitable for use in a mold suitable for use in forming retroreflective sheeting and methods of making such laminae are disclosed. A representative lamina includes a single row of optically opposing cube corner elements disposed on its working surface. The working surface of a lamina is provided with a plurality of cube corner elements formed by the optical surfaces defined by three groove sets. Corresponding surfaces of opposing groove sets intersect substantially orthogonally along a reference edge to define first and second optical surfaces of the respective cube corner elements. The third optical surface of each respective cube corner element is defined by one surface of the third groove set.

Abstract: A method of molding a component such as a headliner or sun visor for the interior of automotive vehicles is molded from different thermoplastic materials from the same family that can be subsequently recycled as a whole without the need of separation into its constituents. The interior component is a multi layer composite of polyester (PET) finishing fabric, a resilient layer of bicomponent polyester fiber padding composed of blend of a low melting point fibers and high melting point fibers, and a relatively stiff core layer of polyester/glass fiber composite of polyester and glass fibers. The different fibers of the core layer are blended into a thin and porous sheet which is cut to size. The cut sheets are consolidated and molded under heat and pressure into a light weight, dense and structurally strong composite. A mold charge comprises the polyester/glass fiber composite layered with the bicomponent.

Abstract: The present invention relates three-dimensional sheet materials which resist nesting of superimposed layers into one another. More particularly, the present invention provides a three-dimensional, nesting-resistant sheet material having a first side and a second side. The first side comprises at least one region having a plurality of spaced three-dimensional protrusions extending outwardly from the first side which are preferably unitarily formed from the sheet material. To provide the nesting-resistant advantages of the present invention, the protrusions form an amorphous pattern of a plurality of different two-dimensional geometrical shapes. Preferably, the second side comprises a plurality of spaced, three-dimensional hollow depressions corresponding to the protrusions, such that the protrusions are hollow. Of particular interest for certain applications, such as a carrier for an adhesive, the protrusions are separated by an interconnected network of three-dimensional spaces between adjacent protrusions.

Abstract: Polymer structures having a laminated surface and enhanced physical properties that can be used for packaging, athletic gear (e.g., padding, water sport equipment), gaskets, and protective garments are described. The structures include a core of a relatively high density material and one or more layers laminated to the surfaces of the core material of relatively low density polymer foam. The structures can be stiff or flexible. The foam layers improve the softness of the surfaces of the core material.

Abstract: The present invention provides a stable nonwoven web having enhanced extensibility and a method for making the same. A neckable nonwoven web is fed in a first direction. The neckable nonwoven web is subjected to incremental stretching in a direction perpendicular to the first direction. A tensioning force is applied to the neckable nonwoven web to neck the nonwoven web. The necked nonwoven web is then subjected to mechanical stabilization to provide a stabilized extensible necked nonwoven web. The stabilized extensible necked nonwoven web is easily extended in a direction parallel to the direction necking.

Abstract: In a process for the production of a transdermal therapeutic system for the administration of active substances to the skin in the form of a plane multichamber or multichamber-channel system an active substance-containing layer is introduced between top layer and bottom layer; subsequently top and bottom layer are squeezed at individual and/or coherent sites under displacement of the intermediary sites of the active substance-containing layer and formation of active substance-containing chambers or channels, and at the same time or after that top layer and bottom layer are bonded permanently at the squeezed places.

Abstract: A truss type extruded aluminum section is formed of a pair of planar plates and ribs, wherein hollow portions are formed within said section by the ribs and the planar plates. Vibration-damping resin is provided on the inner surfaces of hollow portions, and particularly on the inner surface of the planar plate and on a single surface of the inclined rib. With this arrangement, the vibration energy bending the planar plate and the rib is converted into a heat energy. In the case of manufacturing such truss type extruded aluminum vibration-damping section, for making easy the insertion of the vibration-damping resin in the hollow portion, the vibration-damping resin is stuck on a plastic film to form a long planar body. The plastic film serves as a cover or an adhesive. Moreover, in the case of directly inserting the vibration-damping resin sheet, the vibration-damping resin sheet is subjected to embossing on the adhesive-bonding side for allowing air to escape.

Abstract: A house wrap film product includes a laminated poly film with a first poly film ply and a second poly film ply and micropuncture formed in the laminated poly film to allow vapor transmission from a first side of the laminated poly film to a second side of the laminated poly film. Each of the poly plies is formed of a spiral cut film having a first ply with a first orientation and a second ply having a second orientation, the first orientation being at an angle with respect to an edge of said film and said second orientation being at an angle with respect to an edge of said film, said first ply and said second ply being laminated together cross oriented such that said first orientation extends in a different direction from said second orientation. The micropuncture provides a deformed region of said film, surrounding said hole. A method is provided for forming the house wrap product.

Abstract: A waterproof felted material (10) has a thermoplastic polyolefin sheet (20) to which a thermoplastic fibrous polyolefin matting (30) is bonded with a portion of the fibers of the matting (40) embedded in and fused to the thermoplastic polyolefin sheet. A solidifying coating (50) may be applied to the matting.

Abstract: An apparatus and method for creation of a textile fabric that has been patterned with a selective application of heat, which provides a carved portion in registry with a color change. The textile fabric includes a blend of fibers of a first polymer having a first color with fibers of a second polymer having fibers of a second color. The melting point of the first fibers exceeds that of the second fibers. When patterned with a selective application of heat that exceeds that of the second fibers but is less than that of the first fibers, the second fibers melt away leaving the first fibers with the first color dominating. In the uncarved areas, the resulting color is a blend of the first color and the second color.

Abstract: A method for the production of a completely impregnated composite material having the surface thereof coated with a thermosetting resin and essentially consisting of a thermoplastic resin matrix including minute voids filled with a thermosetting resin and reinforcing fibers, which method comprises setting in place a roller and a collecting section disposed in the direction of the rotation of the roller, rotating the roller, feeding thermoplastic resin fibers and reinforcing fibers to the roller, causing the roller to throw a uniform mixture of the two types of fibers onto the collecting section, thereby forming a composite mat of the uniform mixture on the collecting section, then thermally compressing the composite mat and further solidifying the compressed composite mat by cooling and forming a composite material of the shape of a plate, further heating the composite material, thereby melting and expanding the thermoplastic resin forming the matrix, then cooling the expanded composite material, thereby form

Abstract: An absorbent multi-layer sheet, with at least two layers each constituted of at least one embossed ply of creped absorbent paper having a specific surface weight between 10 and 40 g/m.sup.2 per ply, with an external surface forming the outer side of the multi-layer sheet and an inner surface, the inner surface of the first layer including first and second protrusions and the inner surface of the second layer including third protrusions nested between the-protrusions of the first layer, the two layers being bonded together by at least part of the protrusion tips of one layer adhesively joined to the other layer between two protrusions, is characterized in that the bonding is implemented by the first protrusions of the first layer, the second protrusions having a lesser height than the first ones and their tips being adhesive-free.

Abstract: A fastener tab for disposable diapers has improved tactile softness provided by surface morphologies of preselected projection and/or relief dimensions.

Abstract: The invention concerns an absorbing multi-layer web (10) of at least two layers (12, 14) each including at least one embossed ply (16, 18, 20) made of a creped absorbent paper, having an outer side forming the outer side of the multi-layer web and an inner side, the inner side of the first layer (12) including first and second protrusions (22) and (24) respectively, and the inner side of the second layer (14) including third protrusions (26) nesting between the protrusions (22, 24) of the first layer, the two layers (12, 14) being bonded to each other, characterized in that the first layer (12) is a double ply including of an inner ply (16) of which the inner side includes first and second protrusions (22A) and (24A) respectively, and an outer ply (18) of which the inner side includes first protrusions (22B) and second protrusion (24B). The tops of the protrusions (22A) and (22B) are bonded to each other but not the tops of the protrusions (24A) and (24B).

Abstract: A method for coating a transparent carrier plate includes coating a backside of the carrier plate with a first chromatic layer, applying a non-opaque metallic blocking foil coating on top of the first chromatic layer, and applying a second chromatic layer on top of the non-opaque metallic blocking foil layer. The method results in a coated carrier plate having increased color intensity and brightness. Further, by varying the hues in the first and second chromatic layers, a resulting hue may be provided that is different from the hue of the first and/or second chromatic layer. In addition, the hues of the first and second chromatic layers may be varied over the surface area of the carrier plate.

Abstract: SBR and natural rubber articles which can be marked with indicia are formed by curing the SBR or natural rubber under heat and pressure in contact with a fabric material. The curing conditions force the fabric into the cured rubber article. The fabric can then be marked with a heat-activated, indicia-bearing transfer. This provides for unique decoration of articles such as mud flaps and the like, and also permits providing identification for other rubber articles such as tires and the like.

Abstract: A method and apparatus of embossing a pattern into absorbent articles such as sanitary napkins, panty liners, and adult incontinence pads which simultaneously forms a perimeter seal on the absorbent article is disclosed. The method and apparatus utilize a heated sealing member and an anvil surface. The heated sealing member has a recessed region with a lower temperature and lower pressure embossing member therein.

Abstract: A security document such as a bank note, identity card or the like, includes at least one multilayer security element made of at least two layers of reaction lacquer or adhesive between which diffraction structures, in particular holographic structures, exist in the form of a relief. A reflective layer is additionally disposed between the layers of lacquer. The reaction lacquer of adhesive is the type curable or cross-linkable under physical (e.g. radiation) and/or chemical activation.

Abstract: Absorbent articles containing absorbent cores of fluff pulp frequently contain wrinkles in the absorbent core that run from side to side of the article, typically normal to the machine direction in the manufacturing process. Side-to-side wrinkles are deleterious in that they provide large flow channels for urine or other body fluids to escape to the edge of the article. Frequently, such wrinkles are present after manufacturing, before the article has been folded or worn. The cause of the wrinkles is believed to be due to natural instabilities during compression of the fluff pad shortly after it is formed. Means for reducing cross-directional wrinkles include the use of grooved, drilled, or patterned compression rolls to densify the fluff pulp while providing opportunities for reduced in-plane displacement during compression or, if in-plane displacement does occur, providing paths for cross-directional displacement as well as machine-direction displacement so that continuous CD wrinkles cannot form.

Abstract: A nonwoven fabric of superior uniaxial elasticity is provided. The nonwoven fabric comprises of conjugate filaments each of which is about concentric sheath-core type. Core component is composed of polyester and sheath component is composed of polyolefine. In the nonwoven fabric, heat bonded areas are interspersed by heat bonding the conjugate filaments one another by softening or melting the sheath component. The nonwoven fabric satisfies following four properties concurrently: (i) breaking elongation in cross direction is 150% or more, (ii) ratio of breaking elongation in cross direction to breaking elongation in machine direction is 5 or more, (iii) percentage of elastic recovery at the time of extending the nonwoven fabric by 50% in cross direction is 60% or more, and (iv) percentage of elastic recovery at the time of extending the nonwoven fabric by 100% in cross direction is 50% or more. A heat is partially applied to a filamentous web, thereby obtaining a filamentous fleece.

Abstract: An article that includes at least two networks of high strength fibers and a matrix material which impregnates the high strength fibers to form a composite element having a first plane profile and a second plane profile, wherein at least one of the first and second plane profiles has on its surface a textured pattern, and the matrix material is distributed substantially uniformly over the textured plane profile, and a method for making the composite element.

Abstract: A bulky and highly strong filament nonwoven fabric and method of manufacturing the filament nonwoven fabric which is made of conjugated filaments, whose intersections are melted and adhered, and which has a 15-35 cc/g specific volume and satisfies the following Formula (1) between strength and specific volume;Y.gtoreq.-1.25X+125 (1)wherein Y is a geometrical mean of vertical and horizontal strength per 5 cm wide and 1 g/cm.sup.2 nonwoven fabric ?unit: g/(g/m.sup.2 .multidot.5 cm!; Y=(MD.times.CD).sup.1/2 where MD is vertical strength ?unit: g/(g/m.sup.2 .multidot.5 cm! and CD is horizontal strength ?unit: g/(g/m.sup.2 .multidot.5 cm!; and X=specific volume of a nonwoven fabric ?unit: cc/g!; and wherein the conjugated filament is made of a low melting point polymer and a high melting point polymer with a difference in melting points of at least 15.degree. C., and has the low melting point polymer on at least one section of a filament surface and has crimps.

Abstract: To enable bonding flat and corrugated sheets at their contact points by laser welding or other welding methods while laminating and spirally winding the sheets, a process of producing a metal catalyst carrier for exhaust gas purification in the form of a metal honeycomb column composed of flat and corrugated metal sheets alternately laminated, wound together, and bonded to each other, the process includes the steps of: forming plural openings in a flat sheet of a metal; laminating one piece of the flat sheet having the openings formed therein and one piece of a corrugated sheet of a metal and bonding the laminated flat and corrugated sheets to each other to form a composite sheet; and spirally winding the composite sheet around an axis to form columnar turns each composed of an outer flat layer composed of the flat sheet and an inner corrugated layer composed of the corrugated sheet, while bonding an outer turn and an adjoining inner turn by welding an inner corrugated layer of the outer turn, in a portion ex

Abstract: The present invention provides an improved method for laminating a first three-dimensional apertured or non-apertured film material to a second flat or three-dimensional apertured or non-apertured film material utilizing the heat generated by the extrusion of the first and/or second materials and the films produced thereby.

Abstract: A method of producing doilies includes coating sheets of paper stock with a lubricious release fluid, collecting the sheets into a multi-layered web, and cutting and embossing doilies from the web. The fluid is preferably a solution of mineral oil and silicone, and results in the doilies being more easily separable after being adhered by the cutting and embossing process. A solution of mineral oil and 15%-40% silicone is disclosed.

Abstract: A retroreflective sheeting having a multiplicity of discrete, cube-corner elements cured in situ on a transparent, polymeric overlay film deformed into a three-dimensional structure so that base edges of a plurality of cube-corner elements are non-planar with respect to one another. The retroreflective article preferably has at least one target optical property. The present invention is also directed to a method of deforming the retroreflective sheeting to form a retroreflective article in which the base edges of a plurality of cube-corner elements are non-planar with respect to one another.

Abstract: Systems and methods for embedding optical elements in an optical device are described. A method includes: providing a resin layer with a replica surface topography; cutting the resin layer to form an optical element layer that includes the replica surface topography; coating the replica surface topography with a layer; providing a substrate having a substrate refractive index; and connecting the layer to the substrate with an index matching material having a matching refractive index that is substantially equal to the substrate refractive index. The systems and methods provide advantages in that surface topography is replicated with enhanced overall cost effectiveness.

Abstract: An environmentally sound vegetation growth-enhancing erosion control blanket is formed from an elongated rectangular excelsior/wood wool mat. The mat is held together with adhesive and a surface pattern is embossed therein. When the finished blanket is placed atop the ground, the blanket serves to shield the earth area from wind and water erosion forces, without the presence of the plastic netting often used in the prior art. As the ground vegetation grows, it ultimately replaces the blanket which decomposes and furnishes the ground vegetation with a nutritive mulch.

Abstract: The multi-layer paper composed of at least three embossed plies of paper (1,2,3) having regularly distributed projections characterized in that it includes two so-called external plies (1,3) of which the respective projections (10,30) are in tip-to-tip positions and a third embossed so-called middle ply (2) of which the projections (20) nest between projections of one of the two external plies (1 or 3).

Abstract: Undrawn, tough, durably melt-bondable, macrodenier, thermoplastic, multicomponent filaments, such as sheath-core and side-by-side filaments, comprising a first plastic component and a second lower-melting component defining all or at least part of the material-air boundary of the filaments. The filaments can be made by melt-extruding thermoplastics to form hot filaments, cooling and solidifying the hot filaments, and recovering the solidified filaments without any substantial tension being placed thereon. Aggregations of the filaments can be made in the form of floor matting and abrasive articles.

Abstract: A method of prescoring foam board for making composite panels includes impressing a pattern of ridges projecting from a surface of a die into at least one face surface of the foam board. The pattern of ridges on the die forms a pattern of indentations having three series of parallel linear indentations, each series being angularly offset from each series other by 60.degree.. The ridges on the embossing die are pressed into the foam sufficiently deep that the the pattern of indentations impressed in the board surface after whatever springback occurs remain deep enough to enable volatiles generated in an interior zone of a panel to escape when drawn out by a vacuum pump when the foam board is heated under pressure between two face sheets of resin-preimpregnated fabric to form a composite panel.

Abstract: The present invention provides an improved method for laminating a first three-dimensional apertured or non-apertured film material to a second flat or three-dimensional apertured or non-apertured film material utilizing the heat generated by the extrusion of the first and/or second materials and the films produced thereby.

Abstract: A method for embossing a sheet of creped paper composed of at least one ply, whereby the sheet is engaged between two metallic cylinders fitted with protrusions and driven in rotation in a conventional manner and mesh with each other while having a play e1 between the tops of the protrusions of one cylinder and the opposite surface of the other cylinder, and a play e2 between the slopes of two adjacent protrusions wherein e1 and e2 are determined in the direction transverse to the direction of paper advance in such a manner that the ratio of e1/e2 is between 0.8 and 1.