Expandable press felt pintle

Abstract

An industrial fabric includes a base material having ends including a plurality of loops that are intermeshed to form a pintle receiving channel, which an expandable pintle extends through to join the ends to form a continuous belt. The expandable pintle includes a multifilament yarn including a plurality of yarns. At least a portion of the plurality of yarns include a material mixed with a blowing agent. Upon activation of the blowing agent, the yarns including the blowing agent are adapted to expand at least in areas by formation of a foamed or cellular structure to fill a greater volume of the pintle receiving channel. The industrial fabric can also include an expandable stuffer including a material mixed with a blowing agent. The expandable stuffer can be positioned in a first or second channel that extend through the base material parallel to the pintle receiving channel.

Description

EXPANDABLE PRESS FELT PINTLECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from U.S. Provisional Application No. 63 / 468,310, filed May 23, 2023, which is incorporated herein by reference as if fully set forth.FIELD OF INVENTION

[0002] The present disclosure is directed to papermaking fabrics for use in a papermaking process. It is particularly directed to an expandable press felt pintle that is used to couple and join the ends of the papermaking fabric.BACKGROUND

[0003] Industrial fabrics used in papermaking machines are often constructed from woven materials / fabrics including ends that can be joined by a seam to form a continuous fabric belt. A typical seam for a papermaking fabric includes a plurality of loops on each end of the fabric. The loops are generally aligned in an alternating intermeshing configuration / pattern to form a pintle channel through which a pintle is inserted to close the seam and couple the ends of the fabric.

[0004] Previous fabrics including seams utilize a joining wire or a pintle which is inserted through the intermeshed seam loops at each end of the fabric to produce an endless / continuous fabric belt. Some previous pintles are made from standard monofilament yarn(s), mechanically attached by a swedge to a lead wire. The wire is pushed through the intermeshing loops of the fabric and monofilament yarns of various size and number are pulled into the seam loops to fill the void within the loops. The previous process is sufficient to join the open ends of the fabric, but it can leave a looseness to the seam connection based on the fit of the pintle in the seam loops that allows the fabric ends to pull apart slightly from one another at the seam and / or results in the caliper of the fabric decreasing at the seam loop / pintle location. Further, this can result in the batt opening at the seam, which can create an undesirable mark in the sheet and lead to premature seam wear.

[0005] It would therefore be desirable to form a tight seam in order to address or lessen the effects of the aforementioned issues of previous pintles used to join the ends of industrial fabrics.SUMMARY

[0006] In one aspect, the present disclosure is directed to an industrial fabric. The industrial fabric includes a base material having ends which include a plurality of loops that are intermeshed to form a pintle receiving channel. An expandable pintle extends through the pintle receiving channel to join the ends of the base material to form a continuous belt. The expandable pintle includes a multifilament yarn including a plurality of yarns, at least a portion of the plurality of yarns include a material mixed with a blowing agent. Upon activation of the blowing agent, the yarns including the blowing agent are adapted to expand at least in areas by formation of a foamed or cellular structure to fill a greater volume of the pintle receiving channel.

[0007] In one embodiment, at least a portion of the plurality of yarns include a core formed from a first material mixed with carbon black or another laser radiation or heat absorbing material, and a sheath surrounding the core and formed from a second material mixed with the blowing agent.

[0008] In one embodiment, the first material of the core is a first polymer and the second material of the sheath is a second polymer different than the first polymer.

[0009] In one embodiment, the first polymer is a polyamide and the second polymer is thermoplastic polyurethane (TPU).

[0010] In one embodiment, the blowing agent is a heat activated chemical blowing agent.

[0011] In a further embodiment, the chemical blowing agent is heat activated at an activation temperature in a range from 150 - 350°C.

[0012] In one embodiment, each of the plurality of yarns include the sheath surrounding the core and formed from the second material mixed with the blowing agent, such that each of the plurality of yarns is expandable via the foamed or cellular structure.

[0013] In one embodiment, a first portion of the plurality of yarns do not the sheath surrounding the core and being formed from the second materialmixed with the blowing agent; and a second portion of the plurality of yarns include the sheath surrounding the core and being formed from the second material mixed with the blowing agent, such that the second portion of the plurality of yarns are expandable via the foamed or cellular structure.

[0014] In one embodiment, at least a portion of the plurality of yarns further include the material mixed with a laser absorbing pigment or dye.

[0015] In one embodiment, the blowing agent is a physical blowing agent.

[0016] In one embodiment, each of the plurality of yarns are formed from a polymer and at least some of the plurality of yarns are mixed with a blowing agent.

[0017] In one embodiment, at least some of the plurality of yarns formed from the polymeric material mixed with the blowing agent are further mixed with a heat absorbing agent, such as carbon black.

[0018] In one embodiment, each of the plurality of yarns are formed from a polymer mixed with the blowing agent, such that each of the plurality of yarns are expandable into the foamed or cellular structure.

[0019] In one embodiment, a first portion of the plurality of yarns do not include the blowing agent, and a second portion of the plurality of yarns include the blowing agent, such that the second portion of the plurality of yarns are expandable via the foamed or cellular structure.

[0020] In one embodiment, the first portion of the plurality of yarns are formed from a first polymer and the second portion of the plurality of yarns are formed from a second polymer different than the first polymer.

[0021] In one embodiment, the base material is a fabric including a system of MD yarns connected to a system of CD yarns and is formed having ends that are joined in order to form the continuous belt.

[0022] In one embodiment, the industrial fabric is a papermaking fabric.

[0023] In another aspect, the present disclosure is directed to an industrial fabric. The industrial fabric can include a base material having ends which include a plurality of loops that are intermeshed to form a pintle receiving channel. A pintle can extend through the pintle receiving channel to join the ends of the base material to form a continuous belt. An expandable staffer in which at least a portion of the expandable staffer includes a material mixed with a blowing agent, the expandable staffer is positioned in at least one of a first channel or a second channel that extend the base material parallel to the pintle receiving channel, and each of thefirst channel and the second channel are positioned laterally adjacent the plurality of loops on each end of the base material in a direction away from the pintle receiving channel. Upon activation of the blowing agent, the expandable staffer is adapted to expand at least in areas by formation of a foamed or cellular structure to fill a greater volume of at least one of the first channel or the second channel.

[0024] In one embodiment, the pintle is an expandable pintle that is adapted to expand via a foamed or cellular structure upon activation of a blowing agent within the expandable pintle.

[0025] In one embodiment, the expandable staffer includes a plurality of yarns, and at least a portion of the plurality of yarns of the expandable staffer include the material mixed with the blowing agent.

[0026] In one embodiment, the expandable staffer is a monofilament yarn, and at least a portion of the monofilament yarn includes the material mixed with the blowing agent.

[0027] In another aspect, the present disclosure is directed to a method of forming an industrial fabric. The method including providing a base material having ends which include a plurality of loops; intermeshing the plurality of loops to form a pintle receiving channel; joining the ends of the base material by inserting an expandable pintle into the pintle receiving channel to form a continuous belt, the expandable pintle comprising a multifilament yarn including a plurality of yarns and at least a portion of the plurality of yarns are formed from a polymer mixed with a blowing agent; and applying energy to the plurality of yarns to activate the blowing agent to expand the plurality of yarns including the blowing agent at least in areas by formation of a foamed or cellular structure to fill a greater volume of the pintle receiving channel.

[0028] In one embodiment, the applying energy includes applying a laser at the selected locations and generating heat by the laser energy that is absorbed by the plurality of expandable yarns including the blowing agent.

[0029] In one embodiment, the blowing agent is a heat activated chemical blowing agent that is activated at an activation temperature in a range from 150 - 350°C.

[0030] In one embodiment, the method is for making a papermaking fabric.

[0031] In one embodiment, at least a portion of the plurality of yarns include?rmed from a first polymer mixed with carbon black or another laser or heatabsorbing material, and a sheath surrounding the core and formed from a second polymer mixed with the blowing agent.

[0032] In one embodiment, the laser or heat absorbing material can be a laser absorbing pigment or dye.BRIEF DESCRIPTION OF THE DRAWING(S)

[0033] The foregoing Summary as well as the following Detailed Description will be best understood when read in conjunction with the appended drawings, which illustrate a preferred embodiment of the disclosure. In the drawings:

[0034] FIG. 1 is an illustrative view of an exemplary industrial fabric of the present disclosure.

[0035] FIG. 2 is a magnified view of a plurality of loops at each end of the industrial fabric of FIG. 1 before insertion of an expandable pintle, according to the present disclosure.

[0036] FIG. 3 is a side elevation view of the exemplary industrial fabric after insertion of the expandable pintle within the plurality of loops.

[0037] FIG. 4A is a cross-sectional view through a first embodiment of the expandable pintle in an initial state, used in an industrial fabric according to the present disclosure.

[0038] FIG. 4B is a cross-sectional view through the first embodiment of the expandable pintle in FIG. 4A in an expanded state.

[0039] FIG. 5A is a cross-sectional view through a second embodiment of the expandable pintle in an initial state, used in an industrial fabric according to the present disclosure.

[0040] FIG. 5B is a cross-sectional view through the second embodiment of the expandable pintle in FIG. 5A in an expanded state.

[0041] FIG. 6A is a cross-sectional view through a third embodiment of the expandable pintle in an initial state, used in an industrial fabric according to the present disclosure.

[0042] FIG. 6B is a cross-sectional view through the third embodiment of the expandable pintle in FIG. 6A in an expanded state.

[0043] FIG. 7A is a cross-sectional view through a fourth embodiment of the expandable pintle in an initial state, used in an industrial fabric according to the disclosure.

[0044] FIG. 7B is a cross-sectional view through the fourth embodiment of the expandable pintle in FIG. 7A in an expanded state.

[0045] FIG. 8A is a cross-sectional view through an exemplary industrial fabric of the present disclosure including an expandable staffer within a first channel and a second channel positioned adjacent a pintle receiving channel.

[0046] FIG. 8B is a cross-sectional view through the exemplary industrial fabric of FIG. 8A, with the expandable staffers in an expanded state.DETAILED DESCRIPTION

[0047] Certain terminology is used in the following description for convenience only and is not limiting. The words “front”, “rear”, “upper”, and “lower” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions towards and away from parts referenced in the drawings. “Axially” refers to a direction along the axis of a shaft or other cylindrically shaped component. A reference to a list of items that are cited as “at least one of a, b, or c” (where a, b, and c represent the items being listed) means any single one of the items a, b, or c, or combinations thereof are included. The terms “about” and “approximately” encompass + / - 10% of an indicated value unless otherwise noted. The term “generally” in connection with a radial direction encompasses + / - 25 degrees. The terminology includes the words specifically noted above, derivatives thereof and words of similar import.

[0048] Further, the fabric according to the present disclosure is an industrial textile, preferably a papermaking fabric. However, in some embodiments it can have many industrial applications, such as conveyor belts, belts for pulp and filtration applications, etc. The fabric can be woven or non-woven or formed of a structured film, and this term is used with a broad meaning. The words "support side" and "machine side" designate surfaces of the fabric with reference to their use in one preferred application in a conveying application; however, these terms merely represent first and second or upper and lower surfaces of the planar fabric. “Yarn” is used to generically identify a monofilament or multifilament fiber. “Warp” and “weft” are used to designate yarns or monofilaments based on their position in the loom that extend in perpendicular directions in the fabric and either could be a machine direction (MD) or cross-machine direction (CD) yarn in the fabric once it isI on a piece of equipment, depending on whether the fabric is, for example,flat woven or continuously woven. “Seam” or “seam region” refers to the exposed yarn loops of the MD yarns at the CD fold areas at the opposing MD ends of the fabric.

[0049] In one preferred arrangement, as illustrated in FIGS. 1-3, the industrial fabric can be flat woven and seamed at the warp ends in order to form a continuous belt, so that the warp yarns are MD yarns and the weft yarns are CD yarns. The base fabric could also be a multiaxial fabric assembled from a strip of fabric having a narrower width that is wound around two spaced-apart rolls at an angle to the MD, with the longitudinal edges being joined together to form a wider fabric belt. The strip could be a woven strip or a nonwoven strip. For the multiaxial arrangement, the MD and CD yarns would be canted with respect to a true MD and a true CD by about 1 ° to 7°. However, for this disclosure, this is encompassed within the reference to MD and CD yarns. Regardless of how the base fabric is made, the designations of warp, weft, and / or MD and CD as used in the description that follows can be interchanged. Further, for non-woven fabrics, these may be formed of spunbond or meltblown chopped fibers that would have no specific orientation. Further, the base fabric can be a film, preferably a BoPET film, that may have punched openings that can be folded over and laminated to provide more body as well as to adjust permeability.

[0050] Blowing agents are defined as compounds which are thermally unstable and decompose to yield gas or otherwise expand (such as water turning to steam) at the desired polymer processing temperature. One example of a chemical blowing agent is Azodicarbonamide (ADC), which is a known industrial blowing agent. Pure ADC decomposes between 200-210°C. Certain activating agents can be added to ADC to lower its decomposition temperature down to 150°C or even lower. One example of a physical blowing agent is water, which can be absorbed or dispersed in a material which expands as it turns to steam when heated.

[0051] In describing different embodiments of the industrial fabric assemblies, like element numbers are used for elements having the same function, even if there are minor differences in shape, for example, yarns having different cross-sections.

[0052] FIG. 1 is an illustrative view of an exemplary industrial fabric 10 of the disclosure after being removed from rollers and collapsed flat to provide adouble layer industrial fabric 10. FIG. 2 is a magnified view of a fold region of the industrial fabric 10 illustrated in FIG. 1. The industrial fabric 10 includes a system of MD yarns 12 connected to a system of CD yarns 14 to form a base fabric as a base material 16. The base material 16 is collapsed flat and folded inward, such that an opposing first fold region 18 and second fold region 20 face each other. As will be discussed, the first fold region 18 and the second fold region 20 can be joined to form a continuous belt 22 having a first surface, which can be a support surface, and a second surface, which can be a machine side surface. A seam region is provided at the ends of the industrial fabric 10 by removing a portion of the CD yarns 14 at the opposing first fold region 18 and second fold region 20 to expose first seam loops 24 and second seam loops 26, respectively, of the MD yarns 12. A seaming element, such as a pintle, can be inserted into the first seam loops 24 and the second seam loops 26 to couple the opposing first fold region 18 and second fold region 20 of the industrial fabric 10 to form the continuous belt 22, discussed further below.

[0053] FIG. 2 illustrates the industrial fabric 10 before the plurality of first seam loops 24 and the plurality of second seam loops 26 have been intermeshed and an expandable pintle 30, 130, 230, or 330 (see Figs. 4A- 7B) has been inserted through the seam loops 24, 26. As illustrated, the plurality of first seam loops 24 and the plurality of second seam loops 26 are positioned at each end of the industrial fabric 10. A portion of the CD yarns 14 are removed from the base material 16 at the opposing first fold region 18 and the second fold region 20, which exposes the MD yarns 12 of the industrial fabric 10 so that the seam loops 24 and 26 may be used to form a seam in the industrial fabric 10. Further, as illustrated in FIG. 3, the industrial fabric 10 can be joined by intermeshing the first seam loops 24 at the first fold region 18 with the second seam loops 26 at the second fold region 20, and then an expandable pintle 30, 130, 230, or 330 can be inserted into a pintle receiving channel 28 that is formed by the intermeshed first seam loops 24 and second seam loops 26. The expandable pintle 30, 130, 230, or 330 can be inserted across the length of the pintle receiving channel 28 formed between the seam loops 24 and 26 to couple the ends of the base material 16 and secure the industrial fabric 10 in the shape of a continuous belt 22. While the exemplary base fabric of FIGS. 1-3 is shown as being formed by collapsing a tubular fabric structure to form a ayer fabric, it is understood that this is merely exemplary, and that the fabriccould be a single layer, double layer, or triple layer fabric and the seam loops can be formed, for example, during weaving, by back-weaving ends of a flat woven fabric, or using spiral seam elements.

[0054] FIG. 4A is a cross-sectional view through a first embodiment of the expandable pintle 30 in an initial state, used in the industrial fabric 10. FIG. 4B is a cross-sectional view through the first embodiment of the expandable pintle 30 in an expanded state. As discussed above, the expandable pintle 30 can extend through the pintle receiving channel 28 that is formed by the intermeshed first and second seam loops 24, 26 to join the ends of the base material 16 to form the continuous belt 22. As illustrated in FIGS. 4A-4B, in some embodiments the expandable pintle 30 can be a multifilament yarn that is formed from a plurality of yarns 32. Although the illustrated embodiment includes four yarns 32 forming the plurality of yarns 32, it is to be understood that in some embodiments the plurality of yarns 32 could include more than four yarns 32. Further, in some embodiments the plurality of yarns 32 could include less than four yarns 32.

[0055] In addition, at least some of the yarns of the plurality of yarns 32 can include a core 34 that is surrounded by a sheath 36. In the embodiment illustrated in FIGS. 4A-4B, each of the plurality of yarns 32 include the core 34 that is surrounded by the sheath 36. The core 34 can be formed from a first material that is mixed with a heat absorbing material, such as carbon black, and the sheath 36 can be formed from a second material, different from the first material, that is mixed with a blowing agent 38. More specifically, in some examples, the core 34 can be formed from a first polymer mixed with carbon black, and the sheath 36 can be formed from a second polymer mixed with the blowing agent 38. In addition, the second polymer of the sheath 36 can be different from the first polymer of the core 34. In some embodiments, the first polymer of the core 34 can be polyethylene terephthalate (PET) or a polyamide (e.g. PA6, PA66, PA610, PA11 , PA12), or any other suitable polymer, and the second polymer of the sheath 36 can be one or more of a thermoplastic polyurethane (TPU), homopolymer, block copolymers, thermoplastic elastomers, or blends (e.g. PEBA, TPEE or COPE). While TPU is preferred, other polymers could also be used as the second polymer of the sheath 36.

[0056] The core 34 is described as being formed from a first material that is with a heat absorbing material such as carbon black, but it is to beunderstood that the core 34 could be constructed from a first material that is mixed with any other suitable material that absorbs heat when exposed to certain types of energy, for example laser energy. The blowing agent 38 can be a chemical blowing agent as discussed above. However, other blowing agents which, when incorporated into a polymeric material, form a foamed or cellular structure when activated, for example by heat, could also be used, including physical blowing agents. In a preferred embodiment, the blowing agent 38 can be a chemical blowing agent that is activated by heat, and more preferably, the chemical blowing agent 38 is heat activated at an activation temperature T in the range of 150-350°C. In another preferred embodiment, the blowing agent 38 can be a physical blowing agent, such as water, which can be absorbed or dispersed in the sheath 36 of the plurality of yarns 32, and which expands as it turns to steam when heated.

[0057] Each of the plurality of yarns 32 including the core 34 and the sheath 36 can be co-extruded, such that the sheath 36 is concentric with and fully surrounds the core 34. In other words, the sheath 36 can be formed as a single layer with the mixture of the second polymer and the blowing agent 38, and the sheath 36 can fully surround an outer circumference or surface of the core 34 formed from the first polymer and mixed with carbon black. As discussed, FIG. 4A is a cross-sectional view through a first embodiment of the expandable pintle 30 in an initial state, used in the industrial fabric 10. Upon activation of the blowing agent 38, such as through heat activation by application of laser energy, the sheath 36 is adapted to expand at least in areas into a foamed or cellular structure 38A. More specifically, as illustrated in FIG. 4B, the blowing agent 38 mixed with the second polymer of the sheath 36 can be activated through the application of heat, causing the blowing agent 38 to expand into a foamed or cellular structure 38A.

[0058] In turn, expansion of the sheath 36 causes the expandable pintle 30 to fill a greater volume of the pintle receiving channel 28, as compared to before expansion of the sheath 36 and the expandable pintle 30. This can be used to provide more uniform permeability in the seam region of the base fabric that is more similar to a remainder of the industrial fabric 10. Further, expansion of the sheath 36 and the overall expandable pintle 30 within the pintle receiving channel 28 can force the first seam loops 24 and the second seam loops 26 of the base material 16 in opposite directions away from each other. In other words, expansion of the 36 and the overall expandable pintle 30 within the pintle receiving channel28 can force the first seam loops 24 and the second seam loops 26 in a direction away from the expandable pintle 30 within the pintle receiving channel 28. The expansion causes a tightening of the seam of the base material 16 that is formed at the ends of the industrial fabric 10, which may alleviate the issues of undesirable marking in a paper sheet and premature seam wear of previous industrial fabrics including previous pintles joining the ends of the previous fabrics. For at least those reasons, as will be appreciated by those skilled in the art, the disclosed industrial fabric 10 including the expandable pintle 30 is advantageous over previous pintles used in previous industrial fabrics.

[0059] FIG. 5A is a cross-sectional view through a second embodiment of an expandable pintle 130 in an initial state, used in the industrial fabric 10 of the present disclosure. FIG. 5B is a cross-sectional view through the second embodiment of the expandable pintle 130 in an expanded state. The expandable pintle 130 of FIGS. 5A-5B is substantially similar to the expandable pintle 30 of FIGS. 4A-4B, and therefore it is to be understood that the previous disclosure regarding the expandable pintle 30 of FIGS. 4A-4B equally applies to the expandable pintle 130 of FIGS. 5A-5B unless otherwise noted. As such, only the differences between the expandable pintle 130 of FIGS. 5A-5B and the expandable pintle 30 of FIGS. 4A-4B will be discussed below.

[0060] The expandable pintle 30 of FIGS. 4A-4B includes a multifilament yarn including a plurality of yarns 32, with each of the plurality of yarns 32 including the core 34 formed from a first material mixed with the heat absorbing material such as carbon black, and the sheath 36 surrounding the core 34 and formed from a second material mixed with the blowing agent 38. Therefore, each and every one of the plurality of yarns 32 of the expandable pintle 30 of FIGS. 4A-4B are expandable into the foamed or cellular structure 38A which is utilized to fill a greater volume of the pintle receiving channel 28, as compared to before expansion. In contrast, in the embodiment illustrated in FIGS. 5A-5B, only some of the plurality of yarns 132 include the core 134 surrounded by the sheath 136 including the blowing agent 138, while other yarns of the plurality of yarns 132 are illustrated as not including the sheath 136 with the blowing agent 138. Here these other yarns could include a core and sheath as well, and not include the blowing agent 138. As a result, in the expandable pintle 130 of FIGS. 5A-5B, only some of the plurality of 32 are expandable at least in areas by formation of the foamed or cellularstructure 138A. Specifically, only the yarns including the sheath 136 with the blowing agent 138 are expandable at least in areas by formation of the foamed or cellular structure 138A.

[0061] In the embodiment illustrated in FIGS. 5A-5B, the expandable pintle 130 includes a first portion of the plurality of yarns 132 that include the core 134 which is not surrounded by the sheath 136 formed from the second material mixed with the blowing agent 138. Further, the expandable pintle 130 includes a second portion of the plurality of yarns 132 that include the core 134 surrounded by the sheath 136 formed from the second material mixed with the blowing agent 138. In some examples, as illustrated, the first portion of the plurality of yarns 132 and the second portion of the plurality of yarns 132 can alternate in the multifilament yarn. Further, in some examples, the first portion of the plurality of yarns 132 without the blowing agent 138 can include two yarns of the plurality of yarns 132, and the second portion of the plurality of yarns 132 with the blowing agent 138 can include two yarns of the plurality of yarns 132. In other examples, the number of yarns that constitutes the first portion and the second portion of the plurality of yarns 132 does not necessarily need to be equal and may include more or less than four total yarns 132.

[0062] As illustrated in FIG. 5B, the yarns of the expandable pintle 130 including the blowing agent 138 mixed with the second polymer of the sheath 136 can be activated through the application of heat, causing the blowing agent 138 to expand into a foamed or cellular structure 138A. Similar to the embodiment of FIGS. 4A-4B, the yarns including the blowing agent 138 of the expandable pintle 130 of FIGS. 5A-5B expand at least in areas by formation of a foamed or cellular structure 138A to fill a greater volume of the pintle receiving channel 28, as compared to before expansion of the sheath 136 and the expandable pintle 130. The expansion causes a tightening of the seam of the base material 16 that is formed at the ends of the industrial fabric 10, which may alleviate the issues of undesirable marking in a paper sheet and premature seam wear of previous industrial fabrics including previous pintles joining the ends of the previous fabrics. As such, the expandable pintle 130 of FIGS. 5A-5B provides the same advantages as the expandable pintle 30 of FIGS. 4A-4B, but only some of the plurality of yarns 132 of the expandable pintle 130 are expandable, while other yarns are not.

[0063] FIG. 6A is a cross-sectional view through a third embodiment of an expandable pintle 230 in an initial state, used in the industrial fabric 10. FIG. 6B is a cross-sectional view through the third embodiment of the expandable pintle 230 in an expanded state. The expandable pintle 230 of FIGS. 6A-6B is similar to the expandable pintle 30 of FIGS. 4A-4B, and therefore it is to be understood that the previous disclosure regarding the industrial fabric 10, the base material 16, and the material properties of the expandable pintle 30 of FIGS. 4A-4B equally applies to the expandable pintle 230 of FIGS. 6A-6B unless otherwise noted. As such, only the differences between the expandable pintle 230 of FIGS. 6A-6B and the expandable pintle 30 of FIGS. 4A-4B will be discussed below.

[0064] As discussed, the expandable pintle 30 of FIGS. 4A-4B includes a multifilament yarn including a plurality of yarns 32, with each of the plurality of yarns 32 including the core 34 formed from a first material mixed with carbon black or another heat absorbing material, and the sheath 36 surrounding the core 34 and formed from a second material mixed with the blowing agent 38. The third embodiment of the expandable pintle 230 illustrated in FIGS. 6A-6B differs from the expandable pintle 30 of FIGS. 4A-4B in that the expandable pintle 230 does not include a core surrounded by a sheath. Rather, the expandable pintle 230 includes a multifilament yarn including a plurality of yarns 232 that are formed from a polymer mixed with a blowing agent 238, such that each individual yarn of the plurality of yarns 232 is formed from a uniform polymeric material or material blend that is mixed with the blowing agent 238 extending fully through each of the plurality of yarns 232. In other words, the expandable pintle 230 of FIGS. 6A-6B includes a generally constant material composition or material properties through both the radial and axial directions of each of the plurality of yarns 232.

[0065] Therefore, since each of the plurality of yarns 232 of the expandable pintle 230 are formed from a polymer mixed with the blowing agent 238, each of the plurality of yarns 232 are expandable at least in areas by formation of the foamed or cellular structure 238A when the blowing agent 238 is activated. Optionally, a heat absorbing material, such as carbon black or other laser absorbing material, which can be, for example, a laser absorbing pigment or dye, can also be mixed with the polymer and the blowing agent 238 to allow for activation of the blowing agent 238 via application of a laser in order to generate heat. As illustrated in FIG. n activation, such as through the application of heat, each of the plurality ofyarns 232 of the expandable pintle 230 expand at least in areas by formation of a foamed or cellular structure 238A to fill a greater volume of the pintle receiving channel 28, as compared to before expansion of the expandable pintle 230. The expansion causes a tightening of the seam of the base material 16 that is formed at the ends of the industrial fabric 10, which alleviates the issues of undesirable marking in a paper sheet and premature seam wear of previous industrial fabrics including previous pintles joining the ends of the previous fabrics. As such, the expandable pintle 230 of FIGS. 6A-6B provides the same advantages as the expandable pintles 30 and 130 of FIGS. 4A-4B and FIGS. 5A-5B, respectively.

[0066] FIG. 7A is a cross-sectional view through a fourth embodiment of an expandable pintle 330 in an initial state, used in the industrial fabric 10. FIG. 7B is a cross-sectional view through the fourth embodiment of the expandable pintle 330 in an expanded state. The expandable pintle 330 of FIGS. 7A-7B is substantially similar to the expandable pintle 230 of FIGS. 6A-6B, and therefore it is to be understood that the previous disclosure regarding the expandable pintle 230 of FIGS. 6A-6B equally applies to the expandable pintle 330 of FIGS. 7A-7B unless otherwise noted. As such, only the differences between the expandable pintle 330 of FIGS. 7A-7B and the expandable pintle 230 of FIGS. 6A-6B will be discussed below. As discussed, the expandable pintle 230 of FIGS. 6A-6B includes a multifilament in which each of the plurality of yarns 232 of the expandable pintle 230 are formed from a polymer mixed with the blowing agent 238. In contrast, in the embodiment illustrated in FIGS. 7A-7B, only some of the plurality of yarns 332 include the blowing agent 338, while other yarns of the plurality of yarns 332 do not include the blowing agent 338. As a result, in the expandable pintle 330 of FIGS. 7A-7B, only some of the plurality of yarns 332 are expandable at least in areas by formation of the foamed or cellular structure 338A. Specifically, only the yarns including the blowing agent 338 are expandable at least in areas by formation of the foamed or cellular structure 338A.

[0067] In the embodiment illustrated in FIGS. 7A-7B, the expandable pintle 330 includes a first portion of the plurality of yarns 332 that do not include the blowing agent 338 and a second portion of the plurality of yarns 332 that include the blowing agent 338. In some examples, as illustrated, the first portion of the plurality of yarns 332 and the second portion of the plurality of yarns 332 can a in the multifilament yarn. Further, in some examples, the first portion ofthe plurality of yarns 332 without the blowing agent 338 can include three yarns of the plurality of yarns 332, and the second portion of the plurality of yarns 332 with the blowing agent 338 can include three yarns of the plurality of yarns 332. In other examples, the number of yarns that constitutes the first portion and the second portion of the plurality of yarns 332 does not necessarily need to be equal. Additionally, the total number of yarns could vary.

[0068] As illustrated in FIG. 7B, the yarns of the expandable pintle 330 including the blowing agent 338 mixed with the polymer can be activated through the application of heat, causing the blowing agent 338 to expand at least in areas by formation of a foamed or cellular structure 338A. Similar to the other disclosed embodiments, the yarns including the blowing agent 338 of the expandable pintle 330 of FIGS. 7A-7B expand at least in areas by formation of a foamed or cellular structure 338A to fill a greater volume of the pintle receiving channel 28, as compared to before expansion of the expandable pintle 330. The expansion causes a tightening of the seam of the base material 16 that is formed at the ends of the industrial fabric 10, which alleviates the issues of undesirable marking in a paper sheet and premature seam wear of previous industrial fabrics including previous pintles joining the ends of the previous fabrics. As such, the expandable pintle 330 of FIGS. 7A-7B provides the same advantages as the expandable pintle 230 of FIGS. 6A-6B, but only some of the plurality of yarns 332 of the expandable pintle 330 are expandable, while others are not.

[0069] FIG. 8A is a cross-sectional view through the industrial fabric 10 of the present disclosure. In the embodiment illustrated in FIG. 8A, it is to be understood that a pintle 50 can be any one of the expandable pintles 30, 130, 230, or 330 illustrated in FIGS. 4A-7B of the present application. Further, in some embodiments, the pintle 50 may not be an expandable pintle, but rather could be a non-expandable pintle. In the embodiment illustrated in FIG. 8A, it can be seen that the industrial fabric 10 can further include a first channel 40 and a second channel 42 that extend through the base material 16 parallel to the pintle receiving channel 28. Each of the first channel 40 and the second channel 42 can be positioned laterally adjacent to one of the plurality of loops 24, 26 on the ends of the base material 16 in a direction away from the pintle receiving channel 28. In other words, the first channel 40 and the second channel 42 can each be formed between t CD yarns 14 of the base material 16 that are positioned closest to thepintle receiving channel 28, such that each of the first channel 40 and the second channel 42 are positioned on either side of the pintle receiving channel 28.

[0070] An expandable staffer 44 can be positioned within at least one of the first channel 40 and the second channel 42, such that the expandable staffer 44 extends through the first channel 40 and / or the second channel 42 in a direction axially parallel to the pintle 50 extending through the pintle receiving channel 28. In some examples, the expandable staffer 44 may only be positioned within one of the first channel 40 or the second channel 42. In other examples, a first expandable staffer 44 can be positioned within the first channel 40 and a second expandable staffer 44 can be positioned within the second channel 42. Each of the expandable staffers 44 can have a material composition similar to or the same as each of the expandable pintles 30, 130, 230, and 330 as noted above. More specifically, the expandable staffer 44 can include a plurality of yarns 46 and at least a portion of the plurality of yarns 46 include a material mixed with a blowing agent. As such, as illustrated in FIG. 8B, the expandable staffer 44 is adapted to expand at least in areas by formation of a foamed or cellular structure 48 upon activation of the blowing agent to fill a greater volume of the first channel 40 and / or the second channel 42 extending through the industrial fabric 10. The expandable staffer 44 aids in creating more uniform permeability in the seam region of the base fabric so that it is more similar to a remainder of the industrial fabric 10, providing further advantages to the industrial fabric 10. In other examples, the expandable staffer 44 can be formed as a monofilament yarn, and at least a portion of the monofilament yarn can include the material mixed with the blowing agent, which is adapted to expand at least in areas by formation of into a foamed or cellular structure 48 upon activation of the blowing agent to fill a greater volume of the first channel 40 and / or the second channel 42 extending through the industrial fabric 10.

[0071] Although the present disclosure discusses specific examples (FIGS. 4A-4B, 5A-5B, 6A-6B, 7A-7B, and 8A-8B) of expandable pintles 30, 130, 230, 330 including various combinations of expanding or non-expanding yarns 32, 132, 232, 332, it is to be understood that each are non-limiting examples. More specifically, the different examples can be combined in any way that results in the expandable pintles 30, 130, 230, 330 expanding upon activation. For example, one combination could include yarns 132 with a core 134 surrounded by a sheath 136 including the agent 138 alternating in a pattern with yarns formed as a monofilament (i.e.,a single material) and / or a core and sheath arrangement without a blowing agent. In another example, an expandable pintle could include yarns 132 with a core 134 surrounded by a sheath 136 including the blowing agent 138 and / or yarns 232 including the blowing agent 238, and yarns that do not include a blowing agent whatsoever. As such, it is to be understood that the present disclosure includes non-limiting examples and that any combination of yarns 32, 132, 232, 332, as discussed with regards to FIGS. 4A-8B, could be realized by those skilled in the art.

[0072] The present disclosure also provides a method of forming an industrial fabric 10 including any one of the previously disclosed expandable pintles 30, 130, 230, or 330. The method can include a step of providing a base material 16 having ends which include a plurality of loops 24, 26. The method can further include a step of intermeshing the plurality of loops 24, 26 to form a pintle receiving channel 28. The method can further include a step of joining the ends of the base material 16 by inserting the expandable pintle (30, 130, 230, or 330) into the pintle receiving channel 28 to form a continuous belt 22. In some examples, the expandable pintle (30, 130, 230, or 330) can include a multifilament yarn including a plurality of yarns and at least a portion of the plurality of yarns are formed from a polymer mixed with a blowing agent (38, 138, 238, 338). The method can further include applying energy to the plurality of yarns to activate the blowing agent (38, 138, 238, 338) to expand the plurality of yarns including the blowing agent (38, 138, 238, 338) at least in areas by formation of a foamed or cellular structure (38A, 138A, 238A, 338A) to fill a greater volume of the pintle receiving channel 28. In some examples, the step of applying energy can include applying a laser at selected locations and generating heat by the laser energy being absorbed by the plurality of expanded yarns including the blowing agent (38, 138, 238, 338). In other embodiments, the method of forming the industrial fabric 10 can include more or less steps than the aforementioned disclosed method.

[0073] Having thus described the present embodiments in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description of the disclosure, could be made without altering the inventive concepts and principles embodied therein. It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, pect to those parts, the inventive concepts and principles embodied therein.The present embodiment and optional configurations are therefore to be considered in all respects as exemplary and / or illustrative and not restrictive, the scope of the disclosure being indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes to this embodiment which come within the meaning and range of equivalency of said claims are therefore to be embraced therein.

[0074] Log of Reference Numerals

[0075] 10 Industrial Fabric

[0076] 12 MD Yarns

[0077] 14 CD Yarns

[0078] 16 Base Material

[0079] 18 First Fold Region

[0080] 20 Second Fold Region

[0081] 22 Continuous Belt

[0082] 24 First Seam Loops

[0083] 26 Second Seam Loops

[0084] 28 Pintle Receiving Channel

[0085] 30 Expandable Pintle

[0086] 32 Yarns

[0087] 34 Core

[0088] 36 Sheath

[0089] 38 Blowing Agent

[0090] 38A Foamed or Cellular Structure

[0091] 40 First Channel

[0092] 42 Second Channel

[0093] 44 Expandable Staffer

[0094] 46 Yarns

[0095] 48 Foamed or Cellular Structure

[0096] 50 Pintle

[0097] 130 Expandable Pintle

[0098] 132 Yarns

[0099] 134 Core136 Sheath

[0101] 138 Blowing Agent

[0102] 138A Foamed or Cellular Structure

[0103] 230 Expandable Pintle

[0104] 232 Yarns

[0105] 238 Blowing Agent

[0106] 238A Foamed or Cellular Structure

[0107] 330 Expandable Pintle

[0108] 332 Yarns

[0109] 338 Blowing Agent

[0110] 338A Foamed or Cellular Structure

Claims

CLAIMSWhat is claimed is:1 . An industrial fabric comprising: a base material having ends which include a plurality of loops that are intermeshed to form a pintle receiving channel; and an expandable pintle extending through the pintle receiving channel to join the ends of the base material to form a continuous belt, the expandable pintle comprising: a multifilament yarn including a plurality of yarns, at least a portion of the plurality of yarns include a material mixed with a blowing agent; wherein, upon activation of the blowing agent, the yarns including the blowing agent are adapted to expand at least in areas by formation of a foamed or cellular structure to fill a greater volume of the pintle receiving channel.

2. The industrial fabric of claim 1 , wherein at least a portion of the plurality of yarns include a core formed from a first material mixed with carbon black or another laser or heat absorbing material, and a sheath surrounding the core and formed from a second material mixed with the blowing agent.

3. The industrial fabric of claim 2, wherein the first material of the core is a first polymer and the second material of the sheath is a second polymer different than the first polymer.

4. The industrial fabric of claim 3, wherein the first polymer is a polyamide and the second polymer is a thermoplastic elastomer.

5. The industrial fabric of claim 1 , wherein the blowing agent is a heat activated chemical blowing agent.

6. The industrial fabric of claim 5, wherein the chemical blowing agent is heat activated at an activation temperature in a range from 150 - 350°C.

7. The industrial fabric of claim 2, wherein each of the plurality of yarns include the sheath surrounding the core and formed from the second material mixed with the blowing agent, such that each of the plurality of yarns is expandable at least in areas by formation of the foamed or cellular structure.

8. The industrial fabric of claim 2, wherein: a first portion of the plurality of yarns do not include the sheath surrounding the core; and a second portion of the plurality of yarns include the sheath surrounding the core and formed from the second material mixed with the blowing agent, such that the second portion of the plurality of yarns are expandable at least in areas by formation of the foamed or cellular structure.

9. The industrial fabric of claim 1 , wherein at least a portion of the plurality of yarns further include the material mixed with a laser absorbing pigment or dye.

10. The industrial fabric of claim 1 , wherein the blowing agent is a physical blowing agent.

11. The industrial fabric of claim 1 , wherein each of the plurality of yarns are formed from a polymer and at least some of the plurality of yarns include the polymer mixed with the blowing agent.

12. The industrial fabric of claim 11 , wherein at least some of the plurality of yarns formed from the polymeric material mixed with the blowing agent are further mixed with another laser or heat absorbing material.

13. The industrial fabric of claim 11 , wherein each of the plurality of yarns are formed from a polymer mixed with the blowing agent, such that each of the plurality of yarns are expandable at least in areas by formation of the foamed or cellular structure.

14. The industrial fabric of claim 11 , wherein a first portion of the plurality of yarns do not include the blowing agent, and a second portion of the plurality of yarns include the blowing agent, such that the second portion of the plurality of yarns are expandable at least in areas by formation of the foamed or cellular structure.

15. The industrial fabric of claim 14, wherein the first portion of the plurality of yarns are formed from a first polymer and the second portion of the plurality of yarns are formed from a second polymer different than the first polymer.

16. The industrial fabric of claim 1 , wherein the base material is a fabric including a system of MD yarns connected to a system of CD yarns and is formed having ends that are joined in order to form the continuous belt.

17. The industrial fabric of claim 1 , wherein the industrial fabric is a papermaking fabric.

18. An industrial fabric comprising: a base material having ends which include a plurality of loops that are intermeshed to form a pintle receiving channel; a pintle extending through the pintle receiving channel to join the ends of the base material to form a continuous belt; and an expandable staffer in which at least a portion of the expandable staffer includes a material mixed with a blowing agent, the expandable staffer is positioned in at least one of a first channel or a second channel that extend through the base material parallel to the pintle receiving channel, and each of the first channel and the second channel are positioned laterally adjacent the plurality of loops on each end of the base material in a direction away from the pintle receiving channel,wherein, upon activation of the blowing agent, the expandable staffer is adapted to expand at least in areas by formation of a foamed or cellular structure to fill a greater volume of at least one of the first channel or the second channel.

19. The industrial fabric of claim 18, wherein the pintle is an expandable pintle that is adapted to expand into the foamed or cellular structure upon activation of the blowing agent within the expandable pintle.

20. The industrial fabric of claim 18, wherein the expandable staffer includes a plurality of yarns, and at least a portion of the plurality of yarns of the expandable staffer include the material mixed with the blowing agent.

21. The industrial fabric of claim 18, wherein the expandable staffer is a monofilament yarn, and at least a portion of the monofilament yarn includes the material mixed with the blowing agent.

22. A method of forming an industrial fabric, the method comprising: providing a base material having ends which include a plurality of loops; intermeshing the plurality of loops to form a pintle receiving channel; joining the ends of the base material by inserting an expandable pintle into the pintle receiving channel to form a continuous belt, the expandable pintle comprising a multifilament yarn including a plurality of yarns and at least a portion of the plurality of yarns are formed from a polymer mixed with a blowing agent; andapplying energy to the plurality of yarns to activate the blowing agent to expand the yarns including the blowing agent at least in areas to a foamed or cellular structure to fill a greater volume of the pintle receiving channel.

23. The method of claim 22, wherein the applying energy includes applying a laser at selected locations and generating heat by the laser energy being absorbed by the plurality of yarns including the blowing agent.

24. The method of claim 22, wherein the blowing agent is a heat activated chemical blowing agent that is activated at an activation temperature in a range from 150 - 350°C.

25. The method of claim 22, wherein the method is for making a papermaking fabric.

26. The method of claim 22, wherein at least a portion of the plurality of yarns include a core formed from a first polymer mixed with carbon black or another laser or heat absorbing material, and a sheath surrounding the core and formed from a second polymer mixed with the blowing agent.

27. The method of claim 22, wherein at least a portion of the plurality of yarns are further formed from the polymer mixed with a laser absorbing pigment or dye.

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