METHOD OF PRODUCING COMPOUND FABRICS
United States Patent 3837943
A method for producing a pile type fabric in which the pile or fleece is sewn on a base fabric with a stitching thread composed of materials having different thermal softening characteristics, so that one of the components bonds the thread to itself and to the base fabric. Another component may have heat shrinkable characteristics within the range of temperatures of the treatment.
US Patent References:
Velvet-like pile products
Ploch et al. - February 1965 - 3168883
Method of sewing textile webs together
Gardner - February 1966 - 3234061
Method of sewing textile webs together
Kuhn - August 1967 - 3337381
HEAT SEALABLE YARN AND FABRIC
Kuhn - January 1969 - 3420731
/3649428.html
Hughes - March 1972 - 3649428
Velvet-like pile products
Ploch et al. - February 1965 - 3168883
Method of sewing textile webs together
Gardner - February 1966 - 3234061
Method of sewing textile webs together
Kuhn - August 1967 - 3337381
HEAT SEALABLE YARN AND FABRIC
Kuhn - January 1969 - 3420731
/3649428.html
Hughes - March 1972 - 3649428
Inventors:
Ploch, Siegfrid (Karl-Marx-Stadt, DT)
Klinger, Kurt (Leutersdorf, DT)
Reif, Joachim (Karl-Marx-Stadt, DT)
Klinger, Kurt (Leutersdorf, DT)
Reif, Joachim (Karl-Marx-Stadt, DT)
Application Number:
05/295309
Publication Date:
09/24/1974
Filing Date:
10/05/1972
View Patent Images:
Export Citation:
Assignee:
Forschungsinstitut, Fur Textiltechnolgie (Karl-Marx-Stadt, DT)
Primary Class:
Other Classes:
28/107, 112/411, 28/159, 28/153
International Classes:
A41D5/00; D04B21/16; D04B21/14; B32B7/08
Field of Search:
112/411 28/77 156/93
Primary Examiner:
Whitby, Edward G.
Attorney, Agent or Firm:
Nolte, And Nolte
Claims:
What is claimed is
1. A method for producing a compound fabric of the type having a base fabric onto which a layer of threads or fibers of a fiber fleece extending substantially perpendicular to the length of the base fabric are fastened by means of parallel seams of a stitching thread; said method comprising stitching said fiber fleece to said base fabric with stitching threads with filaments of material having different thermal characteristics, at least one filament material component having a lower thermal softening range than another filament component of said stitching thread, and following said stitching, subjecting the resultant compound fabric to a heat treatment at a temperature at which the filament material component having the lower softening range becomes heat bondable and fuses to the threads and fibers in contact therewith.
2. The method of claim 1 further comprising stitching a filament component with said stitching thread which shrinks in the softening range of the heat bondable filament material component.
3. The method of claim 1 wherein said step of stitching comprises stitching a mixed polymeric bi-component or bi-constituent filament material, the component having the lower thermal stability being heat bondable within said range and the other component having heat shrinkable characteristics within said range.
1. A method for producing a compound fabric of the type having a base fabric onto which a layer of threads or fibers of a fiber fleece extending substantially perpendicular to the length of the base fabric are fastened by means of parallel seams of a stitching thread; said method comprising stitching said fiber fleece to said base fabric with stitching threads with filaments of material having different thermal characteristics, at least one filament material component having a lower thermal softening range than another filament component of said stitching thread, and following said stitching, subjecting the resultant compound fabric to a heat treatment at a temperature at which the filament material component having the lower softening range becomes heat bondable and fuses to the threads and fibers in contact therewith.
2. The method of claim 1 further comprising stitching a filament component with said stitching thread which shrinks in the softening range of the heat bondable filament material component.
3. The method of claim 1 wherein said step of stitching comprises stitching a mixed polymeric bi-component or bi-constituent filament material, the component having the lower thermal stability being heat bondable within said range and the other component having heat shrinkable characteristics within said range.
Description:
This invention relates to a method of producing compound fabrics constituted of a pre-formed base fabric onto which yarns or other fibrous material, such as a fleece, extending approximately lengthwise to the fabric are fastened. In such fabrics the fibrous material extends transversely of, preferably perpendicular or approximately perpendicular to, the length of the fabric in the plane of the fabric, and is sewn thereon by means of longitudinally extending parallel stitched seams.
The type of fabric to which the present invention relates is typified by U.S. Pat. No. 3,168,883. The present invention represents an improvement in the manufacture of such fabrics.
The method of the invention may be used for the production of lining fabrics, outer fabrics for clothing, imitation furs and other fabrics having a textured surface. The method is especially suitable, however, for the production of crepe, especially velvet cord, in which the floats between the stitched seams are cut and the resultant fiber ribs give the fabric the configuration of a velvet cord.
The quilt stitched binding between the base fabric and the overlying yarns or fleece is attained by means of a stitching-knitting machine, such as a Malimo machine. Chain stitch seams are formed which bind the base fabric to the overlying yarns or fleece.
Heretofore the thread of the seams constituted of a synthetic material, for example a polyamide or polyester, very quickly broke due to high tension or damage by the needles. The resultant parting of the seam leads to disintegration of the compound fabric.
It is an object of the invention to impede breaking of the seams and provide a method of producing stable, wear-resistant, compound fabrics.
Acording to the invention, a thread for the seams is produced of compound filaments and by an additional tightening of the seams damage to the seams and accompanying disintegration of the fabric is fully avoided.
In order to overcome the above problem, it has been proposed that the thread for the seams be comprised of a monofilament core sheathed with a synthetic material, for example by roll fusing, powder centering or powder fusing techniques. This solution, however, has been found to be unsatisfactory, in view of the economic considerations involved and also since such threads are subject to the "blocking" effect, i.e., the mutual adhesion of the synthetic sheaths of the threads on the cones, whereby the processing of the fabric is rendered more difficult.
In accordance with the invention, the sewing threads for bonding the fabric are comprised of one or more filaments, the sewing threads including at least two fiber materials having different thermal characteristics. Thus, one of the fiber material components has a lower thermal softening range than the other fiber material component or components. In manufacturing a fabric in accordance with the invention, after the seams have been formed the fabric is subjected to a heat treatment to a temperature within the softening range of the component having the lower softening range, so that the component having the lower softening range becomes bonded to the base fabric and to the fibrous material sewn onto the base fabric, as well as bonding the thread to itself wherever contact is made between different parts of the thread. In addition, the softening of the thread simultaneously affects the shrinking of the thread, thereby improving the bonding of the compound fabric.
The sewing thread employed in accordance with the invention may be either in the form of a single filament, or a plurality of filaments, the term "filament" being employed herein to refer either to filaments formed as continuous elements, for example by extrusion, or filaments formed by the drawing out and twisting of fibers.
The thread for sewing the compound fabric, in accordance with the invention, may be in the form of a twisted thread including filaments of different thermal resistance, i.e., the filaments forming the thread are a mixture of filaments having different thermal softening and shrinkability characteristics. Alternatively, filaments of two different thermal characteristics may be disposed closely adjacent each other and introduced simultaneously into the same guiding element, such as the puncturing needle of the stitching-knitting machine employed in the production of the compound fabric, so that the filaments are simultaneously introduced into the machine to form a chain-stitch seam.
Very good results have been obtained when unmodified polypropylene filaments are employed as one of the components of the stitching thread. While modified polypropylene filaments may be employed, such as filaments modified to improve their ability to accept dyes, it is of course important that the modification employed does not have an adverse effect upon the thermal characteristics and adhesive power of the material in the plastic deformable state, and the material must thus be selected to avoid such undesirable change in these characteristics.
Mixtures of polyethylene terephthalate and polypropylene filament materials may also be employed as the stitching threads in accordance with the invention. In order to determine the most desirable stitching thread, from the standpoint of the relative percentages of polyethylene terephthalate and polypropylene filaments forming the twisted filament thread, the two ends of a number of pieces of thread of different relative proportions of these materials were fused at different temperatures to a flat piece of a cellulose material, the test pieces of threads having legs about 10mm long to form clamps to facilitate the testing of the adhesive strength of the bond. The adhesive strength of each bond was determined by a tensile strength test, the results of tests of various threads composed of filaments of the above materials being tabulated in Table 1:
POLYPROPYLENE ADHESIVE THREAD SIZE CONTENT STRENGTH ______________________________________ Nm tex (%) (pounds) (m/g) (g/1000m) ______________________________________ 33,3 30 55,5 270 30,0 34 50,0 286 28,1 36 62,5 314 25,7 38 57,1 368 21,2 48 67,1 479 20,0 50 66,6 399 18,0 56 80,0 333 16,4 64 72,9 408 ______________________________________ Table 1: Dependence of the Adhesive Strength of the Stitching Thread on the Percentage of Polypropylene and on the Thread Size.
The strength of the stitching thread is also influenced by the number of individual filaments employed in the structure of the thread, and by the temperature employed in the bonding process. The strength of the stitching thread is further influenced, although to a lesser extent, by the quality and quantity of the material employed in the preparation of the threads.
Interpolymer filaments may also be employed of one of the constituents of a stitching thread in accordance with the invention. For example, similar high adhesive strengths are obtained when the filaments of the stitching thread contain between 30 and 70 percent of a vinylchloride and vinylacetate (85:15) copolymer. While the remainder of the stitching thread may be comprised of cellulose filaments, the adhesive strength of the stitching thread is increased if polyester filaments are substituted for the cellulose filaments. Strength tests of such stitching threads are illustrated in Table 2. In these tests, it is immaterial whether the polyester component is a polymer of terephthalic acid and ethyleneglycol or 1,4-bis-(hydroxymethyl-)cyclohexane (cyclohexanedimethylol-(1.4) ) or a copolyester with isophthalic acid or p-oxybenozoic acid as a comonomer constituent.
______________________________________ POLYESTER ADHESIVE THREAD SIZE CONTENT STRENGTH ______________________________________ Nm tex (%) (pounds) (m/g) (g/1000m) ______________________________________ 36/2 28×2 33 700 40/3 25×3 50 720 40/3 25×3 67 800 ______________________________________ Table 2: Dependence of the Adhesive Strength of the Mixed Composition of a Twisted Vinylchloride/Vinylacetate-Copolymer filament (85:15) and Polyester Filament Thread.
Polyethylene filament materials may also be employed as one of the constituents of a stitching thread in accordance with the invention, if it is kept in mind with respect to the processing and use of such filaments that this material melts at temperatures between 110° and 135°C. Polyolefin filament materials may also be employed as either the base materials of the stitching thread, or as the shrinkable and bonding component thereof, in the form of very fine monofilaments or multifilaments.
As an alternative, the stitching thread employed in the method of the invention may be formed of bicomponent filament materials of the side-on-side type, the core-sheath type of the matrix-fibril type, provided that the softening of fusing ranges of the polymer components of the bicomponent filaments are sufficiently far apart. For example, in such a structure one component may be a polyethylene terephthalate and the other a polyolefin or a mixture of two polyolefins having a softening range between 115° and 175°C.
It has further been found that especially tight stitching seams may be obtained if the stitching thread includes thermally shrinkable materials, such as highly shrinkable polyester filaments, in addition to the thermally responsive bonding filaments. Further, if it is desired to employ a stitching thread enabling a particularly bulky seam to fill the punctured holes in the base fabric, a stitching thread may be employed comprised of three different types of filaments, such as a thermally responsive bonding thread, a thermally responsive shrinkable thread and a textured filament for effecting the formation of the bulky seam.
The heat treatment necessary to effect the desired shrinking as well as the desired adhesive strength of course depends upon the type of bicomponent or biconstituent filament material employed.
Synthetic fibers of polyoxymethylene, i.e., polyformaldehyde fiber materials, also have very favorable characteristics for use as a constituent of the stitching threads in the manufacturing of bonded fabrics in accordance with the invention. These materials have great breaking strength, are not electrostatically chargeable, and can satisfactorally stand twisting without abrasion. The adhesive strengths obtained with such materials, depending upon the dwell time at a temperature of 160° to 180°C, are satisfactory to meet the requirements of practical applications.
The heat treatment in accordance with the invention may employ infrared radiation, or alternatively hot air treatment may be employed.
Several examples of satisfactory stitching threads that may be employed in accordance with the invention are as follows:
EXAMPLE 1
The stitching thread consisted of a twisted thread of a polyester filament 5.6 tex and a polypropylene filament 5.6 tex, the thread having a twist of 350 turns per meter. A bonded fabric stitch with this twisted thread was subjected, on a stretching frame, to a heat treatment between 165° and 175°C at which the polypropylene filament became bondable, effecting the mutual fusing of the meshes of the seam and the fusing of the thread to the bonded fabric.
EXAMPLE 2
The stitching thread is a mixed spun thread of 14 tex, produced by conventional spinning methods and consisting of fibers of a mixed polymer on a basis of vinyl-acetate/vinyl-chloride or vinylidenchloride/vinyl-chloride copolymers, and cellulose fibers such as viscose fibers or cotton. Mixing ratios of 33:67 and 50:50 were used for the mixed polymer. Bonding of the stitching thread to itself and to the base occurred with a heat treatment at 100° to 170°C, in which range the mixed polymer fibers became heat bondable.
EXAMPLE 3
The stitching thread consisted of a polyester filament 5.6 tex and a bicomponent filament 8.4 tex on the basis of a modified polyester and polypropylene. Both threads were fed jointly and untwisted by way of the same puncturing needle of the stitching-knitting machine. In this Example, the polypropylene may be crystalline and contain admixtures of another polyolefin.
EXAMPLE 4
The stitching thread consisted of a bicomponent or biconstituent filament 10 tex on the basis of a polyamide and polyolefin, fusion occurring after a heat treatment at 130° to 150°C when the polyolefin was a polyethylene. The heat treatment occurred on a stretching frame, although an infrared drying treatment alternatively could have been employed.
While the invention has been disclosed with reference to a limited number of embodiments, it is apparent that many modifications and variations may be made therein, and it is therefore intended in the following claims to cover each such vairation and modification as falls within the true spirit and scope of the invention.
The type of fabric to which the present invention relates is typified by U.S. Pat. No. 3,168,883. The present invention represents an improvement in the manufacture of such fabrics.
The method of the invention may be used for the production of lining fabrics, outer fabrics for clothing, imitation furs and other fabrics having a textured surface. The method is especially suitable, however, for the production of crepe, especially velvet cord, in which the floats between the stitched seams are cut and the resultant fiber ribs give the fabric the configuration of a velvet cord.
The quilt stitched binding between the base fabric and the overlying yarns or fleece is attained by means of a stitching-knitting machine, such as a Malimo machine. Chain stitch seams are formed which bind the base fabric to the overlying yarns or fleece.
Heretofore the thread of the seams constituted of a synthetic material, for example a polyamide or polyester, very quickly broke due to high tension or damage by the needles. The resultant parting of the seam leads to disintegration of the compound fabric.
It is an object of the invention to impede breaking of the seams and provide a method of producing stable, wear-resistant, compound fabrics.
Acording to the invention, a thread for the seams is produced of compound filaments and by an additional tightening of the seams damage to the seams and accompanying disintegration of the fabric is fully avoided.
In order to overcome the above problem, it has been proposed that the thread for the seams be comprised of a monofilament core sheathed with a synthetic material, for example by roll fusing, powder centering or powder fusing techniques. This solution, however, has been found to be unsatisfactory, in view of the economic considerations involved and also since such threads are subject to the "blocking" effect, i.e., the mutual adhesion of the synthetic sheaths of the threads on the cones, whereby the processing of the fabric is rendered more difficult.
In accordance with the invention, the sewing threads for bonding the fabric are comprised of one or more filaments, the sewing threads including at least two fiber materials having different thermal characteristics. Thus, one of the fiber material components has a lower thermal softening range than the other fiber material component or components. In manufacturing a fabric in accordance with the invention, after the seams have been formed the fabric is subjected to a heat treatment to a temperature within the softening range of the component having the lower softening range, so that the component having the lower softening range becomes bonded to the base fabric and to the fibrous material sewn onto the base fabric, as well as bonding the thread to itself wherever contact is made between different parts of the thread. In addition, the softening of the thread simultaneously affects the shrinking of the thread, thereby improving the bonding of the compound fabric.
The sewing thread employed in accordance with the invention may be either in the form of a single filament, or a plurality of filaments, the term "filament" being employed herein to refer either to filaments formed as continuous elements, for example by extrusion, or filaments formed by the drawing out and twisting of fibers.
The thread for sewing the compound fabric, in accordance with the invention, may be in the form of a twisted thread including filaments of different thermal resistance, i.e., the filaments forming the thread are a mixture of filaments having different thermal softening and shrinkability characteristics. Alternatively, filaments of two different thermal characteristics may be disposed closely adjacent each other and introduced simultaneously into the same guiding element, such as the puncturing needle of the stitching-knitting machine employed in the production of the compound fabric, so that the filaments are simultaneously introduced into the machine to form a chain-stitch seam.
Very good results have been obtained when unmodified polypropylene filaments are employed as one of the components of the stitching thread. While modified polypropylene filaments may be employed, such as filaments modified to improve their ability to accept dyes, it is of course important that the modification employed does not have an adverse effect upon the thermal characteristics and adhesive power of the material in the plastic deformable state, and the material must thus be selected to avoid such undesirable change in these characteristics.
Mixtures of polyethylene terephthalate and polypropylene filament materials may also be employed as the stitching threads in accordance with the invention. In order to determine the most desirable stitching thread, from the standpoint of the relative percentages of polyethylene terephthalate and polypropylene filaments forming the twisted filament thread, the two ends of a number of pieces of thread of different relative proportions of these materials were fused at different temperatures to a flat piece of a cellulose material, the test pieces of threads having legs about 10mm long to form clamps to facilitate the testing of the adhesive strength of the bond. The adhesive strength of each bond was determined by a tensile strength test, the results of tests of various threads composed of filaments of the above materials being tabulated in Table 1:
POLYPROPYLENE ADHESIVE THREAD SIZE CONTENT STRENGTH ______________________________________ Nm tex (%) (pounds) (m/g) (g/1000m) ______________________________________ 33,3 30 55,5 270 30,0 34 50,0 286 28,1 36 62,5 314 25,7 38 57,1 368 21,2 48 67,1 479 20,0 50 66,6 399 18,0 56 80,0 333 16,4 64 72,9 408 ______________________________________ Table 1: Dependence of the Adhesive Strength of the Stitching Thread on the Percentage of Polypropylene and on the Thread Size.
The strength of the stitching thread is also influenced by the number of individual filaments employed in the structure of the thread, and by the temperature employed in the bonding process. The strength of the stitching thread is further influenced, although to a lesser extent, by the quality and quantity of the material employed in the preparation of the threads.
Interpolymer filaments may also be employed of one of the constituents of a stitching thread in accordance with the invention. For example, similar high adhesive strengths are obtained when the filaments of the stitching thread contain between 30 and 70 percent of a vinylchloride and vinylacetate (85:15) copolymer. While the remainder of the stitching thread may be comprised of cellulose filaments, the adhesive strength of the stitching thread is increased if polyester filaments are substituted for the cellulose filaments. Strength tests of such stitching threads are illustrated in Table 2. In these tests, it is immaterial whether the polyester component is a polymer of terephthalic acid and ethyleneglycol or 1,4-bis-(hydroxymethyl-)cyclohexane (cyclohexanedimethylol-(1.4) ) or a copolyester with isophthalic acid or p-oxybenozoic acid as a comonomer constituent.
______________________________________ POLYESTER ADHESIVE THREAD SIZE CONTENT STRENGTH ______________________________________ Nm tex (%) (pounds) (m/g) (g/1000m) ______________________________________ 36/2 28×2 33 700 40/3 25×3 50 720 40/3 25×3 67 800 ______________________________________ Table 2: Dependence of the Adhesive Strength of the Mixed Composition of a Twisted Vinylchloride/Vinylacetate-Copolymer filament (85:15) and Polyester Filament Thread.
Polyethylene filament materials may also be employed as one of the constituents of a stitching thread in accordance with the invention, if it is kept in mind with respect to the processing and use of such filaments that this material melts at temperatures between 110° and 135°C. Polyolefin filament materials may also be employed as either the base materials of the stitching thread, or as the shrinkable and bonding component thereof, in the form of very fine monofilaments or multifilaments.
As an alternative, the stitching thread employed in the method of the invention may be formed of bicomponent filament materials of the side-on-side type, the core-sheath type of the matrix-fibril type, provided that the softening of fusing ranges of the polymer components of the bicomponent filaments are sufficiently far apart. For example, in such a structure one component may be a polyethylene terephthalate and the other a polyolefin or a mixture of two polyolefins having a softening range between 115° and 175°C.
It has further been found that especially tight stitching seams may be obtained if the stitching thread includes thermally shrinkable materials, such as highly shrinkable polyester filaments, in addition to the thermally responsive bonding filaments. Further, if it is desired to employ a stitching thread enabling a particularly bulky seam to fill the punctured holes in the base fabric, a stitching thread may be employed comprised of three different types of filaments, such as a thermally responsive bonding thread, a thermally responsive shrinkable thread and a textured filament for effecting the formation of the bulky seam.
The heat treatment necessary to effect the desired shrinking as well as the desired adhesive strength of course depends upon the type of bicomponent or biconstituent filament material employed.
Synthetic fibers of polyoxymethylene, i.e., polyformaldehyde fiber materials, also have very favorable characteristics for use as a constituent of the stitching threads in the manufacturing of bonded fabrics in accordance with the invention. These materials have great breaking strength, are not electrostatically chargeable, and can satisfactorally stand twisting without abrasion. The adhesive strengths obtained with such materials, depending upon the dwell time at a temperature of 160° to 180°C, are satisfactory to meet the requirements of practical applications.
The heat treatment in accordance with the invention may employ infrared radiation, or alternatively hot air treatment may be employed.
Several examples of satisfactory stitching threads that may be employed in accordance with the invention are as follows:
EXAMPLE 1
The stitching thread consisted of a twisted thread of a polyester filament 5.6 tex and a polypropylene filament 5.6 tex, the thread having a twist of 350 turns per meter. A bonded fabric stitch with this twisted thread was subjected, on a stretching frame, to a heat treatment between 165° and 175°C at which the polypropylene filament became bondable, effecting the mutual fusing of the meshes of the seam and the fusing of the thread to the bonded fabric.
EXAMPLE 2
The stitching thread is a mixed spun thread of 14 tex, produced by conventional spinning methods and consisting of fibers of a mixed polymer on a basis of vinyl-acetate/vinyl-chloride or vinylidenchloride/vinyl-chloride copolymers, and cellulose fibers such as viscose fibers or cotton. Mixing ratios of 33:67 and 50:50 were used for the mixed polymer. Bonding of the stitching thread to itself and to the base occurred with a heat treatment at 100° to 170°C, in which range the mixed polymer fibers became heat bondable.
EXAMPLE 3
The stitching thread consisted of a polyester filament 5.6 tex and a bicomponent filament 8.4 tex on the basis of a modified polyester and polypropylene. Both threads were fed jointly and untwisted by way of the same puncturing needle of the stitching-knitting machine. In this Example, the polypropylene may be crystalline and contain admixtures of another polyolefin.
EXAMPLE 4
The stitching thread consisted of a bicomponent or biconstituent filament 10 tex on the basis of a polyamide and polyolefin, fusion occurring after a heat treatment at 130° to 150°C when the polyolefin was a polyethylene. The heat treatment occurred on a stretching frame, although an infrared drying treatment alternatively could have been employed.
While the invention has been disclosed with reference to a limited number of embodiments, it is apparent that many modifications and variations may be made therein, and it is therefore intended in the following claims to cover each such vairation and modification as falls within the true spirit and scope of the invention.