Textile Articles And Thermal Treatment Thereof

Abstract

A textile article comprising a knitted tubular member is disclosed. The tubular member is fixated and being knitted from one or more types of knitting-loops, where each type of knitting-loops is characterized by a substantially uniform shape and size.

Description

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to textile articles and, more particularly, to fixated textile articles having improved properties. The present invention further relates to a method, device and system for thermally treating textile articles.

Traditionally, the fabrication of garments has been a highly labor-intensive and expensive process, typically involving the cutting and sewing together of multiple pieces of a woven fabric according to a predetermined pattern to provide an appropriately shaped garment. Necessarily, such garments are relatively expensive due to the considerable amount of skilled workmanship required for the cutting and sewing operations. It has therefore been proposed to utilize knitting processes in the fabrication of garments. Compared to woven garment, the knitted garment can more easily deform by compressing or elongating the individual knitting-loops forming the garment. This ability to stretch adds to the wearing comfort of garments made from knitted article.

For decades, knitwear articles have traditionally been manufactured in two steps: firstly, a yarn was knitted into a planar article, and secondly opposite sides of the planar article were joined together by stitches to form a tubular knitwear article with a seam connecting the two opposite sides. Typically, for aesthetical reasons, such knitwear has an inwardly protruding seam, resulting in discomfort to the wearer, in particular when the knitwear article is in direct contact with the body. In automated knitting processes, the aforementioned two-step process has a limited efficiency, both in terms of manufacturing time and in terms of machinery, due to the inherent limitation of transferring the planar article from the knitting machine to the stitching machine.

The introduction of circular knitting machines with differentiated diameters has attracted interest in the knitting industry. Circular knitting machines produce tubular articles in a seamless manner. The simplification to the manufacturing process offered by these machines is mainly attributed to the omission of the aforementioned stitching step. The versatility of these machines allows producing a wide range of semi-finished tubular articles, such as, for example, T-shirts, pants, trousers, dresses, skirts, swimsuits, bras, brassieres, teddies, technical items and the like. From the technical-textile point of view, such semi-finished tubular articles are characterized by a high intrinsic elasticity.

The process of knitting a yarn introduces stresses in the produced article, resulting in an article which is not relaxed. In this respect, articles coming out of the knitting machine are vulnerable to extreme humidity and temperature conditions. Thus, during washing, for example, the knitted article may become smaller and/or loose its shape. Such vulnerable knitted articles are said to be “not fixated”.

The manufacturing process of textile articles thus includes a thermal treatment for the purpose of stabilizing the produced article and providing it with the properties required so as to satisfactorily fit or support the concerned anatomic portions. Generally, there are three types of thermal treatments: fixation, relaxation and/or boarding.

In fixation, the article is subjected to heat at high temperature. The heat results in a relaxation of the yarn, the knitting-loops acquire their final shape and the article becomes substantially stable to extreme humidity and temperature conditions. In relaxation, the article is subjected to lower temperature which reduces tension of the yarn and of the knitting-loops. After relaxation, knitting-loops may still possess residual tension. Boarding is similar to relaxation, in the sense that the temperature is lower than the typical temperature in fixation. In boarding, however, the thermal treated is continued until the wrinkles in the article are completely or partially eliminated.

Traditionally in thermal treatment of tubular articles, the articles are mounted on moving forms and enter a treatment zone. When the article is made from synthetic (e.g., thermoplastic) materials, the treatment zone is constructed to provide the article with a combination of heat and moisture. For articles having a cotton component, the treatment zone is constructed to provide heat and moisture followed by drying, so as to fixate the non-cotton component. Depending on the temperature at the treatment zone, the thermal treatment results in boarding and/or dimensional fixation.

Several types of systems for fixation and/or boarding of articles are known.

One type of system is manufactured by Takatori, Japan (see, e.g., trade names/references, TAS-44SI, TAS-72I), and Tecnopea, Italy (see, e.g., trade name/reference GHIBLI XSL). In these systems, the form is made of sheet aluminum and the treatment zone includes a steam chamber. With such configuration, heat is transferred to the article by a combination of heat-convection (via hot steam) and heat-conduction (through the aluminum form).

In another system, manufactured by Leonard Automatics, U.S. (see, e.g., trade name/reference PROFINISHER 12-8B-GH-S/N 081704), the form includes cylindrical rods made of stainless steel and the heating in the treatment zone is by heated air.

In an additional system, manufactured by Cortese, Italy (see, e.g., trade name/reference BOARDING MACINE 832), the treatment zone includes an infrared chamber whereby heat is transferred to the article via radiation.

In still another system, manufactured by PROLL & LOHMANN, Germany, batches of forms are introduced into an autoclave chamber, where they remain statically until processed.

In the above and other prior art systems, the treatment is performed while the treated article is under tension (i.e., not relaxed). The amount of tension applied to the article prior and during treatment depends on the desired size of the article. Specifically, the size of the form is adapted to the desired size, and the mounting of the article on the form is accomplished by stretching the article to the size of the form.

Thermal treatment under tension has two major drawbacks.

First, in such process the tension of the article during fixation is not uniform, whereby regions of the article being in close proximity or in contact with the form are under larger tension relative to farther regions.

Second, in thermal treatment under tension there are non-uniform friction forces between the article and the form. Friction forces act on the knitting-loops of the article and distort their shape. While in theory the friction forces should vary only slightly along the form (provided that the shape of the form matches the shape of the article), in practice such situation is hardly attainable, for example when the mounting of the article on the form is performed manually. Even when the mounting is by automated machines (e.g., robots), non-uniform friction forces are inevitable, because widthwise stretching of the article on the form results in lengthwise shortening, which in turn is accompanied by non-uniform friction forces along the form.

The existence of non-uniform tension and/or non-uniform friction forces during fixation result in a situation in which different knitting-loops of the article are fixated at different size and/or shape. Consequently, textile article produced using prior art techniques is of poor quality with various defects including, concaved and/or unsmooth welt, stretch marks, non-homogeneous hue, bulging corners and the like.

An additional limitation of prior art systems is the direct conductive heat transfer from the metal form to the textile article. The article experiences greater heat at the contact areas relative to other areas of the fabric, resulting in zones of substantially different degrees of fixation and formation of “heat burns” on the contact areas. Although attempts have been made to avoid the creation of “heat burns” by reducing the temperature at the treatment zone, the quality of the article was still not satisfactory, because the reduced temperature was insufficient to achieve stabilization of the entire article, and several regions were not fixated.

There is thus a widely recognized need for, and it would be highly advantageous to have, a textile article and thermal treatment thereof devoid of the above limitations.

SUMMARY OF THE INVENTION

The present invention relates to textile articles and their thermal treatment. The textile article comprises a knitted tubular member defining a longitudinal direction and a circumferential direction. In one aspect of the present invention the tubular member is fixated and knitted from one or more types of knitting-loops, where each type of knitting-loops is characterized by a substantially uniform shape and size along the longitudinal and/or circumferential direction.

According to further features in preferred embodiments of the invention described below, at least one end of the tubular member is substantially devoid of arcs in a plane parallel to the longitudinal direction.

According to still further features in the described preferred embodiments the substantially uniform size is characterized by a variance which is lower than 20%.

According to still further features in the described preferred embodiments the substantially uniform shape is characterized by a similarity parameter which is at least 80% for every two knitting-loops along the circumferential direction.

According to still further features in the described preferred embodiments the at least one end is characterized by a deviation from linearity of less than 10%.

According to still further features in the described preferred embodiments the at least one end is substantially orthogonal to the longitudinal direction.

According to still further features in the described preferred embodiments the tubular member is foldable on a planar surface parallel to the longitudinal direction, such that at least a 95% physical contact is established between a front side of the at least one end and a back side thereof.

According to still further features in the described preferred embodiments the tubular member is foldable on a planar surface parallel to the longitudinal direction, such that there is at least 95% overlap betveen a front side of the tubular member and a back side thereof.

According to still further features in the described preferred embodiments the at least one end comprises a welt.

According to still further features in the described preferred embodiments the tubular member is colored by at least one color wherein each color of the at least one color has a substantially uniform hue.

According to still further features in the described preferred embodiments the density and/or size of the knitting-loops is selected so as to provide the tubular member with at least one of a predetermined size and a predetermined specific weight.

According to still further features in the described preferred embodiments the tubular member is knitted from a yarn material selected from the group consisting of an elastomer, a polyester, a cationic polyester, a nylon, a polyurethane, cotton, viscose and any combination thereof.

According to still further features in the described preferred embodiments the tubular member is knitted spirally about the longitudinal direction in a manner such that each spiral turn comprises N rows of knitting-loops, wherein N is larger than one.

According to still further features in the described preferred embodiments the tubular member is knitted reciprocatively about the longitudinal direction, for example, using a reciprocation knitting machine.

According to still further features in the described preferred embodiments the textile article further comprising at least one additional knitted member.

According to still further features in the described preferred embodiments the at least one additional knitted member comprises an additional tubular member, which can be, for example, a sleeve, a collar and the like.

According to another aspect of the present invention there is provided a device for holding a tubular member in a thermal treatment zone. The device comprises a base and a form having at least two shafts mounted for rotating with respect to the base. The shafts are adapted for receiving the tubular member and revolving the tubular member with respect to the base.

According to an additional aspect of the present invention there is provided a system for thermally treating a tubular member. The system comprises a thermal treatment zone, for transferring heat to the tubular member; and a holding device, for holding the tubular member in the thermal treatment zone.

According to further features in preferred embodiments of the invention described below, the temperature and/or time of treatment in the thermal treatment zone is selected for fixation, relaxation or boarding of the tubular member.

According to still further features in the described preferred embodiments the system further comprises a conveyor for conveying the holding device into the thermal treatment zone.

According to a further aspect of the present invention there is provided a method of thermally treating a tubular member. The method comprises mounting the tubular member on a holding device, and transferring heat to the tubular member while continuously revolving the tubular member with respect to the device.

According to further features in preferred embodiments of the invention described below, the shafts of the holding device are rotated at rate selected such that when the tubular member is in the thermal treatment zone, time of contact between the tubular member and the shafts is distributed among different portions of the tubular member, in a manner such that any portion of the tubular member does not contact the shafts for too long time.

According to still further features in the described preferred embodiments the shafts are generally cylindrical.

According to still further features in the described preferred embodiments the transverse separation between the shafts is selected so as to allow mounting the tubular member thereon while the knitting-loops forming are subjected to tension.

According to still further features in the described preferred embodiments the transverse separation is adjustable.

According to still further features in the described preferred embodiments the shafts are generally parallel one with respect to each other.

According to still further features in the described preferred embodiments the shafts are inclined one with respect to each other so as to allow the form to receive tubular members having a trapezoidal cross section. According to still further features in the described preferred embodiments an inclination angle of the shafts is adjustable.

According to still further features in the described preferred embodiments the form further comprises a cross-piece connecting top ends of the shafts and configured to allow the shafts to rotate with respect to the cross-piece. According to still further features in the described preferred embodiments the cross-piece has a rounded shape.

According to still further features in the described preferred embodiments the shafts are made from a thermally insulating material. According to still further features in the described preferred embodiments the shafts comprise an external layer of thermally insulating material.

According to still further features in the described preferred embodiments the thermally insulating material is characterized by a heat conductivity of less than 40 Watt per meter per degree. According to still further features in the described preferred embodiments the thermally insulating material is characterized by a specific heat of at least 700 Joules per Kg per degree.

According to still further features in the described preferred embodiments the shafts comprise a plurality of cooling holes. According to still further features in the described preferred embodiments the shafts are substantially hollow.

According to still further features in the described preferred embodiments the shafts are made from a thermally conducting material. In this embodiment, the method further comprises a step of cooling the shafts prior to the mounting of the tubular member on the holding device. The cooling can be done by a cooling mechanism, which may be positioned near the loading station of the tubular member.

According to still further features in the described preferred embodiments the device further comprises a mechanism for establishing rotation of at least one of the shafts while being in the thermal treatment zone.

According to still further features in the described preferred embodiments the mechanism comprises a gear wheel or a belt.

The present invention successfully addresses the shortcomings of the presently known configurations by providing a textile article and a method and system for a thermal treatment of textile articles. The article method and system enjoy properties far exceeding the prior art.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.

In the drawings:

FIGS. 1a-h are images of prior art textile articles;

FIGS. 2a-c are images of a knitted tubular member according to a preferred embodiment of the present invention;

FIGS. 3a-b are schematic illustrations describing a procedure for calculating deviation from linearity of an end of the knitted tubular member, according to a preferred embodiment of the present invention;

FIG. 4a is a schematic illustration of a row of knitting-loops from which the knitted tubular member of the present embodiments is formed;

FIG. 4b is a schematic illustration of the relationships between circumferential, longitudinal and radial directions of the knitted tubular member;

FIG. 4c is a schematic illustration describing a mathematical procedure for calculating a similarity parameter between knitting-loops, according to a preferred embodiment of the present invention;

FIG. 5 is a schematic illustration of a textile article, according to a preferred embodiment of the present invention;

FIG. 6 is a schematic illustration of a device for holding a tubular member in a thermal treatment zone, according to a preferred embodiment of the present invention;

FIG. 7 is an image of a system which comprises a conveyor, a plurality of holding devices and a thermal treatment zone, according to a preferred embodiment of the present invention;

FIG. 8 is a schematic illustration of a mechanism for establishing a rotary motion, according to a preferred embodiment of the present invention;

FIG. 9 is a schematic illustration of the mechanism for establishing a rotary motion in a preferred embodiment in which the mechanism comprises two gear wheels;

FIG. 10 is a schematic illustration of the mechanism for establishing a rotary motion in a preferred embodiment in which the mechanism further comprises a central drive gear wheel;

FIG. 11 is a schematic illustration of the mechanism for establishing a rotary motion in a preferred embodiment in which the mechanism comprises a chain and two sets of gear wheels;

FIG. 12 is a schematic illustration of the device for holding the tubular member in the thermal treatment zone in a preferred embodiment in which more than two shafts are employed; and

FIG. 13 is a flowchart diagram of a method for thermally treating a tubular member, according to a preferred embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present embodiments are of a textile article with improved properties, and of method and device which can be used for thermally treating a textile article. Specifically, the method and device of the present embodiments can be used for the purpose of fixation, relaxation and/or boarding of textile article.

For purposes of better understanding the present invention, as illustrated in FIGS. 2-13 of the drawings, reference is first made to a conventional (i.e., prior art) textile article as shown in FIGS. 1a-h.

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

FIGS. 1a-h are images of prior art tubular textile articles folded on a planar surface. Shown in FIGS. 1a-h are colored articles (FIGS. 1a, 1f-h) and white articles (FIGS. 1b, 1c-e). The textile articles are seamless knitted tubular articles which are fixated using conventional PROLL & LOHMANN, fixation machine (FIGS. 1a and 1f) and conventional LEONARD AUTOMATICS fixation machine (FIGS. 1b-e and 1g-h).

The shape as well as color of the prior art textile articles suffer from severe limitations.

Referring to FIGS. 1a-b, the length of the article is not uniform, and an arc with a considerable curvature is formed at the welt area.

Referring to FIGS. 1c-d, the sides of the article, which are longer than the middle part, are fixated with fold marks marking the contact area between the article and the form on which it was mounted during the fixation process.

Referring to FIG. 1e, when the article is folded on the planar surface, there is no full physical contact between the front side and back side of the article, and a bulging corner is formed on the side of the article. The bulging corner is a “stamp mark” of the shaft which holds the article during fixation: once the fixated article is removed from the shaft, the volume engaged by the shaft remains empty leaving gap between the front side and the back side.

Referring to FIGS. 1f-h, the color of the article has a non uniform hue. Areas of the article which are in contact with the shafts for a prolonged period of time developed during the fixation process “heat burns” which are manifested by stripes of different hue along the contact areas.

While conceiving the present invention it has been hypothesized and while reducing the present invention to practice it has been realized that an improved knitted tubular article can be manufactured, substantially devoid of at least one of the above limitations, by employing an appropriate fixation process. Thus, according to one aspect of the present invention there is provided a textile article. The article comprises a fixated knitted tubular member and having at least one end which is substantially devoid of arcs.

As used herein, “knitted tubular member” refers to a knitted structure having no stitches to render it a tube, namely the knitted tubular member is knitted originally into a tube structure. The tubular member can be is typically knitted spirally about the longitudinal direction, such that each spiral turn comprises N rows of knitting-loops, where N is a positive integer. In various exemplary embodiments of the invention N is larger than one, e.g., N=4, N=8 and the like. Alternatively the tubular member can be knitted reciprocatively about the longitudinal direction, for example, using a reciprocation knitting machine as known in the art.

Generally, the knitted tubular member of the present embodiments can be formed of one or more types of knitting-loops. Knitting-loops of different types can differ by size, yarn material and/or color. In rare situations knitting-loops of different types can differ by shape. As will be appreciated by one ordinarily skilled in the art, when the tubular member is knitted from more than one type of knitting-loops, different types can arranged in predetermined patterns for practical and/or aesthetical reasons. For example, when the tubular member is a part of a garment, regions of the tubular member which are in contact with different parts of the body can be formed of different types of knitting-loops. Alternatively or additionally different types of knitting-loops can be arranged so as to form an ornament on the tubular member.

The density and/or size of the knitting-loops of the tubular member is preferably selected in accordance with the desired size of the final product. Thus, knowing the size of the final product, a suitable density (e.g., number of knitting-loops per unit area) is selected during the knitting process. The final size of the tubular member can then achieved by mounting the tubular member onto a form such that the knitting-loops are subjected to tension, and applying a thermal treatment to substantially fixate the member in its stretched state.

The tubular member is fixated in a sense that its size and shape are substantially stable to heat and humidity in amount which does cause chemical modification to the knitting material. Depending on the application for which the tubular member is used and the type of knitting material, the size and shape of the tubular member are preferably stable during bathing, outdoor activities, wet cleaning, (washing), dry cleaning or the like. Nevertheless, although being fixated the tubular member is preferable elastic, with elasticity of from about 10% to about 300%. The elasticity property of the article is preferably preserved under similar conditions for which the size and shape are stable (e.g., during or after wet or dry cleaning).

Reference is now made to FIGS. 2a-c which are typical examples of a tubular member 200 defining a longitudinal direction 202 and having an end 204, according to a preferred embodiment of the present invention. End 204 can be manufactured with a welt. In the embodiment shown in FIGS. 2a-c, end 204 is substantially orthogonal to longitudinal direction 202, however, this need not necessarily be the case, since, for some garments, it may be desired, for example, for aesthetical reasons, to manufacture a tubular member in which the angle between the ends of the member and its longitudinal axis is other than 90°. Nevertheless, in any event, end 204 is substantially devoid of any arcs in a plane parallel to longitudinal direction 202.

The lack of arcs along end 204 can be estimated visually and/or calculated mathematically. Visual estimation can be perfumed, for example, by placing the tubular member on a planar surface such that end 204 close to or in contact with a straight ruler 210, and estimating the degree of conformity between end 204 and ruler 210.

Mathematically, the lack of arcs along end 204 can be defined, for example, by small or no higher order derivatives of a mathematical line describing end 204. As will be appreciated by one of ordinary skill in the art, a mathematical line having small or no higher order derivatives is a substantially straight line. A mathematical second derivative, for example, is a measure of a curvature of a line. When the second derivative of the line is zero, it is said that the line has a infinitely long radius of curvature, i.e., the line is not curved. Thus, according to a preferred embodiment of the present invention the line describing end 204 (with or without a welt) has a small or no second derivative. The second derivative is preferably smaller than 1/L, where L is a typical length describing tubular member 204, which can be, for example, the diameter of member 204 or a fraction (e.g., one third, one half) thereof.

Another mathematical way to define the lack of arcs along 204 is by a quantity referred to herein as deviation from linearity. A preferred procedure for calculating the deviation from linearity of end 204 is illustrated in FIGS. 3a-b. In a first step of the calculation, shown in FIG. 3a, several points, say about ten points or more, are marked on an image of edge 204. The points are designated in FIGS. 3a-b by numeral 302. In a second step of the calculation, illustrated in FIG. 3b, the points are inputted to a linear regression algorithm and a “best fit” straight line 304 is drawn through the points. The deviation from linearity of end 204 can then be defined as the standard error of the fit (root-mean-square average of the deviation of points 302 from line 304). Typically, the deviation from linearity is expressed as a percentage of the length of edge 204. According to a preferred embodiment of the present invention the deviation from linearity is below 10%, more preferably below 5%, even more preferably below 2%.

According to a preferred embodiment of the present invention, when member 200 is folded on the planar surface, there is at least a physical contact of at least 95% between its front side of said at least one end and a back side thereof. Another superior property of the textile article of the present embodiments is that that when the member 200 is folded on the planar surface, there is at least 95% overlap between its front side and its back side. As demonstrated in FIGS. 2a-c and 3a, the two sides of the tubular member superimpose each other to a large extent, and there is a physical contact between the front and back sides of edge 204. Thus, unlike the prior art (see, e.g., FIG. 1e), there are no bulging corners on the textile article of the present embodiments.

The tubular member can be colored (see, e.g., FIGS. 2a and 2b) or non colored (see, e.g., FIG. 2c). As shown in FIGS. 2a-c, when the tubular member is not colored or colored by one color, the tubular member has a substantially uniform hue. The tubular member can also be colored by more than one color. In this embodiment, each color independently has a substantially uniform hue. The present embodiments therefore successfully provide a tubular member which is substantially free of heat burns or other marks formed in conventional articles during fixation.

The superior properties of the textile article of the present embodiments can also be described using smaller scale characteristics, which are described hereinunder with reference to FIGS. 4a-c.

FIG. 4a is a schematic illustration of a row 408 of one type of knitting-loops 404, forming a portion of the knitted tubular member of the present embodiments.

The row is a portion of one spiral or reciprocative turn of the tubular member and is aligned along a circumferential direction 402, which, together with longitudinal direction 202 and a radial direction 406 (not shown, see FIG. 4b) describe the coordinate system embedding the tubular member. The relationships between circumferential direction 402, longitudinal direction 202 and radial direction 406 are depicted in FIG. 4b.

In various exemplary embodiments of the invention, once the tubular member is fixated, knitting-loops of the same type have substantially uniform shape and size. Preferably, the substantially uniform shape and size is realized along circumferential direction 402. Specifically, two adjacent knitting-loops belonging to the same type and sharing the same row (such as row 408) have substantially equal shape and size. Alternatively, the substantially uniform shape and size is realized along longitudinal direction 202. Specifically, two adjacent knitting-loops belonging to the same type and being on adjacent rows have substantially equal shape and size. In various exemplary embodiments of the invention the substantially uniform shape and size is realized along both longitudinal 202 and circumferential direction 402. Preferably, at least 80%, more preferably at least 90%, most preferably substantially all (e.g., 95% or more) of the knitting-loops of the same type have substantially uniform shape and size, irrespectively whether or not they are adjacent or being on the same row.

The uniformity in size of the knitting-loops is preferably characterized by a variance which is lower than 20%, more preferable below 10%, even more preferably below 5%. The variance of the knitting-loops can be expressed in terms of one or more physical quantities. Representative examples include, without limitation: the diameter of the knitting-loops along the circumferential diameter, the “height” of the knitting-loops along the longitudinal direction, the area enclosed by the knitting-loops, and the like. Each an all the above physical quantities can be measured either directly from the tubular member or by first presenting an image of the tubular member on a display device or a hard copy and measuring the desired physical property/properties from the image.

The uniformity in size of the knitting-loops can be estimated visually or calculated mathematically. Visual estimation can be performed by observing selected knitting-loops and determining whether or not these knitting-loops are similar in shape.

Mathematically, the uniformity in size of the knitting-loops can be characterized by a quantity referred to herein as a similarity parameter. The similarity parameter is a measure of the ability to superimpose geometrical objects. For two geometrical objects, for example, the similarity parameter is defined as the maximal degree of overlap which can be achieved by applying translation, rotation and rescaling transformations on the objects such that one object superimposes the other. Typically, the similarity parameter of two objects is defined as the percentage of overlap between the objects. Thus, for example, two objects having identical shape (e.g., two circles, two squares) are characterized by a similarity parameter of 100%.

In various exemplary embodiments of the invention every two knitting-loops along the circumferential direction are characterized by a similarity parameter which is at least 80%, more preferably at least 90%, even more preferably at least 95%.

In the simplest embodiment, the similarity parameter is the distance between adjacent minima points along row 408.

A preferred mathematical procedure for calculating the similarity parameter according to another embodiment is illustrated in FIG. 4c. The respective knitting-loops is imaged and displayed on a display device or a hard copy. Several points (generally designated by numeral 410) are marked on the knitting-loops in a comparative manner. In the exemplified illustration of FIG. 4c, for example, the points are marked pairwise such each pair of points (one on knitting-loop) has a mutual horizontal coordinate but a different vertical coordinate. Each point on one knitting-loop is then compared to its respective point, and the result of comparison is weighted into the similarity parameter. The comparison between points is based on one or more similarity criteria, include, without limitation, vertical distance between points, slope at each point and the like. The similarity parameter is preferably defined as the percentage of pairs for which the similarity criterion (or criteria) is met.

As will be appreciated by one of ordinary skill in the art, the combination of uniform size and uniform shape of the knitting-loops along the circumferential direction results in a high-quality tubular member, devoid of arcs, bulging corners and the like.

In most prior art knitted garments, the final size of the garment depends on the fixation procedure, whereby wider garment are subjected to higher tension during the fixation process. Thus, prior art garments of different size may have the same number of knitting loops on the perimeter, where the actual size of the garments is fixed by the size of the knitting-loops. As a result, the specific weight of the garment depends on its size, where larger garments have smaller specific weight than smaller garments.

Unlike the prior art, the size (typically perimeter) of the tubular member preferably depends on the number of the knitting-loops and not on the fixation procedure, because the size of the knitting-loops is substantially uniform. This embodiment allows independent control on the size as well as specific weight of the garment.

The tubular member of the present embodiments can be knitted from any yarn or thread material known in the art. Additionally, the tubular member of the present embodiments can be knitted from more than one type of yarn or a yarn material which is a combination of more than one yarn material.

The yarn material can be an elastomer, such as, but not limited to, a dry-spun coalesced elastomeric thread marketed under the trade name LYCRA. Also contemplated are other elastomers and a polyester, typically, but not obligatorily, a synthetic polyester, e.g., polycarbonate or polyethylene terephthalate (PET). The yarn material can also be a cationic polyester, a nylon, a polyurethane, cotton, viscose or any combination of such and similar materials.

Alternatively or additionally, the yarn material can be made of a polyamide (e.g., a nylon). Most types of nylon are condensation polymers, formed by reacting a diamine and a dicarboxylic acid, so that peptide bonds form on each end of a given monomer in a process analogous to biological polypeptide formation. A preferred type of nylon is known as nylon (6,6), in which both the diamine and the diacid have 6 carbon backbones. It is to be understood that other types of nylon are not excluded from the scope of the present invention. These include, without limitation, nylon (6,12), nylon (6,11), nylon (10,12) and the like.

Beside the tubular member, the textile article of the present embodiments can comprise one or more additional knitted member.

A representative examples of the textile article of the present embodiments is illustrated FIG. 5. Shown in FIG. 5 is a textile article 500, which comprises tubular member 200, sleeves 502 and a collar 504. Any of the members of article 500 can have any of the aforementioned properties of tubular member 200.

Reference is now made to FIG. 6 which is a schematic illustration of a a device 600 for holding a tubular member in a thermal treatment zone. Device 600 comprises a base 606 and a form 610 having two or more vertically-disposed shafts 602. Shafts 602 are preferably cylindrical or the like. Each shaft is mounted at its lower end for rotation with respect to base 606. The rotation of shafts 602 is indicated in FIG. 6 by arrows 620. Shafts 602 are adapted for receiving the tubular member (not shown in FIG. 6) and revolving the tubular member with respect to base 606.

Device 600 can be used in all types of thermal treatments include, without limitation, fixation and boarding. In use, the tubular member is mounted over form 610 and device 600 is conveyed into a thermal treatment zone (e.g., an autoclave) where heat is transferred to the tubular member by convection, conduction, radiation or any combination thereof. The temperature in the thermal treatment zone depends on the type of yarn from which the tubular member is knitted an on the type of thermal treatment. Typically, for fixation the temperature is above 180° C. (e.g., 200° C.) but below the melting point of the yarn, and for boarding or relaxation the temperature is lower than 170° C. (e.g., 165° C.).

The transverse separation between shafts 602 is preferably selected so as to allow the mounting the tubular member over form 610 while the knitting-loops are subjected to tension. The advantage of this embodiment is that it allows resizing the member to its desired size, while enlarging the size knitting-loops.

In one preferred embodiment, shafts 602 are arranged with their longitudinal axes in substantially parallel and radially spaced relationship one to the other, and are typically of similar lengths. The transverse separation between shafts 602 is preferably adjustable so as to allow fitting differently sized tubular member on form 610. This can be achieved, for example, by providing base 606 with a plurality of mounting stations 636. The mounting stations can also be provided with grooves, sizewise compatible with the external diameter of shafts 602, so as to allow the user to vary the transverse separation between shafts 602 by slide them within the grooves. In this embodiment, the mounting stations are preferably provided with screws 637 for fixing the shafts in place once the desired separation is set.

In another embodiment, shafts 602 are inclined one with respect to the other, preferably by an adjustable inclination angle, so as to allow form 610 to receive tubular members having a trapezoidal cross section.

The adjustment of the separation and/or inclination angle of form 610 can be achieved also by providing a plurality of bases to cater for varying separations and/or inclination angles as required by the manufacturer that uses form 610. In this embodiment, shafts 602 are preferably configured for being interchangeably mounted with respect to any such base.

According to a preferred embodiment of the present invention form 610 comprises a cross-piece 608 is mounted between the top ends of shafts 602, via a suitable bearing arrangement 601 to allow shafts 602 to rotate with respect to cross-piece 608. Preferably, cross-piece 608 has a rounded shape (e.g., an inverted U-shape) to facilitate fitting of the tubular member over form 610.

Shafts 602 are preferably made from a thermally insulating material. In some embodiments the shafts may be made from another material, and may comprise an external layer of thermally insulating material that is to be in contact with the inside of the tubular member.

The thermally insulating material is preferably characterized by a heat conductivity of less than 40 Watt per meter per degree and a specific heat of at least 700 Joules per Kg per degree. Representative examples of such materials include, without limitation, ceramic or composite materials, which may be natural or artificially produced. Shafts 602 can be also be made of wood.

Optionally, shafts 602 may comprise several cooling holes 603, which may be diametric and disposed in any desired manner along shafts 602. Optionally, shafts 602 may be hollow. The base 606 is preferably adapted for moving along a conveyor 660.

Alternatively, shafts 602 can be made from a thermally conducting material. In this embodiment, the shafts are preferably cooled prior to the mounting of the tubular member on the holding device. The cooling can be done by a cooling mechanism 701 (not shown see FIG. 7), which may be positioned near the upstream loading station 664 (not shown see FIG. 7) of the tubular member.

FIG. 7 is an image of a system 700 which comprises conveyor 660, a plurality of devices 600 and a thermal treatment zone 662. Conveyor 660 transports devices 600, together with tubular members 200 mounted thereon, from an upstream loading station 664, into treatment zone 662 and out of treatment zone 662. In treatment zone 662 heat is transferred to tubular member 200, for fixation of boarding of member 200.

At least during part of the transit through treatment zone 662, shafts 602 are rotated, such that a rotary motion of member 200 is established with respect to base 606. The rotation rate of shafts 602 is selected such that when member 200 revolves, the time of contact between tubular member 200 and shafts 602 is distributed, substantially equally, among different portions of tubular member 200. Accordingly, local overheating and over tensioning problems including discoloration and texture changes are avoided on the portions of member 200.

The rotation of the shafts 602 can be effected by a suitable mechanism 622, connected at lower end 604 of at least one of shafts 602. Mechanism 622 can be any known rotation mechanism, such as, but not limited to, an electrical motor, an electromagnetic motor, a pneumatic motor, a hydraulic motor, a mechanical gear and the like.

Reference is now made to FIG. 8 which is a schematic illustration of mechanism 622, according to a preferred embodiment of the present invention. In this embodiment, mechanism 622 comprises a gear wheel 607, connected to shafts 602. Wheel can be a toothed wheel. Wheel 607 engages a toothed rack 605 that is set parallel to convey 660 within zone 662. As the base 606 proceeds along convey 660 and wheel 607 engages rack 605, wheel 607, and thus shaft 602 rotate. The rotational motion of the shaft 602 causes member 200 (not shown in FIG. 8) to revolve and rotate the other shaft 602 about its axis. Alternatively, suitable coupling such as a drive belt or gear wheels may also transmit rotation to the second shaft 602.

FIG. 9 schematically illustrates another embodiment in which mechanism 622 comprises two wheels 607, one for each shaft, and the rack is replaced with static gear wheels 624. Any one or both wheels 607 periodically engage wheels 624 causing member 200 to revolve periodically during transit along convey 660 and through the treatment zone.

FIG. 10 schematically illustrates an additional embodiment in which mechanism 622 comprises a central drive gear wheel 609, provided on base 606 and configured to engage both rack 605 and wheels 607. Wheel 609 is preferably larger in diameter than wheels 607 such that wheels 607 do not engage rack 605. Rotation of wheels 609 as a result of the motion of base 606 along convey 660 causes wheels 607 together with shafts 602 to rotate in the same direction.

FIG. 11 schematically illustrates an additional embodiment in which mechanism 622 comprises central gear wheel 609, a chain 626 and two sets of gear wheels 630 serially positioned on either side of central gear wheel 609. Wheel 609 is configured to engage both rack 605 and chain 626. Chain 626, in turn, engages sets of wheels 630. Each of wheels 30 is configured for receiving and rotating shaft 602 by means of the motive force provided by central gear wheel 609. Accordingly, the user can choose the desired spacing between shafts 602, for example W1, W2 or W3 by mounting the shafts to the appropriate gear wheels 630 on either side of central gear wheel 609.

Optionally and preferably, base 606 may comprise a mechanism for engaging with adjacent bases upstream and downstream thereof. For example, base 606 may comprise a hook at one end thereof, and a loop at the other end thereof, to respectively engage with a loop and a hook of an upstream adjacent base and a downstream adjacent base. In this manner, a train of such bases can be efficiently conveyed.

Reference is now made to FIG. 12 which is a schematic illustration of device 600 in an embodiment in which form 610 comprises more than two shafts. In the exemplified configuration of FIG. 12, form 610 comprises three shafts. It is to be understood that any number of shafts can be used and the configuration shown in FIG. 12 is for illustrative purposes only. Shafts 602 can rotate with respect to base 606 and with respect to cross-members 638, as base 606 travels along convey 605. Clearly, many other embodiments are possible comprising any number and arrangements of rotating shafts mounted onto a base.

Reference is now made to FIG. 13 which is a flowchart diagram of a method which can be used for thermally treating a tubular member, according to a preferred embodiment of the present invention. The method begins at step 700 and continues to step 702 in which the tubular member is mounted on a holding device, e.g., device 600. The method continues to step 704 in which the tubular member is revolved with respect to the device. While the tubular member is revolved, the method continues to step 706 in which heat is transferred to the tubular member, as further detailed hereinabove. The method ends at step 708.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.

Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.

Claims

1. A textile article comprising a knitted tubular member defining a longitudinal direction and a circumferential direction, said tubular member being knitted from at least one type of knitting-loops, each type of said at least one type of knitting-loops being characterized by a substantially uniform shape and size along at least one of said longitudinal and said circumferential directions, whereby said tubular member is fixated.

2. The textile article of claim 1, wherein a density of said knitting-loops is selected so as to provide said tubular member with at least one of a predetermined size and a predetermined specific weight.

3. The textile article of claim 1, wherein said size of said type of knitting-loops is selected so as to provide said tubular member with at least one of a predetermined size and a predetermined specific weight.

4. The textile article of claim 1, wherein said substantially uniform size is characterized by a variance which is lower than 20%.

5. The textile article of claim 1, wherein said substantially uniform shape is characterized by a similarity parameter which is at least 80% for every two knitting-loops along said circumferential direction.

6. A textile article comprising a knitted tubular member defining a longitudinal direction, said tubular member having a first open end and a second open end, wherein at least one end of said first open end and said second open end substantially devoid of arcs in a plane parallel to said longitudinal direction, whereby said tubular member is fixated.

7. The textile article of claim 6, wherein said at least one end is characterized by a deviation from linearity of less than 10%.

8. The textile article of claim 6, wherein said at least one end is substantially orthogonal to said longitudinal direction.

9. The textile article of claim 6, wherein said tubular member is foldable on a planar surface parallel to said longitudinal direction, such that at least a 95% physical contact is established between a front side of said at least one end and a back side thereof.

10. The textile article of claim 6, wherein said tubular member is foldable on a planar surface parallel to said longitudinal direction, such that there is at least 95% overlap between a front side of said tubular member and a back side thereof.

11. The textile article of claim 6, wherein said at least one end comprises a welt.

12. The textile article of claim 1 wherein said tubular member is colored by at least one color wherein each color of said at least one color has a substantially uniform hue.

13. A textile article comprising a knitted tubular member, said tubular member being fixated and colored by at least one color wherein each color of said at least one color has a substantially uniform hue.

14. The textile article of claim 1, wherein said tubular member is knitted from a yarn material selected from the group consisting of an elastomer, a polyester, a cationic polyester, a nylon, a polyurethane, cotton, viscose and any combination thereof.

15. The textile article of claim 1, wherein said tubular member is knitted spirally about said longitudinal direction in a manner such that each spiral turn comprises N rows of knitting-loops, wherein N is larger than one.

16. The textile article of claim 1, wherein said tubular member is knitted reciprocatively about said longitudinal direction.

17. The textile article of claim 1, further comprising at least one additional knitted member.

18. The textile article of claim 17, wherein said at least one additional knitted member comprises an additional tubular member.

19. The textile article of claim 17, wherein said at least one additional knitted member is selected from the group consisting of a sleeve and a collar.

20. A device for holding a tubular member in a thermal treatment zone, the device comprising a base and a form having at least two shafts mounted for rotating with respect to said base, said at least two shafts being adapted for receiving the tubular member and revolving the tubular member with respect to said base.

21. A system for thermally treating a tubular member, comprising

a thermal treatment zone for transferring heat to the tubular member; and

a holding device for holding the tubular member in said thermal treatment zone, wherein said holding device comprises a base and a form having at least two shafts mounted for rotating with respect to said base, said at least two shafts being adapted for receiving the tubular member and revolving the tubular member with respect to said base.

22. The system of claim 21, wherein at least one of a temperature and time of treatment in said thermal treatment zone is selected for fixation of the tubular member.

23. The system of claim 21, wherein at least one of a temperature and time of treatment in said thermal treatment zone is selected for boarding the tubular member.

24. The system of claim 21, wherein at least one of a temperature and time of treatment in said thermal treatment zone is selected for relaxation of the tubular member.

25. The system of claim 21, further comprising a conveyor for conveying said holding device into said thermal treatment zone.

26. A method of thermally treating a tubular member, comprising mounting the tubular member on a holding device and transferring heat to the tubular member while continuously revolving the tubular member with respect to the device.

27. The method of claim 26, wherein said holding device comprises a form having at least two shafts mounted for rotating with respect to a base and adapted for receiving the tubular member and revolving the tubular member with respect to said base.

28. The device, system or method of claim 20, wherein a rotation rate of said shafts is selected such that when the tubular member is in the thermal treatment zone, time of contact between the tubular member and said shafts is substantially equally distributed among different portions of the tubular member.

29. The device, system or method of claim 20, wherein said at least two shafts are generally cylindrical.

30. The device, system or method of claim 20, wherein a transverse separation between said at least two shafts is selected so as to allow mounting the tubular member thereon while knitting-loops forming the tubular member are subjected to tension.

31. The device, system or method of claim 30, wherein said transverse separation is adjustable.

32. The device, system or method of claim 20, wherein said shafts are generally parallel one with respect to each other.

33. The device, system or method of claim 20, wherein said shafts are inclined one with respect to each other so as to allow said form to receive tubular members having a trapezoidal cross section.

34. The device, system or method of claim 33, wherein an inclination angle of said shafts is adjustable.

35. The device, system or method of claim 20, wherein said form further comprises a cross-piece connecting top ends of said shafts and configured to allow said shafts to rotate with respect to said cross-piece.

36. The device, system or method of claim 35, wherein said cross-piece has a rounded shape.

37. The device, system or method of claim 20, wherein said shafts are made from a thermally insulating material.

38. The device, system or method of claim 20, wherein said shafts comprise an external layer of thermally insulating material.

39. The device, system or method of claim 37, wherein said thermally insulating material is characterized by a heat conductivity of less than 40 Watt per meter per degree.

40. The device, system or method of claim 38, wherein said thermally insulating material is characterized by a heat conductivity of less than 40 Watt per meter per degree.

41. The device, system or method of claim 37, wherein said thermally insulating material is characterized by a specific heat of at least 700 Joules per Kg per degree.

42. The device, system or method of claim 38, wherein said thermally insulating material is characterized by a specific heat of at least 700 Joules per Kg per degree.

43. The device, system or method of claim 20, wherein said shafts comprise a plurality of cooling holes.

44. The device, system or method of claim 20, wherein said shafts are substantially hollow.

45. The method of claim 27, wherein said shafts are made from a thermally conducting material and the method further comprises cooling said shafts prior to said mounting of the tubular member on said holding device.

46. The device of claim 20, wherein said shafts are made from a thermally conducting material.

47. The system of claim 21, wherein said shafts are made from a thermally conducting material and the system further comprises a cooling mechanism for cooling said shafts prior to the mounting of the tubular member on said holding device.

48. The device or system of claim 20, further comprising a mechanism for establishing rotation of at least one of said shafts while being in the thermal treatment zone.

49. The device or system of claim 48, wherein said mechanism comprises a gear wheel.

50. The device or system of claim 48, wherein said mechanism comprises a moving belt.