Patent Publication Number: US-2021172099-A1

Title: Velvet fabric knitting method

Description:
CROSS-REFERENCE TO THE RELATED APPLICATIONS 
     This application is the national phase entry of International Application No. PCT/TR2017/050705, filed on Dec. 27, 2017, which is based upon and claims priority to Turkish Patent Application No. 2017/19729, filed on Dec. 6, 2017, the entire contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a method of producing (pile) velveteen (plush) knitted fabric which is produced in circular knitting machines by terry-cloth fabric technique and which is then processed to appear like velvet. 
     BACKGROUND 
     A fabric is a covering surface constructed by linking yarns via various methods. It is obtained from yarns made of natural textile fibers such as cotton, wool, silk, linen, etc. and synthetic, regenerated textile fibers or a mixture thereof. Fabrics are constructed by passing yarns which are perpendicular and parallel to each other from under and above each other. 
     Nowadays, in the circular knitting machines, the needles are arranged next to each other into the needle grooves provided in the circular (tubular) needle plates. They are machines which carry out knitting by moving the needles that move in the grooves during the circular movement of the needle plate independently with the help of the locking mechanisms that are immobile on the needle plate and grooves and that give movement to the needles and by fixed yarn lay-in suitable thereto. The knitting operation is carried out by the needles that are arranged at certain intervals around the needle plate making circular movements all together while receiving suitable movement from the fixed locking systems and forming loops by pulling the yarns laid on them. 
     One of the types of fabric produced is the pile plush which is produced by using the terry-cloth fabric production technique in circular knitting machines and then sheared to have a smooth surface with fine piles giving a velvet appearance. 
     In the state of the art applications, the light effects and surface patterns are obtained in some nylon velvet fabrics, although rare; however they are provided to some extent with a synthetic material (nylon, etc.). Artificial textile fibers are required to achieve such an effect. Processes of patterning and creating effects in velvet fabrics cannot be achieved by using single yarn in plain circular knitting machines. 
     However in the state of the art applications, jacquard terry-cloth machines are used to produce patterns on velvet fabric and the colors obtained in this production method cannot reflect light from different angles. 
     SUMMARY 
     The object of the present invention is to provide a method of producing velvet fabric having a mixture of materials and reflection effect by performing a different shearing method on the roving (roving of velvet/terry-cloth fabric instead of terry-cloth) without making changes in the construction of the fabric. In order to do this, two different yarns are required to be knitted in terry-cloth construction in a double plated circular knitting machine. Following a terry-cloth knitting process carried out by different yarns, the surface is converted to velvet fabric by shearing process. By means of the present invention, light effects and episodic patterning are achieved without applying any printing process and/or using jacquard circular knitting machines. The said progress is achieved by producing ring-spun yarn from different material mixtures and using them as pile yarn in production of velvet fabric. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Velvet fabric knitting production method developed to fulfill the objective of the present invention is illustrated in the accompanying FIGURE, in which; 
         FIG. 1  is a schematic view of the velvet fabric knitting method. 
     
    
    
     The steps in the figures are given reference numbers as follows:
       100 . Velvet fabric knitting method     101 . Mixing the (commercially available) fibers comprising neps used in pile yarn with a textile fiber comprised of natural, synthetic, regenerated fibers or a mixture thereof and making them into slivers upon processing them in the carding machine,     102 . Eliminating roughness of the slivers coming from the carding machine and splicing the sliver cotton pieces with the sliver neps and activating the draw frame for mixing them into the main material,     103 . Activating the roving frame for thinning the draw frame sliver cotton and nep mixture coming from the draw frame and subjecting it to false twist process,     104 . Activating the ring machine for obtaining yarn by thinning the cords coming from the cotton and nep mixture from the roving machine via drawing and winding the yarn onto the cops,     105 . Knitting the greige fabric by the needles which are turning upon upwards-downwards movement of the knitting needles provided in the double plated circular knitting machine,     106 . Knitting the pile yarn and the ground yarn by passing them through the needles in different plates,     107 . Placing the pile yarn on the fabric backcloth for shearing and then shearing thereof,     108 . Activating the fixing machine for fixing the produced yarn and stretching the terry cloth fabric under hot air to prevent electrostatic generation,     109 . Dyeing the terry-cloth fabric,     110 . Activating the centrifugal drying machine for drying the terry-cloth fabric by contacting heated air,     111 . Rotating the dyed fabric at least 4550 revolutions in order to prevent sinking of the nep effects in the terry-cloth tolon machine,     112 . Shearing the pile yarns of the terry-cloth fabric in order to turn it to a velvet fabric by making the closed loops open-end from a blade distance of at least 1.8 mm,     113 . Passing the dyed and sheared velvet fabric through the stenter for drying thereof.   

     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     In the velvet fabric knitting method ( 100 ) of the present invention, the neppy sliver fibers (fiber bundles which may include fibers of different thicknesses and lengths and which can create a 3 dimensional effect on the main fiber sliver or yarn to which they are incorporated as they stand together) used in pile yarn are mixed with staple fibers and made it into slivers upon being processed in the carding machine ( 101 ), and the carding machine is the machine wherein the cotton fiber is made into thick slivers upon being passed through rotary cylinders with needles. 
     The neppy fibers used in pile yarn are mixed with textile fibers comprised of natural, synthetic, regenerated fibers such as cotton, wool, silk, linen, etc. or a mixture thereof and they are made into slivers by being processed in the carding machine. 
     In order to obtain the yarn with nep effects used in pile yarn, the neppy fibers are mixed with the main fiber and made into slivers by being processed in the carding machine and the nep carding slivers of the yarn with nep effects with the staple fibers in the draw frame. 
     The draw frame is used for eliminating roughness of the slivers coming from the carding machine and splicing the sliver cotton pieces leaving the carding machine transversely with the sliver neps and mixing them into the main material ( 102 ). The neps are mixed into the main material as injection or double material feed during the yarn process, nep carding process, draw frame process or yarn spinning process. 
     The roving frame is activated for thinning the draw frame sliver cotton and nep mixture coming from the draw frame and subjecting it to twisting process ( 103 ). After the draw frame process, the cotton and nep mixture is given its thinnest sliver form in the roving machine. These thin slivers are spun in the ring machine. The said ring machine is activated to obtain yarn by thinning the cords coming from the cotton and nep mixture from the roving machine via drawing and to wind the yarn onto the cops ( 104 ). Thus the main material is subjected to carding process and the process of mixing with the neppy sliver is performed in the draw frame. The mixing is enabled during the drawing process. 
     The draw frame is activated in order to obtain a homogenous sliver by splicing the yarn slivers transversely by means of doubling for cleaning the flies formed during the drawing process. 
     The greige (circular terry-cloth knitted) fabric, which is comprised of pile yarn and ground yarn, is knitted by the needles which are turning upon upwards-downwards movement of the knitting needles provided in the double plated circular knitting machine. 
     The pile yarn and the ground yarn are knitted by being passed through the needles in different plates ( 106 ). The filament yarn or staple yarn, which ensures strength of the fabric backcloth, is used. (filament yarn; continuous yarns comprised of natural, synthetic, regenerated yarns or mixtures thereof or ring yarns comprised of staple fibers or open-end yarns comprised of staple fibers or air-jet yarns comprised of staple fibers). 
     The greige fabric is processed in the AIRO machine, wherein shearing (for opening the closed ends of the pile yarns), pre-fixation, exhaust dyeing, centrifuge (drying), stentering and quality control processes are performed on the greige fabric. 
     In the shearing process, the pile yarn is placed on the fabric backcloth for shearing and then it is sheared ( 107 ). During velvet fabric production, the pile yarn and ground yarn are knitted by being separately passed through the needles in two different plates. The fabric backcloth, which is also known as rear side of the fabric, is the napless flat surface of the velvet fabric generally comprised of filament yarns (polyester and nylon are often selected for providing strength). 
     The fixing machine is activated for fixing the produced yarn and stretching the terry-cloth fabric under hot air to prevent electrostatic generation ( 108 ). The terry-cloth fabric is dyed ( 109 ) and then the centrifugal drying machine is activated for drying the terry-cloth fabric by contacting heated air ( 110 ). 
     After the greige fabric is produced in the double plated circular knitting machine, the finishing process begins in terry-cloth fabric construction. The fabric rotates together with warm air in the tolon machine by a specific number of revolutions and the dyed fabric is rotated at least 4550 revolutions in order to prevent sinking of the nep effects in the terry-cloth tolon machine ( 111 ). The purpose of the increase in the number of revolutions in the tolon machine is to ensure that the neps in the pile yarn remain more upright and brisk. 
     2 nd  shearing is performed on the pile yarns of the terry-cloth fabric in order to turn it to a velvet fabric by making the closed loops open-end from a blade distance of at least 1.8 mm ( 112 ). The velvet circular knitted fabric is a version of terry-cloth circular knitted fabric before the shearing process. 
     After the shearing process, the closed loops of the pile yarns are opened and made open-end. The purpose of increasing the distance is to prevent the blades from shearing too deep on the fabric surface. 
     Performing shearing by a certain distance difference prevents the nep effects in the fabric from sinking in the tolon machine. 
     The dyed and sheared velvet fabric is passed through the stenter for being dried ( 113 ). The constructed velvet fabric is finally subjected to various quality control processes ( 114 ). 
     The fabric weight (g/m 2 ) varies according to area of use. The ground yarn and pile yarn numbers vary depending on the weight of the fabric. 
     By means of this invention, velvet fabric with different material mixture and reflection pattern effect is obtained without making any changes in the fabric construction. A more bulky and softer touch is provided by means of the different material mixtures and compositions used in the invention. 
     In one embodiment of the invention, fiber mixtures comprising natural, synthetic or regenerated fibers such as viscose, cotton, polyester, nylon, linen, wool fibers or mixtures thereof are used. 
     In one embodiment of the invention, glossy fiber which provides a soft touch is used. 
     In one embodiment of the invention, the filament yarn is produced of synthetic materials enabling high strength such as polyester, nylon, etc. 
     In one embodiment of the invention, many needles such as single butt needle, 4 butt needle are used. 
     In one embodiment of the invention, when carding process of textile fibers comprised of natural, synthetic, regenerated fibers such as cotton, silk, linen, etc. or mixtures thereof is performed in the carding machine at a low drum rpm (preferably less than 300 rpm) by increasing the distance between the revolving flat and the drum (the starting point is more than 35 mm), similar ones of the sliver nep effects are obtained. The neppy slivers obtained with this method may or may not be mixed with different textile fibers in the draw frame. Thus, decision of making the mixture depends on the desired number of neps in a unit area in the final fabric.