Stretchable fabric, and manufacturing method and manufacturing device for same

An elastic clothing material made of an elastic woven fabric that comprises weft and warp yarns, the weft yarns including a plurality of elastic composite yarns each of which comprises an elastic core yarn and a sheath yarn covering the elastic core yarn, and the warp yarns including a plurality of chemical fiber yarns and/or a plurality of natural fiber yarns,

• wherein the elastic core yarn is a polyurethane elastic yarn of which fineness, before integrated into the elastic composite yarn, is in a range of 78 to 1,300 dtex,
• wherein the sheath yarn is any of a chemical fiber yarn of which fineness is in a range of 10 to 500 dtex and a natural fiber yarn of which fineness is in a range of 100 to 1,000 dtex,
• wherein a fiber for composing the chemical fiber yarn for the sheath yarn is selected from a polyamide fiber, a polyester fiber, a polyolefin fiber, or a combination thereof, and
• wherein a fiber for composing the natural fiber yarn for the sheath yarn is a cotton fiber,
• characterized in that each of the elastic composite yarns is in a form of a singly-covered yarn in which the elastic core yarn is covered by a single layer of the sheath yarn helicoidally wound around a periphery of the elastic core yarn, a number of turns of the sheath yarn per 1 meter of the elastic core yarn being in a range of 1,300 to 2,500 T/m,
• in that each of the elastic composite yarns has the form in which the sheath yarn is helicoidally wound around the elastic core yarn as a result of being produced by a hollow spindle method, wherein the elastic core yarn is in a state of length near its original length as a result that when the elastic composite yarn is produced by the hollow spindle method, the polyurethane elastic yarn is guided to a hollow spindle while being drafted with a feed magnification factor expressed by a ratio (V2/V1) of a yarn take-up rate (V2) to a yarn feed rate (V1) of 0.8 to 1.3,
• in that an elongation rate of each of the elastic composite yarns is equal to or more than 30%, in that an elastic recovery rate of each of the elastic composite yarns is equal to or more than 70%, and
• in that a stretching magnification ratio of each of the elastic composite yarns in the elastic woven fabric in a weaving process is retained equal to or less than 1.30 folds based on the elastic composite yarn before weaving.

Stretch jeans including a stretch denim made of an elastic woven fabric that comprises weft and warp yarns and has a twill weave, the weft yarns including a plurality of elastic composite yarns each of which comprises an elastic core yarn and a sheath yarn covering the elastic core yarn, and the warp yarns including a plurality of chemical fiber yarns and/or a plurality of natural fiber yarns,

• wherein the elastic core yarn is a polyurethane elastic yarn of which fineness, before integrated into the elastic composite yarn, is in a range of 78 to 1,300 dtex,
• wherein the sheath yarn is any of a chemical fiber yarn of which fineness is in a range of 10 to 500 dtex and a natural fiber yarn of which fineness is in a range of 100 to 1,000 dtex,
• wherein a fiber for composing the chemical fiber yarn for the sheath yarn is selected from a polyamide fiber, a polyester fiber, a polyolefin fiber, or a combination thereof, and
• wherein a fiber for composing the natural fiber yarn for the sheath yarn is a cotton fiber,
• characterized in that each of the elastic composite yarns is in a form of a singly-covered yarn in which the elastic core yarn is covered by a single layer of the sheath yarn helicoidally wound around a periphery of the elastic core yarn, a number of turns of the sheath yarn per 1 meter of the elastic core yarn being in a range of 1,300 to 2,500 T/m,
• in that each of the elastic composite yarns has the form in which the sheath yarn is helicoidally wound around the elastic core yarn as a result of being produced by a hollow spindle method, wherein the elastic core yarn is in a state of length near its original length as a result that when the elastic composite yarn is produced by the hollow spindle method, the polyurethane elastic yarn is guided to a hollow spindle while being drafted with a feed magnification factor expressed by a ratio (V2/V1) of a yarn take-up rate (V2) to a yarn feed rate (V1) of 0.8 to 1.3,
• in that an elongation rate of each of the elastic composite yarns is equal to or more than 30%,
• in that an elastic recovery rate of each of the elastic composite yarns is equal to or more than 70%, and in that a stretching magnification ratio of each of the elastic composite yarns in the elastic woven fabric in a weaving process is retained equal to or less than 1.30 folds based on the elastic composite yarn before weaving.

A method for producing an elastic woven fabric by using a gripper loom, the elastic woven fabric comprising weft and warp yarns, the weft yarns including a plurality of elastic composite yarns each of which comprises an elastic core yarn and a sheath yarn covering the elastic core yarn, and the warp yarns including a plurality of chemical fiber yarns and/or a plurality of natural fiber yarns,

• wherein the elastic core yarn is a polyurethane elastic yarn of which fineness, before integrated into the elastic composite yarn, is in a range of 78 to 1,300 dtex,
• wherein the sheath yarn is any of a chemical fiber yarn of which fineness is in a range of 10 to 500 dtex and a natural fiber yarn of which fineness is in a range of 100 to 1,000 dtex, wherein a fiber for composing the chemical fiber yarn for the sheath yarn is selected from a polyamide fiber, a polyester fiber, a polyolefin fiber, or a combination thereof,
• wherein a fiber for composing the natural fiber yarn for the sheath yarn is a cotton fiber,
• wherein each of the elastic composite yarns is in a form of a singly-covered yarn in which the elastic core yarn is covered by a single layer of the sheath yarn helicoidally wound around a periphery of the elastic core yarn, a number of turns of the sheath yarn per 1 meter of the elastic core yarn being in a range of 1,300 to 2,500 T/m,
• wherein each of the elastic composite yarns has the form in which the sheath yarn is helicoidally wound around the elastic core yarn as a result of being produced by a hollow spindle method, wherein the elastic core yarn is in a state of length near its original length as a result that when the elastic composite yarn is produced by the hollow spindle method, the polyurethane elastic yarn is guided to a hollow spindle while being drafted with a feed magnification factor expressed by a ratio (V2/V1) of a yarn take-up rate (V2) to a yarn feed rate (V1) of 0.8 to 1.3,
• wherein an elongation rate of each of the elastic composite yarns is equal to or more than 30%,
• wherein an elastic recovery rate of each of the elastic composite yarns is equal to or more than 70%, and
• wherein a stretching magnification ratio of each of the elastic composite yarns in the elastic woven fabric in a weaving process is retained equal to or less than 1.30 folds based on the elastic composite yarn before weaving, and the gripper loom comprising at least a projectile which is flown through a warp shedding in a weft direction with gripping the elastic composite yarn in order to feed the elastic composite yarn and a weft yarn brake which is provided in a feeding side of the elastic composite yarn to apply a tensile force to the elastic composite yarn pulled by the flying projectile,
• characterized in that the method comprises a step of blowing an air to the elastic composite yarn pulled by the flying projectile by using an air nozzle or an air blower in a direction substantially opposite to the feed direction of the elastic composite yarn in a vicinity of a downstream side of the weft yarn brake, and thereby reducing the tensile force applied by the weft yarn brake to decrease stretching of the elastic composite yarn in a weaving process.

An apparatus for producing an elastic woven fabric comprising weft and warp yarns, the weft yarns including a plurality of elastic composite yarns each of which comprises an elastic core yarn and a sheath yarn covering the elastic core yarn, and the warp yarns including a plurality of chemical fiber yarns and/or a plurality of natural fiber yarns,

• wherein the elastic core yarn is a polyurethane elastic yarn of which fineness, before integrated into the elastic composite yarn, is in a range of 78 to 1,300 dtex,
• wherein the sheath yarn is any of a chemical fiber yarn of which fineness is in a range of 10 to 500 dtex and a natural fiber yarn of which fineness is in a range of 100 to 1,000 dtex,
• wherein a fiber for composing the chemical fiber yarn for the sheath yarn is selected from a polyamide fiber, a polyester fiber, a polyolefin fiber, or a combination thereof,
• wherein a fiber for composing the natural fiber yarn for the sheath yarn is a cotton fiber,
• wherein each of the elastic composite yarns is in a form of a singly-covered yarn in which the elastic core yarn is covered by a single layer of the sheath yarn helicoidally wound around a periphery of the elastic core yarn, a number of turns of the sheath yarn per 1 meter of the elastic core yarn being in a range of 1,300 to 2,500 T/m,
• wherein each of the elastic composite yarns has the form in which the sheath yarn is helicoidally wound around the elastic core yarn as a result of being produced by a hollow spindle method, wherein the elastic core yarn is in a state of length near its original length as a result that when the elastic composite yarn is produced by the hollow spindle method, the polyurethane elastic yarn is guided to a hollow spindle while being drafted with a feed magnification factor expressed by a ratio (V2/V1) of a yarn take-up rate (V2) to a yarn feed rate (V1) of 0.8 to 1.3,
• wherein an elongation rate of each of the elastic composite yarns is equal to or more than 30%,
• wherein an elastic recovery rate of each of the elastic composite yarns is equal to or more than 70%, and
• wherein a stretching magnification ratio of each of the elastic composite yarns in the elastic woven fabric in a weaving process is retained equal to or less than 1.30 folds based on the elastic composite yarn before weaving, and the apparatus including a gripper loom comprising at least a projectile which is flown through a warp shedding in a weft direction with gripping the elastic composite yarn in order to feed the elastic composite yarn and a weft yarn brake which is provided in a feeding side of the elastic composite yarn to apply a tensile force to the elastic composite yarn pulled by the flying projectile,
• wherein the gripper loom further comprises a yarn feeding cheese made by winding the elastic composite yarn, a weft tensioner arranged in the downstream side of the weft yarn brake to control the tensile force of the elastic composite yarn pulled out from the yarn feeding cheese, a projectile feeder arranged in the further downstream side to transfer the elastic composite yarn to the projectile, and a stopping brake to stop the flying projectile, and
• wherein these are arranged in an order of the yarn feeding cheese, the weft yarn brake, the weft tensioner, the projectile feeder and the stopping brake from the feeding side of the elastic composite yarn so that the projectile flies from the projectile feeder toward the stopping brake,
• characterized in that the gripper loom further comprises an air nozzle or an air blower for blowing an air to the elastic composite yarn pulled by the flying projectile in a direction substantially opposite to the feed direction of the elastic composite yarn between the weft tensioner and the projectile feeder, and thereby reducing the tensile force applied by the weft yarn brake to decrease stretching of the elastic composite yarn in a weaving process, and
• in that a discharge pressure of a compressed air flow for blowing to the elastic composite yarn by using the air nozzle or the air blower and the tensile force applied to the elastic composite yarn by the weft yarn brake and the weft tensioner are controlled so that the stretching magnification ratio of each of the elastic composite yarns in the elastic woven fabric in the weaving process is retained equal to or less than 1.30 folds based on the elastic composite yarn before weaving.