Knitted roll type elastic fabric and preparation process thereof

Abstract

The invention relates to a knitted roll type elastic fabric and a preparation process thereof. Comprising elastic yarn in the warp direction and non-elastic yarn in the weft direction, the elastic yarn comprises composite elastic yarn and outer polyester yarn spirally winding and wrapping the composite elastic yarn, the composite elastic yarn is formed by compounding and bonding spandex yarn and inner polyester yarn, nick lines are arranged on the inner polyester yarn at intervals, and the nick lines are arranged on the outer polyester yarn. The inner polyester yarns are arranged on the cutting lines, so that elastic deformation of the spandex yarns is limited by the inner polyester yarns during production, the inner polyester yarns are broken from the cutting lines after being tensioned during use to release elasticity of the spandex yarns, and the technical problems that elastic force is uneven and the elasticity is easily damaged due to the fact that core-spun elastic yarns are difficult to control during production are solved.

Description

Technical Field

[0001] This invention relates to knitted roll elastic fabric and its preparation process. Background Technology

[0002] In the production of disposable hygiene products, production lines are generally required. For example, currently, machine-made disposable underwear is mostly made of non-woven fabric, spandex + adhesive, or non-woven fabric sandwich composite rolls. It can provide coverage and protection. However, composite elastic non-woven fabric has particularly poor breathability (about 1350mm / s) due to the multi-layered and adhesive-coated molding process. Non-woven fabric itself does not have the functions of moisture absorption, sweat wicking, and breathability, which limits the user experience and application scenarios. To address the aforementioned breathability issues, this application proposes a disposable underwear made of knitted unidirectional elastic fabric. This fabric is knitted from elastic yarns along the warp and non-elastic yarns along the weft. The elastic yarns include spandex filaments and polyester filaments spirally wrapped around the spandex filaments. This structure effectively solves the aforementioned problems. However, the core-spun elastic yarns face a new challenge in the production process: due to their elasticity, they are difficult to control during the knitting process. Specifically, during yarn feeding and knitting, the large elastic deformation easily leads to tension fluctuations, resulting in uneven fabric elasticity and making it impossible to guarantee product consistency. Furthermore, some processes can cause excessive tension in the elastic yarns, damaging their elasticity. Summary of the Invention

[0003] The purpose of this invention is to provide a knitted roll elastic fabric and its preparation process to solve the technical problem that the elasticity of core-spun elastic yarn is difficult to control during production, resulting in uneven elasticity and easy damage to its elasticity.

[0004] The technical solution of the knitted roll elastic fabric of the present invention is as follows: the knitted roll elastic fabric is made by knitting elastic yarn along the warp and non-elastic yarn along the weft. The elastic yarn includes composite elastic yarn and outer polyester yarn spirally wrapped around the composite elastic yarn. The composite elastic yarn is made by bonding spandex yarn and inner polyester yarn together. The inner polyester yarn is provided with etched lines at intervals so that the inner polyester yarn restricts the elastic deformation of the spandex yarn during production. When in use, the inner polyester yarn is stretched and breaks off from the etched lines to release the elasticity of the spandex yarn.

[0005] Based on the above scheme, the following improvements are made: the inner polyester yarn has two layers, which are respectively pasted on both sides of the spandex yarn.

[0006] Based on the above scheme, further improvements are made as follows: the fiber fineness of the outer polyester filament is 30-75 dtex, the fiber fineness of the spandex filament is 20-40 dtex, and the spandex content in the elastic yarn is 3-8%.

[0007] The technical solution for preparing the knitted roll elastic fabric of the present invention is as follows: including the following steps:

[0008] S1. Prepare composite elastic yarn, process etched lines at intervals on the inner polyester yarn, and bond the spandex yarn and the inner polyester yarn together.

[0009] S2. Processing elastic yarn: The outer polyester filament is spirally wound and wrapped around the composite elastic yarn through an air-wrapping process.

[0010] S3, Weaving: The prepared elastic and non-elastic yarns are woven together using a warp knitting machine.

[0011] Based on the above scheme, the following improvements are made: three combs are used to weave the elastic fabric. The first and second combs are threaded with non-elastic yarn, while the third comb is threaded with elastic yarn.

[0012] Based on the above scheme, the following improvements are made: the first comb bar adopts a reverse weft weft structure, the second comb bar adopts a unidirectional weft weft structure, and the third comb bar adopts a unidirectional chain weft structure.

[0013] Based on the above scheme, further improvements are made as follows: the padding yarn number of the first comb bar is 0-0 / 3-3 / / ; the padding yarn number of the second comb bar is 0-0 / 2-2 / / ; and the padding yarn number of the third comb bar is 1-0 / 0-1 / / .

[0014] The beneficial effects of this application are as follows: To solve the problem of difficulty in controlling the elasticity of existing elastic yarns during the weaving process, this application improves the structure of the elastic yarn and, in conjunction with the corresponding preparation process, uses composite elastic yarn as the inner core, with outer polyester yarn spirally wrapped around the inner core. During production, because the tension during winding and unwinding can be set less, the inner polyester yarn does not break at the scoring lines, remaining intact. The non-elasticity of the inner polyester yarn binds the spandex yarn bonded to it, preventing elastic deformation of the spandex yarn. This facilitates control during the weaving process, avoiding tension fluctuations and subsequent uneven elasticity of the fabric, ensuring product consistency. This is particularly beneficial for knitted elastic fabrics. During use, such as when wearing underwear, simply wearing or pulling will cause the inner polyester filament of the composite elastic yarn to break at the etched line. This is because the etched line is a pre-designed weak point on the inner polyester filament. When the tension on the inner polyester filament reaches a certain value, it will break at the etched line. After the inner polyester filament breaks, it can relieve the restriction on the elasticity of the spandex filament to a certain extent, that is, the spandex filament can regain its elasticity, thereby maintaining the subsequent wearing comfort. Since the outer polyester filament is spirally wrapped around the composite elastic yarn, the broken inner polyester filament is within the wrapping range of the outer polyester filament, and the inner polyester filament is also attached to the spandex filament. These two reasons prevent the broken inner polyester filament from curling up and "fuzzing". Attached Figure Description

[0015] Figure 1This is a schematic diagram of the structure of an embodiment of the knitted roll elastic fabric of the present invention;

[0016] Figure 2 This is a schematic diagram of the three-dimensional structure of elastic yarn;

[0017] Figure 3 This is a schematic diagram of the longitudinal section structure of elastic yarn (before the notch line breaks).

[0018] Figure 4 This is a schematic diagram of the longitudinal section structure of elastic yarn (after the notch line is broken).

[0019] Figure 5 This is a schematic diagram of the cross-sectional structure of elastic yarn;

[0020] Figure 6 This is a diagram showing the yarn-laying motion of the first comb bar;

[0021] Figure 7 This is a diagram showing the yarn padding motion of the second comb bar;

[0022] Figure 8 Diagram showing the yarn padding motion of the third comb bar;

[0023] In the diagram: 1-Non-elastic yarn, 2-Elastic yarn, 21-Outer polyester filament, 22-Composite elastic filament, 221-Spandex filament, 222-Inner polyester filament, 2221-Score line. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0026] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0027] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0028] Specific embodiments of the knitted roll elastic fabric of the present invention: as follows Figure 1-5 As shown, the knitted roll elastic fabric is made by knitting elastic yarn 2 along the warp and non-elastic yarn 1 along the weft. The elastic yarn 2 includes a composite elastic filament 22 and an outer polyester filament 21 spirally wound around the composite elastic filament 22. The composite elastic filament 22 is made by bonding spandex filament 221 and inner polyester filament 222 together. In this embodiment, the inner polyester filament 222 has two layers, which are respectively bonded to both sides of the spandex filament 221. The inner polyester filament 222 has etched lines 2221 at intervals to restrict the elastic deformation of the spandex filament 221 during production. During use, the inner polyester filament 222 is stretched and breaks off at the etched lines 2221 to release the elasticity of the spandex filament 221. The fiber fineness of the outer polyester filament 21 is 30-75 dtex, the fiber fineness of the spandex filament 221 is 20-40 dtex, and the spandex content in the elastic yarn 2 is 3-8%. For example, the outer polyester filament 21 has a fiber fineness of 55 dtex, the spandex filament 221 has a fiber fineness of 22 dtex, the spandex content in the elastic yarn 2 is 7%, and the fiber fineness of the non-elastic yarn 1 is 45 count. The elastic fabric is made by warp knitting of the elastic yarn 2 and the non-elastic yarn 1, so that the elastic fabric is elastic in the warp direction and not elastic in the weft direction; the stretch ratio of the elastic fabric is 1.1 to 3 times, the weaving density is 8-10 needles / 2.54cm, and the weight is 45-180g / ㎡.

[0029] To address the problem of difficulty in controlling the elasticity of existing elastic yarn 2 during the weaving process, this application improves the structure of elastic yarn 2 and, in conjunction with a corresponding preparation process, uses composite elastic yarn 22 as the inner core, with outer polyester yarn 21 spirally wrapped around the inner core. During production, because the tension during winding and unwinding can be set less, the inner polyester yarn 222 does not break at the notch line 2221, remaining intact. The non-elasticity of the inner polyester yarn 222 binds the spandex yarn 221 bonded to it, preventing elastic deformation of the spandex yarn 221. This facilitates control during weaving, avoiding tension fluctuations and uneven elasticity in the fabric, ensuring product consistency. Furthermore, when using the knitted elastic fabric, such as in underwear, the wearing... The inner polyester filament 222 of the composite elastic yarn 22 can be broken at the etched line 2221 by hand. The etched line 2221 is a pre-designed weak point on the inner polyester filament 222. When the tension on the inner polyester filament 222 reaches a certain value, it will break at the etched line 2221. After the inner polyester filament 222 breaks, the restriction on the elasticity of the spandex filament 221 can be relieved to a certain extent, that is, the spandex filament 221 can regain its elasticity, thereby maintaining the subsequent wearing comfort. Since the outer polyester filament 21 is spirally wrapped around the composite elastic yarn 22, the broken inner polyester filament 222 is within the wrapping range of the outer polyester filament 21, and the inner polyester filament 222 is also pasted on the spandex filament 221. These two reasons prevent the broken inner polyester filament 222 from curling up and "fuzzing".

[0030] An embodiment of the preparation process of the knitted roll elastic fabric of the present invention includes the following steps:

[0031] To prepare composite elastic yarn, grooves are processed at intervals on the inner polyester yarn, and the spandex yarn and the inner polyester yarn are then bonded together.

[0032] The elastic yarn is processed by spirally wrapping the outer polyester filament around the composite elastic yarn using an air-wrapping process.

[0033] The weaving process involves knitting the prepared elastic and non-elastic yarns using a warp knitting machine. Three guide bars are used to weave the elastic fabric. The first and second guide bars are threaded with non-elastic yarn, while the third guide bar is threaded with elastic yarn. The first guide bar uses a reverse weft insertion structure, the second guide bar uses a unidirectional weft insertion structure, and the third guide bar uses a unidirectional chain weaving structure. The yarn padding numbers for the first guide bar are 0-0 / 3-3 / / ; for the second guide bar, they are 0-0 / 2-2 / / ; and for the third guide bar, they are 1-0 / 0-1 / / . See details... Figure 6-8 As shown. The warp feed rate of the first comb bar is 900-1500 mm / gra, the warp feed rate of the second comb bar is 1100-2000 mm / gra, and the warp feed rate of the third comb bar is 2500-3500 mm / gra.

[0034] Specifically, in the preparation of elastic and non-elastic yarns, fiber pretreatment is required. The fibers undergo sequential cleaning, carding, drawing, and roving processes to produce polyester / cotton blended yarn. During weaving, the prepared polyester / spandex core-spun yarn (elastic yarn) and polyester / cotton blended yarn (non-elastic yarn) are warped according to the width and machine type, determining the number of warp ends and coils. This warping process forms loops that interlock, creating the elastic fabric greige. The greige fabric is then subjected to width setting and winding to remove impurities and defects from the weaving process. During dyeing and finishing, pretreatment is performed first, involving boiling and bleaching of the greige fabric. The pretreatment uses a low-temperature process, controlled at 80-100℃, to prevent the polyester / spandex core-spun yarn from losing elasticity at high temperatures. Next, the greige fabric is dyed or printed, with tension controlled during dyeing to prevent excessive stretching and deformation. Finishing involves pre-shrinking and setting the fabric. Pre-shrinking is achieved through mechanical or chemical pre-shrinking to reduce shrinkage during subsequent washing. Setting involves a heat setting process, where the fabric is set at a specific temperature (160-210℃), a setting machine speed of 25-30 meters per minute, and a setting width of 132-138 cm. Afterward, inspection checks the fabric surface for defects, marking and rejecting substandard products. Qualified fabrics are randomly sampled for color fastness (wash / rubbing fastness ≥3), width deviation (≤±1%), and weight deviation (≤±3%). Then, the fabric is slit, trimmed, cut, and rewound, and the width and roll length of the fabric are adjusted. Finally, the fabric roll is wrapped in film.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A knitted roll-type elastic fabric, comprising knitted elastic yarn along the warp direction and non-elastic yarn along the weft direction, characterized in that, Elastic yarn includes composite elastic yarn and outer polyester yarn spirally wound around the composite elastic yarn. The composite elastic yarn is made of spandex yarn and inner polyester yarn bonded together. The inner polyester yarn has serrated lines at intervals to restrict the elastic deformation of the spandex yarn during production. When in use, the inner polyester yarn is stretched and breaks off at the serrated lines to release the elasticity of the spandex yarn.

2. The knitted roll elastic fabric according to claim 1, characterized in that, The inner polyester filament has two layers, which are glued to both sides of the spandex filament.

3. The knitted roll elastic fabric according to claim 1, characterized in that, The outer polyester filament has a fiber fineness of 30-75 dtex, the spandex filament has a fiber fineness of 20-40 dtex, and the spandex content in the elastic yarn is 3-8%.

4. A preparation process for preparing the knitted roll elastic fabric according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Prepare composite elastic yarn, process etched lines at intervals on the inner polyester yarn, and bond the spandex yarn and the inner polyester yarn together. S2. Processing elastic yarn: The outer polyester filament is spirally wound and wrapped around the composite elastic yarn through an air-wrapping process. S3, Weaving: The prepared elastic and non-elastic yarns are woven together using a warp knitting machine.

5. The preparation process of the knitted roll elastic fabric according to claim 4, characterized in that, During weaving, three combs are used to weave the elastic fabric. The first and second combs are threaded with non-elastic yarn, while the third comb is threaded with elastic yarn.

6. The preparation process of the knitted roll elastic fabric according to claim 5, characterized in that, The first comb uses a reverse weft weft structure, the second comb uses a unidirectional weft weft structure, and the third comb uses a unidirectional chain weft structure.

7. The preparation process of the knitted roll elastic fabric according to claim 6, characterized in that, The yarn padding code for the first comb is 0-0 / 3-3 / / ; the yarn padding code for the second comb is 0-0 / 2-2 / / ; and the yarn padding code for the third comb is 1-0 / 0-1 / / .

Images