Patent Application
20240240374
The present invention relates to the technical field of non-woven fabrics, and in particular to a wiping non-woven fabric with anti-shedding and anti-agglomeration properties used for personal care and infant care, and a manufacturing method therefor.
Non-woven fabrics for wiping have gained popularity among consumers due to their convenience in carrying, storage, and use. Currently, wiping non-woven fabrics can be spunlace non-woven fabric products or melt-blown non-woven fabric or spunbond non-woven fabric products. Compared to traditional cloth wipes, the production of non-woven fabrics for wiping is more convenient and cost-effective, and these fabrics are suitable for both dry and wet usage. CN1044015C (Chinese patent invention application number 93118457.6) discloses an abrasion resistant fibrous non-woven composite structure composed of the following two components: (1) a matrix of meltblown fibers having a first exterior surface, a second exterior surface, and an interior portion; and (2) at least one other fibrous material integrated into the meltblown fiber matrix so that the concentration of meltblown fibers adjacent each exterior surface of the nonwoven structure is at least about 60 percent, by weight, and the concentration of meltblown fibers in the interior portion is less than about 40 percent, by weight. The wipe produced according to the above CN patent features a denser melt-blown layer formed by melt-blown fibers on the surface, which to some extent prevents the shedding of auxiliary fibers, such as wood pulp staples, from the interior portion during use. However, the auxiliary fibers within the interior portion are not mutually adhered or fixed, resulting in occurrences of “dusting” and “shedding” of fibers during use. Additionally, there is a tendency for the fibers to agglomerate during wiping after water absorption, thereby affecting the using effect and reducing the service life of the wipes.
It is an object of the present invention to provide a composite wiping non-woven fabric with effective anti-shedding and anti-agglomeration properties as well as higher mechanical strength, and a manufacturing method therefor, thereby overcoming the defects of existing products and production methods.
To achieve the aforementioned object, the present invention provides the following technical solutions: A composite wiping non-woven fabric with a layered structure, comprising sequentially an upper surface layer, a middle fiber layer, and a lower surface layer; the upper surface layer and the lower surface layer of the composite wiping non-woven fabric are mainly formed by melt-blown fibers, and the middle fiber layer is formed at least by viscose fibers, wherein a weight of the middle fiber layer is greater than or equal to 65% of a total weight of the composite wiping non-woven fabric; the viscose fibers have a fiber length of 35 mm to 76 mm, and there are fiber interlacing and intertwining areas between the upper surface layer and the middle fiber layer, as well as between the lower surface layer and the middle fiber layer.
The melt-blown fibers are polyolefin fibers, polyamide fibers, polyurethane fibers, or a mixture thereof.
The melt-blown fibers are single-component fibers, bi-component melt-blown fibers with outer surface of each fiber at least partially formed by low melting point resin, or a mixture thereof.
The bi-component melt-blown fibers are bi-component sheath-core type melt-blown fibers, bi-component orange peel type melt-blown fibers, or bi-component side-by-side type melt-blown fibers.
The middle fiber layer is formed by a mixture of viscose fibers mixed with natural fibers, single-component staples, bi-component staples, or a mixture thereof.
A weight percentage of the viscose fibers in the middle fiber layer is greater than or equal to 15%.
The natural fibers are wood pulp fibers, cotton fibers, or a mixture thereof.
A method for manufacturing a composite wiping non-woven fabric, comprising the following steps: (1) carding viscose fibers into a fiber web using a carding machine, and forming a middle fiber layer from the fiber web through a nozzle under action of auxiliary airflow, wherein the middle fiber layer is formed at least by the viscose fibers;
(2) employing a melt-blown process, wherein a thermoplastic resin is heated and melted; melt trickles of the thermoplastic resin heated and melted are ejected out from spinnerets, and hot air is used to blow the melt trickles ejected out from the spinnerets into fiber bundles, which, together with flows of the hot air, form melt-blown fiber webs that intertwine with two sides of the middle fiber layer respectively, thereby forming a multilayer fiber web with two outer layers being the melt-blown fiber web layers respectively and a middle layer being the middle fiber layer formed at least by the viscose fiber web in between the melt-blown fiber web layers;
(3) consolidating the multilayer fiber web with a heating device to form a composite wiping non-woven fabric with upper and lower layers being the melt-blown fiber web layers respectively and a middle layer being said middle fiber layer formed at least by the viscose fibers.
In step (1), viscose fibers are mixed with other fibers to form mixed fibers, which subsequently form the middle fiber layer through the nozzle under the action of auxiliary airflows.
The heating device is a hot air oven, a pair of press rollers, or a combination thereof.
In accordance with the aforementioned structures and manufacturing method, the middle fiber layer of the composite wiping non-woven fabric is formed at least by the viscose fibers which have a fiber length of approximately 35 mm to 76 mm, whereas the conventional non-woven fabric used for wipes has a middle layer made of wood pulp fibers with a fiber length of approximately 1 mm to 4 mm, viscose fibers with a longer fiber length as the fibers in the middle fiber layer makes it less likely for them to escape from gaps between the melt-blown fibers of the upper and lower melt-blown fiber web layers. In addition, during the manufacturing process of the composite wiping non-woven fabric, the melt-blown fibers on both sides intertwine with the two sides of the middle fiber layer respectively, thereby forming an interwoven network structure, that is to say, there are fiber interlacing and intertwining areas between the upper melt-blown fiber web layer and the middle fiber layer, and also between the lower melt-blown fiber web layer and the middle fiber layer. Accordingly, the viscose fibers of the middle fiber layer are fixed within the interwoven network structure, making the viscose fibers difficult to move. This not only enhances the tensile strength of the composite wiping non-woven fabric but also prevents the occurrence of “shedding” or “dusting” during use, and further this can effectively prevent the occurrence of agglomeration of the middle fiber layer after absorbing water when the composite wiping non-woven fabric is used with liquids. Moreover, viscose fibers possess good moisture absorption and water retention properties. Due to smaller fiber denier of the melt-blown fibers, the composite wiping non-woven fabric as formed gives a softer feeling and has a large fiber specific surface area, and these enhances the cleaning capability of the composite wiping non-woven fabric during wiping.
In order to further explain the technical solutions of the present invention, the present invention will be described in detail with some specific embodiments.
As shown in
By employing a melt-blown process, a thermoplastic polypropylene resin is heated and melted; melt trickles of the heated and melted thermoplastic polypropylene resin are ejected out from spinnerets C1 and C1′, and hot air is used to blow the melt trickles ejected out from the spinnerets C1 and C1′ into ultra-fine fiber bundles, which, together with flows of the hot air, form melt-blown fiber webs 12 and 12′ that intertwine with two sides of the middle fiber layer 13 respectively, thereby forming a multilayer fiber web with two outer layers being the melt-blown fiber web layers 12 and 12′ respectively and a middle layer being the middle fiber layer 13 formed from the viscose fiber web 11 in between the melt-blown fiber web layers 12 and 12′; apart from the thermoplastic polypropylene resin, melt-blown fibers used in the above described melt-blown process can alternatively be single-component propylene fibers, or can also be polyolefin fibers, polyamide fibers, polyurethane fibers, or a mixture thereof; a weight of the viscose fibers is 75% of a total weight of the composite wiping non-woven fabric.
Fiber web layers of the multilayer fiber web are consolidated by a pair of press rollers D1 to form the composite wiping non-woven fabric 14 with an upper layer and a lower layer being the melt-blown fiber web layers 12 and 12′ respectively, and a middle layer being the middle fiber layer 13 formed from the viscose fiber web 11 in between the upper layer and the lower layer, wherein fiber interlacing and intertwining areas exist between a first melt-blown fiber web layer 12 and the middle fiber layer, and also between a second melt-blown fiber web layer 12′ and the middle fiber layer 13.
Tensile strength testing was conducted using the XLW-100N Intelligent Electronic Tensile Tester with following test parameters.
MD (machine direction): sample width: 50 mm, gauge length: 200 mm, stretching velocity: 100 m/min.
CD (cross direction): sample width: 50 mm, gauge length: 100 mm, stretching velocity: 100 m/min.
Reference standard: Chinese national standard GB/T13775-92 “Testing Method for Determination of the Resistance to abrasion of cotton, ramie and silk spinning fabrics”.
Instrument: YG(B)401E Martindale Abrasion Tester.
Standard padding material: standard felt with a square meter weight of 750±50 g/m2, a thickness of 3±0.5 mm, and a diameter of 140 mm.
Sample backing material: polyurethane foam plastic material with a thickness of 3±0.5 mm, a density of 0.04 g/cm3, and a diameter of 38±2 mm.
Sampler 1: disk sampler with a diameter of 140 mm, used for sampling a lower-layer abrasion test sample material with a size of φ140 mm.
Sampler 2: disk sampler with a diameter of 38 mm, used for sampling an upper-layer abrasion test sample material with a size of φ38 mm.
Sample pretreatment: The samples were kept at room temperature for 24 H.
Testing Procedures: 1) Use sampler 1 to take a lower-layer abrasion test sample material with a diameter of 140 mm and place it over the standard padding: then place a sample mounting weight on the lower-layer abrasion test sample material; tighten a circular clamp to fix the lower-layer abrasion test sample material on an abrasion test table.
2) Use sampler 2 to take an upper-layer abrasion test sample material with a diameter of 38 mm, and load the upper-layer abrasion test sample material with a sample holder into a 200 g metal clamp head of an A-type abrasion head, and a polyurethane foam plastic having a diameter of 38 mm is placed between the metal clamp head and the abrasion head.
3) Place the metal clamp head onto the abrasion test table, and pass a core shaft through a bearing of the abrasion head so that the core shaft is inserted into the metal clamp head; then add a 395 g weight on the metal clamp head (a load generated by the 395 g weight plus the weight of the 200 g metal clamp head is 583.1 cN).
4) Set a rotation speed of the instrument to 20 rpm with a total of 15 rotations. After completing the setting, click the “Start” button to start operation of the instrument; once the test is completed according to the setting, the instrument will stop. Inspect the fiber shedding of the lower-layer abrasion test sample material and determine its abrasion resistance level as L (good abrasion resistance), M (moderate abrasion resistance), or H (poor abrasion resistance) based on the shedding condition.
Instruments: dusting rate tester, balance.
Reference testing standard: Dusting Rate Testing according to Appendix B of Chinese national standard GB/T 20810-2018 concerning “Toilet Tissue Paper”.
Testing steps: 1. Take approximately 150 g of sample, weigh it with the balance, and denote its weight as m1; fold the sample into a specimen of 200 mm in length, with longitudinal edges of the folded portions always in alignment during folding.
2. Fix one end of a longitudinal edge of the eventually folded specimen onto the specimen clamp, with specimen surfaces perpendicular to a swinging direction of the specimen during testing, and ensure that the specimen will not come into contact with inner walls of a chamber of the tester during testing.
3. Start the tester and let the specimen swing inside the chamber for 2 min, with a reciprocating frequency of 180±10 times/min and a swing distance of 100±5 mm.
4. After the test is completed, turn off the tester, remove the specimen, weigh the specimen and denote the weight as m2.
5. Calculate the dusting rate of the specimen according to the following formula:
In the formula: X represents the dusting rate of the specimen in percentage; m1 represents the weight of the specimen before the test in gram (g); m2 represents the weight of the specimen after the test in gram (g).
Weigh a 10 cm×10 cm sample and record the weight as M1, then submerge the sample in water to completely wet it, take out the sample 60 s later and hang it in air for 120 s, and then weigh it again, and then record the weight as M2; calculate a liquid absorption amount as M=M2−M1.
The tests and their methods are used to test the composite wiping non-woven fabric produced according to Embodiment 1 and a conventional wiping non-woven fabric; wherein the conventional wiping non-woven fabric has both upper and lower surface layers being melt-blown non-woven fabric layers and a middle layer formed by wood pulp fibers. The test results are shown below.
In the abrasion resistance testing, the mutual frictions created between the composite wiping non-woven fabric and the abrasion head can simulate the actual use of the product during wiping, therefore the testing has tested the abrasion resistance of a melt-blown fiber web layer of the composite wiping non-woven fabric. In the dusting rate testing, the severity of the phenomenon so-called “shedding” or “dusting” which fibers in the middle fiber layer drop off from the middle fiber layer through the two outer melt-blown fiber web layers is assessed by side-to-side swinging of the composite wiping non-woven fabric and then determining a percentage of weight difference of the composite wiping non-woven fabric obtained by a ratio between a difference in weight of the composite wiping non-woven fabric before and after swinging and the weight of the composite wiping non-woven fabric before swinging. As can be seen from the above testing data, the middle fiber layer of the composite wiping non-woven fabric in Embodiment 1 is composed of viscose fibers with a fiber length of approximately 35 mm to 76 mm, whereas the conventional non-woven fabric used for wipes has a middle layer made of wood pulp fibers with a fiber length of approximately 1 mm to 4 mm, viscose fibers with a longer fiber length as the fibers in the middle fiber layer makes it less likely for them to escape from gaps between the melt-blown fibers of the upper and lower melt-blown fiber web layers. In addition, during the manufacturing process of the composite wiping non-woven fabric, the melt-blown fibers on both sides intertwine with the two sides of the middle fiber layer respectively, thereby forming an interwoven network structure, that is to say, there are fiber interlacing and intertwining areas between the upper melt-blown fiber web layer and the middle fiber layer, and also between the lower melt-blown fiber web layer and the middle fiber layer. Accordingly, the viscose fibers of the middle fiber layer are fixed within the interwoven network structure, making the viscose fibers difficult to move. This not only enhances the tensile strength of the composite wiping non-woven fabric but also prevents the occurrence of “shedding” or “dusting” during use. Moreover, viscose fibers possess good moisture absorption and water retention properties. Due to smaller fiber denier of the melt-blown fibers, the composite wiping non-woven fabric as formed gives a softer feeling and has a large fiber specific surface area, and these enhances the cleaning capability of the composite wiping non-woven fabric during wiping.
As shown in
By employing a melt-blown process, a thermoplastic polypropylene (PP) is heated and melted; melt trickles of the heated and melted PP are ejected out from spinnerets C2 and C2′, and hot air is used to blow the melt trickles ejected out from the spinnerets C2 and C2′ into ultra-fine fiber bundles, which, together with flows of the hot air, form melt-blown fiber webs 23 and 23′ that intertwine with two sides of the middle fiber layer 24 respectively, thereby forming a multilayer fiber web with two outer layers being the melt-blown fiber web layers 23 and 23′ respectively and a middle layer being the middle fiber layer 24 comprising the mixture of the viscose fibers and the wood pulp fibers in between the melt-blown fiber web layers 23 and 23′, as said, melt-blown fibers used in the above described melt-blown process are PP fibers, but they can also be polyamide fibers, polyurethane fibers, or a mixture thereof; the PP fibers are bi-component melt-blown fibers with an outer surface of each fiber at least partially formed by a low melting point resin, specifically, the bi-component melt-blown fibers can be bi-component sheath-core type fibers, bi-component orange peel type fibers, or bi-component side-by-side type fibers; a weight of the middle fiber layer is 80% of a total weight of the composite wiping non-woven fabric; 50% by weight of the middle fiber layer is the viscose fibers; also, besides wood pulp fibers, fibers that can also be mixed with the viscose fibers in the middle fiber layer may be single-component or bi-component staples, or other kinds of natural fibers, etc.
The multilayer fiber web is first put into a hot air oven F2, such that the outer surface (which is at least partially formed by said low melting point resin) of the bi-component PP fibers in upper and lower layers of the multilayer fiber web can be melted by hot air in the hot air oven to bond the fibers in the upper and lower layers respectively. Then, the multilayer fiber web is further consolidated with a pair of press rollers D2 to form a composite wiping non-woven fabric 25 with the upper and lower layers being the melt-blown fiber web layers 23 and 23′ and a middle layer in between the melt-blown fiber web layers 23 and 23′ being the middle fiber layer 24 composed of a mixture of the viscose fiber web 21 and the wood pulp fibers 22, wherein fiber interlacing and intertwining areas exist between a first melt-blown fiber web layer 23 and the middle fiber layer 24, and also between a second melt-blown fiber web layer 23′ and the middle fiber layer 24.
The composite wiping non-woven fabric produced in Embodiment 2 and a conventional wiping non-woven fabric (which has both upper and lower surface layers being melt-blown non-woven fabric layers and a middle layer formed by wood pulp fibers) were subjected to tests and evaluations. The test results are shown below.
The composite wiping non-woven fabric produced according to the aforementioned structures and manufacturing method has a middle fiber layer 24 composed of a mixture of the viscose fiber web 21 and the wood pulp fibers 22, wherein the wood pulp fibers may also be replaced with other fibers such as single-component or bi-component staples or other kinds of natural fibers; addition of other fibers in the middle layer 24 imparts more characteristics to the composite wiping non-woven fabric. For example, wood pulp fibers, due to their high specific surface area, can further enhance the moisture absorption of the composite wiping non-woven fabric; single-component or bi-component staples, such as CoPET staples, PE/PET or PE/PP staples, can further enhance the abrasion resistance of the composite wiping non-woven fabric, preventing fiber shedding; and the inclusion of natural fibers like cotton fibers can improve the softness and skin-friendly properties of the composite wiping non-woven fabric.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202110813872.X | Jul 2021 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/074234 | 1/27/2022 | WO |
