NON-WOVEN FABRIC FOR FOOD-GRADE PACKAGING AND PREPARATION METHOD THEREOF

Abstract

The present disclosure provides a non-woven fabric, which includes 20% to 50% by weight of one or more plant-based fibers, 30% to 50% by weight of one or more low-melting point thermoplastic fibers or thermoplastic bicomponent fibers with a melting point below 180 C., and 10% to 30% by weight of one or more water-based binders. The non-woven fabric uses low-melting point thermoplastic fibers or thermoplastic bicomponent fibers, which ensures a low heat-sealing temperature while maintaining heat-sealing strength. The low binder content addresses the adhesion issue during the processing of non-woven fabric and reduces production energy consumption. By optimizing the ratio of each component, various key properties are balanced. In addition to excellent heat-sealing properties, the non-woven fabric also exhibits good processing properties, mechanical properties, and hydrophilic properties. The fabric surface is free of adhesion and has excellent technical effects in dry and wet stiffness, hygroscopicity, and roughness.

Claims

1. A non-woven fabric, comprising: 20% to 50% by weight of one or more plant-based fibers; 30% to 50% by weight of one or more low-melting point thermoplastic fibers or thermoplastic bicomponent fibers with a melting point below 180 C.; and 10% to 30% by weight of one or more water-based binders.

2. The non-woven fabric of claim 1, comprising: 25% to 45% by weight of one or more plant-based fibers; 35% to 45% by weight of one or more low-melting point thermoplastic fibers or thermoplastic bicomponent fibers with a melting point below 180 C.; and 15% to 25% by weight of one or more water-based binders.

3. The non-woven fabric of claim 1, further comprising other thermoplastic fiber(s).

4. The non-woven fabric of claim 3, wherein the non-woven fabric consists of one or more plant-based fibers, one or more low-melting point thermoplastic fibers or thermoplastic bicomponent fibers with a melting point below 180 C., other thermoplastic fiber(s), and one or more water-based binders, with a total content of all components being 100% by weight.

5. The non-woven fabric of claim 1, wherein the non-woven fabric consists of one or more plant-based fibers, one or more low-melting point thermoplastic fibers or thermoplastic bicomponent fibers with a melting point below 180 C., and one or more water-based binders, with a total content of all components being 100% by weight.

6. The non-woven fabric of claim 1, wherein the non-woven fabric consists of 35% by weight of one or more plant-based fibers, 40% by weight of one or more low-melting point thermoplastic fibers or thermoplastic bicomponent fibers with a melting point below 180 C., and 25% by weight of one or more water-based binders.

7. The non-woven fabric of claim 1, wherein the low-melting point thermoplastic fiber or thermoplastic bicomponent fiber is selected from a group consisting of PE, PP, PLA, LPET, PE/PET, LPET/PET, PE/PP, and PE/PLA.

8. The non-woven fabric of claim 1, wherein the low-melting point thermoplastic fiber or thermoplastic bicomponent fiber is selected from a group consisting of PE/PET, and LPET/PET.

9. The non-woven fabric of claim 1, wherein the plant-based fiber is selected from a group consisting of natural plant-based fibers or regenerated plant-based fibers.

10. The non-woven fabric of claim 1, wherein the plant-based fiber is selected from a group consisting of viscose fibers, lyocell fibers, bamboo fibers, hemp fibers, wood fibers, and cotton fibers.

11. The non-woven fabric of claim 1, wherein the plant-based fiber is selected from a group consisting of viscose fibers, bamboo fibers, and hemp fibers.

12. The non-woven fabric of claim 1, wherein the water-based binder is selected from a group consisting of vinyl acetate-ethylene copolymers, acrylates, polyurethanes, polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoates (PHA), vinyl acetate copolymers, vinyl acrylic copolymers, and styrene-butadiene copolymers.

13. The non-woven fabric of claim 1, wherein the water-based binder is selected from a group consisting of vinyl acetate-ethylene copolymers and acrylates.

14. A bagged product comprising a bag formed from the non-woven fabric of claim 1 and a product in the bag.

15. The bagged product of claim 14, wherein the product in the bag is food or traditional Chinese medicine.

16. A method for preparing a non-woven fabric, wherein according to the composition requirements of the non-woven fabric of claim 1, the method comprises the following steps which are performed sequentially: fiber bale unpacking, opening, metering and mixing of fibers, pre-carding, cross lapping, primary carding, longitudinal lapping, web edge trimming, foaming, foam binder application, and drying; and optionally comprising a final winding step.

17. The method of claim 16, wherein a defect inspection step is further included between the drying and the winding.

Description

DETAILED DESCRIPTION

[0039] The present disclosure will now be further described with reference to specific examples, but it is not limited to these specific examples. A person skilled in the art will recognize that the present disclosure encompasses all alternatives, modifications, and equivalents that may be included within the scope of the claims.

[0040] The abbreviations used herein are defined as follows: [0041] PE: polyethylene fiber [0042] PP: polypropylene fiber [0043] PLA: polylactic acid fiber [0044] LPET: low-melting point polyester fiber [0045] PET: polyester fiber [0046] PA: polyamide fiber [0047] PBT: polybutylene terephthalate fiber [0048] PE/PET: polyethylene/polyester skin-core bicomponent low-melting point fiber [0049] PE/PP: ES fiber [0050] PE/PLA: polyethylene/polylactic acid core-shell bicomponent low-melting point fiber [0051] LPET/PET: low-melting point polyester bicomponent fiber [0052] TPU: thermoplastic polyurethane [0053] PHA: polyhydroxyalkanoate [0054] The present disclosure provides a non-woven fabric including: [0055] 20% to 50% by weight of one or two or more plant-based fibers, [0056] 30% to 50% by weight of one or two or more low-melting point thermoplastic fibers or thermoplastic bicomponent fibers with a melting point of less than 180 C, and [0057] 10% to 30% by weight of one or two or more water-based binders.

I. PREPARATION METHOD OF NON-WOVEN FABRIC

[0058] According to the composition requirements of the non-woven fabric, the following steps are performed sequentially: fiber bale unpacking, opening, metering and mixing of fibers, pre-carding, cross lapping, primary carding, longitudinal lapping, web edge trimming, foaming, foam binder application, drying, on-line defect inspection, winding, and slitting.

[0059] During the fiber bale unpacking and opening stages, multiple fibers are synchronously mixed according to the composition requirements of the nonwoven fabric. In the carding stages, the two steps of pre-carding and primary carding ensure more uniform fiber distribution, resulting in more stable longitudinal and transverse properties of the non-woven fabric. During the foam binder application stage, using foam binder technology, a small amount of binder is sufficient to bind the fibers into a web, with foam points uniformly dispersed throughout the fiber web. This results in a final non-woven fabric product with uniform porosity, better breathability, and more consistent release of substances. In the drying stage, the low binder content allows for rapid drying, low energy consumption, and high production efficiency. The defect inspection is carried out using online visual inspection, ensuring full product inspection and enhancing quality safety and reliability The drying is preferably steam drying.

II. EXAMPLES

[0060] The key indicators of the nonwoven fabric are measured according to the internationally recognized standard ISO9073.

1. Comparison of Effects Using Different Thermoplastic Fibers

[0061] Non-woven fabrics were prepared according to the composition requirements shown in Table 1 and tested for their key indicators (using the international general standard ISO9073).

TABLE-US-00001 TABLE 1 Comparison of effects using different thermoplastic fibers Compar- Compar- Compar- ative ative ative Broad Exam- Exam- Exam- Exam- Exam- Exam- Exam- exam- exam- exam- category Key category ple 1 ple 2 ple 3 ple 4 ple 5 ple 6 ple 7 ple 1-1 ple 1-2 ple 1-3 Plant-based Viscose fiber 35% 35% 35% 35% 35% 35% 35% 35% 35% 35% fiber Thermoplastic PE/PET 40% fiber LPET/PET 40% PE/PP 40% PP 40% LPET 40% PE/PLA 40% PLA 40% PET 40% PA 40% PBT 40% Binder Vinyl 25% 25% 25% 25% 25% 25% 25% 25% 25% 25% acetate- ethylene copolymers Key Grammage 32.1 32.1 32.2 31.8 33.3 32.2 32.7 32.8 32.6 31.5 indicator (g/m.sup.2) Thickness 0.228 0.225 0.231 0.234 0.222 0.219 0.227 0.216 0.212 0.221 (mm) Transverse 11.8 12.1 9.8 8.9 8.5 8.6 7.2 9.4 9.4 9.7 tensile force (N/50 mm) Longitudinal 83.6 81.8 74.9 65.4 60.3 62.8 59.8 84.6 85.1 82.9 tensile force (N/50 mm) Heat-sealing 15.6 15.8 14.3 14.2 13.4 12.8 11.3 14.6 16.7 13.1 strength (N/50 mm) Heat-sealing 180 180 170 175 180 170 170 250 230 240 temperature ( C.) Dry stiffness Stiff Stiff Soft Soft Soft Stiff Stiff Stiff Stiff Stiff Wet stiffness Good Good Poor Poor Poor Average Average Good Average Good Hygroscopicity Good Good Good Good Good Good Good Good Good Good (%) fabric surface None None None None None None None None None None adhesion fabric surface Moderate Moderate Smooth Smooth Smooth Moderate Moderate Moderate Rough Rough roughness

[0062] It can be seen from the data in Table 1 that the use of low-melting point thermoplastic fibers or thermoplastic bicomponent fibers and a low content of binder in Examples 1-7 results in non-woven fabrics having a heat-sealing temperature of less than 200 C. while ensuring heat-sealing strength. This solves the problem of fabric surface adhesion during processing and results in low energy consumption. Among Examples 1-7, Examples 1 and 2 exhibited the best heat-sealing strength, higher than 14.5 N. Examples 1 and 2 also showed superior stiffness and fabric surface roughness compared to Examples 6-7, and even more so compared to Examples 3-5.

2. Comparison of Effects Using Different Plant-Based Fibers

[0063] Non-woven fabrics were prepared according to the composition requirements shown in Table 2 and tested for key indicators.

TABLE-US-00002 TABLE 2 Comparison of effect using different plant-based fibers Compar- Compar- Compar- Compar- Compar- Compar- Compar- Compar- ative ative ative ative ative ative ative ative Broad Key Example example example example Example Example Example example example Example example example Example example category category 1: 2-1 2-2 2-3 8: 9: 10 2-4 2-5 11: 2-6 2-7 12: 2-8 Plant- Viscose 35% 20% 50% based fiber fiber Bamboo 20% 25% 35% 45% 50% fiber Lyocell 20% 35% 50% Hemp 20% 35% 50% fiber Thermoplastic PE/PET 40% 55% 25% 55% 50% 40% 30% 25% 55% 40% 25% 55% 40% 25% fiber Binder Vinyl 25% 25% 25% 25% 25% 25% 25% 25% 25% |25% 25% 25% 25% 25% acetate- ethylene copolymers Key Grammage (g/m.sup.2) 32.1 32.3 32.5 31.6 32.1 33 32.7 32.7 32.2 31.8 32 32.7 31.4 31.9 indicator Thickness (mm) 0.228 0.227 0.219 0.231 0.228 0.225 0.231 0.229 0.232 0.218 0.219 0.223 0.228 0.219 Transverse 11.8 13.1 9.4 12.4 10.9 11.6 10.8 9.9 11.1 10.1 8.6 11.7 10.9 9.0 tensile force (N/50 mm) Longitudinal 83.6 84.6 72.9 85.1 81.4 82.7 80.1 73.7 77.9 78.5 57.2 81.8 82.1 69.8 tensile force (N/50 mm) Heat- 15.6 16.7 12.4 16. 16.2 15.1 14.5 11.8 14.7 10.2 8.7 15.1 13.8 11.2 sealing strength (N/50 mm) Heat- 180 170 200 170 175 180 190 200 175 190 210 170 180 200 sealing temperature ( C.) Dry Stiff Soft Stiff Soft Soft Stiff Stiff Stiff Soft Stiff Stiff Soft Stiff Stiff stiffness Wet Good Good Good Good Good Good Good Good Average Average Average Average Good Good stiffness Hygroscopicity (%) Good Average Good Average Average Good Good Good Poor Good Good Poor Average Good fabric None None None None None None None None None None None None None None surface adhesion fabric Mode Smooth Rough Smooth Smooth Mode Rough Rough Smooth Rough Rough Smooth Mode Rough surface rate rate rate roughness

[0064] It can be seen from the data in Table 2 that the use of different plant-based fibers in Examples 1 and 8-12 results in non-woven fabrics having a heat-scaling temperature of less than 200 C while ensuring heat-sealing strength. This solves the problem of fabric surface adhesion during processing and results in low energy consumption. Viscose fibers and bamboo fibers result in higher heat-sealing strength, greater than 14.5 N, and better performance in stiffness, hygroscopicity, and roughness. However, if the content of low-melting point thermoplastic fibers or thermoplastic bicomponent fibers is too low, it may result in a higher heat-sealing temperature and lower heat-sealing strength.

3. Comparison of Effects Using Different Plant-Based Fibers and Low-Melting Point Thermoplastic Fibers or Thermoplastic Bicomponent Fibers

[0065] Non-woven fabrics were prepared according to the composition requirements shown in Table 3 and tested for key indicators.

TABLE-US-00003 TABLE 3 Comparison of effects using different plant-based fibers and low-melting point thermoplastic fibers or thermoplastic bicomponent fibers Broad Example Example Example Example Example Example Example Example Example category Key category 1 13 14 15 16 17 18 19 20 Plant-based Viscose fiber 35% 20% 15% 35% 35% 35% 35% 35% fiber Bamboo fiber 15% 20 20% Hemp fiber 15% Thermoplastic PE/PET 40% 40% 40% 40% 30% 30% 30% 30% 30% fiber PE/PP 10% PP 10% PLA 10% PET LPET 10% LPET/PET 10% Binder Vinyl acetate- 25% 25% 25% 25% 25% 25% 25% 25% 25% ethylene copolymers Key Grammage (g/m.sup.2) 32.1 32.3 32.7 31.7 31.9 32.3 32.5 31.8 32.2 indicator Thickness (mm) 0.228 0.229 0.234 0.226 0.222 0.232 0.231 0.228 0.229 Transverse tensile 11.8 11.5 11.7 11.6 11.1 10.9 10.4 11.2 11.7 force (N/50 mm) Longitudinal 83.6 82.7 83.5 84.1 81.1 81.3 77.4 80.9 82.8 tensile force (N/50 mm) Heat-sealing 15.6 15.3 15.8 15.2 14.3 13.4 12.3 12.2 15.4 strength (N/50 mm) Heat-sealing 180 180 180 180 180 180 180 180 180 temperature ( C.) Dry stiffness Stiff Stiff Stiff Stiff Soft Soft Stiff Soft Stiff Wet stiffness Good Good Good Good Poor Average Average Average Good Hygroscopicity (%) Good Good Good Good Average Average Good Good Good fabric surface None None None None None None None None None adhesion fabric surface Moderate Moderate Moderate Moderate Smooth Smooth Moderate Rough Moderate roughness

[0066] It can be seen from the data in Table 3 that the use of different plant-based fibers and different combinations of low-melting point thermoplastic fibers or thermoplastic bicomponent fibers in Examples 1 and 13-20 results in non-woven fabrics having a heat-sealing temperature below 200 C. while ensuring heat-sealing strength. This solves the problem of fabric surface adhesion during processing and results in low energy consumption. PE/PET and LPET/PET result in higher heat-sealing strength, greater than 14.5 N, and better performance in stiffness, hygroscopicity, and roughness.

4. Comparison of Effects Using Different Binders

[0067] Non-woven fabrics were prepared according to the composition requirements shown in Table 4 and tested for key indicators.

TABLE-US-00004 TABLE 4 Comparison of effects using different binders Compar- Compar- Compar- Compar- Compar- ative ative ative ative ative Broad Key Exam- Exam- Exam- Exam- Exam- exam- exam- exam- exam- exam- category category ple 1: ple 21: ple 22: ple 23 ple 24 ple 4-1 ple 4-2 ple 4-3 ple 4-4 ple 4-5 Plant-based Viscose fiber 35% 35% 50% 45% 30% 25% 10% 35% 35% 35% fiber Thermoplastic PE/PET 40% 40% 40% 40% 40% 40% 40% 30% 20% 20% staple fibers Binder Vinyl 25% 10% 15% 30% 35% 50% 25% 45% 25% acetate- ethylene copolymers Polyurethanes 20% Acrylates 25% 10% Key Grammage 32.1 32.1 31.9 32.2 32.0 32.4 32.8 33.1 31.3 31.7 specification (g/m.sup.2) Thickness 0.228 0.225 0.229 0.238 0.231 0.232 0.229 0.239 0.242 0.236 (mm) Transverse 11.8 11.6 6.4 7.2 12.9 13.2 14.9 12.6 11.1 10.9 tensile force (N/50 mm) Longitudinal 83.6 79.8 48.2 53.1 81.8 71.0 49.7 72.3 68.5 66.6 tensile force (N/50 mm) Heat-sealing 15.6 15.3 14.7 15.1 16.0 16.7 16.2 17.1 17.3 21.4 strength (N/50 mm) Heat-sealing 180 190 195 190 180 180 180 180 180 180 temperature ( C.) Dry stiffness Stiff Stiff Stiff Stiff Stiff Soft Soft Stiff Stiff Stiff Wet stiffness Good Average Good Good Good Average Poor Good Average Poor Hygroscopicity Good Good Good Good Good Average Poor Good Good Poor (%) Fabric None None None None None Minor Serious Minor Serious Serious surface adhesion Fabric Moderate Moderate Smooth Smooth Moderate Moderate Rough Rough Rough Rough surface roughness

[0068] It can be seen from the data in Table 4 that the use of different contents of binders in Examples 1 and 21-24 solves the problem of fabric surface adhesion during processing. The obtained non-woven fabric has a heat-sealing temperature below 200 C. and low energy consumption while ensuring heat-sealing strength. The heat-sealing strength is greater than 14.5 N, and it exhibits excellent performance in stiffness, hygroscopicity, and roughness.

[0069] From the examples of the present disclosure, it can be seen that by using plant-based fibers, low-melting point thermoplastic fibers or thermoplastic bicomponent fibers, and water-based binders, the non-woven fabric achieves a heat-sealing temperature below 200 C. while ensuring heat-sealing strength, with low energy consumption and low binder content. This solves the problem of fabric surface adhesion during processing. In the preferred embodiments of the present disclosure, using specific low-melting point thermoplastic fibers or thermoplastic bicomponent fibers ensures a heat-sealing strength above 14.5 N and further enhances processability, dry and wet stiffness, hygroscopicity, roughness, etc.

[0070] Therefore, by controlling the components and their contents in the non-woven fabric, the present disclosure achieves a balance of heat-sealing performances such as heat-sealing temperature and strength, mechanical properties such as non-adhesion on the fabric surface, dry stiffness and wet stiffness, hygroscopicity, and roughness, hydrophilicity, and processability.

[0071] In the description of the specification, references to terms such as an embodiment and an example, etc., mean that specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present disclosure. In the description, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Additionally, various embodiments or examples described in the description, as well as features of various embodiments or examples, may be integrated and combined by a person skilled in the art without departing from the scope of the disclosure.

[0072] The protective scope of the present disclosure is not limited to the above-described embodiments, and it is apparent that various modifications and variations can be made to the present disclosure by a person skilled in the art without departing from the scope and spirit of the present disclosure. It is intended that the present disclosure covers modifications and variations provided they fall within the scope of the appended claims and their equivalents.