Method for preparing regenerated leather from waste leather collagenous fibers

Abstract

The invention provides a method for preparing regenerated leather from waste leather collagen fibers, and belongs to the technical field of regenerated leather materials. Collagen fibers obtained by recycling waste leather are adopted as main raw materials, a skeleton structure is enhanced by adopting polyester fibers, the tensile strength and the wear resistance are improved, and the tensile strength and the tear resistance are remarkably improved by utilizing basalt fibers; hemp fibers and polyester fibers are used as main raw materials of the antibacterial soft lower layer, the softness is improved, the tensile strength is improved, the air permeability is guaranteed, and phenolic substances in the hemp fibers are used for improving the antibacterial effect; by means of nano-zinc oxide, the antibacterial effect is improved, and meanwhile color fading of the regenerated leather is effectively relieved; and fiber network curing, flexibility adjustment and hardness and elasticity balance are realized by using the adhesive. According to the method provided by the invention, by adjusting the variety and dosage of the raw materials, the prepared regenerated leather is high in tensile resistance and tear resistance, good in softness, not prone to deformation and excellent in antibacterial property.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of regenerated leather material, and particularly relates to a method for preparing regenerated leather by using waste leather collagen fibers. BACKGROUND

[0002] At present, popular leather products on the market are divided into two categories: real leather and artificial leather. Real leather is mainly obtained by physical and chemical processing such as unhairing and tanning of animal skins such as pig, cow and sheep skins, and is not easy to rot. Artificial leather is prepared by polyurethane, polyvinyl chloride resin and base cloth. Although the surface feel and appearance of artificial leather are similar to those of real leather, the physical properties such as air permeability and cold resistance are far inferior to those of real leather.

[0003] Due to the limited amount of real leather, a large amount of waste leather, scraps and other waste materials are inevitably generated in the production process. The traditional method of recycling these waste materials is to crush them into powder, and then to stick and press the powder into a whole piece of regenerated leather by using an adhesive or a hot melt fiber. The regenerated leather has certain moisture absorption, water permeability and air permeability, wear resistance, heat resistance and elasticity. The edges of the regenerated leather are relatively neat, the leather body is relatively thick, and the price is low, so the regenerated leather is widely used in products such as plain briefcases, trolley cases, plain belts and travel shoes. However, the fiber structure of the regenerated leather is not as dense as that of natural leather, and the tensile and tear resistance is weak, so the regenerated leather is prone to cracking and delamination after long-term use. Moreover, the addition of the adhesive (such as polyurethane and latex) may cause the material to harden, lack the softness and elasticity of natural leather, and make the regenerated leather have a pungent odor to some extent. In addition, the regenerated leather is prone to deformation and mildew in a high-temperature and humid environment. The above problems greatly affect the improvement of the product grade of the regenerated leather and the promotion of the regenerated leather. Therefore, it is a technical problem to be solved in the prior art to provide a regenerated leather with strong tensile and tear resistance, good softness, non-deformation and excellent antibacterial property. SUMMARY

[0004] The present application aims to provide a method for preparing regenerated leather by using waste leather collagen fibers. The regenerated leather prepared by the method has strong tensile and tear resistance, good softness, non-deformation and excellent antibacterial property.

[0005] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0006] The present application provides a method for preparing regenerated leather by using waste leather collagen fibers. The raw materials for preparing the regenerated leather include, by mass fraction: 80-110 parts of collagen fibers, 20-40 parts of polyester fibers, 3-6 parts of basalt fibers, 8-16 parts of hemp fibers, 1-5 parts of nano zinc oxide and 5-13 parts of adhesive.

[0007] The collagen fibers are obtained by recycling waste leather.

[0008] The regenerated leather is formed by water jetting and inserting treatment of the collagen fiber upper layer and the antibacterial soft lower layer.

[0009] Preferably, the waste leather is animal skin waste or leftover.

[0010] Preferably, the adhesive comprises oxidized starch and glutaraldehyde, and the mass fraction of the glutaraldehyde accounts for 3-6% of the adhesive.

[0011] Preferably, the method for preparing regenerated leather from waste leather collagen fibers comprises the following steps:

[0012] (1) The recycled animal skin waste or leftover is sequentially classified, arranged, and split open to obtain collagen fibers;

[0013] The collagen fibers are mixed with part of polyester fibers and part of basalt fibers, and are pre-mixed to obtain a mixture;

[0014] The mixture is sequentially first laid and pressed to obtain a collagen fiber upper layer;

[0015] (2) The adhesive, nano-zinc oxide, and water are mixed to obtain a mixed solution;

[0016] The remaining polyester fibers, the remaining basalt fibers, and the hemp fibers are mixed and then second laid to obtain a fiber web, and the mixed solution is coated on one side of the fiber web to obtain an antibacterial soft lower layer;

[0017] (3) The side of the antibacterial soft lower layer obtained in step (2) coated with the mixed solution is attached to the surface of the collagen fiber upper layer obtained in step (1), and water jetting and inserting treatment is performed to obtain regenerated leather.

[0018] Preferably, the pre-mixing time in step (1) is 4-6h.

[0019] Preferably, the mass ratio of polyester fibers in the collagen fiber upper layer in step (1) to polyester fibers in the antibacterial soft lower layer in step (2) is 1:(8-20).

[0020] The mass ratio of basalt fibers in the collagen fiber upper layer in step (1) to basalt fibers in the antibacterial soft lower layer in step (2) is 1:(0.3-0.6).

[0021] Preferably, the first laying in step (1) comprises sequentially combing, laying in longitudinal and transverse directions, and three-dimensional staggered laying.

[0022] Preferably, the pressing temperature in step (1) is 140-170℃, the pressing time is 3-10 min, and the pressing pressure is 300-450 kPa.

[0023] Preferably, the water jetting treatment in step (3) comprises 2-4 times of forward and reverse water jetting treatment, and the water jetting treatment uses 150-300 MPa high-pressure water flow.

[0024] Preferably, after the water jetting treatment in step (3) is completed, the method further comprises the steps of pressing water, drying, trimming, winding and packaging.

[0025] The present application provides a method for preparing regenerated leather by using waste leather collagen fibers, and the raw materials for preparing the regenerated leather include, in terms of mass fraction, 80-110 parts of collagen fibers, 20-40 parts of polyester fibers, 3-6 parts of basalt fibers, 8-16 parts of hemp fibers, 1-5 parts of nano zinc oxide, and 5-13 parts of adhesive; the collagen fibers are obtained by recycling waste leather; and the regenerated leather is formed by water jetting treatment of the upper layer of collagen fibers and the soft and antibacterial lower layer. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The performance statistics of the regenerated leather prepared in examples 1-5 and comparative examples 1 and 2 of the present application. DETAILED DESCRIPTION

[0027] The present application provides a method for preparing regenerated leather by using waste leather collagen fibers, and the raw materials for preparing the regenerated leather include, in terms of mass fraction, 80-110 parts of collagen fibers, 20-40 parts of polyester fibers, 3-6 parts of basalt fibers, 8-16 parts of hemp fibers, 1-5 parts of nano zinc oxide, and 5-13 parts of adhesive;

[0028] The collagen fibers are obtained by recycling waste leather;

[0029] The regenerated leather is formed by water jetting and inserting treatment of the upper layer of collagen fibers and the soft lower layer of antibacterial.

[0030] In the present application, the raw materials used are all conventional commercially available products in the art, unless otherwise specified.

[0031] In the present application, the raw materials used to prepare the regenerated leather preferably include, by mass fraction, 85-105 parts of collagen fibers, 22-38 parts of polyester fibers, 3.5-5.5 parts of basalt fibers, 10-15 parts of hemp fibers, 2-4.5 parts of nano zinc oxide, and 6-12 parts of adhesive.

[0032] In the present application, the waste leather is preferably animal skin waste or leftover materials. In the present application, the collagen fibers preferably include 60wt%-80wt% of main fibers and 20wt%-40wt% of reinforcing fibers; the average length of the main fibers is preferably 3-6mm; and the average length of the reinforcing fibers is preferably 6-9mm. In the present application, the average length of the polyester fibers is preferably 3-10mm; and the average diameter of the polyester fibers is preferably 10-20μm. In the present application, the average length of the basalt fibers is preferably 3-6mm. In the present application, the average length of the hemp fibers is preferably 2-5mm. The present application controls the length and diameter of each fiber within the above range, avoids fiber agglomeration, improves the uniformity of dispersion, and facilitates the formation of a continuous stress transfer network, thereby significantly improving the tensile strength and tear resistance of the prepared regenerated leather.

[0033] In the present application, the adhesive preferably includes oxidized starch and glutaraldehyde; and the mass fraction of the glutaraldehyde preferably accounts for 3%-6% of the adhesive. The present application uses oxidized starch and glutaraldehyde as the adhesive, thereby improving the density of the regenerated leather, enhancing its water resistance, and inhibiting microbial growth, which is green and environmentally friendly.

[0034] In the present application, the method for preparing regenerated leather from collagen fibers of waste leather preferably includes the following steps:

[0035] (1) The recovered animal skin waste or leftover materials are sequentially classified, arranged, and cut open to obtain collagen fibers;

[0036] The collagen fibers are mixed with part of the polyester fibers and part of the basalt fibers, and are pre-mixed to obtain a mixture;

[0037] The mixture is sequentially first laid and pressed to obtain an upper layer of collagen fibers;

[0038] (2) The adhesive, nano zinc oxide, and water are mixed to obtain a mixed solution;

[0039] After mixing the residual polyester fiber, the residual basalt fiber and the hemp fiber, a second laying is performed to obtain a fiber web, and the mixed solution is coated on one side of the fiber web to obtain an antibacterial soft lower layer.

[0040] (3) The side of the antibacterial soft lower layer obtained in step (2) coated with the mixed solution is attached to the surface of the collagen fiber upper layer obtained in step (1), and hydroentangled to obtain the regenerated leather.

[0041] The present application does not have special restrictions on the way of separating, arranging and cutting the fibers, and the technical solutions known in the art can be used.

[0042] In the present application, the premixing time is preferably 4-6h. The present application uniformly mixes the fibers by premixing to improve the performance stability of the regenerated leather prepared subsequently.

[0043] In the present application, the mass ratio of polyester fiber in the collagen fiber upper layer to polyester fiber in the antibacterial soft lower layer is preferably 1:(8-20), and more preferably 1:(10-18). In the present application, the mass ratio of basalt fiber in the collagen fiber upper layer to basalt fiber in the antibacterial soft lower layer is preferably 1:(0.3-0.6), and more preferably 1:(0.35-0.55). The present application controls the mass ratio of polyester fiber in the collagen fiber upper layer to polyester fiber in the antibacterial soft lower layer, and the mass ratio of basalt fiber in the collagen fiber upper layer to basalt fiber in the antibacterial soft lower layer, to improve the tensile strength and tear resistance of the collagen fiber upper layer, and to ensure good softness, so as to ultimately obtain a regenerated leather with good comprehensive performance.

[0044] In the present application, the first laying preferably includes sequentially performing carding, longitudinal and transverse staggered laying, and three-dimensional staggered laying. The present application improves the structural stability of the collagen fiber upper layer prepared by the first laying.

[0045] In the present application, the pressing temperature is preferably 140-170℃; the pressing time is preferably 3-10min; and the pressing pressure is preferably 300-450kPa. The present application improves the compactness of the collagen fiber upper layer by pressing to improve its tensile strength and tear resistance.

[0046] In the present application, the thickness of the collagen fiber upper layer is preferably 0.7-1.0mm.

[0047] In the present application, the mixing method of the adhesive, nano-zinc oxide and water is preferably ultrasonic treatment for 20-40min. The present application uniformly mixes the components by ultrasonic treatment. In the present application, the mass fraction of the adhesive in the mixed solution is preferably 5%-30%.

[0048] In the present application, the second laying is preferably performed by sequentially carrying out carding, longitudinal-transverse staggered laying and three-dimensional staggered laying.

[0049] The present application does not have special restrictions on the coating method, and the mixed solution can be uniformly coated on one side of the fiber web by using a technical solution well known in the art.

[0050] In the present application, the thickness of the antibacterial soft underlayer is preferably 0.2-0.4 mm.

[0051] In the present application, the water jet needling treatment preferably includes 2-4 times of forward and reverse water jet needling treatment; and the water jet needling treatment preferably uses a high-pressure water flow of 150-300 MPa. The present application mechanically entangles the antibacterial soft underlayer and the collagen fiber upper layer through water jet needling treatment, thereby improving the physical properties and structural uniformity of the regenerated leather and improving the comprehensive performance thereof.

[0052] In the present application, after the water jet needling treatment is completed, the regenerated leather is preferably further subjected to water removal by pressing, drying, edge trimming, winding and packaging. In the present application, the thickness of the regenerated leather is preferably 0.8-1.2 mm.

[0053] The technical solutions in the present application will be clearly and completely described below in combination with the embodiments in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0054] Embodiment 1

[0055] A method for preparing regenerated leather from waste leather collagen fibers, the raw materials for preparing the regenerated leather are as follows in terms of mass fraction: 90 parts of collagen fibers, 25 parts of polyester fibers, 3.5 parts of basalt fibers, 12 parts of hemp fibers, 4 parts of nano zinc oxide, and 8 parts of adhesive;

[0056] The collagen fibers are obtained by recycling waste leather, i.e., animal skin waste or leftover materials; the collagen fibers include 80 wt% of main fibers and 20 wt% of reinforcing fibers; the average length of the main fibers is 6 mm; the average length of the reinforcing fibers is 9 mm; the average length of the polyester fibers is 7 mm; the average diameter of the polyester fibers is 16 μm; the average length of the basalt fibers is 5 mm; and the average length of the hemp fibers is 5 mm.

[0057] The regenerated leather is formed by water jet needling treatment of the collagen fiber upper layer and the antibacterial soft underlayer;

[0058] The adhesive comprises oxidized starch and glutaraldehyde, and the mass fraction of the glutaraldehyde accounts for 5% of the adhesive.

[0059] The method for preparing the regenerated leather from the waste leather collagen fibers comprises the following steps:

[0060] (1) The recycled animal skin waste or leftover materials are sequentially classified, arranged, and cut open to obtain collagen fibers;

[0061] According to the above proportions, the collagen fibers are mixed with part of the polyester fibers and part of the basalt fibers, and are pre-mixed for 5 hours to obtain a mixture;

[0062] The mixture is sequentially subjected to carding, longitudinal and transverse staggered laying, and three-dimensional staggered laying, and is then pressed at 160 DEG C and 350 kPa for 10 minutes to obtain a collagen fiber upper layer with a thickness of 0.9 mm;

[0063] (2) An adhesive, nano-zinc oxide, and water are mixed and ultrasonically treated for 20 minutes to obtain a mixed solution; the mass fraction of the adhesive in the mixed solution is 15%;

[0064] The remaining polyester fibers, the remaining basalt fibers, and the hemp fibers are mixed and sequentially subjected to carding, longitudinal and transverse staggered laying, and three-dimensional staggered laying to obtain a fiber web; the mixed solution is coated on one side of the fiber web to obtain an antibacterial and soft lower layer with a thickness of 0.2 mm;

[0065] The mass ratio of the polyester fibers in the collagen fiber upper layer in step (1) to the polyester fibers in the antibacterial and soft lower layer in step (2) is 1:16; the mass ratio of the basalt fibers in the collagen fiber upper layer in step (1) to the basalt fibers in the antibacterial and soft lower layer in step (2) is 1:0.5;

[0066] (3) The side of the antibacterial and soft lower layer obtained in step (2) on which the mixed solution is coated is attached to the surface of the collagen fiber upper layer obtained in step (1), and is subjected to three times of forward and reverse hydroentanglement treatment by using a high-pressure water flow with a pressure of 250 MPa; then, the regenerated leather with a thickness of 1 mm is obtained by sequentially performing moisture compression drying, drying, edge trimming, rolling, and packaging.

[0067] Example 2

[0068] The regenerated leather is prepared according to the method of Example 1, except that 4.5 parts of basalt fibers are added.

[0069] Example 3

[0070] The regenerated leather is prepared according to the method of Example 1, except that 5.5 parts of basalt fibers are added.

[0071] Example 4

[0072] The regenerated leather was prepared according to the method of Example 1, except that 30 parts of polyester fiber was added instead of 30 parts of polypropylene fiber.

[0073] Example 5

[0074] The regenerated leather was prepared according to the method of Example 1, except that 35 parts of polyester fiber was added instead of 30 parts of polypropylene fiber.

[0075] Comparative Example 1

[0076] The regenerated leather was prepared according to the method of Example 1, except that 30 parts of basalt fiber was added instead of 30 parts of polypropylene fiber.

[0077] Comparative Example 2

[0078] The regenerated leather was prepared according to the method of Example 1, except that 30 parts of polyester fiber was added instead of 30 parts of polypropylene fiber.

[0079] The properties of the regenerated leather prepared in Examples 1-5 and Comparative Examples 1 and 2 were tested, and the results are shown in Table 1.

[0080] Table 1 Properties of the regenerated leather prepared in Examples 1-5 and Comparative Examples 1 and 2

[0081]

[0082] As can be seen from the above, according to the method provided by the present application, the tensile strength (transverse, kg / 25mm) of the regenerated leather prepared in Example 3 can reach 7.6, the tensile strength (longitudinal, kg / 25mm) can reach 7.3, the tear strength (transverse, kg / 25mm) can be 4.0, and the tear strength (longitudinal, kg / 25mm) can be 3.9.

[0083] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the scope of protection of the present application.

Claims

1. A method for preparing a regenerated leather using waste leather collagen fibers, characterized by, The raw materials for preparing the regenerated leather include, in mass fraction, 80-110 parts of collagen fibers, 20-40 parts of polyester fibers, 3-6 parts of basalt fibers, 8-16 parts of hemp fibers, 1-5 parts of nano zinc oxide, and 5-13 parts of an adhesive; The collagen fibers are obtained by recycling waste leather; The regenerated leather is formed by hydroentangled insertion of the upper layer of collagen fibers and the soft and antibacterial lower layer.

2. The method of claim 1, wherein, The waste leather is animal skin waste or leftover materials.

3. The method of claim 1, wherein, The adhesive includes oxidized starch and glutaraldehyde, and the mass fraction of the glutaraldehyde accounts for 3-6% of the adhesive.

4. The method of claim 1, wherein, The method for preparing the regenerated leather from waste leather collagen fibers includes the following steps: (1) The recycled animal skin waste or leftover materials are sequentially classified, arranged, and cut open to obtain collagen fibers; The collagen fibers are mixed with part of the polyester fibers and part of the basalt fibers, and are pre-mixed to obtain a mixture; The mixture is sequentially first laid and pressed to obtain an upper layer of collagen fibers; (2) The adhesive, nano zinc oxide, and water are mixed to obtain a mixed solution; The remaining polyester fibers, the remaining basalt fibers, and the hemp fibers are mixed and second laid to obtain a fiber web, and the mixed solution is coated on one side of the fiber web to obtain a soft and antibacterial lower layer; (3) The side of the soft and antibacterial lower layer obtained in step (2) coated with the mixed solution is attached to the surface of the upper layer of collagen fibers obtained in step (1), and is hydroentangled and inserted to obtain the regenerated leather.

5. The method of claim 1, wherein, The pre-mixing time in step (1) is 4-6 h.

6. The method of claim 1, wherein, The mass ratio of the polyester fibers in the upper layer of collagen fibers in step (1) to the polyester fibers in the soft and antibacterial lower layer in step (2) is 1:(8-20); The mass ratio of the basalt fibers in the upper layer of collagen fibers in step (1) to the basalt fibers in the soft and antibacterial lower layer in step (2) is 1:(0.3-0.6).

7. The method of claim 1, wherein, The first laying in step (1) includes sequentially combing, laying in longitudinal and transverse directions, and three-dimensional staggered laying.

8. The method of claim 1, wherein, The pressing temperature in step (1) is 140-170℃, the pressing time is 3-10 min, and the pressing pressure is 300-450 kPa.

9. The method of claim 1, wherein, The hydroentangled insertion in step (3) includes 2-4 times of forward and reverse hydroentangled insertion, and the hydroentangled insertion uses 150-300 MPa high-pressure water flow.

10. The method of claim 1, wherein, After the hydroentangled insertion in step (3) is completed, the method further includes pressing off water, drying, trimming, rolling, and packaging.

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