A method for producing textile products from natural fibers using pressure and vibration.

Abstract

A method for compressing plant fibers using a combination of pressure and vibration is described. This method can achieve higher density at specific processing parameters, densify voids or hard-to-compress areas, and densify surfaces and fiber joints. Using this method, it is possible to create planar and 3D structures in fibrous materials, densify specific areas in an object, and create advanced structures that cannot be achieved by simple pressure or isostatic pressure.

Description

Technical Field

[0001] The present invention relates to a method and a system for producing a fiber-based cellulose material product by converting blanks or web portions into shaped products, and provides a production space including an intermittently converting production unit, a supply station, and a supply path.

Background Art

[0002] Specifically, natural materials and fiber-based cellulose materials are susceptible to the influence of water content when being converted. This includes creasing (when the material is locally delaminated to introduce folds), cutting (when the material and fibers are cut or separated), and press molding (when the material is reshaped with or without delamination, or when fibers are fused into new bonds or structures). Moisture content is particularly important when fiber bonds are broken, or when new bonds are formed during processing. If excess water is introduced into or with the material and needs to be removed by drying during or after the conversion process, excessive heating or energy will be required. Therefore, optimizing moisture content is helpful not only for product quality, but also for optimizing energy consumption. It should be understood that the present invention does not relate to the continuous production of paper and board. Those processes continuously feed a web from a wet end to a roll-up end, resulting in a product in the form of a roll containing multiple layers of paper / board. Instead, the present invention relates to the production of objects that are preferably produced intermittently.

[0003] If excess water is introduced into or with the material, and needs to be dried and removed during or after the conversion process, excessive heating or energy will be required. Therefore, optimizing the moisture content is helpful not only for product quality, but also for optimizing energy consumption. It should be understood that the present invention is not related to the continuous production of paper and board. Those processes continuously feed the web from the wet end to the roll-up end, consequently resulting in a product in the form of a roll containing a large number of paper / board layers. Instead, the present invention relates to the production of objects that are preferably produced intermittently.

[0004] In common operation, flat material is fed from a shape pre-cut as a sheet, or from a roll before the actual operation. In some operations, such as sheet cutting or dry forming, the material can be produced directly before the conversion operation.

[0005] Typical processing conditions are a temperature of 150-250°C and a pressure of 100-10,000 bar (200-2,000 Bar). The moisture content is generally less than 20% water. Textile products can be hollow, such as packaging or closures. Products can be formed from a web of material, punched / cut during formation. For example, they are commonly cut into circles to form circular packaging.

[0006] Forming is generally carried out using two tools: an outer tool called a pad and an inner tool called a punch. Both tools consist of several parts and can be used to eject the final product. Generally, the pad is opened, while the punch is crushed. The punch, punch parts, or pad parts can also be made of compressible material. This allows the tool material to be reformed during compression.

[0007] Capsules can be formed by partially or completely lining a mold from the inside with loosely bound fibrous material. The fibrous material can be draped into the mold or fed into the mold in a form such as a cylindrical winding. The mold can be closed or partially opened when the material is introduced. Examples of the known methods described above are shown in European Patent No. 3736099 and International Publication No. 2020 / 165780. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] European Patent No. 3736099 [Patent Document 2] International Publication No. 2020 / 165780 [Overview of the project]

[0009] The present invention relates to a method for producing textile products from natural fibers using pressure and vibration, according to claim 1.

[0010] The present invention allows for the efficient compression / forming of plant fibers containing wood fibers using a combination of pressure and vibration. Shear force, out-of-plane force, and combinations thereof can be utilized. A vibration frequency of 0.1 to 40 kHz can be used. A temperature range of 50 to 250°C is appropriate. Similarly, the moisture content is 3 to 50%, more preferably 5 to 20%. Several advantages exist. Higher density can be achieved, at least in the surface layer, under specific processing parameters. Void areas or areas that are difficult to compress can be densified. The surface of the object will have a better density, and the fiber bonding areas and areas with planes perpendicular or nearly perpendicular to a specific pressure can be densified, at least in the surface layer. There are several applications to this, including creating flat and 3D structures in fibrous materials, densifying specific areas of an object such as edges or weak areas, or creating advanced structures that cannot be achieved by mere pressure or isostatic pressure alone. [Modes for carrying out the invention]

[0011] Plant fibers, including wood fibers, are widely used to manufacture a variety of items, such as packaging materials, closures, and food-serving items, due to their biodegradability and sustainability. However, dried natural fibers generally require very high pressure to achieve the desired density, which can be time-consuming and inefficient. To address this challenge, methods have been developed to compress plant fibers using a combination of pressure and vibration. This method can achieve higher densities at specific processing parameters, densify voids or hard-to-compress areas, and densify surfaces and fiber joints. It can be used to create flat and 3D structures in fibrous materials, to densify specific areas in an object, and to create advanced structures that cannot be achieved by simple pressure or isostatic pressure alone.

[0012] The method according to the present invention is based on producing textile products using pressure and vibration, and includes the steps defined in claim 1.

[0013] In one embodiment, the frequency is set between 0.1 and 100 Hz to produce enhanced compression. Tests have shown that using such frequencies can produce enhanced compression in layers adjacent to the surface, when combined with high pressure and a suitable or high temperature. Thereafter, enhanced compression can be achieved in depths ranging from 20 μm to at least 1000 μm, at least within the surface layer of the resulting product. In some applications, enhanced compression has been achieved to a depth of 3000 μm. Tests have shown that plant fibers compressed according to the present invention may have a higher density than the original plant fibers at the same processing parameters, and that the compressed plant fibers have increased surface and fiber bonding density.

[0014] In another embodiment, the vibration frequency is set between 0.1 and 40 kHz to produce a reinforced bond between fibers in the generated product, at least within the surface layer. Tests have shown that utilizing such vibration frequencies can produce a reinforced bond in the layer adjacent to the surface, when combined with high pressure and a suitable or high temperature. This reinforced bond can be achieved in the generated product in a depth range from 1 μm to at least 10 μm. In some applications, reinforced compression up to a depth of 20 μm has been achieved.

[0015] One potential benefit is significantly higher productivity. One aspect of this is that most presses, used to apply pressure to dry the shape of a product, have a maximum load capacity of, for example, 1500 kN. In most cases, multiple products are produced during each stroke performed by such a press. This means that there is a limit to the number of products that can be produced during each stroke in order to achieve a given density. Therefore, when combined with vibration, more products can be produced during each stroke / press operation because less pressure is required to achieve a given density.

[0016] According to a preferred embodiment of the present invention, pressure is applied perpendicular or nearly perpendicular to at least 50% of the surface of the plant fiber, preferably at least 90% of the surface of the plant fiber. Furthermore, in some applications, it may be beneficial to apply the pressure using a combination of shear force and out-of-plane force.

[0017] According to another preferred embodiment of the present invention, the pressure is 200 to 1000 MPa. When the textile product is arranged with undercuts such as threads, tests have shown that in some applications, beneficial results can be achieved by utilizing pressures of less than 1000 kPa.

[0018] According to another preferred embodiment of the present invention, compressed plant fibers are used to increase the density of specific areas in the resulting textile product. Tests have shown that the present invention makes it possible to create advanced structures that cannot be achieved by mere pressure or isostatic pressure.

[0019] This invention can significantly increase productivity and enable the manufacture of a wide range of items with flat or 3D structures from wood fibers. These items include: Packaging items: wooden crates, holders, protective packaging, frozen food packaging, bottles, jars, boxes, etc. Closures and other high-performance items. Food serving items: cutlery, bowls, lids and cups, and other examples. Furniture: Compressed wood fibers can be used to create sturdy and environmentally friendly furniture components such as chairs, tables, and cabinets. Sports equipment: Compressed wood fibers can be used to create high-performance sports equipment such as skateboards, snowboards, and surfboards. Decorative items: Using compressed wood fibers, decorative items such as wall panels, picture frames, and sculptures can be created. Medical devices: Compressed wood fibers can be used to create medical devices such as splints and supports, which are biodegradable and environmentally friendly.

Claims

1. A method for producing textile products using pressure and vibration, wherein the method is a) A step of providing a plant fiber source with a water content of 3 to 50%, preferably 5 to 20%. b) The step of placing the plant fibers into a compression mold, c) A step of applying a pressure of at least 100 kPa to the plant fibers in the mold. d) A step of applying vibrations in the range of 0.1 Hz to 40 kHz to the mold and plant fibers during compression. e) A step of providing heat within a temperature range of 50 to 250°C during compression. f) During compression, maintain the moisture content in the range of 3 to 50%, preferably in the range of 5 to 20%. g) After compression is complete, a step of releasing the pressure and vibration, and h) The step of removing the formed product, which consists of compressed plant fibers, from the mold. Methods that include...

2. The method according to claim 1, wherein the frequency is set to 0.1 to 1000 Hz to bring about enhanced compression in the surface layer, and preferably brings about an increase in density of at least 5%, more preferably 6 to 50%, within the surface layer.

3. The method according to claim 2, wherein the frequency is set to 0.1 to 100 Hz to bring about enhanced compression in the surface layer, and preferably the enhanced compression is achieved to a depth of at least 1000 μm, more preferably at least 2000 μm, of the resulting product.

4. The method according to claim 1, wherein the frequency is set between 0.1 and 40 kHz to bring about strengthened bonding between fibers in the resulting product, the Scott bond value in accordance with TAPPI T569 is increased by at least 5%, preferably 6 to 100%, and preferably the strengthened bonding is realized to a depth of at least 1 μm, more preferably at least 10 μm, in the resulting product.

5. The method according to claim 1, wherein the pressure is applied perpendicularly or nearly perpendicularly to at least 50% of the upper surface of the fibrous sheet structure to be formed, preferably at least 90% of the upper surface.

6. The method according to claim 1, wherein the pressure is applied using a combination of shear force and out-of-plane force.

7. The method according to claim 1, wherein the plant fiber is a wood fiber.

8. The method according to claim 1, wherein the compressed plant fibers are used to create a flat structure or a three-dimensional structure.

9. The method according to claim 1, wherein the compressed plant fibers are used to increase the density of a specific area of ​​the product.

10. The method according to claim 1, wherein the compressed plant fibers are used to create a sophisticated structure that cannot be achieved by mere pressure or isostatic pressure.

11. The method according to claim 1, wherein the compressed plant fibers have a densified surface and fiber bonds.

12. The method according to claim 1, wherein the pressure is 200 to 1000 MPa.

13. The method according to claim 1, wherein the pressure is less than 1000 kPa, and preferably the textile product is arranged with undercuts such as threads.

14. A textile product realized according to the method described in any one of claims 1 to 13.

Images