TWI894515B - Plant leather production method - Google Patents

Abstract

The present invention provides a method for producing plant-based leather. The method involves preparing a plant-based base material comprising natural rubber, a first foaming agent, a foaming aid, and a thermoplastic material, kneading the mixture, and then extruding the resulting sheet. A surface material comprising a second foaming agent, a foaming aid, and a thermoplastic material is then applied to the surface of the plant-based base material. Finally, the plant-based base material and the surface material are heated to foam and mature, forming a predetermined pattern on the surface of the plant-based base material. After cooling, the plant-based leather is obtained.

Description

Plant leather production method

This invention relates to the field of leather manufacturing technology, and more specifically, to a method for producing plant leather.

Due to price and animal-friendliness considerations, artificial leather has a higher commercial application rate than natural animal leather. Artificial leather (also known as synthetic leather/artificial leather) is often based on a non-woven fabric. A layer of plastic material such as polyurethane (PU) and polyvinyl chloride (PVC) is adhered to the base surface with an adhesive, or the resin is wrapped around a special non-woven fabric. The surface is further modified and processed (such as printing, embossing, rolling, spraying, polishing, kneading, hot stamping, laminating, flocking, and coating) to create natural wrinkles in the resin layer, enhancing the degree of natural leather imitation and product quality.

Because plastics like resin are petrochemical products, they not only deplete natural resources but are also environmentally unfriendly. Furthermore, artificial leather uses adhesives to bond the resin to non-woven fabrics, which can easily cause water and air pollution during the production process. Furthermore, the steps involved in creating surface textures, such as printing, embossing, and tanning, also complicate the production process.

Secondly, in recent years, some companies have developed plant-based leather (also known as vegan leather), which contains no animal ingredients and incorporates animal conservation principles. Generally, this leather is made from plant fibers (such as pineapple leaves, cactus leaves, banana stems, apple peels, pineapple leaves, orange peels, mushrooms, or tea leaves) combined with rubber and plastic materials. The surface still undergoes processing similar to artificial leather, such as coating, embossing, and printing, to simulate the texture of natural leather. In other words, while plant-based leather has animal-friendly properties, it still requires the same graining processes as artificial leather. From a manufacturing perspective, this represents a minor improvement compared to artificial leather, as it merely changes the material.

Therefore, based on the inventor's many years of experience in leather research and development, he developed this "Method for Making Plant Leather," which can address the aforementioned shortcomings of conventional artificial and plant leather.

The primary objective of this invention is to provide a method for producing plant-based leather that avoids the water and air pollution typically associated with artificial leather production. Furthermore, without the need for the graining process typically associated with artificial leather, this simple process can create a multi-layered, rich grain on the leather surface, effectively simulating natural leather. Furthermore, the graining can be varied flexibly, resulting in a highly practical method.

Therefore, to achieve the aforementioned objectives, the present invention provides a method for producing plant-based leather, comprising at least the following steps: preparing a plant-based substrate, comprising natural rubber, a first foaming agent, a foaming aid, and a thermoplastic material, kneading the mixture, and then extruding the resulting sheet; applying a surface material, comprising a second foaming agent, a foaming aid, and a thermoplastic material, to the surface of the plant-based substrate; and aging and setting the surface material, wherein the plant-based substrate and the surface material are heated to foam and age, thereby forming a predetermined pattern on the surface of the plant-based substrate. After cooling, the plant-based leather is obtained.

Preferably, the thermoplastic material is a polar or non-polar material.

Preferably, in the step of applying the surface material, the second foaming agent in the surface material is a high-temperature foaming agent, or includes high-temperature and medium-temperature foaming agents, or includes high-temperature, medium-temperature and low-temperature foaming agents, or a microsphere foaming agent.

Preferably, during the curing and shaping step, the plant-based base and surface material are placed in a plurality of independent foaming boxes for closed foaming, or placed in a plurality of tunnel-type foaming boxes for open foaming, or placed in a plurality of independent foaming boxes and a tunnel-type foaming box in turn for alternating foaming.

Preferably, the curing and setting step includes the heating means and a destroying means, wherein the destroying means is to create a plurality of holes in the surface material or change the texture formed on the surface material.

Preferably, during the curing and setting step, the destruction means is to cause the surface material to undergo foaming and defoaming, thereby causing the surface material to produce a plurality of holes after foaming, vulcanization and curing.

Preferably, during the shaping step, the destructive means is to attach a mesh to the surface of the surface material to change the texture formed on the surface of the surface material.

Preferably, the curing and setting step includes the heating means and a strengthening means. The strengthening means applies an external force to the surface material during the curing and setting process to strengthen the formation and setting of the texture of the surface material.

Preferably, during the curing and setting step, the heating means is to alternately place the plant-based base material and the surface material into a plurality of independent foaming boxes and a tunnel-type foaming box for alternating foaming, so as to sequentially mature at 50%, 70%, and 85% until the curing is finally completed.

Preferably, during the curing and setting step, the heating means is to sequentially place the plant-based base material and the surface material into a plurality of tunnel-type foaming boxes for open foaming, so as to sequentially mature to 50%, 70%, and finally complete the curing, and the destruction means or strengthening means are performed in several tunnel-type foaming boxes.

The present invention:

100: Preparation method

110: Prepare plant-based substrate

120: Coating surface material

130: Mature and fixed

1301: Heating Methods

200: Preparation method

210: Mature and fixed

2101: Destructive Means

300: Preparation method

310: Mature and firm

3101: Strengthening measures

10: Vegetable leather

12: Plant-based substrate

14: Surface Material

22: Hole Location

24: Netgear

Usage:

1, 2: Independent foaming box

3, 4, 5, 6, 7: Tunnel-type foaming boxes

The first figure is a flow chart of a preferred embodiment of the present invention.

The second figure is a schematic diagram of a preferred embodiment of the present invention, wherein the plant-based base and surface material are alternately placed into several independent foaming boxes and a tunnel-type foaming box for alternating curing.

Figure 3 is a flow chart of another preferred embodiment of the present invention.

Figure 4 is a schematic diagram of a plant leather with multiple perforations made in another preferred embodiment of the present invention.

Figure 5 is a schematic diagram showing another preferred embodiment of the present invention, wherein the plant-based base material and surface material sequentially enter a plurality of tunnel-type foaming boxes for curing.

Figure 6 is a flow chart of another preferred embodiment of the present invention.

Below, several preferred embodiments of the present invention are cited and further described in detail with the help of drawings: First, please refer to the first and second figures, which show the method 100 for making plant leather 10 of a preferred embodiment of the present invention. The first step is to prepare a plant-based substrate 110: prepare a plant-based substrate 12, which is a sheet extruded after natural rubber extracted from rubber tree latex is added with a first foaming agent, a foaming aid, a thermoplastic material and other additives and a certain elastic material. The first foaming agent (e.g., but not limited to, azodicarbonamide ADC/AC, oxybis(benzenesulfonylhydrazine), benzenesulfonylhydrazine, etc.), foaming aids, and other additives are commonly used to control the foaming and vulcanization of natural rubber. These additives are known in the art, and their detailed composition and foaming principles are not detailed here.

The second step of the present invention is applying a surface material 120: a surface material 14 is applied to the surface of the plant-based substrate 12 (for example, the plant-based substrate 12 is placed on a conveyor belt and the surface material 14 is applied to the surface of the plant-based substrate 12 using a coating knife or roller device; the coating method is not limited). The surface material 14 includes a second foaming agent, a foaming aid, and a thermoplastic material. The second foaming agent is a high-temperature foaming agent, or includes a high-temperature and medium-temperature foaming agent, or includes a high-temperature, medium-temperature, and low-temperature foaming agent, and/or a microsphere foaming agent. High-temperature, medium-temperature, and low-temperature foaming agents are commonly known foaming agents with different foaming (decomposition) temperatures (for example, high temperature is above 200°C, medium temperature is between 120°C and 200°C, and low temperature is between 100°C and 120°C, but not limited to these). Expancel is a commonly known type of expanding agent, consisting of tiny spherical particles encapsulating a gas in a plastic shell. When heated, the volume of the particles increases significantly due to the expansion of the gas and the softening of the shell.

The thermoplastic material of the plant-based substrate 12 and surface material 14 can be, but is not limited to, a TPE thermoplastic elastomer such as PU (TPU), TPR, and TPV. It can also be a polar (hydrophilic) or non-polar (lipophilic) material. Polar materials include PU, while non-polar materials include natural rubber or natural latex. Specifically, if the plant-based substrate 12 is primarily made of non-polar natural rubber, the thermoplastic material can be a polar PU (TPU) or a non-polar natural latex. Furthermore, by adding the same thermoplastic material to the plant-based substrate 12 and surface material 14, the plant-based substrate 12 and surface material 14 can be bonded together.

Furthermore, the overall composition ratio of the plant-based substrate 12 and the surface material 14 is that natural rubber accounts for approximately 95% by mass, and the foaming agent, foaming aid, and thermoplastic material account for approximately 5% by mass.

The final step of the present invention is aging and shaping 130: a heating means 1301 is used to foam, vulcanize and mature the plant-based base member 12 and the surface material 14, thereby forming a predetermined pattern on the surface of the plant-based base member 12. After cooling, the plant leather 10 can be obtained. The surface material 14 is formed like the surface layer of natural leather, and the plant-based base member 12 is like the inner layer of natural leather. Specifically, the heating means 1301 places the plant-based substrate 12 and surface material 14 in a known independent foaming box (flat foam vulcanization equipment) for closed foaming (foaming within the mold cavity), or in a known tunnel foaming box (passing through the tunnel foaming box via a conveyor belt) for open foaming, or alternately places them in several independent foaming boxes and tunnel foaming boxes for alternating foaming. This allows the thermoplastic material contained in the plant-based substrate 12 to bond with the thermoplastic material of the surface material 14, and the thermoplastic material of the surface material 14 forms a surface layer and a predetermined pattern on the surface of the plant-based substrate 12. The detailed structure of the independent foaming box and the tunnel foaming box will not be described here. Regardless of whether foaming is performed through an independent foaming box or a tunnel foaming box, the first and second foaming agents are decomposed and foamed by controlling the temperature. The texture of the surface material 14 is formed naturally by the force generated by the decomposition and foaming process of the second foaming agent acting on the thermoplastic material. Therefore, as previously mentioned, the second foaming agent can be a high-temperature foaming agent, or a combination of high-temperature and medium-temperature foaming agents, or a combination of high-temperature, medium-temperature, and low-temperature foaming agents, or a microsphere foaming agent. When multiple types of second foaming agents are used, the decomposition and foaming of different foaming agents at different temperatures can provide a greater variety of texture patterns on the surface material 14. When microsphere foaming agents are used as the second foaming agent, the texture of the surface material 14 can be made more three-dimensional (the expansion of the microsphere foaming agent causes the thermoplastic material of the surface material 14 to bulge).

Furthermore, the aforementioned heating means 1301 alternately places the plant-based substrate 12 and the surface material 14 into a plurality of independent foaming boxes and a tunnel-type foaming box for alternating foaming. As shown in the second figure, the plant-based substrate 12 and the surface material 14 alternately enter the plurality of independent foaming boxes 1 and 2 and the tunnel-type foaming boxes 3 and 4 for alternating foaming, and are sequentially matured to 50%, 70%, 85%, and finally matured.

As can be seen from the above, the manufacturing method 100 of the present invention utilizes plant-based natural rubber as the primary raw material (the plant-based base material 12). A small amount of thermoplastic material is added to the plant-based base material 12 and the surface material 14 as a bonding material. After foaming and aging, the plant-based leather 10 is produced. The plant-based base material 12 resembles the fiber layer of genuine leather, and the surface material 14 resembles the surface layer of genuine leather. Because the plant-based leather 10 comprises approximately 95% to almost 100% natural materials (for example, when the thermoplastic material of the surface material 14 is natural latex, the proportions of the various foaming agents and foaming aids are low), it can be referred to as natural material leather or plant leather. Furthermore, the surface texture of the plant leather 10 is naturally formed during the foaming and curing process of the thermoplastic material of the surface material 14. The manufacturing method 100 of the present invention further allows for the addition of different foaming agents to the surface material 14. The different foaming agents decompose and foam at different temperatures during the foaming and curing process, acting on the thermoplastic material. This allows the texture formed on the surface material 14 to be more varied, multi-layered, and natural. Compared to conventional natural or artificial leather, which requires tanning and embossing processes, the manufacturing process of the present invention is simpler. By selecting and controlling the thermoplastic material and the second foaming agent, the surface texture can be formed after foaming and curing, resulting in higher manufacturing efficiency and considerable practical value.

As shown in FIG. 3 , another preferred embodiment of the present invention, a plant leather production method 200 , includes steps generally identical to those of method 100 , with identical steps using identical reference numerals. The difference lies in the aging and setting step 210 , which includes a heating means 1301 and a destroying means 2101 . The destroying means 2101 creates a plurality of holes in the surface material 14 or alters the texture formed on the surface material 14 .

Specifically, the method for causing the surface material 14 to undergo foaming and breaking in the destruction means 2101 is to control the temperature of the foaming chamber and the amount of the second foaming agent, so that the internal pressure of the thermoplastic material during the curing process is greater than the external pressure (the internal pressure is generated by the decomposition and foaming of the second foaming agent). This causes the plant leather 10 to form a plurality of puncture sites 22 (punctures in the thermoplastic material of the surface material 14), as shown in FIG. 4. In this way, not only can the texture pattern of the surface material 14 be changed, but also the texture pattern of the surface material 14 can be changed. The patterns are more varied, multi-layered, and natural. Furthermore, the perforated areas 22 do not obscure the plant-based substrate 12. Therefore, the color of the plant-based substrate 12 can be seen through the perforated areas 22. This allows the surface of the plant-based leather 10 to exhibit two colors (the color of the thermoplastic material in the surface material 14 and the color of the plant-based substrate 12 at the bottom of each perforated area 22) and multiple variations (i.e., the color of the plant-based substrate 12 at the bottom of each perforated area 22). This eliminates the printing process typically associated with artificial leather.

Secondly, when touching the surface of the plant leather 10, the thermoplastic material of the surface material 14 and the plant-based base 12 at the bottom of each perforation 22 produce two different tactile sensations. Furthermore, if microspheres are added to the second foaming agent of the surface material 14, the surface texture of the plant leather 10 can be raised, creating a more three-dimensional effect. Therefore, the manufacturing method 100 of the present invention can replace conventional 3D printing processes for artificial leather.

Controlling the aforementioned foaming box temperature and the amount of the second foaming agent is well-known in the art and will not be detailed here.

Furthermore, as shown in Figure 5, the method for altering the texture of the surface material 14 in the destructive means 2101 involves sequentially introducing the plant-based substrate 12 and the surface material 14 into a plurality of tunnel-type foaming boxes 5, 6, and 7 for open foaming, where they are matured to 50%, 70%, and finally to full maturity. Specifically, a mesh 24 is simultaneously introduced into the tunnel-type foaming box 6 and affixed to the surface of the surface material 14. This way, the texture of the surface material 14, which has just entered the tunnel-type foaming box 6 (at approximately 50% maturity), is destroyed by the affixation of the mesh 24, allowing continued maturation, thereby altering the surface texture of the surface material 14.

As shown in FIG6 , another preferred embodiment of the present invention, a plant leather production method 300 , includes steps generally similar to those of method 200 , with the following difference: In the aging and setting step 310 , in addition to the heating means 1301 , a strengthening means 3101 is further included. The strengthening means 3101 applies an external force to the surface material 14 during the heating means 1301 to strengthen the formation and setting of the texture of the surface material 14 . The external force can be a physical force, such as wind, electricity (high-voltage discharge), laser irradiation, or magnetic wave irradiation. It primarily hardens the texture of the surface material 14 , further solidifying the texture of the plant-based substrate 12 .

As can be seen from the above, the method for producing plant leather provided by the present invention, through the steps of preparing plant base material, applying surface material and curing and setting, does not cause water and air pollution generated in the artificial leather production process, and uses at least 95% plant material to produce plant leather that can be called natural material. In addition, the method can produce plant leather by decomposing the second foaming agent added to the surface material during the foaming and curing process, and the force generated by the foaming acts on the thermoplastic material. The plant-based substrate naturally forms a texture on its surface, eliminating the need for the embossing and tanning processes typically required in artificial leather production, simplifying the manufacturing process. Furthermore, by selectively controlling the decomposition and foaming of different secondary foaming agents at different temperatures during the foaming and aging process, the surface material can achieve a more diverse and multi-layered texture pattern, resulting in higher manufacturing efficiency and significant practical value. Therefore, this invention meets the patent requirements and is hereby filed in accordance with the law.

The above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any person skilled in the art may make modifications, alterations, and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of the attached patent application.

100: Preparation method

110: Prepare plant-based substrate

120: Coating surface material

130: Mature and fixed

1301: Heating Methods

Claims (9)

A method for producing plant leather comprises at least the following steps: preparing a plant-based substrate: preparing a plant-based substrate comprising at least 95% by mass of a plant-based material and adding a first foaming agent, a foaming aid, and a thermoplastic material to the substrate, mixing and kneading the resulting sheet, wherein the total mass of the first foaming agent, the foaming aid, and the thermoplastic material is at most 5% or less; the plant-based material comprises natural rubber; the first foaming agent is a foaming agent that promotes foaming molding of natural rubber, and comprises one of organic chemical foaming agents such as azodicarbonamide ADC/AC and benzenesulfonylhydrazine; applying a surface material: applying a surface material on the surface of the plant-based substrate, wherein the surface material comprises a second foaming agent, a foaming aid, and a thermoplastic material, and the second foaming agent is a foaming agent that promotes thermoplastic molding. The foaming agent used for plastic material foam molding is a high-temperature foaming agent, a foaming agent with different foaming temperatures, or a foaming agent with different foaming temperatures, such as a high-temperature and medium-temperature foaming agent, or a microsphere foaming agent. High temperature is above 200°C, medium temperature is between 120°C and 200°C, and low temperature is between 100°C and 120°C. Curing and setting: The plant-based base material and surface material are foamed and cured by a heating method. The heating method is to place the plant-based base material and surface material in a plurality of foaming boxes for foaming and curing. During the curing process, the thermoplastic material of the surface material is foamed by different foaming agents in the second foaming agent at different foaming temperatures, thereby forming patterns on the surface of the plant-based base material. After cooling, the plant leather is obtained. The method for producing plant leather as described in claim 1, wherein the thermoplastic material is a polar or non-polar material. The method for producing plant leather as described in claim 1, wherein, in the curing and setting step, the plant-based base and surface material are placed in a plurality of independent foaming boxes for closed foaming, or in a plurality of tunnel-type foaming boxes for open foaming, or alternately placed in a plurality of independent foaming boxes and a tunnel-type foaming box for alternating foaming. In the method for producing plant leather as described in claim 3, the aging and setting step includes the heating means and a destructive means, wherein the destructive means is to create a plurality of holes in the surface material or change the texture formed on the surface material. In the method for producing vegetable leather as described in claim 4, in the curing and setting step, the destructive means is to cause the surface material to undergo foaming and defoaming, thereby causing a plurality of holes to form in the surface material after foaming, vulcanization and curing. The method for producing vegetable leather as described in claim 4, wherein, during the aging and shaping step, the destructive means is to attach a mesh to the surface of the surface material to change the texture formed on the surface material. The method for producing plant leather as described in claim 3, wherein the aging and setting step includes the heating means and a strengthening means, wherein the strengthening means applies an external force to the surface material during the aging and setting process to strengthen the formation and setting of the texture of the surface material. The method for producing plant leather as described in claim 4 or 7, wherein, during the curing and setting step, the heating means is to alternately place the plant-based base material and the surface material into a plurality of independent foaming boxes and a tunnel-type foaming box for alternating foaming, so as to sequentially mature the plant-based base material and the surface material to 50%, 70%, and 85% until the curing is finally completed. The method for producing plant leather as described in claim 4 or 7, wherein: During the curing and setting step, the heating means is to sequentially place the plant-based base material and the surface material into a plurality of tunnel-type foaming boxes for open foaming, curing them successively to 50%, 70%, and finally to complete curing, and the destructive means or strengthening means are performed in several tunnel-type foaming boxes.