Production method of flexible high-strength large-breadth micro thin bamboo

Abstract

The invention discloses a production method of flexible high-strength large-breadth thin bamboo strips. The production method comprises the following steps: [1] manufacturing rough planed bamboo strips; (2) carbonizing the bamboo canes; (3) drying the bamboo canes; (4) bamboo board manufacturing; (5) humidifying the bamboo board; the wet laminated bamboo board is directly placed on a slicing machine, the board is fixed through a vacuum adsorption device and sliced, the included angle between the rear angle and the wedge angle of a slicing tool and the horizontal plane of the bamboo board ranges from 15 degrees to 25 degrees, the included angle between the cutting edge of the slicing tool and the slicing feeding direction is the cutting edge inclination angle ranging from 30 degrees to 55 degrees, and micro thin bamboos with the thickness ranging from 0.08 mm to 0.5 mm are obtained through slicing; and (7) drying and laminating are conducted, specifically, the micro thin bamboo is manually leveled and fed into a drying machine, the hot air drying temperature ranges from 70 DEG C to 120 DEG C, the hot air speed ranges from 6 m / s to 8 m / s, the micro thin bamboo is dried till the water content is lower than 12%, then the micro thin bamboo enters a laminating machine, the micro thin bamboo and a polymer film are compounded at the temperature ranging from 70 DEG C to 190 DEG C, and the large-breadth micro thin bamboo material is prepared. The finished product rate of sliced thin bamboos is increased, and the application field of bamboos is greatly expanded.

Description

Technical Field

[0001] The invention relates to the technical field of bamboo material processing, in particular to a method for producing flexible, high-strength, large-format, thin bamboo. Background Art

[0002] Thin bamboo is made by laminating bamboo composite materials or flattened bamboo materials with bamboo squares, and then planing them after softening process. First of all, the thin bamboo sliced ​​by bamboo composite materials is mainly composed of side pressing plates and flat pressing plates. After soaking in water, they are glued into bamboo squares with wet glue and steamed at a temperature of 50-55℃ for 8-10 hours. This method has high requirements for bamboo square glue. The glue layer is easy to crack during the planing process after steaming, and non-woven paper needs to be pasted for reinforcement. There are many processes and high costs. Secondly, there are many glued layers in the thickness direction of bamboo squares. When pressing bamboo squares and installing bamboo composite materials, they cannot keep a high degree of parallelism with the planing tool. Therefore, when planing, each board glue layer will lose 3-5 thin bamboo sheets, and the glue layer of 15-layer boards will lose 45-75 thin bamboo sheets, which is wasteful and has a low yield. In addition, the thin bamboo produced by the existing process has poor flexibility, is easy to crack and break, and is difficult to meet the production needs of some curved bamboo products; the existing bamboo composite material manufacturing uses modified urea-formaldehyde resin adhesives, which are less environmentally friendly. Finally, it is easy to absorb moisture during use and difficult to prevent seepage, and it is also easy to cause mildew. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art, provide a method for producing flexible, high-strength, large-format thin bamboo, reduce the energy-consuming, time-consuming and water-polluting softening process in the production of traditional bamboo integrated materials, improve the yield and product quality of sliced ​​thin bamboo, reduce the production cost of thin bamboo, and develop a large-format sliced ​​thin bamboo material that is flexible, waterproof and mildew-proof.

[0004] The present invention adopts the following technical solution: a method for producing flexible, high-strength, large-format, thin bamboo, comprising the following steps:

[0005] [1] Rough-planed bamboo strip production: 4-6 year old raw bamboo is cut into bamboo tubes with a length of 1.0m-3.0m, split by a large crusher or cut by a circular saw, and rough-planed bamboo strips of various specifications with a length of 1.0m-3.0m, a width of 2.0cm-3.0cm, and a thickness of 6mm-14mm are prepared by a rough-planing machine;

[0006] [2] Carbonization treatment of bamboo strips: The bamboo strips are placed in a high-temperature steam tank at 120-150℃ for 30-180 minutes to degrade and remove starch, sugars and lipids inside the bamboo.

[0007] [3] Bamboo strip drying treatment: The high-temperature carbonized bamboo strips are placed in a drying kiln, and the temperature is gradually raised from room temperature to 54°C. After being kept for 2-4 days, the temperature is slowly lowered. The drying time is 5-7 days, so that the moisture content of the bamboo strips drops below 12%;

[0008] [4] Bamboo board manufacturing: The dried bamboo strips are processed by fine planing, selected, glued and assembled according to the color difference and pressed into bamboo laminated materials;

[0009] [5] Humidification treatment of bamboo boards: The prepared bamboo laminated wood boards are subjected to pressure impregnation treatment to increase the moisture content of the bamboo boards to more than 25%;

[0010] [6] Planing: Place the wet bamboo laminated wood board directly on the planer and fix the board by a vacuum adsorption device, and then plane it. The angle between the back angle and wedge angle of the planer and the horizontal plane of the bamboo board is 15°-25°, and the angle between the planer blade and the planing feed direction is 30°-55°. Thin bamboo with a thickness of 0.08-0.5 mm is planed;

[0011] [7] Drying and laminating: The thin bamboo is manually leveled and sent into the dryer. The hot air drying temperature is 70-120℃ and the hot air speed is 6-8m / s. The thin bamboo is dried until the moisture content is less than 12%. Then it enters the laminating machine at a temperature of 70-190℃ to compound the thin bamboo and polymer film to produce a large-format thin bamboo material that is flexible, waterproof and mildew-proof.

[0012] As an improvement, in step [4] of manufacturing the bamboo board, the gluing is applied on both sides by a gluing machine, and the adhesive is a modified polyvinyl acetate isocyanate adhesive (EPI) or a modified phenolic resin adhesive for gluing, and the amount of glue applied is 200-220 g / m 2 .

[0013] As an improvement, in step [4] of manufacturing the bamboo board, the hot pressing temperature is 100-140°C, the time is 0.9-1.1 min / mm, the positive pressure unit pressure is 1.0-2.0 MPa, and the side pressure unit pressure is 2.0-3.0 MPa.

[0014] As an improvement, in step [6] planing, the planer is a vertical planer or a transverse planer.

[0015] As an improvement, in step [7] of drying and coating, the polymer film is made of one or more of food-grade 91 PE polyethylene, PLA polylactic acid biodegradable material, and industrial-grade polypropylene.

[0016] Beneficial effects of the present invention:

[0017] 1. The carbonization, drying and humidification treatment before planing reduces the two original bamboo pressing and steaming processes, removes the energy-consuming, time-consuming and water-polluting steaming process in the production of traditional bamboo composite materials, improves the veneer planing method and planing process, and can increase the output of 3-5 thin bamboo sheets for every reduction of one gluing layer, thereby improving the yield of planed thin bamboo.

[0018] 2. The bamboo strips are subjected to high-temperature steam treatment. Compared with conventional treatment, the pretreatment temperature is increased, which can more effectively degrade the starch, sugars and lipids inside the bamboo material, soften it, and thus reduce the stress difference caused by uneven density in the thickness direction of the bamboo strips.

[0019] 3. By compounding and melting thin bamboo with polymer film materials, an environmentally friendly new material of flexible, high-strength, large-format planed thin bamboo has been developed, which can be used for color inkjet printing, lead printing, offset printing, mimeographing and photocopying. It can be used to manufacture artificial board facing materials, tableware and daily necessities, etc., greatly expanding the application field of bamboo materials. DETAILED DESCRIPTION

[0020] The specific embodiments of the present invention are described in detail below.

[0021] A method for producing flexible, high-strength, large-format, thin bamboo comprises the following steps:

[0022] [1] Rough-planed bamboo strip production: 4-6 year old raw bamboo is cut into bamboo tubes with a length of 1.0m-3.0m, split by a large crusher or cut by a circular saw, and rough-planed bamboo strips of various specifications with a length of 1.0m-3.0m, a width of 2.0cm-3.0cm, and a thickness of 6mm-14mm are prepared by a rough-planing machine;

[0023] [2] Carbonization treatment of bamboo strips: The bamboo strips are placed in a high-temperature steam tank at 120-150℃ for 30-180 minutes to degrade and remove starch, sugars and lipids inside the bamboo.

[0024] [3] Bamboo strip drying treatment: The high-temperature carbonized bamboo strips are placed in a drying kiln, and the temperature is gradually raised from room temperature to 54°C. After being kept for 2-4 days, the temperature is slowly lowered. The drying time is 5-7 days, so that the moisture content of the bamboo strips drops below 12%;

[0025] [4] Bamboo board manufacturing: The dried bamboo strips are processed by fine planing, selected, glued and assembled according to the color difference and pressed into bamboo laminated materials;

[0026] [5] Humidification treatment of bamboo boards: The prepared bamboo laminated wood boards are subjected to pressure impregnation treatment to increase the moisture content of the bamboo boards to more than 25%;

[0027] [6] Planing: Place the wet bamboo laminated wood board directly on the planer and fix the board by a vacuum adsorption device, and then plane it. The angle between the back angle and wedge angle of the planer and the horizontal plane of the bamboo board is 15°-25°, and the angle between the planer blade and the planing feed direction is 30°-55°. Thin bamboo with a thickness of 0.08-0.5 mm is planed;

[0028] [7] Drying and laminating: The thin bamboo is manually leveled and sent into the dryer. The hot air drying temperature is 70-120℃ and the hot air speed is 6-8m / s. The thin bamboo is dried until the moisture content is less than 12%. Then it enters the laminating machine at a temperature of 70-190℃ to compound the thin bamboo and polymer film to produce a large-format thin bamboo material that is flexible, waterproof and mildew-proof.

[0029] The present invention performs high-temperature steam treatment on the bamboo strips through a bamboo strip carbonization treatment step, which increases the pretreatment temperature compared with conventional treatment, can more effectively degrade starch, sugar and lipid inside the bamboo material, plays a certain anti-corrosion and anti-mildew effect, and plays a softening effect, thereby reducing the stress difference caused by uneven density in the thickness direction of the bamboo strips.

[0030] The bamboo boards are manufactured and humidified before planing, so that the bamboo boards are planed and formed into thin bamboos, reducing the two original bamboo pressing and steaming processes, eliminating the energy-consuming, time-consuming and water-polluting steaming process in the production of traditional bamboo composite materials, and improving the veneer planing method and planing process. The output of 3-5 thin bamboos can be increased for every reduction of one gluing layer, thereby improving the yield of planed thin bamboos.

[0031] By compounding and melting thin bamboo with polymer film materials, an environmentally friendly, flexible, high-strength, large-format planed thin bamboo new material has been developed that can be used for color inkjet printing, lead printing, offset printing, mimeographing and photocopying. The material has good flexibility, waterproofness and mildew resistance, and can be used to manufacture artificial board finishing materials, tableware and daily necessities, etc., greatly expanding the application areas of bamboo materials.

[0032] As an improved specific implementation method, in step [4] of manufacturing the bamboo board, the gluing is performed by a gluing machine on both sides, and the adhesive is a modified polyvinyl acetate isocyanate adhesive (EPI) or a modified phenolic resin adhesive for gluing, and the amount of glue applied is 200-220 g / m 2 .

[0033] By adopting the above adhesives and using a suitable amount of adhesive, the finely planed bamboo strips can be assembled and pressed into a stable integrated bamboo composite material, which is conducive to subsequent humidification treatment and planing.

[0034] As an improved specific implementation method, in step [4] of manufacturing the bamboo board, the hot pressing temperature is 100-140°C, the time is 0.9-1.1 min / mm, the positive pressure unit pressure is 1.0-2.0 MPa, and the side pressure unit pressure is 2.0-3.0 MPa.

[0035] By adopting the above specific selection of hot pressing temperature, time and pressure, the bamboo laminated wood is pressed and formed, the yield of the bamboo laminated wood is guaranteed and it is beneficial to the subsequent humidification treatment and planing.

[0036] As an improved specific implementation method, in step [6] planing, the planer is a vertical planer or a transverse planer.

[0037] The type of planer is selected according to actual needs, which can well complete the positioning of the required planing angle, and then plan out thin bamboo that meets the requirements.

[0038] As an improved specific implementation method, in step [7] of drying and coating, the polymer film is made of one or more of food-grade 91PE polyethylene, PLA polylactic acid biodegradable material, and industrial-grade polypropylene.

[0039] Depending on the different application scenarios of the large-format, thin bamboo material, such as its future use in the manufacture of artificial board finishing materials or tableware and daily necessities, different polymer films are selected to achieve the corresponding functional requirements such as safety, environmental protection, and durability.

[0040] The above are only preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for producing flexible, high-strength, large-format, thin bamboo. Features: It includes the following steps: [1] Rough-planed bamboo strip production: 4-6 year old raw bamboo is cut into bamboo tubes with a length of 1.0m-3.0m, split by a large crusher or cut by a circular saw, and rough-planed bamboo strips of various specifications with a length of 1.0m-3.0m, a width of 2.0cm-3.0cm, and a thickness of 6mm-14mm are prepared by a rough-planing machine; [2] Carbonization treatment of bamboo strips: The bamboo strips are placed in a high-temperature steam tank at 120-150℃ for 30-180 minutes to degrade and remove starch, sugars and lipids inside the bamboo. [3] Bamboo strip drying treatment: The high-temperature carbonized bamboo strips are placed in a drying kiln, and the temperature is gradually raised from room temperature to 54°C. After being kept for 2-4 days, the temperature is slowly lowered. The drying time is 5-7 days, so that the moisture content of the bamboo strips drops below 12%; [4] Bamboo board manufacturing: The dried bamboo strips are processed by fine planing, selected, glued and assembled according to the color difference and pressed into bamboo laminated materials; [5] Humidification treatment of bamboo boards: The prepared bamboo laminated wood boards are subjected to pressure impregnation treatment to increase the moisture content of the bamboo boards to more than 25%; [6] Planing: Place the wet bamboo laminated wood board directly on the planer and fix the board by a vacuum adsorption device, and then plane it. The angle between the back angle and wedge angle of the planer and the horizontal plane of the bamboo board is 15°-25°, and the angle between the planer blade and the planing feed direction is 30°-55°. Thin bamboo with a thickness of 0.08-0.5 mm is planed; [7] Drying and laminating: The thin bamboo is manually leveled and sent into the dryer. The hot air drying temperature is 70-120℃ and the hot air speed is 6-8m / s. The thin bamboo is dried until the moisture content is less than 12%. Then it enters the laminating machine at a temperature of 70-190℃ to compound the thin bamboo and polymer film to produce a large-format thin bamboo material that is flexible, waterproof and mildew-proof.

2. A method for producing flexible, high-strength, large-format, thin bamboo according to claim 1, Features: Step [4] During the manufacture of bamboo board, gluing is performed by gluing machine on both sides, and the adhesive is modified polyvinyl acetate isocyanate adhesive (EPI) or modified phenolic resin adhesive for gluing, with the gluing amount being 200-220 g / m 2 .

3. The method for producing flexible, high-strength, large-format, thin bamboo according to claim 2, Features: In step [4] of manufacturing the bamboo board, the hot pressing temperature is 100-140° C., the time is 0.9-1.1 min / mm, the positive pressure unit pressure is 1.0-2.0 MPa, and the side pressure unit pressure is 2.0-3.0 MPa.

4. A method for producing flexible, high-strength, large-format, thin bamboo according to claim 1, 2 or 3, Features: In step [6] planing, the planer is a vertical planer or a horizontal planer.

5. A method for producing flexible, high-strength, large-format, thin bamboo according to claim 1, 2 or 3, Features: In step [7] of drying and laminating, the polymer film is made of one or more of food-grade 91 PE polyethylene, PLA polylactic acid biodegradable material, and industrial-grade polypropylene.