Lignocellulose straw with high bamboo powder content and preparation method thereof

Abstract

The invention provides a lignocellulose straw with high bamboo powder content and a preparation method thereof. The lignocellulose straw comprises a straw body and a protective layer. The green degradable straw with the bamboo powder content as high as 90% can be prepared through the method. According to the method, lignin is used as a main body material, and a three-layer structure of a protective layer, a lignin straw and a protective layer is formed. And the protective layer is a naturally degradable protective film or an environment-friendly coating. The preparation method comprises the following steps: compounding bamboo wood, cellulose, a protective auxiliary agent and the like according to a ratio, then carrying out negative pressure dehydration, manufacturing into a straw by using a coiling machine with a specified size, drying, rapidly immersing the dried straw into a protective agent, then taking out and airing, and finally cutting into the straw with a specified length by using a pipe cutting machine. The straw effectively relieves plastic pollution, meanwhile, the bamboo wood is utilized in a high-efficiency and high-proportion mode to the maximum extent, and the bamboo wood utilization rate is far higher than that of products sold in the current market. The method has great industrial application value.

Description

Technical Field

[0001] The invention provides a method for preparing green degradable straws by utilizing bamboo powder in a high proportion. Background Art

[0002] Traditional plastic straws, as an indispensable disposable item in daily life, are widely popular because of their lightness, durability and low cost. However, with the increasingly serious global plastic pollution problem, especially the potential threat of marine plastic waste to the ecosystem and human health, the use of traditional plastic straws has been faced with unprecedented challenges. Through continuous exploration and innovation, degradable straws are expected to become an important part of the plastic products field in the future and make positive contributions to promoting global environmental protection.

[0003] As a biomass resource, bamboo has the advantages of low cost, renewable, environmental protection, and high strength compared to petroleum-based plastics. It shows great application potential in the fields of bioengineering, electronic energy storage, and energy-saving building materials. In the context of global green development, bamboo will play a more prominent role in reducing plastic pollution and replacing plastic products. At present, bamboo straws have problems such as easy cracking, small product output scale, low resource utilization, high process requirements, and high technical difficulty and cost in the production process. Therefore, the development and exploration of new technologies for bamboo products is imminent.

[0004] Prior art CN112662191 discloses "a degradable straw and its preparation method". This invention uses fine bamboo powder and prepares a green degradable straw by adding functional additives, functional fillers and other materials. However, this method requires thermoplastic modification of bamboo powder, the proportion of bamboo powder is low, the process is complicated and the energy consumption is high.

[0005] CN112961394 discloses a "method for preparing degradable bamboo fiber straws". This method involves steam explosion, water washing, drying, etc. of bamboo materials to obtain pre-treated bamboo fibers, and then adding polyvinyl alcohol, azodicarbonamide, etc. to prepare degradable bamboo fiber straws. The process reduces the hygroscopicity of bamboo fiber by removing the lignin and hemicellulose content in bamboo powder. However, the process is complicated and dangerous, and is not universal.

[0006] CN117584235 discloses a "method for making bamboo straws". The method is to prepare bamboo slices into soft thin bamboo slices through pretreatment, milling, slicing, softening, etc., and then further curl them into a tube and then carbonize them. This method is not only complicated in process and labor cost, but also requires carbonization and shaping, which consumes a lot of energy.

[0007] With the improvement of global environmental awareness and the pursuit of sustainable development goals, bamboo-based plastic products are gradually being integrated into people's daily lives and are widely used in many fields. With the continuous advancement of technology and further reduction of costs, the bamboo-based plastic industry is expected to usher in more vigorous development and provide technical support for promoting resource utilization and green and sustainable development. Summary of the invention

[0008] The present invention aims to address the deficiencies of the prior art and provides a method for preparing green degradable straws by using bamboo powder in a high proportion in a simpler and more environmentally friendly manner. The method provided by the present invention can effectively achieve efficient and high-proportion utilization of bamboo materials, and can prepare green degradable straws with a bamboo powder content of up to 90%, further realizing maximum resource utilization; and the present invention is low-cost, the production scheme is green and low-carbon, and carbon emissions are minimized to the maximum extent, which is in line with the national sustainable development concept.

[0009] The method comprises the following steps:

[0010] (1) Wash and dry the bamboo, then crush and classify;

[0011] (2) dispersing the bamboo powder in step (1) in water in appropriate proportions with cellulose dispersion and food-grade additives;

[0012] (3) using a negative pressure dehydration device to initially remove moisture;

[0013] (4) the material after preliminary dehydration is wound into a straw using a coiler of specified size;

[0014] (5) drying the straws from step (4) at 60-80° C.;

[0015] (6) quickly immersing the dried straw in step (5) into a protective agent and then taking it out to dry;

[0016] (7) Use a pipe cutter to cut the straws into the required length.

[0017] The beneficial effects of the present invention are:

[0018] (1) The existing bamboo straw preparation method is complicated, and a large amount of auxiliary materials are added to shape the straw, the bamboo ratio is low, and the resource utilization is poor. The bamboo ratio of the present invention is as high as 90%, achieving efficient and high-ratio utilization of bamboo.

[0019] (2) The waste utilization method of the present invention can bring economic benefits. On the one hand, it can create new business opportunities for enterprises and improve their competitiveness; on the other hand, a higher proportion of bamboo materials improves resource utilization, thereby bringing higher profits to enterprises.

[0020] (3) The method of the present invention has the advantages of simple process, good stability, no organic reagents in the processing process, green and low-carbon environmental protection, low cost, etc. The overall process is conducive to large-scale industrial processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Preparation process flow chart;

[0022] Figure 2 Figure 1. Preparation of different sized straws. DETAILED DESCRIPTION

[0023] The accompanying drawings of the present invention are described in detail below. It should be noted that all other embodiments obtained by ordinary technicians in this field without creative work based on other embodiments of the present invention, or equivalent replacement or change based on the technical solution and concept of the present invention, all belong to the protection scope of the present invention. Further detailed explanation is given below in conjunction with the accompanying drawings.

[0024] Example 1

[0025] A method for preparing green and degradable straws by utilizing bamboo powder in a high proportion comprises the following steps: selecting bamboo powder with a mesh size of 600 and dispersing it into water, adding 10% bacterial cellulose and mixing it with the bamboo powder at a high speed to obtain bamboo powder-bacterial cellulose slurry; stirring the mixture for 45 minutes at room temperature, transferring the mixed slurry into a hopper of a twin-screw extruder for extrusion, and obtaining a slender tube with a wall thickness of 0.2 to 3 mm and a diameter of 4 mm through a straw former; and cutting the tubes into 15 cm straws by a tube cutter and drying them in a drying oven at 80°C.

[0026] Example 2

[0027] A method for preparing green and degradable straws by utilizing bamboo powder in a high proportion comprises the following steps: selecting bamboo powder with a mesh size of 600 and dispersing it into water, adding 10% bacterial cellulose and mixing it with the bamboo powder at a high speed to obtain bamboo powder-bacterial cellulose slurry; stirring the mixture for 45 minutes at room temperature, transferring the mixed slurry into a hopper of a twin-screw extruder for extrusion, and obtaining a slender tube with a wall thickness of 0.2 to 3 mm and a diameter of 8 mm through a straw former; and cutting the tubes into 15 cm straws by a tube cutter and drying them in a drying oven at 80°C.

[0028] Example 3

[0029] A method for preparing green and degradable straws by utilizing bamboo powder in a high proportion comprises the following steps: selecting bamboo powder with a mesh size of 600 and dispersing it into water, adding 10% bacterial cellulose and mixing it with the bamboo powder at a high speed to obtain bamboo powder-bacterial cellulose slurry; stirring the slurry at room temperature for 45 minutes, transferring the mixed slurry into a hopper of a twin-screw extruder for extrusion, and obtaining a slender tube with a wall thickness of 0.2 to 3 mm and a diameter of 12 mm through a straw former; and cutting the tube into 15 cm straws by a tube cutter and drying them in a drying oven at 80°C.

Claims

1. A method for preparing green degradable straws using bamboo powder in high proportion, characterized in that The straw is prepared from the following raw materials in percentage by weight: bamboo powder accounts for 80% to 90%, bacterial cellulose accounts for 8% to 16%, food-grade additives account for 1.9% to 3.8%, and PLA accounts for 0.1% to 0.2%.

2. The green degradable straw according to claim 1, characterized in that: The bamboo powder should be of 300 mesh or finer specifications, and the fineness of the powder directly affects the smoothness of the straw surface.

3. The green degradable straw according to claim 1, characterized in that: The types of cellulose mentioned include nanocellulose, bacterial cellulose and cellulose nanocrystals, which can be any one of the three or a combination of multiple ones.

4. The self-degradable straw according to claim 2, characterized in that: The bacterial cellulose is edible bacterial cellulose; it refers to cellulose synthesized by microorganisms such as Acetobacter, Agrobacterium, Rhizobium and Sarcina under different conditions, and is insoluble in water.

5. The self-degradable straw according to claim 1, characterized in that: The food-grade additive comprises any one of starch, glycerol, beeswax and chitosan, or a combination of these ingredients.

6. The self-degradable straw according to claim 1, characterized in that: The PLA is polylactic acid that meets food grade standards.

7. The method for preparing a biodegradable straw according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: (1) Wash and dry the bamboo, then crush and classify; (2) dispersing the bamboo powder in step (1) in water in appropriate proportions with cellulose dispersion and food-grade additives; (3) using a negative pressure dehydration device to initially remove moisture; (4) the material after preliminary dehydration is wound into a straw using a coiler of specified size; (5) drying the straws from step (4) at 60-80° C.; (6) quickly immersing the dried straw in step (5) into a protective agent and then taking it out to dry; (7) Use a pipe cutter to cut the straws into the required length.

8. Use of the straws obtained by the method for preparing wood cellulose with high bamboo powder content as claimed in any one of claims 1 to 7.

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