CN111171589A

CN111171589A - Coconut branch and leaf fiber-based wood-plastic composite material and preparation method thereof

Info

Publication number: CN111171589A
Application number: CN201911345075.2A
Authority: CN
Inventors: 熊雪平
Original assignee: Hainan Kunlun New Material Science And Technology Co ltd
Current assignee: Hainan Kunlun New Material Science And Technology Co ltd
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2020-05-19

Abstract

The invention discloses a coconut branch and leaf fiber-based wood-plastic composite material, which contains coconut branch and leaf fibers, recycled thermoplastic resin, calcium carbonate and related auxiliary agents, and is prepared by a coconut branch and leaf fiber powder preparation method comprising reverse rolling feeding, cutting and grinding under a specific process formula and a production process comprising low-speed and high-speed mixing, high-temperature and high-pressure granulation and temperature extrusion control in each area.

Description

Coconut branch and leaf fiber-based wood-plastic composite material and preparation method thereof

Technical Field

The invention belongs to the field of wood-plastic composite materials, and particularly relates to a coconut branch and leaf fiber-based wood-plastic composite material and a preparation method thereof.

Background

The coconut tree has the advantages of complete pinnate branches and leaves, 4-6 m long and thick leaf stalks. Branches and leaves of immature tangerine orange peel on the tree are 2.3 kg per piece, and when the branches and leaves naturally mature and fall off, 1.29 kg per piece. One coconut tree naturally drops more than 10 branches and leaves on average per year, namely each coconut tree naturally drops at least 12.9 kilograms of branches and leaves per year. Preliminary statistics shows that 720 ten thousand coconut trees are totally collected in Hainan province, and the total weight of naturally-fallen branches and leaves is 9.5 ten thousand tons every year. And branches and leaves of areca and palm, and the like are added, so that more than 12 ten thousand tons of biomass resources can be developed and utilized. At present, the waste gasoline is mainly treated by a method of stacking and burning, but the environment is polluted and resources are wasted.

Each year, 1000 million tons of waste plastics are produced in China. Containing thermoplastic resins such as: PE (polyethylene), PP (polypropylene), PVC (polyvinyl chloride), PET (polyethylene terephthalate), PA (polyamide nylon) and the like. The resin belongs to a chemical macromolecule, has a stable structure, is not easy to be damaged by natural microorganism bacteria, and forms the following hazards if the resin is not recycled and exists in the environment for a long time and is accumulated continuously: firstly, the development of industrial and agricultural production is influenced. Secondly, the animal survival is threatened. Thirdly, the sustainable utilization of the land is influenced. Fourthly, toxic gas is generated by burning with fire, and the environmental pollution is increased.

If the resource waste can be modified and utilized, the decay is miraculous, and the wood-plastic composite material which has the advantages of water resistance, moth prevention, corrosion prevention, strong wood texture, high surface hardness, strong wear resistance, long service life and no formaldehyde is prepared, namely the biomass composite material which is a typical green building material for saving and replacing wood. The method conforms to the national industrial policy, the processing process is environment-friendly, the product quality is environment-friendly, and the final use is environment-friendly; can be recycled, and is beneficial to the nation and the people.

However, in the prior art, the preparation of the coconut branch and leaf fiber powder is difficult, and the winding of the coconut branch and leaf fiber filaments on the cutter head of the crusher often occurs, so that the motor of the device is shut down in an overload power-off manner, and the length-diameter ratio of the powder is uneven. The analysis reason is that the coconut palm branches and leaves are uneven and uneven, have different lengths, are thick and long in fibers (the average diameter is 1 mm and the average length is 2m), have good strength and toughness, are extremely easy to entangle in a rotary hammer crusher barrel, are stopped frequently, are extremely difficult to clean and take long time. In addition, High Density Polyethylene (HDPE), which is known in the prior art formulations, has high melt viscosity, low flow to length ratio, poor mechanical properties, poor gas permeability, is easily deformed, easily ages, has a brittleness lower than that of PP, and generally has poor Environmental Stress Cracking Resistance (ESCR).

Disclosure of Invention

The invention aims to provide a coconut branch and leaf fiber-based wood-plastic composite material and a preparation method thereof. The biomass composite material of the coconut branch and leaf fibers and the recycled thermoplastic resin is prepared by a preparation method of coconut branch and leaf fiber powder which is prepared by reversely rolling and feeding, cutting and grinding the coconut branch and leaf fibers, the recycled thermoplastic resin (HDPE, LDPE and PP), calcium carbonate and other auxiliary agents according to a weight ratio of 55:28:9:8, and then a production process of mixing at low speed and high speed, granulating at high temperature and high pressure and extruding by controlling the temperature of each area.

In order to achieve the purpose, the invention adopts the following technical scheme:

a coconut branch and leaf fiber-based wood-plastic composite material comprises the following raw materials: the coconut palm fiber powder is prepared from coconut palm branches and leaves, and the recycled thermoplastic resin is composed of PE resin and PP resin. Polypropylene (PP) is added, the density is small, the strength, rigidity, hardness and heat resistance are all superior to those of low-pressure polyethylene, and the continuous use temperature can reach 110-120 ℃. Has good dielectric property and high-frequency insulation and is not influenced by humidity. Common organic solvents such as acids and bases hardly act on it. Good mechanical property, hardly absorbs water, and does not react with most chemicals. Pure texture and no toxicity. Besides impact resistance, other mechanical properties are better than those of polyethylene, and the molding processability is good.

The further technical proposal is that the PE resin consists of high-density polyethylene and linear low-density polyethylene. High Density Polyethylene (HDPE), which is known by the abbreviation High Density Polyethylene, has High melt viscosity, small flow length ratio, poor mechanical properties, poor gas permeability, easy deformation, easy aging, brittleness lower than PP, and generally poor Environmental Stress Cracking Resistance (ESCR); thus adding Linear Low Density Polyethylene (LLDPE), which is ethylene with a small amount of higher order

Copolymers obtained by polymerization of olefins in the presence of catalysts, having the advantages of low-temperature toughness, high modulus, resistance to bending and stress cracking, good impact strength at low temperatures, etc.

The further technical proposal is that the raw material also comprises calcium carbonate. The calcium carbonate is added to play a filling role, the thixotropy of a system is improved, and the strength and the surface smoothness of a product are improved.

The further technical scheme is that the raw materials also comprise an auxiliary agent: the anti-bacterial agent comprises a polymer graft, a composite lubricant, a composite antioxidant, a UV (ultraviolet) stabilizer, an anti-bacterial agent and a coloring agent, wherein the polymer graft is a copolymer of maleic anhydride grafted PE, and the composite lubricant is one or two of polyethylene wax, stearic acid, zinc stearate and EBS. Wherein the composite lubricant comprises: polyethylene wax (tissuemat E, PE wax), stearic acid (octadecanoic acid) and Ethylene Bis Stearamide (EBS) ensure internal lubrication and external lubrication in the production process of the product; the polymer graft (maleic anhydride grafted PE) improves the compatibility of the recycled thermoplastic resin and the coconut branch and leaf fiber and improves the mechanical property. Meanwhile, the internal lubricant is properly reduced in view of the characteristic that the coconut branches and leaves contain trace oil.

The further technical scheme is that the weight ratio of the raw materials is as follows: the coconut branch and leaf fiber powder is prepared from recycled thermoplastic resin, calcium carbonate and auxiliary agent in a ratio of 55:28:9: 8.

The further technical scheme is that the weight ratio of the recycled thermoplastic resin is as follows: high density polyethylene linear low density polyethylene polypropylene 15:5: 8.

A preparation method of the coconut branch and leaf fiber-based wood-plastic composite material comprises the following steps: (1) preparing coconut branch and leaf fiber powder: collecting naturally fallen coconut branches and leaves, rolling and flattening by a feeding rod, cutting by a fly cutter, drying and dehydrating, hammering and grinding to prepare coconut branch and leaf fiber powder;

(2) preparing a coconut branch and leaf fiber-based wood-plastic composite material: firstly, mixing coconut branch and leaf fiber powder, high-density polyethylene, linear low-density polyethylene and polypropylene at a low speed, then adding calcium carbonate and an auxiliary agent for high-speed mixing, and granulating and extruding to prepare the coconut branch and leaf fiber-based wood-plastic composite material. The biomass composite material of the coconut branch and leaf fibers and the recycled thermoplastic resin is prepared by a production process of mixing at low speed and high speed, granulating at high temperature and high pressure and controlling the temperature of each area to extrude under the process formula of mixing the coconut branch and leaf fibers, the recycled thermoplastic resin (HDPE, LDPE and PP), calcium carbonate and other auxiliary agents according to the weight ratio of 55:9:28:8, the production process is smooth, the indexes of the product such as strength, toughness, bending breaking load, screw holding force, impact resistance, water absorption size change rate and the like are improved, and the phenomena of deformation, cracking, frangibility and the like in practical application are greatly improved.

The further technical scheme is that the rolling and flattening of the feeding roller specifically comprises the following steps: in the coconut branch and leaf conveying section, a 1.5 kilowatt motor is used for driving a first pointed tooth-shaped rolling shaft with the diameter of 200 mm and the length of 800 mm to feed materials in the anti-clockwise direction, and then a 1.5 kilowatt motor is used for driving a second pointed tooth-shaped rolling shaft with the diameter of 40 mm and the length of 800 mm to feed materials in the anti-clockwise direction, so that the feeding rods are rolled and flattened twice.

The further technical scheme is that after the two feeding rods are rolled and flattened, a rolling fly cutter is matched to cut the coconut branches and leaves into short pieces of 5-15 mm, and then drying, dehydration, hammer crushing, grinding and the like are carried out to prepare the coconut branch and leaf fiber powder with the basic granularity of 60-80 meshes and the length-diameter ratio of 3: 1. The original fiber filaments of the coconut branches and leaves are firstly cut short, and the hammer crusher tool bit is not wound any more, so that the continuous operation of the equipment motor is ensured, the operation efficiency is greatly improved, and the production cost is reduced.

The further technical scheme is that the granulation extrusion specifically comprises the following steps: granulating by using a 75-parallel straight-cone double-screw granulator and extruding by using a cone-type double-screw extruder, wherein the whole-process temperature is less than or equal to 200 ℃, and the method comprises the following steps: the first barrel zone is 200 ℃, the second barrel zone is 195 ℃, the third barrel zone is 175 ℃, the fourth barrel zone is 155 ℃, the confluence core zone is 140 ℃ and the die is 150 ℃.

The invention has the beneficial effects that:

(1) according to the characteristics of natural corrosion resistance, aging resistance, strong toughness and trace oil quality of the coconut branch and leaf fibers, the high-density polyethylene is used as a main raw material in the composite material, the specific gravity of the coconut branch and leaf fibers is reduced, the linear low-density polyethylene is added, the polypropylene is added, the calcium carbonate is added, the indexes of the product such as bending strength, toughness, bending failure load, screw holding force, impact resistance, water absorption size change rate and the like are improved, the phenomena of deformation, cracking, frangibility and the like in practical application are greatly improved, the production cost is reduced, and the use value of the product is improved.

(2) The coconut branch and leaf fiber is a polar hydrophilic substance, the recycled thermoplastic resin (HDPE, LDPE, PP) is a non-hydrophilic substance, the affinity of the two substances is extremely poor, and the coconut branch and leaf fiber is modified and processed into coconut branch and leaf fiber powder, so that the compatible combination of two interfaces of the coconut branch and leaf fiber and the recycled thermoplastic resin is enhanced, and the environment-friendly material for producing the biomass fiber with good physical and chemical properties is prepared.

(3) The coconut branch and leaf fiber is added with the recycled thermoplastic resin, and generates high temperature and dispersion under the friction of the blades of the stirrer to complete dehydration, and the strengthening effect is as follows: the function of the recycled thermoplastic resin in the curing process is exerted to remove the pyroligneous acid in the coconut branch and leaf fibers, and the bubbling and the cracks of the product are prevented. The affinity relationship between two interfaces of the coconut branch and leaf fiber and the recycled thermoplastic resin is improved, the function of a polymer graft is exerted, and the physical and mechanical properties of the product are enhanced. Improve the thermal stability of the coconut branch and leaf fiber.

Drawings

FIG. 1 is a process flow chart of the preparation method of the coconut branch and leaf fiber-based wood-plastic composite section bar.

Fig. 2 is a schematic view of a double-feeding roller rolling and flattening structure of the present invention.

Wherein, 1 is the coconut palm branch and leaf direction of delivery, 2 is anti-clockwise direction, 3 is first cusp form roller bearing, and 4 is second cusp form roller bearing.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Example 1

The coconut branch and leaf fiber-based wood-plastic composite material comprises the following components in parts by weight: coconut branch and leaf fiber about 55% wood fiber powder 60-80 mesh, calcium carbonate about 9%, High Density Polyethylene (HDPE) about 15%, linear Low Density Polyethylene (LDPE) about 5%, polypropylene (PP) about 8%, polymer graft about 3% (maleic anhydride grafted PE), composite lubricant about 1.3%, composite antioxidant about 0.3%, UV ultraviolet stabilizer about 0.4%, antibacterial agent 2.5%, and colorant 0.5%. The lubricant includes an inner lubricant and an outer lubricant.

The preparation method of the coconut branch and leaf fiber-based wood-plastic composite material comprises the following steps: the method comprises the following steps:

(1) preparing coconut branch and leaf fiber powder: collecting naturally fallen coconut branches and leaves, rolling and flattening by a feeding roller, cutting by a fly cutter, drying and dehydrating, hammering and grinding to prepare the coconut branch and leaf fiber powder. Specifically, in the coconut branch and leaf conveying section, a 1.5 kilowatt motor is used for driving a first pointed tooth-shaped rolling shaft 3 with the diameter of 200 mm and the length of 800 mm to feed materials in the anti-clockwise direction, and then a 1.5 kilowatt motor is used for driving a second pointed tooth-shaped rolling shaft 4 with the diameter of 40 mm and the length of 800 mm to feed materials in the anti-clockwise direction, so that the feeding rods are rolled and flattened twice. After the two feeding rollers are rolled and flattened, the coco branches and leaves are cut into short pieces of 5-15 mm by a rolling fly cutter, and then the coco branches and leaves are dried, dehydrated, hammered, ground and the like to prepare the coco branches and leaves fiber powder with the basic granularity of 60 meshes to 80 meshes and the length-diameter ratio of 3: 1.

(2) Preparing a coconut branch and leaf fiber-based wood-plastic composite material: firstly mixing coconut palm branch and leaf fiber powder, high-density polyethylene, linear low-density polyethylene and polypropylene at a low speed, then adding calcium carbonate and an auxiliary agent to perform high-speed mixing, granulating by using a 75-parallel straight-cone double-screw granulator, and extruding by using a cone double-screw extruder, wherein the temperature of the whole extrusion process is less than or equal to 200 ℃, wherein: and finally preparing the coconut branch and leaf fiber-based wood-plastic composite material by using a machine barrel I zone at 200 ℃, a machine barrel II zone at 195 ℃, a machine barrel three zone at 175 ℃, a machine barrel four zone at 155 ℃, a confluence core zone at 140 ℃ and a mold at 150 ℃, and forming, cooling and cutting the coconut branch and leaf fiber-based wood-plastic composite material.

(3) And (3) carrying out post-treatment such as polishing and sanding or napping, on-line hot-stamping of textures, co-extrusion and the like on the surface of the cut coconut branch and leaf fiber-based wood-plastic composite material to obtain a finished product.

Example 2

The coconut branch and leaf fiber-based wood-plastic composite material comprises the following components in parts by weight: coconut branch and leaf fiber about 55% wood fiber powder 60-80 mesh, calcium carbonate about 9%, High Density Polyethylene (HDPE) about 10%, linear Low Density Polyethylene (LDPE) about 10%, polypropylene (PP) about 8%, polymer graft about 3% (maleic anhydride grafted PE), composite lubricant about 1.3%, composite antioxidant about 0.3%, UV ultraviolet stabilizer about 0.4%, antibacterial agent 2.5%, and colorant 0.5%. The lubricant includes an inner lubricant and an outer lubricant.

Example 3

The coconut branch and leaf fiber-based wood-plastic composite material comprises the following components in parts by weight: coconut branch and leaf fiber about 55% wood fiber powder 60-80 mesh, calcium carbonate about 9%, High Density Polyethylene (HDPE) about 10%, linear Low Density Polyethylene (LDPE) about 8%, polypropylene (PP) about 10%, polymer graft about 3% (maleic anhydride grafted PE), composite lubricant about 1.3%, composite antioxidant about 0.3%, UV ultraviolet stabilizer about 0.4%, antibacterial agent 2.5%, and colorant 0.5%. The lubricant includes an inner lubricant and an outer lubricant.

The finished products of the three examples obtained were tested according to GB/T245908-2009 Wood Plastic flooring, ASTM D6109-13 method A, ASTM D1037-12 section 16, and the data of the results are shown in Table 1.

Table 1 performance test results of coconut branch and leaf fiber-based wood-plastic composite finished products of the present invention

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims

1. The coconut branch and leaf fiber-based wood-plastic composite material is characterized in that: the method comprises the following raw materials: the coconut palm fiber powder is prepared from coconut palm branches and leaves, and the recycled thermoplastic resin is composed of PE resin and PP resin.

2. The coconut branch and leaf fiber-based wood-plastic composite material as claimed in claim 1, wherein: the PE resin is composed of high-density polyethylene and linear low-density polyethylene.

3. The coconut branch and leaf fiber-based wood-plastic composite material as claimed in claim 2, wherein: the raw material also comprises calcium carbonate.

4. The coconut branch and leaf fiber-based wood-plastic composite material as claimed in claim 3, wherein: the raw materials also comprise an auxiliary agent: the anti-bacterial agent comprises a polymer graft, a composite lubricant, a composite antioxidant, a UV (ultraviolet) stabilizer, an anti-bacterial agent and a coloring agent, wherein the polymer graft is a copolymer of maleic anhydride grafted PE, and the composite lubricant is one or two of polyethylene wax, stearic acid, zinc stearate and EBS.

5. The coconut branch and leaf fiber-based wood-plastic composite material according to claim 4, wherein: the weight ratio of the raw materials is as follows: the coconut branch and leaf fiber powder is prepared from recycled thermoplastic resin, calcium carbonate and auxiliary agent in a ratio of 55:28:9: 8.

6. The coconut branch and leaf fiber-based wood-plastic composite material as claimed in claim 5, wherein: the weight ratio of the recycled thermoplastic resin is as follows: high density polyethylene linear low density polyethylene polypropylene 15:5: 8.

7. A method for preparing the coconut branch and leaf fiber-based wood-plastic composite material as claimed in any one of claims 4 to 6, which is characterized in that: the method comprises the following steps: (1) preparing coconut branch and leaf fiber powder: collecting naturally fallen coconut branches and leaves, rolling and flattening by a feeding rod, cutting by a fly cutter, drying and dehydrating, hammering and grinding to prepare coconut branch and leaf fiber powder;

(2) preparing a coconut branch and leaf fiber-based wood-plastic composite material: firstly, mixing coconut branch and leaf fiber powder, high-density polyethylene, linear low-density polyethylene and polypropylene at a low speed, then adding calcium carbonate and an auxiliary agent for high-speed mixing, and granulating and extruding to prepare the coconut branch and leaf fiber-based wood-plastic composite material.

8. The preparation method of the coconut branch and leaf fiber-based wood-plastic composite material according to claim 7, characterized in that: the rolling and flattening of the feeding roller is as follows: in the coconut branch and leaf conveying section, a 1.5 kilowatt motor is used for driving a first pointed tooth-shaped rolling shaft with the diameter of 200 mm and the length of 800 mm to feed materials in the anti-clockwise direction, and then a 1.5 kilowatt motor is used for driving a second pointed tooth-shaped rolling shaft with the diameter of 40 mm and the length of 800 mm to feed materials in the anti-clockwise direction, so that the feeding rods are rolled and flattened twice.

9. The preparation method of the coconut branch and leaf fiber-based wood-plastic composite material according to claim 8, characterized in that: after the two feeding rollers are rolled and flattened, the coco branches and leaves are cut into short pieces of 5-15 mm by a rolling fly cutter, and then the coco branches and leaves are dried, dehydrated, hammered, ground and the like to prepare the coco branches and leaves fiber powder with the basic granularity of 60 meshes to 80 meshes and the length-diameter ratio of 3: 1.

10. The preparation method of the coconut branch and leaf fiber-based wood-plastic composite material according to claim 9, characterized in that: the granulation extrusion specifically comprises the following steps: granulating by using a 75-parallel straight-cone double-screw granulator and extruding by using a cone-type double-screw extruder, wherein the whole-process temperature is less than or equal to 200 ℃, and the method comprises the following steps: the first barrel zone is 200 ℃, the second barrel zone is 195 ℃, the third barrel zone is 175 ℃, the fourth barrel zone is 155 ℃, the confluence core zone is 140 ℃ and the die is 150 ℃.