TWI784251B - Production method of an environment-friendly product and application thereof - Google Patents

Abstract

Present invention is related to a production method of an environment-friendly product and application thereof. The production method comprises steps of: blending a PLA, a plant fiber and a supplemental material by a first shear parameter to form a pre-blended mixture; further blending the pre-blended mixture by at least one second shear parameter to form a finished mixture which the plant fiber will be arranged in certain order within the PLA; forming a PLA composite granule by the finished mixture; and forming a final product by injection molding the PLA composite granule where the forming time is less than 30 seconds.

Description

Manufacturing method of environmentally friendly polymer products and derivatives thereof

A manufacturing method of an environment-friendly polymer product and its derivatives.

Plastic is a problem for the planet's environment and one of the most intractable problems of this century. Due to the convenience of production and price advantages, it is almost impossible to completely eliminate waste. Therefore, in addition to reducing use, choosing biodegradable raw materials is the only right way.

Excluding materials from petrochemical sources, it is a common model in recent years to obtain polymer sources that can be used to make plastics from biological materials. One of the good substitutes for general-purpose plastic properties. Although PLA has advantages at present, if you want to increase the heat resistance of its products, you need to maintain a certain time (about 80 seconds) and temperature in the plastic injection mold to crystallize, so as to improve the mechanical properties and resistance of PLA products. warm. However, for the general production process, long-term temperature holding means that the production method is limited (for example, only the injection process can be used), the production rate is reduced, the process parameters are not easy to control, the equipment cost is high, and the material consumption is large. Costs skyrocketed.

In order to solve the problem that the existing Poly Lactic Acid (PLA) material must be kept in temperature for a long time in the molding process to improve the product's heat resistance or mechanical strength, resulting in a significant increase in overall cost and limited production methods. The invention proposes a method for manufacturing a polylactic acid composite material, the steps of which include: mixing a polylactic acid raw material, a plant fiber, and a supplementary material with a first shear parameter to produce a premix; kneading the pre-mixture with different second shear parameters to produce a finished mixture, in which the plant fiber, the polylactic acid and the supplementary material are mixed in the finished mixture, the plant fiber forms a pre-arrangement in the polylactic acid; the finished The mixture is granulated to form a masterbatch; and the masterbatch is formed into a fluid state by mechanical force and heating, and then injected into a mold, and kept in the mold for a molding time and molding, and the molding time is within 30 seconds.

Wherein, the second shear parameter is that the shear force, the length of the kneading unit or the temperature of the kneading unit are greater than the first shear parameter.

Wherein, the content of the polylactic acid raw material is between 40-70 wt %; the content of the plant fiber is between 10 wt % and 30 wt %; and the content of the supplementary material is between 10-35 wt %.

Wherein, the plant fiber length is between 0.01mm~3mm, including rice grain powder, coconut husk powder, coffee grounds, rice husk powder, willow powder, bamboo powder or wood powder; and the supplementary material includes a crystal nucleus agent 0.5~6wt %, a waterproofing agent 0.5~5wt%, a bacteriostatic agent 1~10wt%, a bridging agent 0.1~5wt%, a slip agent, a pressure modifier, a decomposition promoting material 0.1~2wt% or the above materials combination.

Wherein, the crystal nucleating agent includes talcum powder and calcium salt of carboxylic acid with long carbon chain as main components; the antibacterial agent includes coral powder; the slippery agent includes edible wax or grease; the anti-pressure modifier includes butanediol, carbonate, polyethylene terephthalate, vinyl resin, vinyl alcohol, polybutylene terephthalate, or glycerin; and the decomposition promoting material contains protein.

Wherein, the masterbatch is formed into disposable tableware.

Preferably, the disposable tableware is a knife, fork, spoon or straw.

Preferably, the aforementioned environment-friendly polymer product can be used as fuel after being cut into sections.

As can be seen from the above description, the present invention has the following advantages:

1. The PLA molding process provided by the present invention takes a short time and can produce finished products with good temperature resistance. At present, if a product with a heat resistance temperature greater than 100 ^oC is to be produced, it is necessary to maintain the molding time in the mold for about 80 seconds during molding to complete the crystallization of polylactic acid and improve its temperature resistance. However, the aforementioned method of the present invention can allow the materials to be pre-arranged in the material tube through the control of multi-stage shear parameters, greatly reducing the temperature holding time in the mold during injection molding, and further shortening the molding time to within 30 seconds, which effectively solves the existing technology. Long molding time leads to technical problems of cost increase.

2. After the recovery of the present invention, it can be cut into sections and can be used as fuel. When burning, the main materials, polylactic acid and plant fiber, are biologically derived materials, which will not cause air pollution and can be effectively used as fire or high-density fuel.

Please refer to Fig. 1, a kind of manufacturing method of polylactic acid (Poly Lactic Acid, PLA) composite material product of the present invention, its step comprises:

STEP 1 : Mix a polylactic acid raw material, a plant fiber and a supplementary material with a first shear parameter to produce a premix. Wherein, when using the first shear parameter, the content of the polylactic acid raw material is between 40-70wt%, the plant fiber is between 10wt% and 30wt%, and the supplementary material is supplemented according to the ratio of polylactic acid and plant fiber to supplement the remaining content , and its content can be adjusted according to requirements, for example, between 10-35 wt%.

The plant fiber can be rice grain powder, coconut husk, coffee grounds, rice husk powder, willow powder, bamboo powder, wood powder, bamboo charcoal powder, rubbing powder, dragon fruit powder, pomegranate powder, green algae powder, leaf vegetable powder, etc. Dried plant short fibers such as body. The fiber length can be between 0.01mm~3mm, preferably less than 1mm so as to be uniformly dispersed in the polylactic acid. The natural pigments contained in the above-mentioned plant fiber powder can be used as a dyeing agent for finished products of polylactic acid composite materials and have double unexpected effects of improving biodegradation efficiency.

The supplementary material comprises 0.5-6wt% (preferably 2-4wt%) of a crystal nucleating agent, 0.5-5wt% (preferably 3wt%) of a waterproofing agent, 1-10wt% of a bacteriostat (preferably 5wt%), a bridging agent 0.1-5wt% (preferably 3wt%), a slip agent (preferably 1-4wt%), a pressure modifier (preferably 1-10wt%), a decomposition Promoter material 0.1-2wt% (preferably less than 0.5wt%) or a combination of the aforementioned materials.

The crystal nucleating agent can be talc (Talc), calcium salt of carboxylate (cav102, Clariant nucleating agent) with long carbon chain as the main component, and other materials that are conducive to the crystallization of polylactic acid. The antibacterial agent can be coral powder, and the addition ratio is between 1-10wt%, preferably 5wt%±1, which can not only inhibit the formation of bacteria, but also improve the rigidity of the material. The slip agent can be edible wax, oil, etc., such as rice bran oil, etc., to assist the processability of kneading and mixing. The pressure modifier can be butanediol, carbonate, polyethylene terephthalate (Polyethylene terephthalate), vinyl resin (Vinyl ester resin), vinyl alcohol, polybutylene terephthalate (Polybutylene terephthalate) terephthalate), glycerides, etc. The decomposition promoting material may be protein.

The plant fiber, the polylactic acid raw material, and the supplementary material are melted and kneaded together, and the melt kneading system can utilize a multi-section material tube mixing equipment for melting and kneading. A front section of the equipment applies mechanical force and temperature to melt and soften the polylactic acid, and then adds supplementary materials to the opening of a middle section of the multi-section material tube kneading equipment, and the plant fibers are melted and kneaded together in the polylactic acid.

STEP 2 : Mixing the premix with one or more second shear parameters different from the first shear parameter to produce a finished mixture. Compared to the pre-mix, the finish mix uniformly mixes the plant fibers with the PLA and supplementary materials, and a pre-arrangement of the plant fibers and the PLA is produced.

The difference between the first shearing parameter and more than one second shearing parameter may include the rotational speed of the mixing unit of the multi-section barrel mixing equipment, the shear force provided by the mixing unit to the material, the length of the mixing unit, and the temperature of the mixing unit. Preferably, more than one of the second shearing parameters have a relatively large shearing force; preferably, more than one of the second shearing parameters provide the material with a relatively large rotational speed; preferably , and one or more of the second shear parameters have relatively large barrel lengths. Preferably, the first shear parameter and more than one second shear parameter are distributed in different processing stages of the multi-stage barrel kneading equipment.

STEP 3 : The finished mixture is granulated to form a masterbatch. In this step, the completed mixture is extruded from the kneader to cool down to form the masterbatch, which can be cut into granules to facilitate subsequent processing requirements.

STEP 4 : Process the masterbatch to produce polylactic acid composite products: after the masterbatch is formed into a flow state with mechanical force and temperature control, it is output to an output unit, so that the flow state of the masterbatch is in the output Cell injection maintains a molding appearance for a molding time, wherein the molding time is less than 30 seconds.

According to different products, different shapes of the output unit can be selected, so that the masterbatch can finally maintain the molded appearance during the molding time, and then cool down to fix the molded appearance. For example, the molded appearance can be a plastic injection mold structure, and the molding time is the temperature holding time of the masterbatch injected into the mold, so that the masterbatch can be combined to produce the polylactic acid composite product with the molded appearance. The appearance can be the appearance of tableware such as straws, disposable tableware (knives, forks, spoons), flower pots, etc., or for example, when the polylactic acid composite product is chopsticks or straws, the molding appearance can be an extrusion die, which can be adjusted by adjusting The length of the die is such that the masterbatch is crystallized in the die to produce chopsticks and straws with high strength and temperature resistance.

"Example 1 "

Take 60wt% of polylactic acid raw material, 10% of plant fiber (rice grain powder), and 30% of supplementary material and knead with the first shear parameter, and then knead with the second shear parameter with relatively high shear force to make the plant The fibers are pre-arranged in the polylactic acid, and then pelletized to form a masterbatch and processed.

"Example 2 "

Take 50wt% of polylactic acid, 20% of plant fiber, and 30% of supplementary material and knead with the first shear parameter, and then knead with the second shear parameter with a relatively high shear speed, so that the plant fiber is mixed in the polylactic acid. A pre-arranged state is formed, followed by granulation to form a masterbatch and processing molding steps.

"Example 3 "

Take 55wt% of polylactic acid, 15% of plant fiber, and 30% of supplementary material and knead with the first shear parameter, and then knead with the second shear parameter with a relatively high kneading length, so that the plant fiber is formed in the polylactic acid Pre-arranged state, followed by granulation to form masterbatch and processing molding steps.

" Example 4 "

When manufacturing disposable cutlery and spoons, the following ingredients and conditions may be included:

A. Polylactic acid raw material 50wt%

B. Plant fiber 20wt%

C. Supplementary material 30wt%. The supplementary material contains at least 10wt% of anti-pressure modifier, 3-5wt% of slip agent, 7-10wt% of talcum powder, 1-5wt% of cav102, etc.

After the above-mentioned formula is completed according to the manufacturing steps provided by the present invention, the masterbatch is matched with the mold by the injection equipment to complete the finished product manufacturing. Among them, the injection process conditions can be that the temperature of an outlet tube is between 180-220 ^o C, and the temperature inside the injection mold is maintained at 45-70 o ^C for 20-30 seconds, and the finished product with temperature-resistant effect can be taken out.

" Example 5 "

When manufacturing single-use products, such as straws and other products that need to be quickly decomposed, the following ingredients and conditions can be included:

A. Polylactic acid raw material 60wt%

B. Plant fiber 20~30wt%

C. Supplementary material 10-20wt%. The supplementary material at least contains 0.3-0.5wt% of protein, 3-6wt% of glyceride, 3-5wt% of wax, 0.2-0.4wt% of rice bran oil and 1-5wt% of waterproofing agent.

"Example 6 "

When manufacturing disposable products, such as chopsticks, the following ingredients and conditions may be included:

A. Polylactic acid raw material 50~60wt%

B. Plant fiber 10~20wt%

C. Supplementary material 10-20wt%. The supplementary material contains at least 3-5wt% of wax, 4-6wt% of coral powder, 5-10wt% of talc powder, 2-4wt% of anti-pressure modifier, 2-5wt% of bridging agent and 1-5wt% of waterproofing agent.

Furthermore, the polylactic acid composite product can be recycled after use, and after washing to remove surface dirt, it can be cut into sections to form fuel or kindling.

As can be seen from the above description, the present invention has the following advantages:

1. The molding time is short, and the finished product with good temperature resistance can be produced: if you want to produce a product with a heat resistance temperature greater than 100 ^oC , you must maintain the molding time in the mold for about 80 seconds during molding to complete the crystallization of polylactic acid , which can improve its temperature resistance. However, the aforementioned method of the present invention can allow the materials to be pre-arranged in the material tube through the control of multi-stage shear parameters, greatly reducing the temperature holding time in the mold during injection molding, and further shortening the molding time to within 30 seconds, which effectively solves the existing technology. Long molding time leads to technical problems of cost increase.

2. The molding time is short, greatly improving the technical problem that the traditional manufacturing method can only use injection to complete the product; the shortened manufacturing time can use extrusion and other methods to manufacture different products, and further overcome the problem of poor continuous output capacity of plastic injection.

2. After the recovery of the present invention, it can be cut into sections and can be used as fuel. When burning, the main materials, polylactic acid and plant fiber, are biologically derived materials, which will not cause air pollution and can be effectively used as fire or high-density fuel.

Fig. 1 is a flow chart of a preferred embodiment of the manufacturing method of the present invention.

Claims (7)

A method for manufacturing environmentally friendly polymer products, the steps of which include: mixing a polylactic acid raw material, a plant fiber, and a supplementary material with a first shear parameter to produce a pre-mixture; The second shear parameter kneads the pre-mixture to produce a finished mixture. After the plant fibers, the polylactic acid and supplementary materials in the complete mixture are completely mixed, the plant fibers form a pre-arrangement in the polylactic acid, wherein the second The shear parameter is that the shear force, the length of the kneading unit or the temperature of the kneading unit is greater than the first shear parameter; the finished mixture is granulated to form a masterbatch; and the masterbatch is formed into a fluid state by mechanical force and heating and then injected Into a mold, and maintain a molding time and molding in the mold, the molding time is within 30 seconds. The manufacturing method of environmentally friendly polymer products as described in the first patent scope of the application, wherein: the content of the polylactic acid raw material is between 40-70wt%; the content of the plant fiber is between 10wt% and 30wt%; and the content of the supplementary material is between 10~35wt%. Such as the manufacturing method of environmentally friendly polymer products in item 2 of the patent scope, wherein: the length of the plant fibers is between 0.01mm and 3mm, including rice grain powder, coconut shell powder, coffee grounds, rice husk powder, willow tree powder, and bamboo powder , wood powder, bamboo charcoal powder, wiping powder, dragon fruit powder, pomegranate powder, green algae powder or leaf vegetable powder; 1~10wt% agent, 0.1~5wt% bridging agent, 0.1~2wt% decomposing agent, or a combination of the aforementioned materials. Such as the manufacturing method of environmentally friendly polymer products in item 3 of the scope of patent application, in which: The crystal nucleating agent contains talcum powder and calcium salt of carboxylic acid with long carbon chain as main components; the antibacterial agent contains coral powder; the slippery agent contains edible wax or grease; , polyethylene terephthalate, vinyl resin, vinyl alcohol, polybutylene terephthalate, or glycerin; and the decomposition promoting material contains protein. As the manufacturing method of the environment-friendly polymer product described in the first patent scope of the application, the masterbatch is molded into disposable tableware. For example, the manufacturing method of the environment-friendly polymer product in item 5 of the scope of the patent application, the disposable tableware is a knife, fork, spoon or straw. A derivative of an environmentally-friendly polymer product, which is the fuel of the environmentally-friendly polymer product in any one of items 1 to 6 of the patent application after being cut into segments.

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