Simulated shell tableware made of plant particle / fiber and polypropylene material and preparation process of simulated shell tableware

Abstract

The invention relates to simulated shell tableware made of a plant particle / fiber and polypropylene material, in particular to environment-friendly tableware made of a plant fiber composite material. The composite material of the food tableware consists of the following components in percentage by weight: 30wt% of food-grade polypropylene, 60wt% of plant particles, 5wt% of a compatibilizer, 2wt% of a lubricant and the balance of an antioxidant, a light stabilizer and an ultraviolet light absorber. By adopting a mode of blending the plant particles and the food-grade polypropylene, the tableware has good mechanical strength and durability, also has an environment-friendly characteristic, is suitable for replacing traditional shell requirements, and reduces pollution to the environment.

Description

Technical Field

[0001] This invention relates to the field of food-grade polypropylene materials technology, and more specifically to a simulated seashell tableware made of plant particles / fibers and polypropylene materials, and its preparation process. Background Technology

[0002] Food-grade polypropylene is an important thermoplastic, widely used in food packaging and other fields due to its excellent mechanical properties, chemical stability, processability, and low cost. The basic chemical structure of food-grade polypropylene is a polymer formed by the polymerization of high molecular weight propylene monomers. Based on its molecular structure and density, food-grade polypropylene can be divided into several categories, including low-density food-grade polypropylene, linear low-density food-grade polypropylene, and high-density food-grade polypropylene.

[0003] Traditionally, the main methods for preparing food-grade polypropylene are as follows:

[0004] Free radical polymerization: Free radical-initiated reactions of food-grade polypropylene are typically carried out under high temperature and pressure. The polymerization of ethylene is initiated by a free radical initiator (such as peroxide) to produce low-density food-grade polypropylene (LDPE). Due to the complexity of the high-pressure equipment and process conditions used, this method is generally used for the production of flexible packaging materials.

[0005] Ziegler-Natta polymerization: This method utilizes transition metal catalysts (such as titanium compounds and alkylaluminum) to perform low-pressure polymerization of ethylene at moderate temperatures and ambient pressures, producing high-density food-grade polypropylene (HDPE). Due to its mild production conditions, high yield, and narrow molecular weight distribution, this method is widely used in the production of pipes, containers, and injection-molded products.

[0006] Phyllis catalytic process: The polymerization of ethylene is carried out using a chromium-containing catalyst (such as chromium oxide). It is mainly used to produce high-density food-grade polypropylene (HDPE), and its process conditions are relatively simple.

[0007] In recent years, with increasing environmental awareness and growing concern about plastic waste pollution, the biodegradability and environmental friendliness of food-grade polypropylene have received increasing attention. Based on this, bio-based food-grade polypropylene, biodegradable food-grade polypropylene, and environmentally friendly composite materials have become hot research directions in food-grade polypropylene development. By introducing renewable plant fibers (such as wood flour and rice husks) into food-grade polypropylene blends, it is possible to reduce dependence on petrochemical resources while maintaining its excellent properties and improving the material's biodegradability. Furthermore, the development of functionalized food-grade polypropylene composites, such as those incorporating antibacterial agents, conductive materials, or reinforcing fibers, has also promoted the expansion of food-grade polypropylene applications in specialized fields.

[0008] Therefore, recent research has focused on improving the performance of food-grade polypropylene through modification techniques, including improving compatibility with other materials by introducing compatibilizers, improving its mechanical properties through copolymerization or blending, and developing biodegradable or environmentally friendly food-grade polypropylene materials to meet increasingly stringent environmental regulations and market demands. Summary of the Invention

[0009] To address the aforementioned problems, this invention provides food tableware made from plant microparticles and food-grade polypropylene, along with a preparation process. By adjusting the formulation, a composite material for use in food tableware is manufactured.

[0010] To achieve the above objectives, the present invention provides the following technical solution, which mainly includes:

[0011] A simulated seashell tableware made of plant granules / fibers and polypropylene material, wherein the tableware is made of a plant fiber composite material, and the weight percentage of the composite material includes:

[0012] Food-grade polypropylene: 30 wt%;

[0013] Plant granules: 60 wt%;

[0014] Compatibilizer: 5wt%;

[0015] Lubricant: 2wt%;

[0016] The remainder consists of antioxidants, light stabilizers, and ultraviolet absorbers.

[0017] Preferably, the plant particles are one or a mixture of natural cellulose particles such as wood fiber, rice husk, bamboo powder, coconut shell, and sugarcane bagasse, and the fineness of the plant particles is 40-100 mesh.

[0018] Preferably, the compatibilizer is maleic anhydride-grafted food-grade polypropylene with a grafting rate of 2%.

[0019] Preferably, the lubricant is stearic acid or stearate.

[0020] A process for preparing simulated seashell tableware made of plant particles / fibers and polypropylene material includes the following steps:

[0021] S1. Raw Material Preparation

[0022] The plant granules are made from rice husk powder: ensure that the particle size of the plant granules is 40-100 mesh, and the granules are thoroughly dried in a drying oven at 80℃-100℃ for 4-6 hours to reduce their moisture content to below 1%-2%.

[0023] Food-grade polypropylene is selected from high-density food-grade polypropylene HDPE or low-density food-grade polypropylene LDPE.

[0024] The compatibilizer selected is maleic anhydride-grafted food-grade polypropylene: used to improve the interfacial compatibility between food-grade polypropylene and plant particles, and enhance the mechanical properties of the composite material.

[0025] Stearate was selected as the lubricant.

[0026] The remainder consists of antioxidants, light stabilizers, and ultraviolet absorbers.

[0027] S2. Ingredients and Premixing

[0028] Weigh out the pre-mixed components as follows: food-grade polypropylene: 30 wt%; plant granules: 60 wt%; compatibilizer: 5 wt%; lubricant: 2 wt%; remaining antioxidant, light stabilizer, and UV absorber: 3 wt%.

[0029] Premixing: The above raw materials are premixed using a high-speed mixer to dry mix them so that the components are initially evenly distributed.

[0030] S3. Melt blending

[0031] Using a twin-screw extruder, the extrusion temperature is set as follows: Temperature settings for each section are:

[0032] Feeding section: 150℃-170℃;

[0033] Melting zone: 180℃-200℃;

[0034] Metering range: 170℃-190℃;

[0035] Die head temperature: 180℃-190℃;

[0036] Extrusion speed: Adjust the speed of the extruder and the feeding speed to control them between 50-150 rpm to ensure that the material is fully mixed during the extrusion process;

[0037] At high temperatures, food-grade polypropylene gradually melts and mixes evenly with plant particles;

[0038] S4. Cooling and Granulation

[0039] Cooling: After the blended molten material is extruded from the extruder die, it is cooled by a water bath or air cooling system. The cooled material hardens into a solid state.

[0040] Pelletizing: The cooled strip material is cut into small particles of 3-5mm by a pelletizer to facilitate subsequent molding and processing;

[0041] S5. Molding Process

[0042] Injection molding: The granules are heated and melted, then injected into the mold under high pressure in the injection molding machine. After cooling and solidification, they are demolded. The mold is for food tableware. The injection temperature is set to 200℃-260℃ and the injection pressure is 60-100MPa.

[0043] S6. Performance Test

[0044] Conduct physical performance tests on the molded products to ensure that they meet the expected quality requirements;

[0045] The tests include: tensile strength: generally required to be ≥20MPa;

[0046] Bending strength: ≥30MPa;

[0047] Impact strength: ≥2kJ / m 2 ;

[0048] Thermal stability: Remains thermally stable below 120℃ and does not undergo thermal degradation;

[0049] Water absorption rate: less than 1%.

[0050] As can be seen from the above technical solution, compared with the existing technology, the beneficial effects are as follows:

[0051] 1. Because it uses a composite material of plant particles and food-grade polypropylene, the use of petrochemical-based materials is reduced, which reduces the dependence on and pollution of traditional plastic products on the environment. At the same time, plant particles are renewable and meet environmental protection requirements.

[0052] 2. Through reasonable formula design and the use of compatibilizers, the interfacial compatibility between plant particles and food-grade polypropylene has been improved, so that the tableware can maintain its lightweight while having excellent mechanical strength, toughness and impact resistance, making it suitable for daily use.

[0053] 3. Antioxidants, light stabilizers, and UV absorbers have been added, which significantly improves the aging resistance of the tableware, enabling it to maintain good physical properties even outdoors or under high temperature conditions, thus extending its service life.

[0054] 4. The composite material is safe and reliable in composition, suitable for food contact applications, meets food safety standards, and will not have any harmful effects on food. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0056] Figure 1 The attached figure is a three-dimensional schematic diagram of the structure of the present invention.

[0057] Figure 2 The attached figure is a front view of the structure of the present invention.

[0058] Figure 3 The attached figure is a front view of the second structure of the present invention.

[0059] Figure 4 The attached figure is a schematic diagram of the back side of structure two of the present invention. Detailed Implementation

[0060] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] Example 1

[0062] The preparation process of a simulated seashell tableware made of plant particles / fibers and polypropylene material is as follows:

[0063] 1. Raw material preparation

[0064] In this embodiment, the following raw materials are selected:

[0065] Plant Particles: Rice husk powder is selected as the source of plant cellulose, ensuring a particle size of 40-100 mesh (325-150μm) to guarantee the uniformity and strength of the material. The rice husk powder is dried in a drying oven at 80℃-100℃ for 4-6 hours to reduce its moisture content to below 1%-2%, preventing the formation of bubbles or material degradation during high-temperature processing.

[0066] Food-grade polypropylene: High-density food-grade polypropylene (HDPE) is used as the matrix material. High-density food-grade polypropylene has good mechanical strength and chemical resistance.

[0067] Compatibilizer: Maleic anhydride-grafted food-grade polypropylene (PE-g-MAH) with a grafting rate of 2% is selected to improve the interfacial compatibility between food-grade polypropylene and rice husk powder and improve the mechanical properties of the composite material.

[0068] Lubricant: Stearates are selected to improve the flowability of the material during extrusion and molding processes.

[0069] Additives: Common antioxidants, light stabilizers, and ultraviolet absorbers are selected to improve the anti-aging properties of the material, accounting for 3% by weight.

[0070] 2. Ingredients and Premixing

[0071] Ingredients should be prepared according to the following weight percentages:

[0072] Food-grade polypropylene: 60wt%

[0073] Plant granules (rice husk powder): 30wt%

[0074] Compatibilizer (PE-g-MAH): 5wt%

[0075] Lubricant (stearate): 2wt%

[0076] Other additives: 3wt%

[0077] The weighed components are dry-mixed in a high-speed mixer for 5-10 minutes to ensure uniform distribution of the components and prepare for subsequent melt blending.

[0078] 3. Melt blending

[0079] The melt blending was performed using a twin-screw extruder, with the following specific parameter settings:

[0080] Feeding section temperature: 150℃-170℃

[0081] Melting zone temperature: 180℃-200℃

[0082] Metering section temperature: 170℃-190℃

[0083] Die head temperature: 180℃-190℃

[0084] Extrusion speed: Controlled between 50-150 rpm

[0085] Under these temperature conditions, food-grade polypropylene gradually melts and mixes thoroughly and evenly with rice husk powder. The compatibilizer improves the interfacial compatibility between plant fiber and food-grade polypropylene, forming a uniform molten composite.

[0086] 4. Cooling and Granulation

[0087] After the melt-blended material is extruded from the extruder die, it is cooled by a water bath or air cooling system, and the cooled material hardens into solid strips. Subsequently, a pelletizer is used to cut the strips into small particles of 3-5mm for subsequent processing.

[0088] 5. Molding and processing

[0089] The above-mentioned granular material is processed into food tableware using injection molding.

[0090] The granules are heated to 180℃-200℃ and injected into the mold under high pressure of 60-100MPa in an injection molding machine. After cooling and solidification, they are demolded. The mold shape is tableware (such as simulated seashell tableware).

[0091] 6. Performance Testing

[0092] Physical performance tests were conducted on the molded food tableware to ensure that the products met the expected quality requirements. The test results are as follows:

[0093] Tensile strength: ≥20MPa

[0094] Bending strength: ≥30MPa

[0095] Impact strength: ≥2kJ / m 2

[0096] Thermal stability: The material remains stable below 120℃ and does not undergo thermal degradation.

[0097] Water absorption rate: less than 1%.

[0098]

[0099] The simulated seashell tableware prepared using the above process has the following advantages:

[0100] Environmentally friendly materials: The simulated seashell tableware is made of biodegradable or recyclable plant fiber composite materials, which reduces environmental pollution and is more environmentally friendly than disposable plastic tableware;

[0101] Aesthetically pleasing: The simulated seashell tableware has an exquisite appearance, and its texture and pattern imitate natural seashells, which can enhance the beauty of the dining table and bring a better visual experience to diners;

[0102] High durability: This type of tableware is usually processed with special technology, which gives it high hardness and drop resistance, long service life and is not easy to break; at the same time, it has a certain degree of corrosion resistance, will not deform in high or low temperature environments, and will not release toxic gases during use.

[0103] Food safety: The simulated seashell tableware is made of non-toxic and harmless materials, meets food contact safety standards, and is safe to use.

[0104] Reusable: Due to the durability of its material, the simulated seashell tableware can be used multiple times, reducing resource waste and lowering the cost of tableware used over a long period of time.

[0105] Lightweight and portable: Compared with some heavy tableware, imitation seashell tableware is usually lighter and easier to carry when going out, making it suitable for occasions such as picnics or travel.

[0106] These advantages make simulated seashell tableware a popular choice for many, especially in occasions where environmental protection and aesthetics are important.

[0107] Therefore, it is not possible to directly use shellfish from the ocean, but there is still a considerable demand for shellfish. Existing shellfish products are all processed from shellfish caught from the ocean. This product provides a simulated shell made of rice husk powder, which can partially replace marine shellfish (including but not limited to oysters, clams, scallops, and mussels).

[0108] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0109] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A simulated shell tableware made of plant particles / fibers and polypropylene material, characterized in that: The simulated shell tableware is made of a plant fiber composite material, and the weight percentage of the composite material includes: Food grade polypropylene: 30wt%; Plant particles: 60wt%; Compatibilizer: 5wt%; Lubricant: 2wt%; The rest are antioxidants, light stabilizers, and UV absorbers.

2. The simulated shell tableware made of plant particles / fibers and polypropylene material according to claim 1, characterized in that: The plant particles are natural cellulose particles such as wood fiber, rice husk, bamboo powder, coconut shell, bagasse or the like, or mixed particles thereof, and the plant particles have a fineness of 40-100 meshes.

3. The simulated shell tableware made of plant particles / fibers and polypropylene material according to claim 1, characterized in that: The compatibilizer is maleic anhydride grafted food-grade polypropylene, and the grafting rate is 2%.

4. The simulated shell tableware made of plant particles / fibers and polypropylene material according to claim 1, characterized in that: The lubricant is stearic acid or stearate.

5. A simulated shell tableware made of plant particles / fibers and polypropylene material as described in any one of claims 1 to 5, characterized in that The steps include: S1. Raw material preparation Rice husk powder is used for plant particles: the particle size of the plant particles is ensured to be 40-100 mesh, and the particles are fully dried in a drying oven at 80℃-100℃ for 4-6 hours to reduce their moisture content to below 1%-2%; Food grade polypropylene uses high-density food grade polypropylene PP material; The compatibilizer is maleic anhydride grafted food-grade polypropylene: it is used to improve the interface compatibility between food-grade polypropylene and plant particles and enhance the mechanical properties of the composite material; The lubricant is stearate; The rest are antioxidants, light stabilizers, and UV absorbers. S2. Ingredients and premixing According to food grade polypropylene: 30wt%; plant particles: 60wt%; compatibilizer: 5wt%; Lubricant: 2wt%; remaining antioxidant, light stabilizer, ultraviolet absorber: 3wt% Weigh the components in a good proportion; Premixing: Premix the above raw materials and use a high-speed mixer for dry mixing to ensure that the components are initially evenly distributed; S3. Melt Blending Use a twin-screw extruder, extrusion temperature: the temperature of each section is set to: Feeding section: 150℃-170℃; Melting stage: 180℃-200℃; Metering section: 170℃-190℃; Die temperature: 180℃-190℃; Extrusion speed: adjust the extruder speed and feeding speed to control between 50-150rpm so that the materials are fully mixed during the extrusion process; Under high temperature, food-grade polypropylene gradually melts and mixes evenly with plant particles; S4. Cooling and granulation Cooling: After the blended molten material is extruded from the extruder die, it is cooled in a water bath or air cooling system, and the cooled material hardens into a solid state; Pelletizing: The cooled strip material is cut into small particles of 3-5 mm by a pelletizer to facilitate subsequent molding processing; S5. Molding Injection molding: The particles are heated and melted, and then injected into the mold under high pressure in the injection molding machine. After cooling and solidification, they are demoulded. The mold is food tableware. The injection temperature is set at 200℃-260℃, and the injection pressure is 60-100MPa. S6. Performance test Conduct physical property tests on molded products to ensure that the products meet the expected quality requirements; Tests include: Tensile strength: generally required to be ≥20MPa; Bending strength: ≥30MPa; Impact strength: ≥2kJ / m 2 ; Thermal stability: thermal stability below 120°C, no thermal degradation occurs; Water absorption: The water absorption is less than 1%.

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