Novel full-bio-based degradable plastic polymer material and preparation method thereof

Abstract

The invention discloses a novel full-bio-based degradable plastic polymer material and a preparation method thereof, and belongs to the technical field of degradable plastic products. According to the material, through the synergistic effect of the high-proportion bamboo powder and the degradable plastic, the target material is expected to have excellent mechanical properties such as light weight and high impact strength, meanwhile, complete biodegradation is achieved, and a new technical path is provided for solving the problem of dependence of plastic pollution and fossil resources. The mechanical property of the full-bio-based degradable novel plastic polymer is remarkably optimized, and light weight and high toughness are both considered. Wherein 65-75% of high-proportion bamboo powder is used for filling, so that the impact strength and fracture resistance of the material are effectively improved through interface combination with a degradable plastic body while the density of the material is reduced, the problems of high brittleness and weak impact resistance of biodegradable materials such as degradable plastics are solved, and the requirements of the fields of packaging, daily necessities and the like on light weight and impact resistance are met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of degradable plastic products, and particularly relates to a full-bio-based degradable new plastic polymer material and a preparation method thereof. BACKGROUND

[0002] With the acceleration of global industrialization and urbanization, plastic materials have deeply penetrated into many fields such as packaging, building materials and daily necessities due to their light weight, durability and easy processing, and have become an indispensable basic material in modern society. However, the widespread use of plastics has also brought serious environmental problems - according to incomplete statistics, the annual amount of waste plastics is as high as 60 million to 63 million tons, and the current market recycling rate is only about 31%, a large amount of unrecycled plastic waste enters the natural environment, forming "white pollution", which threatens the safety of soil, water and biological ecology. Under this background, developing new materials that can replace traditional petroleum-based plastics and have environmental friendliness and practicality has become a key direction to solve the problem of plastic pollution.

[0003] Bio-based materials, as a kind of material prepared from renewable biomass (such as plant fibers, starch, and microbial synthesis products), can reduce dependence on fossil resources and reduce carbon emissions throughout the life cycle, and are considered an important solution to plastic pollution. At present, the mainstream bio-based material technology on the market mainly falls into the following three categories:

[0004] The first type is the modification of traditional thermoplastic plastics with natural fibers. This technology blends natural fibers (such as bamboo fibers, wood fibers, and hemp fibers) with polyethylene (PE) and polypropylene (PP) and other traditional thermoplastic plastics, uses the reinforcing effect of the fibers to improve the mechanical properties (such as tensile strength and modulus) of the materials, reduces the use of fossil resources, and reduces carbon emissions throughout the life cycle of the materials. However, this type of material is still essentially based on traditional plastics, and the products are difficult to completely degrade after being discarded, and can only be recycled for limited cycles. If the recycling system is not perfect, it will still cause long-term environmental burden.

[0005] The second type is biodegradable materials, represented by polylactic acid (PLA) and polyhydroxyalkanoate (PHA). This type of material can be completely decomposed by microorganisms into carbon dioxide and water under specific conditions (such as industrial composting), theoretically realizing "closed loop" degradation and avoiding the consumption of fossil resources. However, typical biodegradable materials such as PLA have significant defects: their molecular chains are relatively rigid, resulting in high brittleness and poor impact resistance; the glass transition temperature (Tg) is relatively low (about 55°C), and the heat resistance is insufficient, making it difficult to meet the use requirements in high-temperature environments; in addition, the production of PLA relies on high-purity lactic acid monomers, and the preparation of raw materials and polymerization process are complex, resulting in a production cost much higher than that of traditional plastics, which limits its large-scale application.

[0006] The third type: inorganic filler modified biodegradable material. In order to improve the mechanical properties of biodegradable materials, some studies attempt to add short glass fiber, talc, calcium carbonate and other inorganic fillers for reinforcement. For example, the blending of glass fiber and PLA can improve the rigidity and dimensional stability of the material, and talc can reduce the shrinkage rate of the material. However, this kind of modification still does not solve the degradation limitation of biodegradable materials in essence. Inorganic fillers are not biodegradable and will hinder the decomposition of microorganisms to the matrix, resulting in a decrease in the final degradation efficiency of the material. At the same time, the addition of inorganic fillers may increase the density and cost of the material, and the addition of some fillers (such as glass fiber) will further exacerbate the brittleness problem of the material.

[0007] In addition to the above technologies, bamboo fiber as a high-quality natural biomass resource has not been fully tapped for its application potential in biobased degradable materials for a long time. Bamboo, as a fast-growing renewable resource, has a short growth cycle (3-5 years to reach maturity), high yield, and contains 26%-43% cellulose, 21%-32% lignin and 15%-23% hemicellulose in its stem. The fiber length and aspect ratio are excellent, and the mechanical properties can be comparable to glass fiber (tensile strength up to 200-400 MPa). Currently, bamboo fiber is mainly used in building materials, textiles, composites and other fields, but research on its blending with biodegradable plastics to prepare high-performance degradable materials is still in its infancy and has not yet formed a systematic solution.

[0008] In summary, although existing biobased material technologies have shown advantages in reducing dependence on fossil resources and reducing carbon emissions, they still have the bottleneck problems of "incomplete degradation", "performance defects" or "high cost". Especially in the field of fully biobased degradable plastics with high proportion of natural fibers (such as bamboo powder), there is still no mature solution that takes into account mechanical properties, degradation efficiency and economy, and it is urgent to break through the existing limitations through technological innovation. SUMMARY

[0009] The purpose of the present application is to provide a fully biobased degradable new plastic polymer material. Through the synergistic effect of high proportion of bamboo powder and degradable plastics in the material, the target material is expected to have excellent mechanical properties such as light weight and high impact strength, while achieving complete biodegradation, providing a new technical path to solve plastic pollution and dependence on fossil resources.

[0010] The present application is realized by the following technical solutions:

[0011] A fully biobased degradable new plastic polymer material is composed of 65-75% bamboo powder by mass fraction and 25-35% degradable plastics by mass fraction.

[0012] The degradable plastics are a mixture of polylactic acid and butylene glycol adipate-tetraphthalate in a certain proportion.

[0013] As preferably, the weight average molecular weight of the poly-lactic acid is 150000-300000;

[0014] The poly-lactic acid is at least one selected from poly-D-lactic acid, poly-L-lactic acid and poly-D,L-lactic acid.

[0015] As preferably, the weight average molecular weight of the polybutylene adipate-co-terephthalate is 40000-150000, the specific gravity is <1.3, and the melting point is over 140℃.

[0016] The degradable plastic is made of poly-lactic acid and polybutylene adipate-co-terephthalate; the weight average molecular weight of the poly-lactic acid is 150000-300000, the poly-lactic acid is at least one selected from poly-D-lactic acid, poly-L-lactic acid and poly-D,L-lactic acid; the weight average molecular weight of the polybutylene adipate-co-terephthalate is 40000-150000. Both are polymerized according to the ratio of 1:1, characterized by specific gravity index (less than 1.3) and melting point over 140℃.

[0017] The main raw material of the above-mentioned poly-lactic acid is starch biomass (such as corn, cassava, sugarcane, etc.) or cellulose raw material (such as straw, wood chips). It is a biodegradable polymer material made of renewable biomass through microbial fermentation and chemical polymerization. Its production process mainly includes key steps such as raw material acquisition, lactic acid fermentation, lactide preparation, ring-opening polymerization and post-processing.

[0018] The above-mentioned polybutylene adipate-co-terephthalate can be decomposed by microorganisms in the natural environment, reducing white pollution. By direct esterification or transesterification, adipic acid, terephthalic acid and 1,4-butylene glycol are polymerized to generate copolyesters with both aliphatic and aromatic characteristics. This structure makes PBAT not only biodegradable, but also has good mechanical properties.

[0019] As preferably, the particle size of the bamboo powder is 100-200 mesh, and the specific gravity index is less than 0.35g.

[0020] A preparation method of a full-biobased degradable new plastic polymer material, comprising the following steps:

[0021] S1, preparation of bamboo powder:

[0022] Select bamboo, remove leaves and stems, and then perform primary drying, crushing, and secondary drying to obtain bamboo powder;

[0023] S2, select bamboo powder and dried degradable plastic, mix and place in an extrusion device, heat treat to prepare granules, and then dry to obtain a full-biobased degradable new plastic polymer material.

[0024] As preferred, the temperature of the preliminary drying is 35-45 DEG C, the time length is 3-7 days, and the size is 100-200 mesh;

[0025] The temperature of the secondary drying is 70-80 DEG C, and the time length is 1-3 hours.

[0026] As preferred, the degraded plastic is dried at 75-85 DEG C for 1-3 hours.

[0027] As preferred, the heating is to 160-230 DEG C to prepare granules; and the granules are dried at 75-85 DEG C.

[0028] The application of a full-biobased degradable new plastic polymer material in preparing a molded product, wherein the molded product is a product molded by injection of a high-molecular resin.

[0029] The product includes any one of a spoon and a helmet.

[0030] Compared with the prior art, the application has at least the following technical effects:

[0031] The application provides a full-biobased degradable new plastic polymer material, wherein through synergistic action of a high proportion of bamboo powder and degraded plastic, the target material is expected to have excellent mechanical properties such as light weight and high impact strength, and simultaneously realizes complete biodegradation, thereby providing a new technical path for solving plastic pollution and dependence on fossil resources.

[0032] The full-biobased degradable new plastic polymer realizes a significant breakthrough in degradation performance, mechanical property, resource sustainability and cost control through an innovative formula of synergistic blending of 65%-75% bamboo powder and 25%-30% degradable plastic, and has the following specific technical effects:

[0033] First, complete biodegradation in the whole life cycle solves the problem of white pollution completely. Different from traditional natural fiber modified plastic (mainly PE / PP, only partially degradable) and inorganic filler modified biodegradable material (inorganic filler hinders microbial decomposition), the matrix of the full-biobased degradable new plastic polymer is degradable plastic, and the filling phase bamboo powder is natural biomass (containing degradable components such as cellulose and lignin). Both of them are degradable components, and after being discarded, microorganisms can gradually decompose the matrix and bamboo fibers in compost or natural environment, and finally convert into carbon dioxide and water, realizing "complete degradation" and completely eliminating the environmental residue risk of traditional plastic or semi-degradable material.

[0034] Second, the mechanical property is significantly optimized, and light weight and high toughness are considered. Bamboo fiber itself has excellent mechanical properties-tensile strength of 200-400 MPa (close to glass fiber), and density of only 1.4-1.8 g / cm 3(lower than 0.9 g / cm of most conventional plastics such as PP 3 , 0.92 g / cm of PE 3 ). The high proportion of 65% to 75% of bamboo powder filling in the whole-biomass-based degradable new plastic polymer effectively improves the impact strength and fracture resistance of the material by interfacial combination with the degradable plastic body, solves the pain points of high brittleness and weak impact resistance of degradable plastics and other biodegradable materials, and meets the demand for "light weight + impact resistance" in the fields of packaging, daily necessities and the like.

[0035] Thirdly, the resources are renewable and the cost is controllable, promoting large-scale application. Bamboo, as a fast-growing biomass (3-5 years of growth), has an annual growth rate far exceeding that of wood, and does not require fertilizers and pesticides during planting, so the resource supply is stable and sustainable. Compared with traditional plastics (greatly affected by international oil price fluctuations) and high-cost PLA (complex production process and high raw material purification cost), bamboo powder has a wide source and low cost (about 1 / 3 to 1 / 2 of the cost of PLA raw materials), which can significantly reduce the production cost of the whole-biomass-based degradable new plastic polymer, providing economic feasibility for its promotion in large-scale civilian scenarios such as disposable tableware and express packaging.

[0036] In addition, due to the light specific gravity, more molded products can be produced with the same weight of resin polymer, thereby providing the effect of reducing production cost. The main substrate source is a whole-biomass-based material that can be degraded by landfill when discarded.

[0037] In summary, the whole-biomass-based degradable new plastic polymer, through the synergistic design of "high proportion of degradable biomass filling + degradable plastic body", balances between degradation thoroughness, mechanical properties and economy, provides key technical support for the transition of biobased materials from "laboratory research and development" to "large-scale application", and helps to achieve the coordinated realization of plastic pollution control and carbon neutralization targets. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The schematic diagram of the whole-biomass-based degradable new plastic polymer finished product particles prepared in Example 1 is shown. DETAILED DESCRIPTION

[0039] The embodiments of the present application will be described in detail below with reference to the examples, but those skilled in the art will understand that the following examples are only for illustration of the present application and should not be regarded as limiting the scope of the present application. The specific conditions not mentioned in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer, and the reagents or instruments not mentioned by the manufacturer are all conventional products that can be purchased on the market.

[0040] The technical solution of one specific embodiment of the present application is:

[0041] Generally, the cellulose content of bamboo is 26% to 43%, the lignin content is 21% to 32%, and the hemicellulose content is 15% to 23%. The bamboo fiber is used to change the particle size, content, or length, which can improve the performance of the bio-composite material using the high molecular resin.

[0042] The present technical solution contains 65% to 75% of the full-bio-based degradable new plastic polymer of bamboo. The degradable plastic is used as a polymer resin. The degradable plastic is selected from polylactic acid and butylene glycol adipate-tetraphthalate with a 1:1 polymer.

[0043] When the content of the degradable plastic is less than 25%, there is a problem of insufficient adhesion and mechanical performance of the resin polymer. When the content of the degradable plastic exceeds 35%, the content of 65% to 75% of the bamboo powder is relatively reduced. Since the desired value cannot be achieved, the above range is desirable. The degradable plastic needs to be dried. The drying can be performed at a temperature of 75 to 85°C for 1 to 3 hours.

[0044] The bamboo is in the form of powder, and the particle size can be 100 to 200 mesh, and the specific gravity is less than 0.35 / g. When the particle size of the above-mentioned bamboo powder is less than 100 mesh, the reinforcing effect of the bamboo powder cannot reach the expected value. When the particle size of the bamboo powder exceeds 200 mesh, since the particle size is relatively small, the powder will be lost when it is compounded with the degradable plastic, and the physical properties will be reduced, so the above range is preferred. The bamboo powder includes the steps of preparing the bamboo and removing the leaves and stems; the leaves and stems removed bamboo is preliminarily dried at a temperature of 35 to 45°C for 3 to 7 days and crushed; the crushed bamboo is secondarily dried at a temperature of 70 to 80°C for 1 to 3 hours; and can include the step of sterilizing the secondarily dried bamboo using an ultraviolet sterilizer. The step of preparing the bamboo and removing the leaves and stems is to use the bamboo stem. This is because the trunk of the bamboo is easy to handle, and the trunk contains a large amount of silicic acid, triene, and tannin components with sterilization components. The leaves and stems removed bamboo is preliminarily dried and crushed at a temperature of 35 to 45°C for 3 to 7 days to facilitate the crushing of the bamboo.

[0045] When the above-mentioned primary drying is performed at a temperature lower than 35°C, there is a problem of poor drying effect and long drying time, and when the temperature exceeds 45°C, there is a problem of rapid drying and only the surface is dried, so the above-mentioned range is appropriate.

[0046] The crushing can be performed using a crusher, and the number of times is not limited, and can be until the particle size of the bamboo powder is crushed to 100 to 200 mesh. The crushed bamboo is secondarily dried at a temperature of 70 to 80°C for 1 to 3 hours to reduce the defective rate of the final molded product. If the moisture content of the crushed bamboo is 15% or more, there is a problem that the defective rate increases when the molded product is manufactured due to the high moisture content. The secondary drying is performed at a low temperature for a short time in order to prevent oxidation of the bamboo.

[0047] The step of sterilizing the twice-dried bamboo powder material using a UV sterilizer is to remove microorganisms or mold from the bamboo material. At this time, the wavelength of the UV sterilizer can be at a wavelength that effectively removes microorganisms or mold.

[0048] The all-biomass-based degradable new plastic polymer containing 65% to 75% of bamboo has light weight, superior machine performance and physical properties, and low carbon emissions.

[0049] The preparation method of the all-biomass-based degradable new plastic polymer includes: placing 65% to 75% of bamboo with a content of 25% to 35% of degradable plastic into an extruder, heating to 160 to 230°C to form particles, and drying the formed particles in a dryer at 75 to 85°C.

[0050] When the temperature of the extruder is less than 160 to 230°C, there is a problem of insufficient melting of the degradable plastic, and when the temperature exceeds 230°C, the processability of the particle formation is reduced, and there is a problem of oxidation and carbonization of the polymer in the extruder, so the above range is preferred.

[0051] The following is a comparison between the molded product made using the present invention and the conventional degradable plastic.

[0052] The above molded product is applied to high molecular resin injection molding such as disposable spoons, disposable helmets, disposable plates, etc.

[0053] Example 1:

[0054] An all-biomass-based degradable new plastic polymer material is composed of 75% of bamboo powder by mass fraction and 25% of degradable plastic by mass fraction.

[0055] The degradable plastic is a mixture of polylactic acid and polybutylene adipate terephthalate in a certain ratio.

[0056] The weight average molecular weight of the polylactic acid is 150,000 to 300,000.

[0057] The polylactic acid is poly-D-lactic acid.

[0058] The weight average molecular weight of the polybutylene adipate terephthalate is 40,000 to 150,000, the specific gravity is <1.3, and the melting point is >140°C.

[0059] The particle size of the bamboo powder is 200 mesh, and the specific gravity index is less than 0.35g.

[0060] A preparation method of an all-biomass-based degradable new plastic polymer material includes the following steps:

[0061] S1, preparation of bamboo powder:

[0062] Select bamboo, remove leaves and stems, and then perform primary drying, crushing, and secondary drying to obtain bamboo powder;

[0063] S2, select bamboo powder and dried degraded plastic, mix and place in an extrusion device, heat treat to prepare granules, and then dry to obtain a full-bio-based degradable new plastic polymer material. The specific product is granular, as shown in Figure 1 .

[0064] The primary drying temperature is 45°C, and the time is 7 days, and the crushing is to 200 mesh;

[0065] The secondary drying temperature is 80°C, and the time is 3h.

[0066] The degraded plastic is dried at 85°C for 3h.

[0067] The heating is to 230°C to prepare granules; and drying at 85°C.

[0068] The application of a full-bio-based degradable new plastic polymer material in the preparation of a molded product, wherein the molded product is a product molded by injection molding of a high molecular weight resin;

[0069] The product is a spoon.

[0070] Example 2:

[0071] A full-bio-based degradable new plastic polymer material is composed of 65% by mass of bamboo powder and 35% by mass of degraded plastic;

[0072] The degraded plastic is a mixture of polylactic acid and polybutylene adipate terephthalate in a certain ratio.

[0073] The weight average molecular weight of the polylactic acid is 150000-300000;

[0074] The polylactic acid is poly-L-lactic acid.

[0075] The weight average molecular weight of the polybutylene adipate terephthalate is 40000-150000, the specific gravity is <1.3, and the melting point is >140°C.

[0076] The particle size of the bamboo powder is 100 mesh, and the specific gravity index is less than 0.35g.

[0077] A preparation method of a full-bio-based degradable new plastic polymer material, comprising the following steps:

[0078] S1, preparation of bamboo powder:

[0079] Select bamboo, remove leaves and stems, and then perform preliminary drying, crushing, and secondary drying to obtain bamboo powder;

[0080] S2, select bamboo powder and dried degraded plastic, mix and put into an extrusion device, heat treat to prepare granules, and then dry to obtain a full-bio-based degradable new plastic polymer material.

[0081] The preliminary drying temperature is 35°C, and the time is 3 days, and the crushing is to 100 mesh;

[0082] The secondary drying temperature is 70°C, and the time is 1h.

[0083] The degraded plastic is dried at 75°C for 1h.

[0084] The heating is to 160°C to prepare granules; and drying at 75°C.

[0085] The application of a full-bio-based degradable new plastic polymer material in preparing a shaped product, wherein the shaped product is a product molded by high molecular resin injection molding;

[0086] The product includes any one of a spoon and a helmet.

[0087] Experimental example:

[0088] The ingredients shown in Examples 1 and 2 are put into a mixer at a specified content and mixed well, and then the mixture is extruded using a twin-screw extruder. Melt mixing is performed in a temperature range of 160-230°C, and then extrusion processing is performed (a granulator is used to manufacture granules with a size of about Φ5MM. In order to test the performance of the shaped product made from the granules, a disposable spoon and a helmet are respectively manufactured.

[0089] Classification Example 1 Example 2 Polylactic acid (g) 25 35 Bamboo powder (g) 75 65

[0090] Conventional comparative example 1

[0091] According to ASTM D1238, a disposable spoon is manufactured using degraded plastic with an MI of 20, measured at a temperature of 180°C and a load of 2.16kg for 10 minutes.

[0092] Conventional comparative example 2

[0093] According to ASTM D1238, a disposable helmet is manufactured using degraded plastic with an MI of 10, measured at a temperature of 180°C and a load of 2.16kg for 10 minutes.

[0094] Conclusion:

[0095] 1. Comparison of input and output

[0096] The output ratio of the output of the spoon and the helmet manufactured using the above-described Example 1 to the input of the disposable molded product manufactured using the polypropylene polymer of Comparative Examples 1 and 2 was measured, as shown in Table 2 below.

[0097] Classification Amount of input (kg) Number of molds manufactured Example 1 (spoon) 500 162,000 Example 1 (helmet) 500 2，200 Comparative Example 1 (spoon) 500 80,000 Comparative Example 2 (helmet) 500 1,000

[0098] As can be seen from Table 2 above, when the disposable spoon and the helmet are manufactured by the same weight of the resin polymer, when the new polymer of Example 1 is used, a greater amount of the disposable spoon and the helmet can be manufactured.

[0099] 2. Mechanical physicality

[0100] The physical properties of the disposable spoon manufactured according to the patent example 1 and the conventional example 2 were tested, as shown in Table 3 below.

[0101] The mechanical physicality of the cantilever beam notch impact strength, the tensile strength, and the elongation at break of the present technical solution are significantly improved. The use performance of the product is effectively improved.

[0102]

[0103] As can be seen from the experimental results of Table 3 above, in the case of the patent example 1 of the present application containing 65% to 75% of bamboo, compared with the conventional plastic, the specific example 1 of the full-biobased degradable new plastic polymer containing 65% to 75% of bamboo according to the patent of the present application and the molded product obtained therefrom has achieved the mechanical performance close to the use of the conventional plastic. Various modifications can be made to the example without departing from the scope of the present application.

[0104] Finally, it should be noted that: the above only describes the preferred embodiments of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A new type of biodegradable plastic polymer material, characterized in that: It is composed of 65-75% by mass of bamboo powder and 25-35% by mass of degradable plastic. The degradable plastic is prepared by mixing polylactic acid and butylene adipate-butylene terephthalate in equal proportions.

2. The novel biodegradable plastic polymer material according to claim 1, characterized in that: The weight average molecular weight of the polylactic acid is 150,000 to 300,000; The polylactic acid is at least one selected from poly D-lactic acid, poly L-lactic acid and poly D,L-lactic acid.

3. The novel biodegradable plastic polymer material according to claim 1, characterized in that: The butylene adipate-butylene terephthalate has a weight average molecular weight of 40,000 to 150,000, a specific gravity of less than 1.3, and a melting point of more than 140°C.

4. The novel biodegradable plastic polymer material according to claim 1, characterized in that: The particle size of the bamboo powder is 100-200 meshes, and the specific gravity index is less than 0.35g.

5. A method for preparing a fully biodegradable new plastic polymer material according to any one of claims 1 to 4, characterized in that: The method includes the following steps: S1. Preparation of bamboo powder: Select bamboo, remove leaves and stems, perform primary drying, crushing, and secondary drying to obtain bamboo powder; S2. Select bamboo powder and dried degradable plastic, mix them and place them into an extruder, heat treat them to prepare them into granules, and then dry them to obtain a fully bio-based degradable new plastic polymer material.

6. The method for preparing a new biodegradable plastic polymer material according to claim 5, characterized in that: The preliminary drying temperature is 35-45°C for 3-7 days, and the particles are crushed to 100-200 mesh; The secondary drying temperature is 70-80° C. and the drying time is 1-3 hours.

7. The method for preparing a new biodegradable plastic polymer material according to claim 5, characterized in that: The degradable plastic is obtained by drying at 75-85° C. for 1-3 hours.

8. The method for preparing a new biodegradable plastic polymer material according to claim 5, characterized in that: The step of heating the mixture to 160-230° C. to prepare granules is followed by drying at 75-85° C.

9. A use of the fully biodegradable novel plastic polymer material according to any one of claims 1 to 4 in the preparation of molded products, characterized in that: The molded product is a product formed by injection molding of a polymer resin; The product includes any one of a spoon and a helmet.

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