A method for preparing environmentally friendly clothing fasteners made from marine recycled PET

Abstract

This application provides a method for preparing environmentally friendly clothing fasteners made from marine recycled PET, relating to the field of environmentally friendly clothing accessory manufacturing technology. The use of marine recycled PET material in this application reduces the demand for virgin plastics and decreases the consumption of non-renewable resources such as petroleum; it effectively reduces plastic pollution in the ocean and protects the marine ecological environment; compared to virgin PET materials, it saves energy and reduces carbon footprint; marine recycled PET fasteners are derived from the same source as polyester clothing fabrics, enabling "material homogeneous recycling" of clothing; furthermore, the cellulose nanocrystals (CNC) in the reinforcing phase composite are derived from renewable resources and are biodegradable, further enhancing the green sustainability of the environmentally friendly fasteners; the graphene-cellulose nanocrystal CNC composite is compounded and combined in a silane coupling agent ethanol solution to form an interpenetrating network structure, thereby synergistically improving the strength, rigidity, toughness, and heat resistance of marine recycled PET, and increasing tensile strength.

Description

Technical Field

[0001] This invention relates to the field of environmentally friendly clothing accessory manufacturing technology, and more specifically, to a method for preparing environmentally friendly clothing fasteners made from marine recycled PET. Background Technology

[0002] Traditional fasteners are mostly made of urea-formaldehyde resin, polyester resin, and plastics such as ABS, PA, POM, and PMMA. Relying on petroleum-based traditional fasteners presents an environmental disadvantage. Therefore, the application of recycled plastic fasteners in clothing accessories is gradually becoming more widespread, especially marine recycled PET fasteners, which are highly favored.

[0003] PET, or polyethylene terephthalate, is derived from the ocean. Ocean-recycled PET, which benefits marine environmental management, saves 52% of energy and reduces its carbon footprint by 80% compared to virgin PET. More significantly, using ocean-recycled PET to make fasteners, which are homogenized with polyester fabric, enables "material homogenization and recycling" in clothing. However, ocean-recycled PET is exposed to ultraviolet radiation, salt water, and microorganisms in the ocean for extended periods, leading to molecular chain breakage. This reduces the mechanical and heat resistance properties of the recycled material, making it difficult for fasteners made from ocean-recycled PET to meet the performance requirements of clothing fasteners. Therefore, we propose an improvement method for preparing environmentally friendly clothing fasteners from ocean-recycled PET. Summary of the Invention

[0004] This invention provides a method for preparing environmentally friendly clothing fasteners made from marine recycled PET, comprising the following steps:

[0005] S1, modified with marine recycled PET composite;

[0006] S2, segmented temperature-controlled injection molding.

[0007] As a preferred technical solution of this application, the marine recycled PET composite modification includes: mixing marine recycled PET particles, graphene-cellulose nanocrystal CNC composite, plasticizer, antioxidant and lubricant in a mass percentage, and then performing melt blending and granulation through a twin-screw extruder to obtain a marine recycled PET composite modified material.

[0008] As a preferred technical solution of this application, the temperature segments of the twin-screw extruder are set as follows: Zone 1 220℃, Zone 2 235℃, Zone 3 240℃, and the screw speed is controlled at 200 rpm.

[0009] As a preferred technical solution of this application, the marine recycled PET composite modified material comprises: 80-95% marine recycled PET, 3-15% graphene-cellulose nanocrystal CNC composite, 1-8% plasticizer, 0.5-1.5% antioxidant and 0.5-1.5% lubricant.

[0010] As a preferred technical solution of this application, the intrinsic viscosity of marine recycled PET is 0.75-0.85 dL / g; the graphene-cellulose nanocrystal CNC composite is ultrasonically treated in an ethanol solution of silane coupling agent KH560 for 30 minutes.

[0011] As a preferred technical solution of this application, the graphene-cellulose nanocrystal CNC composite is ultrasonically treated in an ethanol solution of silane coupling agent KH560 for 30 minutes, and then dried to evaporate the ethanol liquid, so that the silane coupling agent KH560 is coated on the surface of the graphene-cellulose nanocrystal CNC composite.

[0012] As a preferred technical solution of this application, the weight ratio of the graphene-cellulose nanocrystal CNC composite to the silane coupling agent KH560 ethanol solution is 1:4, the weight ratio of graphene to cellulose nanocrystals is 1:30, and the KH560 content in the silane coupling agent ethanol solution is 5% of the weight of the graphene-cellulose nanocrystal CNC composite.

[0013] As a preferred technical solution of this application, the segmented temperature-controlled injection molding includes: color matching of marine recycled PET composite modified material, placing it in an injection molding machine, and using segmented temperature control to obtain environmentally friendly clothing fasteners.

[0014] As a preferred technical solution of this application, the injection molding machine has the following injection barrel temperatures: Zone I 210℃, Zone II 225℃, Zone III 230℃, injection mold temperature 70-100℃, injection pressure 80-100MPa, and holding time 10-15 seconds.

[0015] As a preferred technical solution of this application, environmentally friendly fasteners are used in clothing and bags, and are derived from the same source as polyester fabrics.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] In the scheme of this application:

[0018] 1. Environmental friendliness: The use of marine recycled PET materials reduces the demand for virgin plastics and the consumption of non-renewable resources such as petroleum; it effectively reduces plastic pollution in the ocean and protects the marine ecological environment; compared with virgin PET materials, it can save energy and reduce carbon footprint; marine recycled PET fasteners are derived from the same source as polyester clothing fabrics, enabling "material homogeneous recycling" of clothing; in addition, the cellulose nanocrystals (CNC) in the reinforcing phase composite are derived from renewable resources and are biodegradable, further enhancing the green sustainability of environmentally friendly fasteners;

[0019] 2. Performance enhancement: The graphene-cellulose nanocrystal CNC composite is compounded and combined in silane coupling agent ethanol solution to form an interpenetrating network structure, which enhances the phase synergy to improve the strength, rigidity, toughness and heat resistance of marine recycled PET, improves the tensile strength and has a high heat distortion temperature (HDT).

[0020] 3. Interface optimization: The combination of graphene and cellulose nanocrystals has a synergistic effect. The two-dimensional structure of graphene can provide anchoring points for CNC and form an interpenetrating network structure. Combined with the surface modification treatment of silane coupling agent, the interfacial bonding between the composite and the marine recycled PET matrix is ​​enhanced, promoting the chemical bonding between marine recycled PET and the composite and avoiding phase separation. Attached Figure Description

[0021] Figure 1 A flowchart illustrating the preparation method of the environmentally friendly clothing fastener made of marine recycled PET provided in this application;

[0022] Figure 2 A scale diagram of the marine recycled PET composite modified material provided in this application. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0024] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0026] Example 1, please refer to Figures 1-2 A method for preparing environmentally friendly clothing fasteners made from recycled marine PET, comprising the following steps:

[0027] S1, Marine recycled PET composite modification; used to improve the mechanical properties and thermal stability of marine recycled PET to meet the high strength and high temperature resistance requirements of clothing fasteners;

[0028] S2, segmented temperature-controlled injection molding.

[0029] Furthermore, the marine recycled PET composite modification includes: mixing marine recycled PET particles, graphene-cellulose nanocrystal CNC composite, plasticizer, antioxidant and lubricant in a certain mass percentage, and then performing melt blending and granulation through a twin-screw extruder to obtain marine recycled PET composite modified material.

[0030] Furthermore, the temperature zones of the twin-screw extruder are set as follows: Zone 1 220℃, Zone 2 235℃, Zone 3 240℃, and the screw speed is controlled at 200 rpm.

[0031] Furthermore, the marine recycled PET composite modified material contains: 80% marine recycled PET, 15% graphene-cellulose nanocrystal CNC composite, 3.5% plasticizer, 1% antioxidant and 0.5% lubricant;

[0032] The injection-molded fastener has a tensile strength of 68 MPa and a heat distortion temperature (HDT) of 110℃.

[0033] Furthermore, the intrinsic viscosity of marine recycled PET is 0.75-0.85 dL / g; the graphene-cellulose nanocrystal CNC composite is ultrasonically treated in an ethanol solution of silane coupling agent KH560 for 30 minutes.

[0034] Marine recycled PET, derived from the ocean, undergoes collection, sorting, washing, crushing, and reprocessing. Considering the performance requirements of environmentally friendly fasteners, marine recycled PET that has undergone adhesive enhancement is preferred. Specifically, marine recycled PET raw materials are derived from marine plastic waste (such as discarded fishing nets, beverage bottles, etc.) and are produced through the following recycling processes:

[0035] Collection and sorting: Screening for marine plastic waste made of PET material;

[0036] Cleaning and impurity removal: Soak and clean in 5% sodium hydroxide solution (60℃) for 2 hours to remove salt stains, microorganisms and oil stains;

[0037] Crushing and granulation: Crushing to a particle size of 2-5mm, then melt extrusion granulation;

[0038] Thickening treatment: Solid-phase thickening technology is used, or 0.5% chain extender (such as ADR-4370S) is added through a twin-screw reactive extruder to increase the intrinsic viscosity to 0.75-0.85 dL / g (tested in GB / T 14190-2017).

[0039] Furthermore, graphene-cellulose nanocrystal CNC composites serve as a reinforcing phase for marine recycled PET;

[0040] Plasticizers can weaken the intermolecular forces in PET and increase the mobility of chain segments, thereby improving the flexibility and processability of marine recycled PET materials. Based on thermodynamic compatibility and intermolecular interactions, and considering the environmental friendliness and safety of plasticizers, acetylthiol tributyl citrate (ATBC) is the preferred choice. Specifically, the solubility parameter (SP value) of PET is 10.7 (cal / cm³)^0.5, while the solubility parameter (SP value) of ATBC is 9.5-10.5 (cal / cm³)^0.5. The close SP values ​​of the two ensure good compatibility and reduce the risk of plasticizer migration and precipitation. Furthermore, ATBC molecules contain polar ester groups (-COO-) and acetyl groups (-OAc), which can form dipole interactions or weak hydrogen bonds with the ester bonds (-COO-) of PET, reducing the cohesive energy between PET chain segments and increasing the degree of freedom of chain segment movement. In addition, ATBC is a non-toxic, biodegradable citrate plasticizer that meets the requirements of food contact materials and environmental regulations.

[0041] Antioxidants can inhibit the thermo-oxidative degradation process of marine recycled PET materials, delay their aging, improve their service life, and maintain stable performance. Based on synergistic effects and dual protection considerations, antioxidants 1010 and 168 are preferred in a 1:1 ratio. Specifically, antioxidant 1010 is a hindered phenolic antioxidant. During long-term use, it terminates free radical chain reactions through the hydroxyl groups in its hindered phenolic structure, thus delaying molecular chain breakage and mechanical property degradation caused by oxidation in marine recycled PET. Antioxidant 168 is a phosphite antioxidant. During the high-temperature processing of PET, it decomposes hydroperoxides through trivalent phosphorus (P³⁺), preventing further decomposition and the generation of new free radicals, and maintaining processing thermal stability. The combination of antioxidants 1010 and 168 complements each other, forming a dual defense mechanism that covers the oxidation risks of marine recycled PET throughout its entire life cycle from processing to use.

[0042] Lubricants reduce friction, improve fluidity, and enhance mold release properties during the processing of marine recycled PET materials. Considering the lubricant's high-temperature stability, low addition efficiency, and multifunctionality, PETS (pentaerythritol stearate) is the preferred lubricant. Specifically, the stearate groups in the PETS molecule form a polar-nonpolar interface in the marine recycled PET melt. The polar ends bind to the PET molecular chains, while the nonpolar ends align outwards, reducing intermolecular friction and achieving synergistic internal and external lubrication. A relatively small addition amount can achieve the desired lubrication effect. Furthermore, PETS has a high thermal decomposition temperature of up to 400°C, exhibiting almost no volatilization or degradation within the processing temperature range of marine recycled PET, thus maintaining a stable lubrication effect. In addition, PETS can promote the uniform dispersion of graphene-cellulose nanocrystal CNC composites and has good compatibility with antioxidants.

[0043] Furthermore, the graphene-cellulose nanocrystal CNC composite was ultrasonically treated in an ethanol solution of silane coupling agent KH560 for 30 minutes, and then dried to evaporate the ethanol liquid. The silane coupling agent KH560 was then coated on the surface of the graphene-cellulose nanocrystal CNC composite. Because graphene and cellulose nanocrystals are prone to agglomeration, they are difficult to disperse and mix uniformly in the ethanol solution of silane coupling agent KH560, affecting the uniformity of the graphene and cellulose nanocrystal composite and the surface treatment effect of the silane coupling agent. Therefore, ultrasonic treatment was used. The high-frequency vibration generated by ultrasound can generate strong eddies and shear forces in the ethanol solution of silane coupling agent KH560, which can destroy the agglomeration force and achieve uniform dispersion and mixing of graphene and cellulose nanocrystals. After drying, the ethanol liquid evaporates, and the silane coupling agent is coated on the surface of the composite.

[0044] Furthermore, the weight ratio of the graphene-cellulose nanocrystal CNC composite to the silane coupling agent KH560 ethanol solution is 1:4, the weight ratio of graphene to cellulose nanocrystals is 1:30, and the KH560 content in the silane coupling agent ethanol solution is 5% of the weight of the graphene-cellulose nanocrystal CNC composite. The combination of graphene and cellulose nanocrystals produces a synergistic effect. The two-dimensional structure of graphene can provide anchoring points for the rod-shaped structure of cellulose nanocrystal CNC, forming an interpenetrating network structure. Combined with the surface modification treatment of the silane coupling agent, the interfacial bonding with marine recycled PET materials is enhanced.

[0045] Cellulose nanocrystals (CNC) possess high specific strength and a dense structure, with a modulus as high as 150 GPa, which can significantly improve the mechanical properties of marine recycled PET. Graphene, a two-dimensional network of carbon nanomaterials, has an ultra-large specific surface area, ultra-high strength, and excellent thermal and electrical conductivity, with a tensile strength as high as 130 GPa. Graphene can also improve the crystallization behavior of PET, increase the crystallization rate, and enhance the thermal stability and mechanical strength of marine recycled PET. Therefore, the synergistic combination of graphene and cellulose nanocrystals can simultaneously improve the strength, rigidity, toughness, and heat resistance of marine recycled PET.

[0046] In addition, the cellulose nanocrystals (CNC) in the composite are derived from renewable resources such as wood and cotton. Compared with traditional reinforcing materials such as carbon fiber, glass fiber or mineral fillers, CNC is lighter and more environmentally friendly, which also enhances the green sustainability of environmentally friendly fasteners.

[0047] Furthermore, segmented temperature-controlled injection molding includes: color matching of marine recycled PET composite modified material, placing it in an injection molding machine, and using segmented temperature control to obtain environmentally friendly clothing fasteners.

[0048] Furthermore, the injection barrel temperature of the injection molding machine is: Zone I 210℃, Zone II 225℃, Zone III 230℃, injection mold temperature 70-100℃, injection pressure 80-100MPa, and holding time 10-15 seconds.

[0049] Furthermore, environmentally friendly fasteners are used in clothing and bags, and are derived from the same source as polyester fabrics.

[0050] Example 2 differs from Example 1 in that the marine recycled PET composite modified material contains: 85% marine recycled PET, 10% graphene-cellulose nanocrystal CNC composite, 3.5% plasticizer, 1% antioxidant and 0.5% lubricant; the injection molded fastener has a tensile strength of 65MPa and a heat distortion temperature (HDT) of 105℃, and the rest are the same, so they will not be described again.

[0051] Example 3 differs from Example 1 in that the modified marine recycled PET composite material contains: 90% marine recycled PET, 5% graphene-cellulose nanocrystal CNC composite, 3.5% plasticizer, 1% antioxidant, and 0.5% lubricant; the injection molded fastener has a tensile strength of 62 MPa and a heat distortion temperature (HDT) of 100°C, and the rest are the same and will not be described in detail.

[0052] Example 4, this example is a comparative example, does not use graphene-cellulose nanocrystal CNC composite, contains: 95% marine recycled PET, 3.5% plasticizer, 1% antioxidant and 0.5% lubricant; the injection molded fastener has a tensile strength of 46MPa and a heat distortion temperature (HDT) of 80℃.

[0053] Example 5, Test Method:

[0054] Tensile strength: ASTM D638; ASTM D638 is an international standard developed by the American Society for Testing and Materials (ASTM). It is mainly used to determine the tensile properties of plastics (including reinforced and unreinforced plastics), providing a scientific basis for the design, production, and quality control of plastic products. This standard specifies the mechanical properties of plastic materials under stress through tensile testing, including key indicators such as tensile strength (yield and fracture), tensile modulus (elastic modulus), elongation, and Poisson's ratio, used to evaluate the durability, damage resistance, and processability of materials.

[0055] HDT: ASTM D648 (0.45MPa load); ASTM D648 is a standard test method developed by the American Society for Testing and Materials (ASTM). It is mainly used to determine the heat deflection temperature (HDT) of plastics and elastic materials, which is the temperature at which the material deforms by 0.25mm under a specific bending load. It is an important indicator for evaluating the heat resistance of plastics.

[0056] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0057] Obviously, the embodiments described above are merely some embodiments of the present invention, not all embodiments. The accompanying drawings show preferred embodiments of the present invention, but do not limit the patent scope of the present invention. The present invention can be implemented in many different forms; rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this invention.

Claims

1. A method of making an eco-friendly garment fastener from ocean regenerated PET, characterized by, The method comprises the following steps: S1, ocean regenerated PET composite modification; S2, sectional temperature control injection molding; The ocean regenerated PET composite modification comprises: mixing ocean regenerated PET particles, graphene-cellulose nanocrystal CNC complex, plasticizer, antioxidant and lubricant according to the mass percentage, and then performing melt blending and granulation through a double-screw extruder to obtain an ocean regenerated PET composite modified material. The temperature of the double-screw extruder is set in sections as follows: 220 DEG C in a first zone, 235 DEG C in a second zone, and 240 DEG C in a third zone, and the screw rotation speed is controlled at 200 rpm; the ocean regenerated PET composite modified material comprises 80-95% of ocean regenerated PET, 3-15% of graphene-cellulose nanocrystal CNC complex, 1-8% of plasticizer, 0.5-1.5% of antioxidant, and 0.5-1.5% of lubricant. The intrinsic viscosity of the ocean regenerated PET is 0.75-0.85 dL / g; the graphene-cellulose nanocrystal CNC complex is ultrasonically treated in an ethanol solution of silane coupling agent KH560 for 30 minutes.

2. The method for preparing environmentally friendly clothing fasteners made from marine recycled PET according to claim 1, characterized in that, Drying causes the ethanol solution to volatilize, and the silane coupling agent KH560 is coated on the surface of the graphene-cellulose nanocrystal CNC complex.

3. The method for preparing environmentally friendly clothing fasteners made from marine recycled PET according to claim 2, characterized in that, The weight ratio of the graphene-cellulose nanocrystal CNC complex to the ethanol solution of silane coupling agent KH560 is 1:4, the weight ratio of graphene to cellulose nanocrystal is 1:30, and the content of KH560 in the ethanol solution of silane coupling agent is 5% of the weight of the graphene-cellulose nanocrystal CNC complex.

4. The process for the production of an environmentally friendly marine regenerative PET garment fastener according to any one of claims 1-3, characterized in that, The sectional temperature control injection molding comprises: color matching the ocean regenerated PET composite modified material, placing it in an injection molding machine, and adopting sectional temperature control to obtain an environmentally friendly clothing fastener.

5. The method for preparing environmentally friendly clothing fasteners made from marine recycled PET according to claim 4, characterized in that, The temperature of the injection molding cylinder of the injection molding machine is: 210 DEG C in a first zone, 225 DEG C in a second zone, and 230 DEG C in a third zone, the injection mold temperature is 70-100 DEG C, the injection pressure is 80-100 MPa, and the pressure holding time is 10-15 seconds.

6. The method for preparing environmentally friendly clothing fasteners made from marine recycled PET according to claim 4, characterized in that, The environmentally friendly fastener is applied to clothing and luggage and is homologous to polyester fabric.

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