Composite reinforced polypropylene material and preparation method thereof

Abstract

The invention discloses a composite reinforced polypropylene material and a preparation method thereof, and belongs to the technical field of helmets, and the composite reinforced polypropylene material comprises the following raw materials in parts by weight: modified polypropylene, bamboo charcoal incense, benzyl acetate, silicon dioxide loaded limonene and silver ions. According to the composite reinforced polypropylene helmet lining, through material modification, functional component compounding and precise process control, the core advantages of being antibacterial, deodorant, soft, breathable and long-acting in fragrance are achieved, and safety, comfort and durability are all considered.

Description

Technical Field

[0001] The present invention relates to the technical field of helmets, and in particular to a composite reinforced polypropylene material and a preparation method thereof. Background Art

[0002] Helmets, as equipment for protecting the head, are widely used in the fields of construction, cycling, electric bicycles, motorcycles, etc. Especially in recent years, with the continuous increase in personal travel needs and the acceleration of riding speed, the demand for wearing helmets has been growing.

[0003] Existing helmets primarily consist of an outer shell, an inner lining, and a suspension device. When worn, they cover at least the top of the head, preventing casualties from impacting the ground in the event of a fall, providing excellent protection. However, after prolonged wear, existing helmets can emit an unpleasant odor due to substances such as hair oil and bodily fluids that seep into the helmet's interior. This, combined with the odor of the original plastic lining, can negatively impact the user experience. Furthermore, this odor is difficult to mask over time with external perfume sprays, and prolonged wear can easily breed bacteria, exacerbating the odor's volatility.

[0004] Therefore, how to provide a composite reinforced polypropylene material with long-lasting fragrance and odor suppression effects as the lining of a helmet is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0005] To this end, the present invention provides a composite reinforced polypropylene material and a preparation method thereof to solve the related technical problems existing in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] According to a first aspect of the present invention, a composite reinforced polypropylene material comprises the following raw materials in parts by weight:

[0008] 20-28 parts modified polypropylene

[0009] 2-4 portions of bamboo charcoal incense

[0010]

[0011] Furthermore, the following raw materials are included in parts by weight:

[0012]

[0013] Furthermore, the following raw materials are included in parts by weight:

[0014]

[0015] In a second aspect of the present application, a method for preparing a composite reinforced polypropylene material is provided, comprising the following steps:

[0016] 1) Weighing modified polypropylene particles according to a preset ratio, drying the modified polypropylene particles in an oven at 80-85° C. for 3-4 hours to remove moisture for later use;

[0017] Weigh the silica carrier according to the preset ratio, gradually add limonene to the silica carrier while stirring at 60-120 rpm. After the loading is completed, dry the silica-loaded limonene in an oven at 55-60°C for later use;

[0018] Weigh silver ions according to a preset ratio, pre-mix the silver ion antibacterial agent and modified polypropylene at a ratio of 1:1 to form granules, ensuring uniform dispersion to prepare silver ion masterbatch, and dry in an oven at 55-60°C for later use:

[0019] 2) Add the dried modified polypropylene to the main feed port of the twin-screw extruder and set the temperature gradient, where the temperature of zone 1 is 180°C, the temperature of zone 2 is 190°C, the temperature of zone 3 is 200°C, and the die head temperature is 195°C;

[0020] The prepared silver ion masterbatch is added to the modified polypropylene through the side feeding port, the shear force of the screw is evenly dispersed, and the mixing temperature is controlled below 180℃;

[0021] The prepared silica is loaded with limonene through the side feed port, the shear force of the screw is evenly dispersed, and the mixing temperature is controlled below 180℃;

[0022] Mix the prepared bamboo charcoal incense and benzyl acetate in proportion, inject into the melt through a liquid injection pump, control the mixing temperature below 180°C, and mix at high speed for 10 seconds;

[0023] 3) The mixed melt is pelletized by water-cooling and stranding to a particle size of ≤3 mm, and the particles are sieved and vacuum-dried at 50-55° C. for 2 h for later use; the particles are injected into a helmet liner mold using an injection molding machine at a temperature of 190-200° C., a holding pressure of 80-85 MPa, and a cooling time of 30 s to obtain a helmet liner.

[0024] Furthermore, the method further comprises the following steps:

[0025] 4) The finished helmet lining is placed in an oven at 35-40°C for 24-36 hours to allow the silver ions to evenly migrate to the surface of the helmet lining and enhance the antibacterial effect.

[0026] Furthermore, the preparation method of the modified polypropylene is as follows:

[0027] Weigh polypropylene, dioctyl adipate and talc according to the proportion, pre-mix the polypropylene and talc, and then add dioctyl adipate and mix at high speed;

[0028] The mixed materials were melt blended in a twin-screw extruder with the extruder temperature set at 160-200°C and the screw speed at 200-300 rpm;

[0029] The melt is granulated and dried to obtain modified polypropylene material.

[0030] Furthermore, the weight ratio is as follows:

[0031] Polypropylene 70-85 parts

[0032] 5-15 parts of dioctyl adipate

[0033] 5-15 parts of talcum powder.

[0034] Furthermore, the talc powder is nano-scale talc powder surface-treated with a silane coupling agent, and has an average particle size of 1-5 μm.

[0035] Furthermore, vacuum exhaust is used during the melt blending process, and the pressure is -0.08 to -0.1 MPa.

[0036] The present invention has the following advantages:

[0037] In this application, the polypropylene used as the helmet lining is modified. The modified polypropylene is plasticized with dioctyl adipate and filled with talcum powder to reduce the flexural modulus, improve softness, fit the curve of the head, and reduce the sense of oppression. The addition of talcum powder reduces the material density while maintaining strength, and the microporous structure improves breathability and avoids stuffiness. The addition of silver ions forms an antibacterial layer by migrating to the surface, effectively inhibiting bacterial growth, reducing sweat odor, and extending the cleaning cycle of the lining; combined with the adsorption capacity of bamboo charcoal fragrance, it has a dual effect of eliminating odor and improving hygiene. Silica-loaded limonene achieves a sustained release of fragrance, and benzyl acetate provides a fresh jasmine scent, masking head odor while improving the wearing experience. Through material modification, functional component compounding and precise process control, this composite reinforced polypropylene helmet lining achieves the core advantages of antibacterial and odor-proofing, softness and breathability, and long-lasting fragrance, while taking into account safety, comfort and durability. DETAILED DESCRIPTION

[0038] The following describes the implementation of the present invention using specific embodiments. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. Obviously, the embodiments described are only a portion of the present invention, not all of it. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0039] According to a first aspect of the present invention, a composite reinforced polypropylene material comprises the following raw materials in parts by weight:

[0040]

[0041] Furthermore, the following raw materials are included in parts by weight:

[0042]

[0043] Furthermore, the following raw materials are included in parts by weight:

[0044]

[0045] In a second aspect of the present application, a method for preparing a composite reinforced polypropylene material is provided, comprising the following steps:

[0046] 1) Weighing modified polypropylene particles according to a preset ratio, drying the modified polypropylene particles in an oven at 80-85° C. for 3-4 hours to remove moisture for later use;

[0047] Weigh the silica carrier according to the preset ratio, gradually add limonene to the silica carrier while stirring at 60-120 rpm. After the loading is completed, dry the silica-loaded limonene in an oven at 55-60°C for later use;

[0048] Weigh silver ions according to a preset ratio, pre-mix the silver ion antibacterial agent and modified polypropylene at a ratio of 1:1 to form granules, ensuring uniform dispersion to prepare silver ion masterbatch, and dry in an oven at 55-60°C for later use:

[0049] 2) Add the dried modified polypropylene to the main feed port of the twin-screw extruder and set the temperature gradient, where the temperature of zone 1 is 180°C, the temperature of zone 2 is 190°C, the temperature of zone 3 is 200°C, and the die head temperature is 195°C;

[0050] The prepared silver ion masterbatch is added to the modified polypropylene through the side feeding port, the shear force of the screw is evenly dispersed, and the mixing temperature is controlled below 180℃;

[0051] The prepared silica is loaded with limonene through the side feed port, the shear force of the screw is evenly dispersed, and the mixing temperature is controlled below 180℃;

[0052] Mix the prepared bamboo charcoal incense and benzyl acetate in proportion, inject into the melt through a liquid injection pump, control the mixing temperature below 180°C, and mix at high speed for 10 seconds;

[0053] 3) The mixed melt is pelletized by water-cooling and stranding to a particle size of ≤3 mm, and the particles are sieved and vacuum-dried at 50-55° C. for 2 h for later use; the particles are injected into a helmet liner mold using an injection molding machine at a temperature of 190-200° C., a holding pressure of 80-85 MPa, and a cooling time of 30 s to obtain a helmet liner.

[0054] Furthermore, the method further comprises the following steps:

[0055] 4) The finished helmet lining is placed in an oven at 35-40°C for 24-36 hours to allow the silver ions to evenly migrate to the surface of the helmet lining and enhance the antibacterial effect.

[0056] Furthermore, the preparation method of the modified polypropylene is as follows:

[0057] Weigh polypropylene, dioctyl adipate and talc according to the proportion, pre-mix the polypropylene and talc, and then add dioctyl adipate and mix at high speed;

[0058] The mixed materials were melt blended in a twin-screw extruder with the extruder temperature set at 160-200°C and the screw speed at 200-300 rpm;

[0059] The melt is granulated and dried to obtain modified polypropylene material.

[0060] Furthermore, the weight ratio is as follows:

[0061] Polypropylene 70-85 parts

[0062] 5-15 parts of dioctyl adipate

[0063] 5-15 parts of talcum powder.

[0064] Furthermore, the talc powder is nano-scale talc powder surface-treated with a silane coupling agent, and has an average particle size of 1-5 μm.

[0065] Furthermore, vacuum exhaust is used during the melt blending process, and the pressure is -0.08 to -0.1 MPa.

[0066] The technical solution of the present invention is described below with reference to specific embodiments.

[0067] Example 1

[0068] Preparation of composite reinforced polypropylene materials (preferred ratio)

[0069] 1. Raw materials and ratio (by weight)

[0070] Modified polypropylene: 25 parts (made from 80 parts of polypropylene, 12 parts of dioctyl adipate, and 8 parts of talc, the talc surface treated with silane coupling agent KH-570, with an average particle size of 3 μm);

[0071] Bamboo charcoal incense: 3 parts

[0072] Benzyl acetate: 5 parts

[0073] Silica-supported limonene: 2 parts (preparation method: 50 nm silica support and limonene were mixed in a mass ratio of 1:0.5, stirred at 60 rpm for 30 minutes, and dried at 60°C);

[0074] Silver ion masterbatch: 2 parts (preparation method: pre-mixing silver ion antibacterial agent with a silver loading of 2% with modified polypropylene in a ratio of 1:1 to form granules);

[0075] 2. Preparation Steps

[0076] Raw material pretreatment:

[0077] The modified polypropylene particles were placed in an oven at 80°C and dried for 4 hours, with the moisture content controlled to ≤0.02%;

[0078] Silica-loaded limonene was dried in an oven at 60 °C for 2 h;

[0079] The silver ion masterbatch was dried in an oven at 55°C for 3 hours.

[0080] Melt blending:

[0081] A co-rotating twin-screw extruder (length-to-diameter ratio L / D=40) was used, and the temperature was set to:

[0082] Zone 1: 180°C; Zone 2: 190°C; Zone 3: 200°C; Die head: 195°C.

[0083] Modified polypropylene particles were added through the main feed port, and silver ion masterbatch and silica-loaded limonene were added twice through the side feed port. After the bamboo charcoal incense was mixed with benzyl acetate, it was injected into the melt through a liquid injection pump (injection rate 5 mL / min). The screw speed was 250 rpm and the vacuum exhaust pressure was -0.09 MPa.

[0084] Granulation and injection molding:

[0085] The melt was pelletized by water-cooling strands (particle size ≤ 3 mm) and vacuum dried at 55 °C for 2 hours;

[0086] Injection molding: temperature 195°C, holding pressure 85 MPa, cooling time 30 seconds to produce the helmet lining.

[0087] Post-processing:

[0088] The finished product was placed in an oven at 38°C for 30 hours to promote the migration of silver ions to the surface.

[0089] Example 2

[0090] 1. Raw materials and ratio (by weight)

[0091] Modified polypropylene: 22 parts

[0092] Bamboo charcoal incense: 2 parts

[0093] Benzyl acetate: 4 parts

[0094] Silica loaded limonene: 2 parts

[0095] Silver ion masterbatch: 1 part

[0096] 2. Preparation steps:

[0097] Same as Example 1, except that the injection temperature was adjusted to 190° C. and the holding pressure was adjusted to 80 MPa.

[0098] Example 3

[0099] 1. Raw materials and ratio (by weight)

[0100] Modified polypropylene: 28 parts

[0101] Bamboo charcoal incense: 4 parts

[0102] Benzyl acetate: 6 parts

[0103] Silica loaded limonene: 3 parts

[0104] Silver ion masterbatch: 2 parts

[0105] 2. Preparation steps:

[0106] Same as Example 1, except that the screw speed was adjusted to 300 rpm and the die temperature was adjusted to 200°C.

[0107] Comparative Example 1

[0108] Unmodified polypropylene (PP 100%) was directly injection molded at a temperature of 200°C and a holding pressure of 90 MPa.

[0109] Performance testing and data analysis

[0110] 1. Antibacterial properties (according to GB / T 31402-2015)

[0111] sample Escherichia coli inhibition rate (%) Staphylococcus aureus inhibition rate (%) Example 1 99.8 99.5 Example 2 95.3 94.7 Example 3 98.6 97.7 Comparative Example 1 5.2 4.8

[0112] When the amount of silver ions added is ≥1 part, the antibacterial rate is >95%; in Example 1, the silver ions and the bamboo charcoal incense act synergistically, and the antibacterial effect is optimal.

[0113] 2. Fragrance persistence (accelerated release test)

[0114] Test method: Place the sample in a 40°C constant temperature box and detect the limonene residual rate by GC-MS.

[0115]

[0116] Silica-loaded limonene significantly delays the volatilization of fragrance, and the 30-day residual rate of Example 1 is about 8.5 times that of Comparative Example 1.

[0117] 3. Mechanics and comfort (according to ASTM standards)

[0118] sample Flexural modulus (MPa) Shore hardness (HD) <![CDATA[Air permeability (cm 3 / cm 2 / s)]]> Example 1 750 65 0.12 Comparative Example 1 1500 85 0.03

[0119] After modification, the bending modulus of the material is reduced by 50%, the air permeability is increased by 4 times, and the wearing comfort is significantly improved.

[0120] 4. Odor adsorption (sensory evaluation)

[0121] Test method: 20 subjects were divided into 4 groups, 5 in each group, and evaluated the odor intensity (0-5 levels, 0 is no odor) after wearing the helmet for 6 hours.

[0122] evaluate Example 1 Example 2 Example 3 Comparative Example 1 score 0.5 0.6 0.5 3.8

[0123] The charcoal fragrance adsorption and benzyl acetate aroma worked synergistically, reducing the odor score by 78%.

[0124] In this application, the polypropylene used as the helmet lining is modified. The modified polypropylene is plasticized with dioctyl adipate and filled with talcum powder to reduce the flexural modulus, improve softness, fit the curve of the head, and reduce the sense of oppression. The addition of talcum powder reduces the material density while maintaining strength, and the microporous structure improves breathability and avoids stuffiness. The addition of silver ions forms an antibacterial layer by migrating to the surface, effectively inhibiting bacterial growth, reducing sweat odor, and extending the cleaning cycle of the lining; combined with the adsorption capacity of bamboo charcoal fragrance, it has a dual effect of eliminating odor and improving hygiene. Silica-loaded limonene achieves a sustained release of fragrance, and benzyl acetate provides a fresh jasmine scent, masking head odor while improving the wearing experience. Through material modification, functional component compounding and precise process control, this composite reinforced polypropylene helmet lining achieves the core advantages of antibacterial and odor-proofing, softness and breathability, and long-lasting fragrance, while taking into account safety, comfort and durability.

[0125] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made thereto. Therefore, such modifications and improvements, without departing from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A composite reinforced polypropylene material, characterized in that: The invention comprises the following raw materials in parts by weight:

2. The composite reinforced polypropylene material according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight:

3. The composite reinforced polypropylene material according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight:

4. A method for preparing a composite reinforced polypropylene material, characterized in that: The steps include: 1) Weighing modified polypropylene particles according to a preset ratio, drying the modified polypropylene particles in an oven at 80-85° C. for 3-4 hours to remove moisture for later use; Weigh the silica carrier according to the preset ratio, gradually add limonene to the silica carrier while stirring at 60-120 rpm. After the loading is completed, dry the silica-loaded limonene in an oven at 55-60°C for later use; Weigh silver ions according to a preset ratio, pre-mix the silver ion antibacterial agent and modified polypropylene at a ratio of 1:1 to form granules, ensuring uniform dispersion to prepare silver ion masterbatch, and dry in an oven at 55-60°C for later use: 2) Add the dried modified polypropylene to the main feed port of the twin-screw extruder and set the temperature gradient, where the temperature of zone 1 is 180°C, the temperature of zone 2 is 190°C, the temperature of zone 3 is 200°C, and the die head temperature is 195°C; The prepared silver ion masterbatch is added to the modified polypropylene through the side feeding port, the shear force of the screw is evenly dispersed, and the mixing temperature is controlled below 180℃; The prepared silica is loaded with limonene through the side feed port, the shear force of the screw is evenly dispersed, and the mixing temperature is controlled below 180℃; Mix the prepared bamboo charcoal incense and benzyl acetate in proportion, inject into the melt through a liquid injection pump, control the mixing temperature below 180°C, and mix at high speed for 10 seconds; 3) The mixed melt is pelletized by water-cooling and stranding to a particle size of ≤3 mm, and the particles are sieved and vacuum-dried at 50-55° C. for 2 h for later use; the particles are injected into a helmet liner mold using an injection molding machine at a temperature of 190-200° C., a holding pressure of 80-85 MPa, and a cooling time of 30 s to obtain a helmet liner.

5. The method for preparing the composite reinforced polypropylene material according to claim 4, wherein: The following steps are also included: 4) The finished helmet lining is placed in an oven at 35-40°C for 24-36 hours to allow the silver ions to evenly migrate to the surface of the helmet lining and enhance the antibacterial effect.

6. The method for preparing the composite reinforced polypropylene material according to claim 4, wherein: in, The preparation method of modified polypropylene is as follows: Weigh polypropylene, dioctyl adipate and talc according to the proportion, pre-mix the polypropylene and talc, and then add dioctyl adipate and mix at high speed; The mixed materials were melt blended in a twin-screw extruder with the extruder temperature set at 160-200°C and the screw speed at 200-300 rpm; The melt is granulated and dried to obtain modified polypropylene material.

7. The method for preparing the composite reinforced polypropylene material according to claim 6, wherein: in, The weight ratio is as follows: Polypropylene 70-85 parts 5-15 parts of dioctyl adipate 5-15 parts of talcum powder.

8. The method for preparing the composite reinforced polypropylene material according to claim 6, wherein: in, The talc powder is nano-scale talc powder surface-treated with a silane coupling agent, and has an average particle size of 1-5 μm.

9. The method for preparing the composite reinforced polypropylene material according to claim 6, wherein: in, Vacuum exhaust is used during the melt blending process, and the pressure is -0.08 to -0.1 MPa.

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