A powder dipping process for plastic parts

Abstract

The present application relates to the technical field of plastic parts processing, and in particular to a powder dipping process for plastic parts; a powder dipping process for plastic parts, comprising the following steps: subjecting the plastic parts to sandblasting, ultrasonic degreasing, spray water washing, spot welding, spray water washing, preheating, powder dipping, curing, and cooling to obtain the powdered plastic parts; the cooling steps are as follows: (1) dissolving a surface treatment agent in water to obtain a coolant; (2) placing the plastic parts in the coolant for cooling to obtain the cooled plastic parts; wherein the surface treatment agent comprises the following raw materials in parts by mass: 15-25 parts of a brightener, 5-15 parts of an active agent, 10-20 parts of a lignin / titanium dioxide composite material, and 4-8 parts of a hexadecyl alcohol ester; the present application discloses a powder dipping process for plastic parts, which effectively improves the surface gloss and retention time, UV resistance, and mechanical strength of the plastic parts.

Description

Technical Field

[0001] The present application relates to the technical field of plastic parts processing, and in particular to a powder dipping process for plastic parts. Background Art

[0002] Powder dipping is a commonly used coating process, suitable for coating the surfaces of various metals, plastics and other materials. Compared with traditional spraying processes, powder dipping has better adhesion, corrosion resistance and oxidation resistance, and is suitable for use in various environments and complex working conditions.

[0003] Usually, the coating is prepared using thermoplastic resin powder or thermosetting resin powder. Different powder materials are selected according to different substrates and working conditions. Before processing, the coating powder needs to be sieved to remove larger and smaller impurity particles to ensure uniformity and stability of the coating.

[0004] In the related art, the bowl baskets used in dishwashers are mostly made of PA material, PP material or stainless steel. The outer side of the bowl baskets made of PA material and PP material needs to be coated through a powder dipping process. For example, the outer side of the PA material product is attached with PA material, and the outer side of the PP material is attached with PP material. The coating formed by the powder dipping process has a low surface gloss and poor appearance, which affects the user experience when using the bowl basket.

[0005] Therefore, how to effectively improve the glossiness of plastic surface has become an urgent problem to be solved. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the present application provides a powder dipping process for plastic parts.

[0007] In a first aspect, the present application provides a powder dipping process for plastic parts, which adopts the following technical solution:

[0008] A powder dipping process for plastic parts, comprising the following steps: subjecting the plastic parts to sandblasting, ultrasonic degreasing, spray water washing, spot welding, spray water washing, preheating, powder dipping, curing, and cooling to obtain the powder-dipping plastic parts;

[0009] The cooling steps are as follows:

[0010] (1) Dissolve the surface treatment agent in water to obtain a coolant;

[0011] (2) placing the plastic parts into the coolant for cooling to obtain cooled plastic parts;

[0012] The surface treatment agent comprises the following raw materials in parts by mass: 15-25 parts of a brightener, 5-15 parts of a surfactant, 10-20 parts of a lignin / titanium dioxide composite material, and 4-8 parts of hexadecyl alcohol ester.

[0013] Due to long-term exposure of plastic to oxygen in the air or ultraviolet radiation, oxidation reactions will occur, causing the surface to become rough and black. By adopting the above-mentioned technical solution, a lignin / titanium dioxide composite material is added in this application. The added lignin / titanium dioxide composite material has a small particle size and good dispersibility, ultraviolet shielding performance, and antioxidant performance. The added lignin / titanium dioxide composite material is combined with the surface of the plastic part under the action of surfactants and hexadecanol esters, and forms a dense anti-ultraviolet and anti-oxidation coating on the plastic surface, which plays a good protective role on the surface of the plastic part and makes the surface of the plastic part have good ultraviolet shielding performance and antioxidant performance.

[0014] In this application, the formula is improved by adding hexadecanol ester, which has film-forming properties and slow volatilization rate. After dissolving the various substances in deionized water, an oily composite film is formed on the surface of the plastic part, which can keep the surface of the plastic part bright for a long time.

[0015] In the present application, the formula is improved by adding a brightener. Under the action of surfactants and hexadecanol ester, the added brightener allows the brightener to better contact with the surface of the plastic part, thereby improving its adhesion and treatment effect; the added brightener forms a protective film on the surface of the plastic part, which can keep the surface of the plastic part bright for a long time.

[0016] In this application, after the plastic parts are solidified, a surfactant is added to the water tank in which the product is immersed during the cooling stage. The surfactant activates the coating surface, so that the surface of the product becomes bright after being immersed in water and cooled. The surface of the product treated by this process can remain bright for a long time, and the addition of the surfactant helps prevent the product from shrinking and forming voids in the cooling water.

[0017] By adopting the above technical solution, the brightener, surfactant, lignin / titanium dioxide composite material and hexadecyl alcohol ester are coordinated with each other to make the plastic parts have higher gloss, and at the same time have good UV shielding performance, antioxidant performance and mechanical properties.

[0018] Preferably, the surface treatment agent further comprises 5-10 parts by mass of a grafted polyethylene / glyceryl monostearate grafted SiO2 blend.

[0019] By adopting the above technical solution, the added grafted polyethylene / glyceryl monostearate grafted SiO2 blend is better in contact with the surface of the plastic parts under the action of surfactants and hexadecanol esters, effectively avoiding condensation on the surface of the plastic parts due to excessive temperature differences during the processing of the plastic parts, and effectively improving the mechanical properties of the plastic parts.

[0020] Preferably, the brightener is at least one of acrylonitrile-styrene copolymer, styrene-butadiene block copolymer, butadiene-styrene copolymer, and maleic anhydride grafted polyolefin.

[0021] Preferably, the surfactant is at least one of anionic surfactant, nonionic surfactant and amphoteric surfactant.

[0022] In a specific embodiment, the surfactant can be replaced with a detergent containing a surfactant. The addition of the detergent helps prevent the product from shrinking in cooling water to form cavities and reduces processing costs.

[0023] Preferably, the anionic surfactant is at least one of sodium fatty alcohol polyoxyethylene ether sulfate, sodium fatty alcohol polyoxyethylene ether carboxylate, sodium alkyl sulfonate, and sodium α-olefin sulfonate.

[0024] Preferably, the nonionic surfactant is at least one of fatty alcohol polyoxyethylene ether-9, fatty alcohol polyoxyethylene ether-7, polyethylene glycol, alkyl glucoside, monoolein, sucrose ester, fatty acid methyl ester ethoxylate, polyglycerol fatty acid ester, and amine oxide.

[0025] Preferably, the amphoteric surfactant is at least one of lauryl alanine diethanolamine salt, sodium lauryl aminopropionate, and betaine.

[0026] Preferably, the temperature of the coolant in step (2) is 50°C-60°C; and the cooling time is 1s-7s.

[0027] Preferably, the mass ratio of the surface treatment agent to water in step (1) is (1-5):10.

[0028] Preferably, the preparation steps of the surface treatment agent are as follows:

[0029] Weigh each raw material according to the formula;

[0030] The brightener, surfactant, lignin / titanium dioxide composite material, grafted polyethylene / glyceryl monostearate grafted SiO2 blend, hexadecyl alcohol ester and water are mixed to obtain a surface treatment agent.

[0031] Preferably, the mixing time is 20-35 minutes.

[0032] In summary, this application includes at least one of the following beneficial technical effects:

[0033] The present application discloses a powder dipping process for plastic parts. By adding a surface treatment agent to treat the plastic parts during the cooling step, the surface glossiness and retention time of the plastic parts are effectively improved, so that the prepared plastic parts have good UV resistance and mechanical strength. DETAILED DESCRIPTION

[0034] The technical solution of the present application is further illustrated below through specific embodiments. The specific embodiments do not limit the scope of protection of the present application; some non-essential modifications and adjustments made by others based on the concept of the present application still fall within the scope of protection of the present application.

[0035] The raw materials involved in this application are all commercially available products, among which:

[0036] Acrylonitrile-styrene copolymer, molecular weight 157.21646;

[0037] Fatty alcohol polyoxyethylene ether sodium sulfate, molecular weight 272.37987;

[0038] Sodium lauryl aminopropionate, molecular weight 279.39397;

[0039] Fatty alcohol polyoxyethylene ether-9, AEO-9, molecular weight 582.81;

[0040] Hexadecyl alcohol ester, molecular weight is 286.407.

[0041] The present application is further described in detail below with reference to the following examples and comparative examples.

[0042] Source of raw materials:

[0043] The preparation steps of lignin / titanium dioxide composite material are as follows:

[0044] (1) After mixing 6 mL of carbon nanofiber (solid content 2%) and 1.5 g of lignin, 30 mL of anhydrous ethanol was added and mixed for 30 minutes. 10 mL of butyl titanate was added and mixed for 20 minutes. 2 mL of 20 wt% sulfuric acid solution was added and mixed. The mixture was then placed in a high-temperature and high-pressure reactor, sealed, and reacted at 120 °C for 2 hours. The reactor was cooled to 80 °C, dried and aged to obtain a lignin / titanium dioxide composite material.

[0045] (2) 15 g of TOCNF gel (carboxylated nanocellulose, solid content 2%) was added to 15 mL of deionized water for dissolution, and lignin / titanium dioxide composite material (the amount added was 10% of the solid content of TOCNF gel) was added and mixed for 30 minutes at a speed of 200 r / min; then moved to an ultrasonic disperser and ultrasonically dispersed for 10 minutes to obtain a lignin / titanium dioxide composite material.

[0046] Preparation of grafted polyethylene / glyceryl monostearate grafted SiO2 blends, the steps are as follows:

[0047] (1) Mix 100 mL of deionized water and 300 mL of anhydrous ethanol, add 4 g of nano-silica, and ultrasonically disperse for 2 hours;

[0048] (2) 10 mL of anhydrous ethanol and 10 mL of acetic acid solution were added to 0.8 g of KH570, mixed, and added to the mixture prepared in step (1), and then reacted at 75°C for 4 hours, centrifuged at 8000 r / min for 10 minutes, and dried at 80°C for 12 hours to obtain modified nano-silica;

[0049] (3) Melting monostearate acrylate diglyceride at 80°C, adding azobisisobutyronitrile and modified nano-silica, and introducing nitrogen to react for 8 hours to obtain a silica grafted product, wherein the mass ratio of modified nano-silica / monostearate acrylate diglyceride / azobisisobutyronitrile is 1:5:0.05;

[0050] (4) Add 5 g of silica grafted product to a beaker, melt it at 60 °C, add 30 mL of acetone, stir for 10 min, and let it stand in air and room temperature for 1 h; after the solid and liquid layers are separated, pour out the upper liquid, and add acetone again and repeat the experiment until the upper liquid becomes colorless and clear; remove the remaining acetone from the obtained precipitate using a rotary evaporator, and dry the solid after rotary evaporation at 60 °C in vacuum for 3 h to obtain SiO2-g-PAGMS grafted product;

[0051] (5) SiO2-g-PAGMS grafted product, linear low-density polyethylene (LLDPE), and bisphenol AF were mixed in a mass ratio of 145:340:10 to obtain grafted polyethylene / monostearin grafted SiO2 blend.

[0052] Preparation Example 1:

[0053] The preparation steps of the surface treatment agent are as follows:

[0054] (1) Weigh the following raw materials according to the formula: 20 kg of brightener, 10 kg of surfactant, 15 kg of lignin / titanium dioxide composite material, 6 kg of hexadecyl alcohol ester, and 70 kg of water.

[0055] The brightener is a copolymer of acrylonitrile and styrene.

[0056] The surfactant is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate, sodium lauryl aminopropionate, and fatty alcohol polyoxyethylene ether-9, with a mass ratio of 3:1:1.

[0057] (2) The brightener, surfactant, lignin / titanium dioxide composite material, hexadecyl alcohol ester and water were mixed for 30 minutes to obtain a surface treatment agent.

[0058] Preparation Example 2:

[0059] The preparation steps of the surface treatment agent are as follows:

[0060] (1) Weigh the raw materials according to the formula: 15 kg of brightener, 5 kg of surfactant, 10 kg of lignin / titanium dioxide composite material, 4 kg of hexadecyl alcohol ester and 60 kg of water.

[0061] The brightener is a copolymer of acrylonitrile and styrene.

[0062] The surfactant is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate, sodium lauryl aminopropionate, and fatty alcohol polyoxyethylene ether-9, with a mass ratio of 3:1:1.

[0063] (2) The brightener, surfactant, lignin / titanium dioxide composite material, hexadecyl alcohol ester and water were mixed for 30 minutes to obtain a surface treatment agent.

[0064] Preparation Example 3:

[0065] The preparation steps of the surface treatment agent are as follows:

[0066] (1) Weigh the following raw materials according to the formula: 25 kg of brightener, 15 kg of surfactant, 20 kg of lignin / titanium dioxide composite material, 8 kg of hexadecyl alcohol ester, and 80 kg of water.

[0067] The brightener is a copolymer of acrylonitrile and styrene.

[0068] The surfactant is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate, sodium lauryl aminopropionate, and fatty alcohol polyoxyethylene ether-9, with a mass ratio of 3:1:1.

[0069] (2) The brightener, surfactant, lignin / titanium dioxide composite material, hexadecyl alcohol ester and water were mixed for 30 minutes to obtain a surface treatment agent.

[0070] Preparation Example 4:

[0071] The preparation steps of the surface treatment agent are as follows:

[0072] (1) Weigh the following raw materials according to the formula: 20 kg of brightener, 10 kg of surfactant, 15 kg of lignin / titanium dioxide composite material, 6 kg of hexadecyl alcohol ester, 8 kg of grafted polyethylene / glyceryl monostearate grafted SiO2 blend, and 70 kg of water.

[0073] The brightener is a copolymer of acrylonitrile and styrene.

[0074] The surfactant is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate, sodium lauryl aminopropionate, and fatty alcohol polyoxyethylene ether-9, with a mass ratio of 3:1:1.

[0075] (2) The brightener, surfactant, lignin / titanium dioxide composite material, grafted polyethylene / glyceryl monostearate grafted SiO2 blend, hexadecyl alcohol ester and water were mixed for 30 minutes to obtain a surface treatment agent.

[0076] Preparation Example 5:

[0077] The preparation steps of the surface treatment agent are as follows:

[0078] (1) Weigh the following raw materials according to the formula: 20 kg of brightener, 10 kg of surfactant, 15 kg of lignin / titanium dioxide composite material, 6 kg of hexadecyl alcohol ester, 5 kg of grafted polyethylene / glyceryl monostearate grafted SiO2 blend, and 70 kg of water.

[0079] The brightener is a copolymer of acrylonitrile and styrene.

[0080] The surfactant is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate, sodium lauryl aminopropionate, and fatty alcohol polyoxyethylene ether-9, with a mass ratio of 3:1:1.

[0081] (2) The brightener, surfactant, lignin / titanium dioxide composite material, grafted polyethylene / glyceryl monostearate grafted SiO2 blend, hexadecyl alcohol ester and water were mixed for 30 minutes to obtain a surface treatment agent.

[0082] Preparation Example 6:

[0083] The preparation steps of the surface treatment agent are as follows:

[0084] (1) Weigh the following raw materials according to the formula: 20 kg of brightener, 10 kg of surfactant, 15 kg of lignin / titanium dioxide composite material, 6 kg of hexadecyl alcohol ester, 10 kg of grafted polyethylene / glyceryl monostearate grafted SiO2 blend, and 70 kg of water.

[0085] The brightener is a copolymer of acrylonitrile and styrene.

[0086] The surfactant is a mixture of sodium fatty alcohol polyoxyethylene ether sulfate, sodium lauryl aminopropionate, and fatty alcohol polyoxyethylene ether-9, with a mass ratio of 3:1:1.

[0087] (2) The brightener, surfactant, lignin / titanium dioxide composite material, grafted polyethylene / glyceryl monostearate grafted SiO2 blend, hexadecyl alcohol ester and water were mixed for 30 minutes to obtain a surface treatment agent.

[0088] Example 1:

[0089] A powder dipping process for plastic parts, comprising the following steps: subjecting the plastic parts to sandblasting, ultrasonic degreasing, spray water washing, spot welding, spray water washing, preheating, powder dipping, curing, and cooling to obtain the powder-dipping plastic parts;

[0090] The details are as follows:

[0091] (1) Hanging on plastic parts;

[0092] (2) Sand blasting: processing time is 150 seconds, current is 7A;

[0093] (3) Ultrasonic degreasing: Use a degreasing agent (commercially available) for ultrasonic degreasing, with a treatment time of 75 seconds and a treatment temperature of 38°C;

[0094] (4) Spray washing: Use tap water for spray washing at room temperature and the spray washing time is 80 seconds;

[0095] (5) Spot welding: electric welding accessories, welding current is 10KVA;

[0096] (6) Spray washing: Use tap water for spray washing at room temperature and the spray washing time is 100 seconds;

[0097] (7) Preheating: The preheating time is 165 seconds and the preheating temperature is 380°C;

[0098] (8) Dipping powder: Dipping powder time is 3 seconds; powdering time is 5.2 seconds;

[0099] (9) Curing: The curing temperature is 200°C and the curing time is 90 seconds;

[0100] (10) Cooling:

[0101] (a) Dissolve 3 kg of the surface treatment agent in 10 kg of water to obtain a coolant;

[0102] (b) The temperature of the coolant is adjusted to 55°C, and the plastic part is placed in the coolant for cooling for 5 seconds to obtain a cooled plastic part;

[0103] (11) Cut off the remaining hanging equipment.

[0104] The surface treatment agent was prepared in Preparation Example 1.

[0105] Example 2:

[0106] A powder dipping process for plastic parts, comprising the following steps: subjecting the plastic parts to sandblasting, ultrasonic degreasing, spray water washing, spot welding, spray water washing, preheating, powder dipping, curing, and cooling to obtain the powder-dipping plastic parts;

[0107] The details are as follows:

[0108] (1) Hanging on plastic parts;

[0109] (2) Sand blasting: processing time is 150 seconds, current is 7A;

[0110] (3) Ultrasonic degreasing: Use a degreasing agent (commercially available) for ultrasonic degreasing, with a treatment time of 75 seconds and a treatment temperature of 38°C;

[0111] (4) Spray washing: Use tap water for spray washing at room temperature and the spray washing time is 80 seconds;

[0112] (5) Spot welding: electric welding accessories, welding current is 10KVA;

[0113] (6) Spray washing: Use tap water for spray washing at room temperature and the spray washing time is 100 seconds;

[0114] (7) Preheating: The preheating time is 165 seconds and the preheating temperature is 380°C;

[0115] (8) Dipping powder: Dipping powder time is 3 seconds; powdering time is 5.2 seconds;

[0116] (9) Curing: The curing temperature is 200°C and the curing time is 90 seconds;

[0117] (10) Cooling:

[0118] (a) Dissolve 1 kg of the surface treatment agent in 10 kg of water to obtain a coolant;

[0119] (b) The temperature of the coolant is adjusted to 50°C, and the plastic part is placed in the coolant for cooling for 5 seconds to obtain a cooled plastic part;

[0120] (11) Cut off the remaining hanging equipment.

[0121] The surface treatment agent was prepared in Preparation Example 1.

[0122] Example 3:

[0123] A powder dipping process for plastic parts, comprising the following steps: subjecting the plastic parts to sandblasting, ultrasonic degreasing, spray water washing, spot welding, spray water washing, preheating, powder dipping, curing, and cooling to obtain the powder-dipping plastic parts;

[0124] The details are as follows:

[0125] (1) Hanging on plastic parts;

[0126] (2) Sand blasting: processing time is 150 seconds, current is 7A;

[0127] (3) Ultrasonic degreasing: Use a degreasing agent (commercially available) for ultrasonic degreasing, with a treatment time of 75 seconds and a treatment temperature of 38°C;

[0128] (4) Spray washing: Use tap water for spray washing at room temperature and the spray washing time is 80 seconds;

[0129] (5) Spot welding: electric welding accessories, welding current is 10KVA;

[0130] (6) Spray washing: Use tap water for spray washing at room temperature and the spray washing time is 100 seconds;

[0131] (7) Preheating: The preheating time is 165 seconds and the preheating temperature is 380°C;

[0132] (8) Dipping powder: Dipping powder time is 3 seconds; powdering time is 5.2 seconds;

[0133] (9) Curing: The curing temperature is 200°C and the curing time is 90 seconds;

[0134] (10) Cooling:

[0135] (a) dissolving 5 kg of a surface treatment agent in 10 kg of water to obtain a coolant;

[0136] (b) The temperature of the coolant is adjusted to 60°C, and the plastic part is placed in the coolant for cooling for 5 seconds to obtain a cooled plastic part;

[0137] (11) Cut off the remaining hanging equipment.

[0138] The surface treatment agent was prepared in Preparation Example 1.

[0139] Example 4:

[0140] The difference from Example 1 is that the surface treatment agent is prepared in Preparation Example 2.

[0141] Example 5:

[0142] The difference from Example 1 is that the surface treatment agent is prepared in Preparation Example 3.

[0143] Example 6:

[0144] The difference from Example 1 is that the surface treatment agent is prepared in Preparation Example 4.

[0145] Example 7:

[0146] The difference from Example 1 is that the surface treatment agent is prepared in Preparation Example 5.

[0147] Example 8:

[0148] The difference from Example 1 is that the surface treatment agent is prepared in Preparation Example 6.

[0149] Comparative Example 1:

[0150] The difference from Example 1 is that no surface treatment agent is added when cooling the plastic part.

[0151] Comparative Example 2:

[0152] The difference from Example 6 is that no surface treatment agent is added when cooling the plastic part.

[0153] Comparative Example 3:

[0154] The difference from Example 1 is that when preparing the surface treatment agent, no lignin / titanium dioxide composite material is added.

[0155] Comparative Example 4:

[0156] The difference from Example 6 is that when preparing the surface treatment agent, no lignin / titanium dioxide composite material is added.

[0157] Comparative Example 5:

[0158] The difference from Example 1 is that no surfactant is added when preparing the surface treatment agent.

[0159] Comparative Example 6:

[0160] The difference from Example 6 is that no surfactant is added when preparing the surface treatment agent.

[0161] Performance testing:

[0162] 1. Glossiness detection:

[0163] The glossiness and gloss retention time of the plastic parts prepared in the examples and comparative examples were tested using a micro gloss meter A-4430 (BYK, Germany). The results are as follows:

[0164] Table 1 Glossiness test results

[0165]

[0166] As shown in Table 1, the plastic parts prepared by the method of the present application have high gloss, which can be maintained for up to 38 days.

[0167] Combined with the test results of Examples 1-8, it can be seen that the test results of Examples 6-8 are better than the test results of Examples 1-5, indicating that the addition of grafted polyethylene / glyceryl monostearate grafted SiO2 blend further improves the glossiness of the product and effectively prolongs the gloss retention time.

[0168] Combining Example 1 and Comparative Example 1, it can be seen that the test result of Example 1 is better than the test result of Comparative Example 1, indicating that the addition of the surface treatment agent in this application further improves the glossiness of the product and effectively prolongs the gloss retention time.

[0169] Combining Example 6 and Comparative Example 2, it can be seen that the test result of Example 6 is better than the test result of Comparative Example 2, indicating that the addition of the surface treatment agent in this application further improves the glossiness of the product and effectively prolongs the gloss retention time.

[0170] Combining Example 1 and Comparative Example 3, it can be seen that the test result of Example 1 is better than the test result of Comparative Example 3, indicating that the addition of lignin / titanium dioxide composite material in this application further improves the glossiness of the product and effectively prolongs the gloss retention time.

[0171] Combining Example 6 and Comparative Example 4, it can be seen that the test result of Example 6 is better than the test result of Comparative Example 4, indicating that the addition of lignin / titanium dioxide composite material in this application further improves the glossiness of the product and effectively prolongs the gloss retention time.

[0172] Combining Example 1 and Comparative Example 5, it can be seen that the test result of Example 1 is better than the test result of Comparative Example 5, indicating that the addition of surfactant in this application further improves the glossiness of the product and effectively prolongs the gloss retention time.

[0173] Combining Example 6 and Comparative Example 6, it can be seen that the test result of Example 6 is better than the test result of Comparative Example 6, indicating that the addition of surfactant in this application further improves the glossiness of the product and effectively prolongs the gloss retention time.

[0174] 2. Ultraviolet detection:

[0175] The plastic ultraviolet light exposure test method ASTM D4329-05 was used to irradiate the plastic parts prepared in the examples and comparative examples under an ultraviolet lamp, and the aging degree of the plastic parts was observed at different time periods.

[0176] Table 2 Effect of UV irradiation on plastic aging (UV intensity 3000uW / cm 2 )

[0177]

[0178] As shown in Table 2, the degree of aging of the plastic parts prepared by the method of the present application is significantly reduced under ultraviolet irradiation.

[0179] Combined with the test results of Examples 1-8, it can be seen that the test results of Examples 6-8 are better than the test results of Examples 1-5, indicating that the addition of grafted polyethylene / glyceryl monostearate grafted SiO2 blend further improves the UV resistance of the product.

[0180] Combining Example 1 and Comparative Example 1, it can be seen that the test result of Example 1 is better than the test result of Comparative Example 1, indicating that the addition of the surface treatment agent in this application further improves the anti-ultraviolet performance of the product.

[0181] Combining Example 6 and Comparative Example 2, it can be seen that the test result of Example 6 is better than the test result of Comparative Example 2, indicating that the addition of the surface treatment agent in this application further improves the anti-ultraviolet performance of the product.

[0182] Combining Example 1 and Comparative Example 3, it can be seen that the test result of Example 1 is better than the test result of Comparative Example 3, indicating that the addition of the lignin / titanium dioxide composite material in the present application further improves the anti-ultraviolet performance of the product.

[0183] Combining Example 6 and Comparative Example 4, it can be seen that the test result of Example 6 is better than the test result of Comparative Example 4, indicating that the addition of the lignin / titanium dioxide composite material in the present application further improves the anti-ultraviolet performance of the product.

[0184] Combining Example 1 and Comparative Example 5, it can be seen that the test result of Example 1 is better than the test result of Comparative Example 5, indicating that the addition of surfactant in this application further improves the anti-ultraviolet performance of the product.

[0185] Combining Example 6 and Comparative Example 6, it can be seen that the test result of Example 6 is better than the test result of Comparative Example 6, indicating that the addition of surfactant in this application further improves the anti-ultraviolet performance of the product.

[0186] 3. Mechanical strength test:

[0187] The tensile properties of the plastic parts prepared in the examples and comparative examples were tested, and the tensile strength and elongation at break of the plastic parts were tested with reference to GB / T1040.2-2006 standard.

[0188] Table 3 Tensile strength and elongation at break

[0189]

[0190] It can be seen from Table 2 that the plastic parts prepared by the method of the present application have good mechanical strength.

[0191] Combined with the test results of Examples 1-8, it can be seen that the test results of Examples 6-8 are better than the test results of Examples 1-5, indicating that the addition of grafted polyethylene / glyceryl monostearate grafted SiO2 blend further improves the tensile strength and elongation at break of the product, effectively improving the mechanical properties of the product.

[0192] Combining Example 1 and Comparative Example 1, it can be seen that the test result of Example 1 is better than the test result of Comparative Example 1, indicating that the addition of the surface treatment agent in this application further improves the tensile strength and elongation at break of the product, and effectively improves the mechanical properties of the product.

[0193] Combining Example 6 and Comparative Example 2, it can be seen that the test results of Example 6 are better than the test results of Comparative Example 2, indicating that the addition of the surface treatment agent in this application further improves the tensile strength and elongation at break of the product, and effectively improves the mechanical properties of the product.

[0194] Combining Example 1 and Comparative Example 3, it can be seen that the test result of Example 1 is better than the test result of Comparative Example 3, indicating that the addition of lignin / titanium dioxide composite material in this application further improves the tensile strength and elongation at break of the product, and effectively improves the mechanical properties of the product.

[0195] Combining Example 6 and Comparative Example 4, it can be seen that the test results of Example 6 are better than the test results of Comparative Example 4, indicating that the addition of lignin / titanium dioxide composite material in this application further improves the tensile strength and elongation at break of the product, effectively improving the mechanical properties of the product.

[0196] Combining Example 1 and Comparative Example 5, it can be seen that the test result of Example 1 is better than the test result of Comparative Example 5, indicating that the addition of surfactant in this application further improves the tensile strength and elongation at break of the product, and effectively improves the mechanical properties of the product.

[0197] Combining Example 6 and Comparative Example 6, it can be seen that the test results of Example 6 are better than the test results of Comparative Example 6, indicating that the addition of surfactants in this application further improves the tensile strength and elongation at break of the product, and effectively improves the mechanical properties of the product.

Claims

1. A powder dipping process for plastic parts, characterized in that: The steps are as follows: the plastic parts are subjected to sandblasting, ultrasonic degreasing, spray water washing, spot welding, spray water washing, preheating, powder dipping, curing, and cooling to obtain powder-dipping plastic parts; The cooling steps are as follows: (1) Dissolve the surface treatment agent in water to obtain a coolant; (2) placing the plastic parts into the coolant for cooling to obtain cooled plastic parts; The surface treatment agent comprises the following raw materials in parts by mass: 15-25 parts of a brightener, 5-15 parts of a surfactant, 10-20 parts of a lignin / titanium dioxide composite material, 4-8 parts of hexadecyl alcohol ester, and 5-10 parts by mass of a grafted polyethylene / glyceryl monostearate grafted SiO2 blend; The preparation steps of lignin / titanium dioxide composite material are as follows: S1. After mixing 6 mL of carbon nanofibers with a solid content of 2% and 1.5 g of lignin, 30 mL of anhydrous ethanol was added and mixed for 30 minutes. 10 mL of butyl titanate was added and mixed for 20 minutes. 2 mL of a 20 wt % sulfuric acid solution was added and mixed. The mixture was then placed in a reactor and reacted at 120° C. for 2 hours. The reactor was cooled to 80° C., dried and aged to obtain a dried and aged lignin / titanium dioxide composite material. S2. Dissolve 15 g of carboxylated nanocellulose gel with a solid content of 2% in 15 mL of deionized water, add the dried and aged lignin / titanium dioxide composite material, and mix for 30 minutes at a speed of 200 r / min; then move to an ultrasonic disperser and ultrasonically disperse for 10 minutes to obtain a lignin / titanium dioxide composite material; The addition amount of the dried and aged lignin / titanium dioxide composite material was 10% of the solid content of the carboxylated nanocellulose gel.

2. The powder dipping process for plastic parts according to claim 1, characterized in that: The brightener is at least one of acrylonitrile-styrene copolymer, styrene-butadiene block copolymer, butadiene-styrene copolymer, and maleic anhydride grafted polyolefin.

3. The powder dipping process for plastic parts according to claim 1, characterized in that: The surfactant is at least one of anionic surfactant, nonionic surfactant and amphoteric surfactant.

4. The powder dipping process for plastic parts according to claim 3, characterized in that: The anionic surfactant is at least one of sodium fatty alcohol polyoxyethylene ether sulfate, sodium fatty alcohol polyoxyethylene ether carboxylate, sodium alkyl sulfonate, and sodium α-olefin sulfonate; The nonionic surfactant is at least one of fatty alcohol polyoxyethylene ether-9, fatty alcohol polyoxyethylene ether-7, polyethylene glycol, alkyl glucoside, monoolein, sucrose ester, fatty acid methyl ester ethoxylate, polyglycerol fatty acid ester, and amine oxide; The amphoteric surfactant is at least one of lauryl alanine diethanolamine salt, sodium lauryl aminopropionate, and betaine.

5. The powder dipping process for plastic parts according to claim 1, characterized in that: The temperature of the cooling liquid in step (2) is 50°C-60°C.

6. The powder dipping process for plastic parts according to claim 1, characterized in that: The cooling time in step (2) is 1s-7s.

7. The powder dipping process for plastic parts according to claim 1, characterized in that: The mass ratio of the surface treatment agent to water in step (1) is (1-5):

10.

8. The powder dipping process for plastic parts according to claim 1, characterized in that: The preparation steps of the surface treatment agent are as follows: Weigh each raw material according to the recipe; The brightener, the surfactant, the lignin / titanium dioxide composite material, the grafted polyethylene / glyceryl monostearate grafted SiO2 blend and the hexadecanol ester are mixed to obtain a surface treatment agent.

9. The powder dipping process for plastic parts according to claim 8, characterized in that: The mixing time is 20-35 minutes.

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