Wear-resistant anti-collodion silk food-grade PP grinding cover and injection molding process thereof

Abstract

The wear-resistant and anti-collodion-silk food-grade PP grinding cover is prepared from the following components in parts by weight: 100 to 150 parts of food-grade PP resin, 5 to 10 parts of wear-resistant additive, 2 to 5 parts of anti-collodion-silk additive, 0.5 to 1 part of antioxidant and 0.5 to 1 part of lubricant, by adding the wear-resistant additive, the nano silicon dioxide and the silicon carbide, the additive has high hardness and good wear resistance and is uniformly dispersed in a food-grade PP resin matrix, and the additive can bear part of friction force and reduce the wear of the PP resin when being rubbed, so that the wear resistance of the grinding cover is remarkably improved, the service life of a product is prolonged, and the production cost is reduced. The replacement frequency is reduced, and meanwhile, the problem of foreign matter pollution caused by product abrasion in the seasoning grinding process is also avoided; the anti-rubber-thread auxiliary agent contains an organosilicon compound, and the organosilicon compound has low surface energy and good lubricity, so that the friction force between the plastic and a ground object can be reduced, and the phenomena of damage and wire drawing of the plastic caused by friction are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of abrasive cover preparation, and particularly relates to a wear-resistant and anti-gum filament food-grade PP abrasive cover and its injection molding process. Background Art

[0002] With the increasing improvement of people's living standards, the demand for beverages has also increased accordingly. As the bottle caps for holding beverages, they play a very important role in the filling, sealing, preservation, transportation, and sales of beverages. PP material, namely the high-polymer polypropylene material, is non-toxic, odorless, has a small density, can be used at about 100 °C, has good dielectric properties and high-frequency insulation properties and is not affected by humidity, has low anti-ultraviolet performance and is easy to age, and common organic solvents such as acids and alkalis have almost no effect on it. It can be used for food utensils and food packaging materials, especially for the bottle cap materials of pressurized carbonated beverages and beverages that require hot filling.

[0003] Ordinary PP material has a relatively soft texture and is prone to wear during use. Especially when producing dark main caps such as black, black gum filaments are easily generated due to wear during the grinding of white salts, which is extremely prone to wear, resulting in a short service life of the product, high replacement cost, and the wear debris mixing into the condiments, causing foreign matter pollution.

[0004] Therefore, we propose a wear-resistant and anti-gum filament food-grade PP abrasive cover and its injection molding process to solve the problems mentioned in the above background art. Summary of the Invention

[0005] The purpose of the present invention is to provide a wear-resistant and anti-gum filament food-grade PP abrasive cover and its injection molding process to solve the problems raised in the above background art.

[0006] To achieve the above purpose, the present invention provides the following technical solution: A wear-resistant and anti-gum filament food-grade PP abrasive cover, by weight, includes: 100 - 150 parts of food-grade PP resin, 5 - 10 parts of wear-resistant additive, 2 - 5 parts of anti-gum filament auxiliary agent, 0.5 - 1 part of antioxidant, 0.5 - 1 part of lubricant. After accurately weighing the food-grade PP resin, wear-resistant additive, anti-gum filament auxiliary agent, antioxidant, and lubricant, place them in a high-speed mixer and stir at a speed of 800 - 1200 r / min for 10 - 15 minutes to ensure that all raw materials are fully and evenly mixed.

[0007] Preferably, by weight, it includes: 100 parts of the food-grade PP resin, 5 parts of wear-resistant additive, 3 parts of anti-gum filament auxiliary agent, 0.8 part of antioxidant, and 0.5 part of lubricant.

[0008] Preferably, the wear-resistant additive is selected from nano-silica and silicon carbide.

[0009] Preferably, the anti-gum filament auxiliary agent contains organosilicon compounds to prevent the generation of gum filaments.

[0010] The injection molding process of the wear-resistant and anti-gumming wire food-grade PP grinding cover specifically includes the following steps:

[0011] S1. In this stage, 100 - 150 parts of food-grade PP resin, 5 - 10 parts of wear-resistant additive, 2 - 5 parts of anti-gumming wire additive, 0.5 - 1 part of antioxidant, and 0.5 - 1 part of lubricant are heated to a molten state to make them have fluidity;

[0012] S2. The two halves of the mold are combined to form the shape of the product. The accuracy and force of mold closing are crucial for ensuring the dimensional accuracy and structural integrity of the product;

[0013] S3. The molten plastic is injected into the cavity of the mold under high pressure, and the injection speed, pressure, and time parameters will all affect the quality and appearance of the product;

[0014] S4. After injection, the mold and the plastic start to cool. The purpose of cooling is to solidify the plastic and maintain its shape and structure;

[0015] S5. The two halves of the processed mold are separated to expose the formed product;

[0016] S6. Use ejector pins or other ejection mechanisms to push the product out of the mold;

[0017] S7. To avoid contamination and errors that may be brought by manual operation, use a manipulator to take out the product from the mold and possibly perform subsequent sorting or quality inspection;

[0018] S8. Next cycle action: After the above steps are completed, the mold is ready for the production of the next product.

[0019] Preferably, in S1, the uniformly stirred raw materials are put into a twin-screw extruder for melt blending. The temperature of the extruder is set as follows: zone 1: 180 - 200 °C, zone 2: 200 - 220 °C, zone 3: 220 - 240 °C, zone 4: 240 - 260 °C, and the head temperature is 260 - 280 °C. Under the condition that the screw speed is 200 - 300 r / min, the raw materials are fully melted and mixed in the extruder, and then extruded through the die head, cooled by water, drawn into strips, and pelletized to obtain the wear-resistant and anti-gumming wire food-grade PP masterbatch.

[0020] Preferably, in S3, the prepared masterbatch is added to the hopper of the injection molding machine. The temperature of the injection molding machine is set as follows: feeding section 180 - 200 °C, compression section 200 - 220 °C, homogenization section 220 - 240 °C. The mold temperature is controlled at 40 - 60 °C, the injection pressure is 80 - 120 MPa, the holding pressure is 60 - 80 MPa, the holding time is 10 - 15 seconds, and the cooling time is 15 - 20 seconds.

[0021] Preferably, the processed and formed grinding cover is subjected to surface grinding treatment to remove burrs and defects on the surface, improve the surface finish, and place it in an ultraviolet sterilization device. Under the irradiation of ultraviolet light with a wavelength of 254 nm, it is sterilized for 10-15 minutes.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] (1) By adding wear-resistant additives such as nano-silica and silicon carbide, these additives have high hardness and good wear resistance. They are evenly dispersed in the food-grade PP resin matrix. During the use of the product, when subjected to friction, the additives can bear part of the frictional force, reduce the wear of the PP resin itself, thus significantly improving the wear resistance of the grinding cover, extending the service life of the product, reducing the replacement frequency, and at the same time avoiding the problem of foreign matter pollution caused by product wear during the grinding of seasonings.

[0024] (2) The anti-gumming wire aid contains organosilicon compounds. Organosilicon compounds have low surface energy and good lubricity. During the grinding process, it can reduce the frictional force between the plastic and the grinding material, reduce the breakage and wire drawing phenomena of the plastic caused by friction, effectively prevent the generation of gum wires, avoid contaminating the ground food, and ensure the safety and hygiene of the food. Specific embodiments

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0026] The present invention provides a wear-resistant and anti-gumming wire food-grade PP grinding cover and its injection molding process. By weight, it includes: 100-150 parts of food-grade PP resin, 5-10 parts of wear-resistant additive, 2-5 parts of anti-gumming wire aid, 0.5-1 part of antioxidant, and 0.5-1 part of lubricant. After accurately weighing the above raw materials, they are placed in a high-speed mixer and stirred at a speed of 800-1200 r / min for 10-15 minutes to ensure that all raw materials are fully and evenly mixed.

[0027] Food-grade PP resin: As the basic material, it has good processing performance and chemical stability, providing basic physical property guarantees for the grinding cover, ensuring that the product can withstand certain external forces during daily use without breakage or other damage.

[0028] Wear-resistant additive: Materials such as nano-silica and silicon carbide are selected. These additives have high hardness and excellent wear-resistant performance. They are evenly dispersed in the PP resin, which can effectively improve the wear-resistant performance of the grinding cover, significantly extend the service life of the product, reduce material loss caused by friction during long-term grinding, and lower the probability of problems such as wear and deformation.

[0029] Anti-gumming wire additive: It contains organosilicon compounds. Organosilicon compounds can reduce the friction between the plastic and the grinding material, effectively prevent the generation of gumming wires during grinding, avoid contaminating the ground food, and ensure the safety and hygiene of the food.

[0030] Antioxidant: Its function is to inhibit the oxidation reaction of food-grade PP resin during processing and use, prevent the resin from aging and degrading, maintain the stable performance of the product, and further extend the service life of the grinding cover.

[0031] Lubricant: During the plastic processing process, it can reduce the friction between plastic molecules, improve the fluidity of the plastic, make the raw materials fill the mold cavity more smoothly during injection molding, reduce pressure loss, and lower the energy consumption of the equipment. At the same time, during the use of the product, it can also make the grinding operation smoother and improve the user experience.

[0032] By weight, it includes: 100 parts of the food-grade PP resin, 5 parts of the wear-resistant additive, 3 parts of the anti-gumming wire additive, 0.8 parts of the antioxidant, and 0.5 parts of the lubricant.

[0033] The injection molding process of the wear-resistant and anti-gumming wire food-grade PP grinding cover specifically includes the following steps:

[0034] S1. In this stage, 100 - 150 parts of the food-grade PP resin, 5 - 10 parts of the wear-resistant additive, 2 - 5 parts of the anti-gumming wire additive, 0.5 - 1 part of the antioxidant, and 0.5 - 1 part of the lubricant are heated to the molten state to make them have fluidity;

[0035] S2. The two halves of the mold are combined to form the shape of the product. The accuracy and strength of mold closing are crucial for ensuring the dimensional accuracy and structural integrity of the product;

[0036] S3. The molten plastic is injected into the cavity of the mold under high pressure, and the injection speed, pressure, and time parameters will all affect the quality and appearance of the product;

[0037] S4. After injection, the mold and the plastic start to cool. The purpose of cooling is to solidify the plastic and maintain its shape and structure;

[0038] S5. The two halves of the processed mold are separated to expose the molded product;

[0039] S6. Use ejector pins or other ejection mechanisms to push the product out of the mold;

[0040] S7. To avoid the pollution and errors that may be brought by manual operation, a manipulator is used to take out the product from the mold, and subsequent sorting or quality inspection may be carried out.

[0041] S8. Next cycle action: After the above steps are completed, the mold is ready for the production of the next product.

[0042] Example 1

[0043] Raw material preparation: Accurately weigh 100 parts of food-grade PP resin, 5 parts of wear-resistant additive (nano-silica), 3 parts of anti-gumming wire additive (containing organosilicon compound), 0.8 part of antioxidant, and 0.5 part of lubricant. Place these raw materials in a high-speed mixer and stir at a speed of 1000 r / min for 12 minutes to make the raw materials fully mixed and uniform.

[0044] Injection molding process

[0045] S1: Raw material melting: Put the evenly stirred raw materials into a twin-screw extruder, and carry out melt blending according to the temperature settings of 180°C in zone 1, 200°C in zone 2, 220°C in zone 3, 240°C in zone 4, and 260°C at the die head. Control the screw speed at 220 r / min. After the raw materials are fully melted and mixed in the extruder, they are extruded through the die head, and are made into wear-resistant and anti-gumming wire food-grade PP masterbatch through water-cooled stretching and granulation.

[0046] S2: Mold clamping: Precisely combine the two halves of the mold to ensure that the mold clamping accuracy and force meet the requirements, and form the product shape of the grinding cover.

[0047] S3: Injection: Add the prepared masterbatch to the hopper of the injection molding machine, set the temperature of the feeding section of the injection molding machine to 180°C, the compression section to 200°C, and the homogenization section to 220°C. Control the mold temperature at 45°C, the injection pressure at 90 MPa, the holding pressure at 65 MPa, and the holding time at 12 seconds. Under the action of high pressure, inject the molten plastic into the mold cavity.

[0048] S4: Cooling: After injection is completed, the mold and the plastic start to cool, and the cooling time is set to 16 seconds to solidify the plastic and maintain its shape structure.

[0049] S5: Mold opening: Separate the two halves of the mold to expose the formed grinding cover.

[0050] S6: Ejection: Use the ejector pin to smoothly eject the product from the mold.

[0051] S7: Post-treatment: Use a manipulator to take out the grinding cover, perform surface grinding treatment on it to remove surface burrs and defects, improve the surface finish, and then place the grinding cover in an ultraviolet sterilization device and perform sterilization treatment for 12 minutes under ultraviolet irradiation with a wavelength of 254 nm.

[0052] S8: Cyclic production: After completing the above steps, the mold is ready for the production of the next product.

[0053] Example 2

[0054] Raw material preparation: Weigh 120 parts of food-grade PP resin, 8 parts of wear-resistant additive (silicon carbide), 4 parts of anti-gumming wire additive, 0.9 part of antioxidant, and 0.8 part of lubricant. Put them into a high-speed mixer and stir at a speed of 1100 r / min for 13 minutes to achieve full mixing of the raw materials.

[0055] Injection molding process

[0056] S1: Melting of raw materials: Put the mixed raw materials into a twin-screw extruder. Set the extruder temperature as zone 1: 190 °C, zone 2: 210 °C, zone 3: 230 °C, zone 4: 250 °C, and head temperature: 270 °C. The screw speed is 250 r / min. After extrusion, water cooling, drawing, and pelletizing, masterbatch is obtained.

[0057] S2: Mold clamping: Clamp the mold precisely to ensure that the mold forms an accurate shape of the grinding cover.

[0058] S3: Injection: Add the masterbatch to the hopper of the injection molding machine. Set the feeding section temperature of the injection molding machine as 190 °C, compression section temperature as 210 °C, homogenization section temperature as 230 °C, mold temperature as 50 °C, injection pressure as 100 MPa, holding pressure as 70 MPa, and holding time as 13 seconds. Inject the molten plastic into the cavity.

[0059] S4: Cooling: The cooling time is 18 seconds to ensure that the plastic is fully cured.

[0060] S5 - S8: Perform mold opening, ejection, removal by robot, grinding, and ultraviolet sterilization in sequence (grinding improves the surface finish, and ultraviolet sterilization lasts for 13 minutes). Then the mold enters the next production cycle.

[0061] Example 3

[0062] Raw material preparation: Measure 100 parts of food-grade PP resin, 5 parts of wear-resistant additive (a 1:1 mixture of nano-silica and silicon carbide), 2 parts of anti-gumming wire additive, 0.5 part of antioxidant, and 0.5 part of lubricant. Stir in a high-speed mixer at a speed of 800 r / min for 10 minutes to mix evenly.

[0063] Injection molding process

[0064] S1: Melting of raw materials: Put the raw materials into a twin-screw extruder. Set the extruder temperature as zone 1: 180 °C, zone 2: 200 °C, zone 3: 220 °C, zone 4: 240 °C, and head temperature: 260 °C. The screw speed is 200 r / min to prepare the masterbatch.

[0065] S2: Mold closing: Accurately close the mold to ensure the forming accuracy of the mold.

[0066] S3: Injection: Add masterbatch to the hopper of the injection molding machine. Set the temperature of the feeding section of the injection molding machine to 180°C, the compression section to 200°C, the homogenization section to 220°C, the mold temperature to 40°C, the injection pressure to 80 MPa, the holding pressure to 60 MPa, and the holding time to 10 seconds to complete plastic injection.

[0067] S4: Cooling: Control the cooling time within 15 seconds.

[0068] S5 - S8: Complete the mold opening and ejection operations. Use a manipulator to take out the product for grinding and 10 - minute ultraviolet sterilization treatment. The mold is ready for the production of the next product.

[0069] Comparative Example 1: Do not add wear - resistant additives and anti - sticking wire additives. Other raw materials and preparation steps are the same as those in Examples 1 - 3.

[0070] Table 1 Comparative Experimental Results of the Grinding Cover of the Invention and the Traditional Grinding Cover in Comparative Example 1

[0071]

[0072]

[0073] Wear Resistance Analysis

[0074] After simulating 1000 - time grinding tests, the wear amounts of Examples 1, 2, and 3 are 20 mg, 18 mg, and 22 mg respectively, while the wear amount of Comparative Example 1 is as high as 50 mg. This shows that by adding wear - resistant additives to the raw materials, the invention significantly improves the wear resistance of the grinding cover. Comparing each example, Example 2 has the lowest wear amount in the wear resistance test because 8 parts of silicon carbide are used as the wear - resistant additive. It indicates that within a certain range, increasing the dosage of wear - resistant additives or reasonably selecting the type of additives can further enhance the wear resistance of the product.

[0075] Anti - Sticking Wire Performance Analysis

[0076] From the observation results of the anti - sticking wire performance, almost no sticking wire is generated in Example 1, there is a small amount of sticking wire in Example 2, there is a small amount of sticking wire in Example 3, while a large amount of sticking wire appears in Comparative Example 1. This result fully proves that the anti - sticking wire additive added in the invention effectively inhibits the generation of sticking wire. Example 1 shows the best anti - sticking wire performance with an optimized raw material ratio, indicating that scientific raw material formula design is crucial for improving the anti - sticking wire performance of the product.

[0077] Surface Finish Analysis

[0078] The Ra values of the surface finish of Examples 1, 2, and 3 are 0.8 μm, 0.7 μm, and 0.9 μm respectively, while the Ra value of Comparative Example 1 is 1.5 μm. The grinding cover prepared by the present invention is significantly superior to Comparative Example 1 in terms of surface finish. The surface finish of Example 2 is the best, which may benefit from the optimization of its injection molding process parameters. Appropriate temperature, pressure, and cooling time contribute to improving the surface quality of the product.

[0079] Food-grade safety detection and analysis

[0080] Examples 1, 2, and 3 all meet the food-grade safety detection standards, while some indicators of Comparative Example 1 do not meet the requirements. This shows that in the raw material selection and preparation process of the present invention, the product quality is strictly controlled, ensuring the safety of the product and meeting the usage requirements of fields with high safety requirements such as food processing.

[0081] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Wear-resistant and anti-glue food-grade PP grinding cover, characterized by: Measured by weight, it includes: 100-150 parts of food-grade PP resin, 5-10 parts of wear-resistant additives, 2-5 parts of anti-glue auxiliary agents, 0.5-1 parts of antioxidants, and 0.5-1 parts of lubricants. After accurately weighing the food-grade PP resin, wear-resistant additives, anti-glue auxiliary agents, antioxidants, and lubricants, place them in a high-speed mixer and stir them at a speed of 800-1200r / min for 10-15 minutes to ensure that all the raw materials are fully mixed.

2. The wear-resistant and anti-glue food-grade PP grinding cover according to claim 1 is characterized by: Calculated by weight, it includes: 100 parts of the food-grade PP resin, 5 parts of wear-resistant additives, 3 parts of anti-glue additives, 0.8 parts of antioxidants, and 0.5 parts of lubricants.

3. The wear-resistant and anti-glue food-grade PP grinding cover according to claim 1 is characterized by: The wear-resistant additives are nano silicon dioxide and silicon carbide.

4. The wear-resistant and anti-glue food-grade PP grinding cover according to claim 3 is characterized by: The anti-glue auxiliary agent contains organic silicon compound to prevent the generation of glue threads.

5. An injection molding process for the wear-resistant and anti-glue food-grade PP grinding cover according to any one of claims 1 to 4, characterized in that: The specific steps include: S1. In this stage, 100-150 parts of food-grade PP resin, 5-10 parts of wear-resistant additives, 2-5 parts of anti-glue additives, 0.5-1 parts of antioxidants, and 0.5-1 parts of lubricants are heated to a molten state to make them fluid; S2. The two halves of the mold are combined to form the shape of the product. The precision and strength of the mold closing are crucial to ensure the dimensional accuracy and structural integrity of the product; S3. The molten plastic is injected into the mold cavity under high pressure, and the injection speed, pressure and time parameters will affect the quality and appearance of the product; S4. After the injection is completed, the mold and plastic begin to cool. The purpose of cooling is to solidify the plastic and maintain its shape and structure. S5, separating the two halves of the processed mold to expose the formed product; S6. Use ejector pins or other ejection mechanisms to push the product out of the mold; S7. In order to avoid possible contamination and errors caused by manual operation, a robot is used to remove the product from the mold, and subsequent sorting or quality inspection may be carried out; S8, next cycle action: After the above steps are completed, the mold is ready to produce the next product.

6. The injection molding process of the wear-resistant and anti-glue food-grade PP grinding cover according to claim 5 is characterized in that: In S1, the uniformly stirred raw materials are put into a twin-screw extruder for melt blending. The temperature of the extruder is set to: 180-200°C for zone 1, 200-220°C for zone 2, 220-240°C for zone 3, 240-260°C for zone 4, and the head temperature is 260-280°C. Under the condition of a screw speed of 200-300r / min, the raw materials are fully melted and mixed in the extruder, and then extruded through a die head, and water-cooled, drawn, and pelletized to obtain wear-resistant and anti-glue food-grade PP masterbatch.

7. The injection molding process of the wear-resistant and anti-glue food-grade PP grinding cover according to claim 5 is characterized by: In S3, the prepared masterbatch is added to the hopper of the injection molding machine, and the temperature of the injection molding machine is set as follows: 180-200°C in the feeding section, 200-220°C in the compression section, and 220-240°C in the homogenization section. The mold temperature is controlled at 40-60°C, the injection pressure is 80-120MPa, the holding pressure is 60-80MPa, the holding time is 10-15 seconds, and the cooling time is 15-20 seconds.

8. The injection molding process of the wear-resistant and anti-glue food-grade PP grinding cover according to claim 5 is characterized by: The processed grinding cover is surface polished to remove burrs and flaws on the surface and improve the surface smoothness. It is then placed in an ultraviolet sterilization device and sterilized for 10-15 minutes under ultraviolet light with a wavelength of 254nm.

Images