Multifunctional draining basket shell forming preparation process
By fully drying the PET raw material, using segmented temperature control and gradient cooling processes, the problems of bubbles and silver streaks in the molding process of the drain basket shell were solved, achieving the production of high-quality drain basket shells with good transparency and strength.
Patent Information
- Application Number
- CN202511189428.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-25
- Publication Date
- 2025-12-02
AI Technical Summary
During the molding process of the drain basket shell, residual moisture that is not removed quickly vaporizes, causing defects such as bubbles and silver streaks, which affect the product's appearance and structural integrity.
By thoroughly drying the PET raw materials, using segmented temperature control and gradient cooling methods, and combining specific additives for modification, we ensure that the molten material melts and crystallizes uniformly, thus avoiding the generation of defects such as bubbles and silver streaks.
The improved transparency and overall strength of the drain basket shell significantly enhance product quality and production efficiency, meeting market demands.
Smart Images
Figure CN121043364A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of drain basket shell preparation technology, specifically a multifunctional drain basket shell forming and preparation process. Background Technology
[0002] As a tool in the kitchen, the drain basket plays a crucial role in draining residual water from washed fruits and vegetables. Its draining efficiency, durability, and safety directly affect the convenience and hygiene of daily cooking, and therefore it has always been a key focus for consumers. From the perspective of market product structure, due to the advantages of plastic materials such as being lightweight and portable, having a smooth and easy-to-clean surface, and being cost-effective, more than 80% of drain baskets on the market are currently made of plastic. Among the many plastic materials, PET (polyethylene terephthalate) is widely used due to its good transparency, mechanical strength, and chemical resistance. Food-grade PET material meets national food safety standards and is not prone to releasing harmful substances at high temperatures, so there is no need to worry about health hazards when using it, which makes it more popular in home kitchens.
[0003] During daily storage and handling, PET raw materials are prone to absorbing moisture from the air due to environmental humidity. Existing patent CN118752726A discloses an injection molding method for rPET, including the following steps: Step 1) Drying rPET granules at 150℃ for 4-8 hours to remove residual moisture and prevent hydrolysis and degradation; Step 2) Selecting an injection molding machine with a screw length-to-diameter ratio (L / D) of 25-27 and a compression ratio of 2.5-3.1 to ensure the plasticization quality of rPET; Step 3) Controlling the mold cooling water temperature at 15-18℃ to ensure uniform cooling and dimensional stability during product molding; Step 4) During injection molding, controlling the screw speed at 60-90 rpm, the back pressure at 5-10 kg / cm², the barrel temperature at 260-280℃, and the melt residence time within 5 minutes.
[0004] However, during the production of drain baskets, residual moisture that is not removed will rapidly vaporize during the heating process of forming the outer shell of the drain basket. If the vaporized gas cannot be discharged in time, it will form obvious defects such as bubbles and silver streaks inside or on the surface of the product. Bubbles will cause uneven density of the material in some areas of the outer shell, while silver streaks will be distributed on the surface of the product in the form of irregular patterns. This not only seriously damages the appearance integrity of the drain basket outer shell, making the product lose its smooth and clean visual texture, but also causes hidden damage to the product structure. Summary of the Invention
[0005] The purpose of this invention is to provide a multifunctional drain basket shell forming process to solve the problem that residual moisture that is not removed during the production of drain baskets will rapidly vaporize during the heating process of the drain basket shell forming. The gas generated by vaporization cannot be discharged in time, which will form obvious defects such as bubbles and silver streaks inside or on the surface of the product.
[0006] To achieve the above objectives, the present invention provides the following technical solution:
[0007] A process for forming and manufacturing the outer shell of a multifunctional drain basket includes the following steps:
[0008] (1) Raw material pretreatment: PET raw materials are selected and dried using a dryer for 6 hours;
[0009] (2) Melting treatment: The PET raw material after step (1) is added to the injection molding machine, and the PET material is melted evenly by controlling the screw heating temperature;
[0010] (3) Injection molding: Inject the molten material obtained in step (2) into the mold, control the hot runner mold temperature to 120℃, adopt a centrally symmetrical gate, after the drain basket shell is injection molded, the pouring point is located at the center of the bottom of the shell, the gate position is precisely laid out, so that the melt fills the cavity synchronously and evenly from the gate, reducing weld lines, flow lines and stress concentration.
[0011] (4) Cooling and molding: After the molten material is injected into the mold cavity, the mold is cooled to allow the PET molten material to crystallize and form, while controlling the mold temperature within the range of 20-25℃;
[0012] (5) Demolding: After molding is completed, remove the molded drain basket shell from the mold.
[0013] Preferably, in step (1), the drying temperature of the dryer is 160-180℃.
[0014] Preferably, in step (2), the screw heating temperature is controlled in three sections along the material flow direction: the first section temperature is 240-250℃, the second section temperature is 250-260℃, and the third section temperature is 260-270℃.
[0015] Preferably, in step (3), the injection pressure is 80-100MPa and the injection speed is 50-80mm / s.
[0016] Preferably, in step (1), the PET raw material is made by mixing and granulating 95% PET chips, 3% maleic anhydride-grafted POE, and 2% nano-SiO2 by mass ratio.
[0017] Preferably, in step (4), the cooling process is controlled in stages.
[0018] Preferably, in the first stage of cooling, the mold temperature is rapidly reduced from 120°C to 40°C using an ice water machine;
[0019] In the second cooling stage, the system switches to a warm water machine, using 25℃ warm water to circulate, and the mold temperature is stabilized at 30-35℃.
[0020] In the third cooling stage, the process switches back to chiller cooling, and the mold temperature drops to 20-25℃.
[0021] Preferably, the cooling water temperature of the chiller system is 5-10℃.
[0022] Compared with the prior art, the beneficial effects of the present invention are:
[0023] 1. This invention, by thoroughly drying the PET raw material, removes moisture, preventing defects such as bubbles and silver streaks during molding, thus improving product quality.
[0024] 2. The screw heating temperature is precisely controlled by segmented temperature control, which ensures that the PET material melts evenly, avoids material degradation caused by local overheating, and guarantees the quality of the melt.
[0025] 3. By controlling the crystallization process through gradient cooling, the crystallinity of PET is stabilized at 25-30%, the heat distortion temperature of the product is increased from 70℃ to 85℃, and the dimensional stability is reduced from 1.2% to 0.5%.
[0026] In summary, the multifunctional drain basket shell forming process of the present invention not only improves production efficiency, but also significantly enhances the forming quality of the drain basket, giving it excellent transparency and overall strength, thus better meeting market demands. Attached Figure Description
[0027] Figure 1 This is a flowchart of the present invention. Detailed Implementation
[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.
[0029] Please see Figure 1 The present invention provides a technical solution.
[0030] A process for forming and manufacturing the outer shell of a multifunctional drain basket includes the following steps:
[0031] (1) Raw material pretreatment: High-quality PET raw materials are selected and dried using a European-style dryer for 6 hours. The moisture in the PET raw materials will cause defects such as bubbles and silver lines in the product during the molding process, affecting the product quality. The 6-hour drying process using the European-style dryer can effectively remove the moisture in the raw materials and ensure the smooth progress of the subsequent molding process. Preferably, the drying temperature of the European-style dryer is 160-180℃. This temperature range can effectively remove moisture while avoiding degradation of the PET raw materials.
[0032] (2) Melting treatment: The PET raw material after step (1) is added to the injection molding machine. The PET material is melted evenly by controlling the screw heating temperature. The screw heating temperature is controlled in three sections along the material flow direction. The temperature of the first section is 240-250℃, the temperature of the second section is 250-260℃, and the temperature of the third section is 260-270℃. This segmented temperature control method can make the PET material melt gradually, avoid local overheating leading to material degradation, and ensure the uniformity of the melt.
[0033] (3) Injection molding: Inject the molten material obtained in step (2) into the mold, and control the hot runner mold temperature at 120℃. Controlling the hot runner mold temperature at 120℃ can ensure that the molten material maintains good fluidity during injection, which is conducive to filling the mold cavity. The injection pressure is 80-100MPa and the injection speed is 50-80mm / s. This parameter range can ensure that the molten material fills the mold cavity smoothly and avoid defects such as missing material and flash.
[0034] (4) Cooling and molding: After the molten material is injected into the mold cavity, the mold is cooled by an ice water system to allow the PET molten material to crystallize and form. At the same time, the mold temperature is controlled within the range of 20-25℃. The cooling water temperature of the ice water system is 5-10℃, which can achieve rapid cooling of the mold. Rapid cooling allows the PET molten material to crystallize and form instantly, reducing thermal stress and internal orientation effect of the material, thereby improving the transparency and dimensional stability of the product. Then, it can be switched to a warm water machine for circulation and heat preservation, and then switched back to a cold water machine to lock and cool down to 20-25℃. The mold temperature is controlled within the range of 20-25℃, which can ensure that the crystallinity of the PET material is moderate and further improve the mechanical strength of the product.
[0035] (5) Demolding: After molding is completed, the molded drain basket shell is removed from the mold to obtain the final product.
[0036] A melt blending modification step is added before the traditional drying step to resolve the inherent contradiction between PET's brittleness and transparency by adding specific additives.
[0037] Modified formulation: Mix 95% PET chips + 3% maleic anhydride-grafted POE (toughening agent) + 2% nano-SiO2 (0.01-0.05μm, transparency promoter) by weight.
[0038] Processing method: Add the mixture to a twin-screw extruder, melt-blend at 250-260℃, granulate, and then dry in an Ouhua dryer;
[0039] Nano-SiO2 can induce PET to form uniform microcrystals (size <50nm, without affecting light transmittance). At the same time, POE molecular chains are embedded in the PET matrix to alleviate stress concentration. Experimental data show that this modification increases the impact strength to over 25kJ / m², while maintaining light transmittance of over 88% (traditional toughening agents will reduce light transmittance by 5-8%).
[0040]
[0041] Cooling process controlled in stages:
[0042] First stage (0-5 seconds): Powerful cooling by an ice water machine, the mold temperature drops rapidly from 120℃ to 40℃ (cooling rate 16℃ / s), inhibiting excessive movement of PET molecular chains;
[0043] Second stage (5-15 seconds): Switch to a warm water machine, use 25℃ warm water to circulate, stabilize the mold temperature at 30-35℃ (hold for 10 seconds), promote the formation of uniform microcrystal nuclei in PET;
[0044] The third stage (15-20 seconds): switch back to the chiller for cooling, and the mold temperature drops to 20-25℃, locking in the crystallization form.
[0045] By controlling the crystallization process through gradient cooling, the crystallinity of PET is stabilized at 25-30% (compared to 15-40% for traditional processes), the heat distortion temperature of the product is increased from 70℃ to 85℃ (which can withstand hot water washing), and the dimensional stability (heat shrinkage rate) is reduced from 1.2% to 0.5%.
[0046] Specifically: Example 1, a process for forming and manufacturing a multifunctional drain basket shell, includes the following steps:
[0047] (1) Raw material pretreatment: PET raw materials are selected and dried at 160℃ using an Ouhua dryer for 6 hours.
[0048] (2) Melting treatment: The PET raw material after step (1) is added to the injection molding machine. The screw heating temperature is controlled in three sections along the material flow direction. The temperature of the first section is 240℃, the temperature of the second section is 250℃, and the temperature of the third section is 260℃, so that the PET material melts evenly.
[0049] (3) Injection molding: Inject the molten material obtained in step (2) into the mold, control the hot runner mold temperature to be 120℃, the injection pressure to be 80MPa, and the injection speed to be 50mm / s.
[0050] (4) Cooling and molding: After the molten material is injected into the mold cavity, the mold is cooled by an ice water system (cooling water temperature is 5℃) to make the PET molten material crystallize and form, while controlling the mold temperature at 20℃.
[0051] (5) Demolding: After molding is completed, remove the molded drain basket shell from the mold.
[0052] Example 2: A process for forming and manufacturing the outer shell of a multifunctional drain basket, comprising the following steps:
[0053] (1) Raw material pretreatment: PET raw materials are selected and dried at 170°C using an Ouhua dryer for 6 hours.
[0054] (2) Melting treatment: The PET raw material after step (1) is added to the injection molding machine. The screw heating temperature is controlled in three sections along the material flow direction. The temperature of the first section is 245℃, the temperature of the second section is 255℃, and the temperature of the third section is 265℃, so that the PET material melts evenly.
[0055] (3) Injection molding: Inject the molten material obtained in step (2) into the mold, control the hot runner mold temperature to be 120℃, the injection pressure to be 90MPa, and the injection speed to be 65mm / s.
[0056] (4) Cooling and molding: After the molten material is injected into the mold cavity, the mold is cooled by an ice water system (cooling water temperature is 8℃) to make the PET molten material crystallize and form, while controlling the mold temperature at 23℃.
[0057] (5) Demolding: After molding is completed, remove the molded drain basket shell from the mold.
[0058]
[0059] Example 3: A process for forming and manufacturing the outer shell of a multifunctional drain basket, comprising the following steps:
[0060] (1) Raw material pretreatment: PET raw materials are selected and dried at 180°C using an Ouhua dryer for 6 hours.
[0061] (2) Melting treatment: The PET raw material after step (1) is added to the injection molding machine. The screw heating temperature is controlled in three sections along the material flow direction. The temperature of the first section is 250℃, the temperature of the second section is 260℃, and the temperature of the third section is 270℃, so that the PET material melts evenly.
[0062] (3) Injection molding: Inject the molten material obtained in step (2) into the mold, control the hot runner mold temperature to be 120℃, the injection pressure to be 100MPa, and the injection speed to be 80mm / s.
[0063] (4) Cooling and molding: After the molten material is injected into the mold cavity, the mold is cooled by an ice water system (cooling water temperature is 10℃) to make the PET molten material crystallize and form, while controlling the mold temperature at 25℃.
[0064] (5) Demolding: After molding is completed, remove the molded drain basket shell from the mold.
[0065] The multifunctional drain basket shells prepared in the above embodiments all have good transparency and overall strength, and are highly efficient in production, which can meet market demand.
[0066] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A process for forming and manufacturing the outer shell of a multifunctional drain basket, characterized in that, The specific steps are as follows: (1) Raw material pretreatment: PET raw materials are selected and dried using a dryer for 6 hours; (2) Melting treatment: The PET raw material after step (1) is added to the injection molding machine, and the PET material is melted evenly by controlling the screw heating temperature; (3) Injection molding: Inject the molten material obtained in step (2) into the mold, control the hot runner mold temperature to 120℃, and use a centrally symmetrical gate; (4) Cooling and molding: After the molten material is injected into the mold cavity, the mold is cooled to allow the PET molten material to crystallize and form, while controlling the mold temperature within the range of 20-25℃; (5) Demolding: After molding is completed, remove the molded drain basket shell from the mold.
2. The manufacturing process for the shell forming of a multifunctional drain basket according to claim 1, characterized in that, In step (1), the drying temperature of the dryer is 160-180℃.
3. The manufacturing process for the shell of a multifunctional drain basket according to claim 1, characterized in that, In step (2), the screw heating temperature is controlled in three sections along the material flow direction: the first section temperature is 240-250℃, the second section temperature is 250-260℃, and the third section temperature is 260-270℃.
4. The manufacturing process for the shell forming of a multifunctional drain basket according to claim 1, characterized in that, In step (3), the injection pressure is 80-100MPa and the injection speed is 50-80mm / s.
5. The manufacturing process for the shell forming of a multifunctional drain basket according to claim 1, characterized in that, In step (1), the PET raw material is made by mixing and granulating 95% PET chips, 3% maleic anhydride-grafted POE, and 2% nano-SiO2 by mass ratio.
6. The manufacturing process for the shell of a multifunctional drain basket according to claim 1, characterized in that, In step (4), the cooling process is controlled in stages.
7. The manufacturing process for the shell of a multifunctional drain basket according to claim 6, characterized in that, In the first stage of cooling, the mold temperature is rapidly reduced from 120°C to 40°C using an ice water machine; In the second cooling stage, the system switches to a warm water machine, using 25℃ warm water to circulate, and the mold temperature is stabilized at 30-35℃. In the third cooling stage, the process switches back to chiller cooling, and the mold temperature drops to 20-25℃.
8. The manufacturing process for the shell of a multifunctional drain basket according to claim 7, characterized in that, The cooling water temperature of the chiller system is 5-10℃.