As a highly standardized product in modern industry, injection molding water cup needs to follow strict technical specifications in each link of its production process. Based on the general technical standards and production practices in the industry, this paper analyzes the core process of injection molding cup production from the dimensions of technical principles, parameter Settings and quality control, aiming to provide an objective reference for purchasers, technical practitioners and injection molding mold processing.
First, mold design and precision control: the scientific basis of the sealing structure
Mold is the core carrier of injection molding process, and its design needs to take into account function, production efficiency and cost control.
1. Optimization of parting surface and flow path: simulate the melt flow path through mold flow analysis software (such as Moldflow) to reduce the risk of leakage caused by fusion marks. It has been shown that for every 10% increase in the cross-sectional area of the flow channel, the filling time can be shortened by about 15%.
2. Thread matching accuracy: stepwise thread design with 0.05mm mold processing tolerance, can meet the air tightness test standards (such as negative pressure 0.08MPa pressure holding 30 seconds without leakage).
3. Temperature balanced design: the mold built-in multi-point independent cooling circuit, the temperature difference is controlled within ±2℃, to avoid deformation caused by uneven shrinkage, this technology has been widely used in the production of food grade water cups.
Two, material selection and performance verification: safety and durability of the dual considerations
The properties of plastic raw materials directly affect the final quality of products, which need to pass a number of international certifications and laboratory tests.
1. Comparison of mainstream materials:
PP (polypropylene) : temperature 120℃, in line with FDA certification, impact strength of 86.8MPa, suitable for microwave scene.
PET: the advantages of lightweight are obvious, but the temperature resistance is only 70℃, and it is mostly used for disposable water cups.
2. Additive management: the proportion of non-migratory pigments and antioxidants (such as Irganox 1010) should be controlled at 0.5%-1% to avoid affecting food safety.
3. Recycling material limit: the industry generally requires that the proportion of recycled PP is ≤10% to ensure that the material strength and health indicators meet the standards.
3. Optimization of injection molding parameters: systematic engineering to balance efficiency and quality
The precise control of process parameters should be combined with equipment performance and material characteristics. Common technical indicators include:
1. Temperature gradient control:
The barrel is heated in sections (180-240℃ gradient heating) to prevent material degradation.
Mold temperature 20-60℃, too high will lead to prolonged cooling time, affecting production efficiency.
2. Pressure and speed match:
The injection pressure is 80-140MPa, and the thin-walled parts should be raised to 180MPa to ensure the filling integrity.
The back pressure of 5-20MPa can effectively exclude melt bubbles, but too high will reduce the plasticization efficiency.
3. Production cycle control: the typical injection cycle is 15-30 seconds, of which the cooling time accounts for about 60%.
Fourth, post-processing technology: the key link of functional improvement
The processing after molding directly affects the user experience and product life, and needs to follow quantifiable testing standards.
1. Surface treatment technology:
Ultrasonic deburring technology can control the cup roughness at Ra≤0.8μm.
Double color injection molding process through the rotating core mold to achieve a double layer structure, thermal insulation performance increased by 30%.
2. Sealing test: using underwater pressure test (0.1MPa for 1 minute), the factory pass rate should be ≥99.5%.
3. Durability test: simulation of 1.2m drop, -20℃ to 100℃ thermal cycle and other extreme scenarios, to ensure the service life of ≥3 years.
V. Quality control system: full link traceability from raw materials to finished products
Raw material detection: melt finger meter (MFR) was used to test the fluidity, and infrared spectrum (FTIR) was used to verify the consistency of components.
Process monitoring: The online sensor collects the pressure and temperature data of the injection molding machine in real time, and the alarm is triggered when the fluctuation exceeds ±5%.
Environmental compliance: through ROHS, REACH and other certifications, the proportion of bio-based PP materials used has increased to 15% year by year.
Technology trends and industry challenges
At present, the injection molding water cup process is facing two major transformations:
Intelligent upgrade: AI parameter optimization system can increase the yield by 5%-8%, but the cost of equipment modification is high.
Exploration of environmental protection: The industrial application of degradable additives (such as PLA) is still limited by the balance between cost and performance.
ZIBO HUIWEN Plastics offers a full range of plastic molding capabilities to efficiently mass-produce parts specializing in injection molding and have served customers in variety of industries such as medical, automotive, packaging, construction, home appliances , and agriculture. The company has two factories which occupy a total area of more than 18,000 square meters, and a total of 102 sets of injection molding machines .
COmpetitive products:
3.500+ Material Choices Custom Injection Molding
Source of technical data:
In this paper, the process parameters refer to "Plastic water Cup Forming Process" (GB/T 18006.1-202X), SPE technical white paper and public report of third-party testing institutions.
