English
Español
عربى1. Material selection and preparation
Material selection: Choose high molecular weight polypropylene (PP) material, which can maintain good stability and mechanical properties at high temperatures, while also having good heat resistance, chemical stability, and portability.
Material pretreatment: Prior to injection molding, the polypropylene material is dried to remove moisture and prevent the formation of bubbles or defects during the injection molding process.
2. Mold design and manufacturing
Mold design: Produce corresponding molds according to the design requirements of polypropylene injection cups. Molds are typically made of metal, such as steel or aluminum, to ensure high precision and durability. When designing, factors such as parting surface, pouring system, and molded parts need to be considered to ensure that the plastic melt can evenly fill the mold cavity and smoothly demold.
Mold preheating: Preheat the mold before injection molding to improve the flowability and molding effect of the plastic material.
3. Injection molding process
Plastic heating and plasticization: Polypropylene particles are fed into the heating cylinder of an injection molding machine and heated to a molten state by a heater. The heating temperature is usually between 220 ° C and 280 ° C, and the specific temperature is adjusted according to the equipment model and production conditions. At the same time, the screw rotates inside the heating cylinder, pushing the molten polypropylene towards the injection position and achieving uniform mixing.
Injection: When the plastic melt reaches the appropriate temperature and pressure, the screw moves forward and injects the melted polypropylene into the mold cavity at high speed through the nozzle. The injection speed and pressure are adjusted according to the requirements of the polypropylene injection cup to ensure that the plastic melt can evenly fill the mold and avoid defects.
Pressure holding and cooling: After injection, the screw continues to apply pressure (pressure holding) to supplement the reduced material due to cooling shrinkage, ensuring the precise size of the polypropylene injection cup. At the same time, the mold is usually equipped with cooling channels inside, which take away heat through circulating coolant and accelerate the cooling process. The cooling time is adjusted according to the thickness and material characteristics of the product, usually ranging from a few seconds to a few minutes.
4. Post processing and quality control
Demolding: After cooling, the mold is opened and the molded polypropylene injection cup is ejected from the mold through an ejector rod or ejector plate.
Deburring and trimming: Remove burrs and excess material from the edges of polypropylene injection cups to improve the appearance and dimensional accuracy of the product.
Quality inspection: Conduct quality inspection on polypropylene injection cups, including size measurement, appearance inspection, sealing performance testing, etc., to ensure that the product meets design requirements.
5. Packaging and Storage
Pack the polypropylene injection cups that have undergone quality inspection to prevent damage during storage and transportation. The packaging material should have good sealing and barrier properties to ensure that the polypropylene injection molded cup remains dry and clean during storage. At the same time, store the packaged polypropylene injection cups in a cool, dry, and ventilated place to avoid moisture and spoilage.
