Introduction: Processing and production of food-grade plastic sauce cups.

Processing and production of food-grade plastic sauce cup

Food-grade plastic sauce cups are commonly used consumables in catering and food packaging fields, featuring portability, sealing and temperature resistance. The core is made of food-contact plastic raw materials, which are mass-produced through standardized injection molding process. The whole process should strictly follow the food packaging safety standards, control the compliance of raw materials, production cleanliness and finished product performance, and adapt to the single loading and portable use of various sauces such as salad dressing, tomato sauce, Chili sauce and sauce. The following is its complete processing and production process and core.

The selection of raw materials is the core premise of the production of food-grade sauce cups, and it is necessary to give priority to the selection of PP (polypropylene), PS (polystyrene) or PET (polyethylene terephthalate) for food contact. Among them, PP is the mainstream raw material of sauce cups because of its good temperature resistance (-20℃~120℃), microwave heating and good toughness, while PS is suitable for thin-walled sauce cups held at low temperature at one time, with more PET. All raw materials must have the national food contact product inspection report, which meets the national standard of GB 4806.7-2016. It is forbidden to use recycled materials and recycled materials. After the raw materials enter the factory, they must undergo component testing and purity screening to prevent impurities and plasticizers from exceeding the standard.

Before production, raw material pretreatment and mold debugging should be completed, and raw material particles should be treated by hot air dryer to remove moisture (PP material drying temperature is 80~90℃ for 2~3 hours) to avoid bubbles and depressions in the finished product after injection molding; At the same time, according to the specifications of sauce cups (commonly 15ml, 30ml, 50ml and 100ml), the special injection mold should be debugged, and the mold cavity should be polished (surface roughness Ra≤0.4μm) to ensure that the inner wall of the finished product is smooth and burr-free, and the mold should be sterilized at high temperature to avoid oil stain and impurity residue.

The core production link is high-speed injection molding, in which the dried plastic particles are added into the hopper of the injection molding machine, melted by the barrel at high temperature (the melting temperature of PP material is 200-230℃, and that of PS material is 180-210℃), and the molten material is injected into the closed mold cavity through the high pressure of the screw, and the mold is opened after pressure maintaining and shaping, and the blank is automatically taken out by the manipulator. The whole process is completed in a closed environment. The shooting speed, holding pressure and cooling time of the injection molding machine need to be accurately controlled-the cooling time is generally 5-10 seconds, so as to ensure that the finished product is completely shaped without deformation, material shortage, flash and other defects, and the linear speed of mass production can reach 50-100 pieces per minute, which is suitable for the needs of large-scale production.

After molding, strict post-processing and quality control inspection are required. Firstly, the gate and flash of the blank are removed by manual or automatic equipment, and the cup mouth and the cup body are polished to ensure smooth edges without sharp edges to prevent scratching hands. Then enter the clean area for cleaning and disinfection. After high-pressure washing with pure water, it is dried by ultraviolet or hot air (temperature 60~70℃, time 15~20 minutes) to ensure that the finished product has no dust and oil residue. Quality control inspection is the key to the whole process, and the appearance, size, sealing and temperature resistance of finished products are sampled batch by batch: the appearance is free of color difference, deformation and bubbles, and the size deviation is ≤ 0.1 mm; The tightness passed the negative pressure test, and there was no air leakage or water leakage when immersed in water; The temperature resistance is tested by high and low temperature cycles to ensure that the hot and cold sauces are not deformed and harmful substances are not precipitated, and the unqualified products are directly eliminated to prevent them from entering the market.

Finally, for the packaging and storage, after sorting and counting, the finished products are packaged in vacuum with food-grade PE film or aseptic carton, and the information such as raw material material, specification, production date, shelf life, food contact logo and so on should be clearly marked on the packaging; The storage environment should be kept dry, ventilated and dust-free. The temperature should be controlled at 15~25℃ and the relative humidity should be ≤60%. It should be far away from acid, alkali, oil and high temperature environment to prevent the sauce cup from deformation and pollution and ensure the stable performance during storage.

On the whole, the core of the production of food-grade plastic sauce cups is "compliance of raw materials, precise technology and cleanness in the whole process". From raw material screening to finished products leaving the factory, every step revolves around the safety of food packaging, and at the same time, large-scale and low-cost production is realized through high-speed injection molding, which meets the portable, hygienic and standardized requirements of the catering industry for disposable sauce packaging.