Structure of food packaging container

Common bottle caps are as follows (Figure 2):① Crown cap. Originally made of aluminum, it was made of tinned sheet and chrome-plated sheet, and lined with PVC plastic cushion, which was mostly used for packaging beer, soft drinks and seasonings. ② Screw cover. The metal screw cap is made of aluminum plate or tinplate and lined with PVC pad, which is mostly used for packaging solid drinks in jars. Plastic screw caps are made of polyethylene, polyvinyl chloride and other resins, which can be used to package wine, juice drinks, seasonings and solid drinks in narrow or wide-mouth bottles. ③ Unscrew the nut. Also known as anti-theft cover, because there is an indentation at the lower end of the bottle cap, the bottle cap can be twisted off along the indentation line when it is opened to show that the bottle cap has been opened. This kind of cover is an improvement of screw cover, made of aluminum plate, lined with cork, cardboard and aluminum foil, plastic film and so on. , mostly used for wine packaging. ④ Unscrew the cover. Also known as four-turn cover. Made of tinplate or chrome plate. According to the diameter of the bottle (27 ~ 1 10 mm), there are 3, 4, 6 and 8 claws on the edge, lined with PVC plastic pads. Can be used for packaging fruit juice, jam, fruit, baby food, vegetables and meat in narrow-mouth bottles or wide-mouth bottles. ⑤ Press and unscrew the cover. Also known as thermoplastic screw cap, press-in screw cap. This is a new variety developed in 1970s. Made of tinplate or chrome plate. There is a plastic lining around the lid, which is sealed by hot pressing when filling cans. After cooling to room temperature, the plastic lining is formed by multi-thread of the bottle mouth. Its characteristics are fast sealing speed, good sealing performance and convenient opening. The bottle cap has a series of 27 ~ 27~77mm, which is suitable for packaging a variety of foods. ⑥ Bite the lid. Also known as grabbing the cover. Made of sheet metal. Designed to seal the annular glass bottle mouth. When the bottle cap is pressed into the bottle mouth, the pressure generated by the metal flange around the bottle cap and the bottle wall makes the bottle cap firmly press on the bottle mouth, and the inner container in the bottle cap plays a sealing role. The diameter of the bottle cap is 28 ~ 77 mm, which can be used to package fruit juice, jam, fruit and other foods. ⑦ Edge sealing. Also known as pry open the lid. Belonging to a press-in type cover. Made of sheet metal. There is a rubber gasket around the cover, which has a sealing effect. Suitable for round glass bottle mouth or glass. Tools are needed to open the lid, and the pried lid can be pressed back to the bottle mouth and closed again. The bottle cap is 27 ~ 77 mm in diameter and can be used for packaging fruit juice, fruits and vegetables. 8. Roll up the lid. Also known as the victory bottle cap. Made of tinplate. There is a rubber gasket on the inner edge of the cover, which has good sealing performance. Suitable for packaging fruits, vegetables and meat. The disadvantage is that the bottle cap is difficult to open.