Claw-type unscrew cap with PE (poly-ethylene) or PP (poly-propylene) cushion layer, and production technology of claw-type unscrew cap

Abstract

The invention provides a claw-type unscrew cap with a PE (poly-ethylene) or PP (poly-propylene) cushion layer, and a production technology of the claw-type unscrew cap. The cap body of the unscrew cap comprises a tin plate cap with no inner film coating and the poly-ethylene or poly-propylene cushion layer covering the inner surface of the tin plate cap, wherein the cushion layer is a 0.5 to 2.0 mm sealing gasket layer formed by conducting injection molding or dripping molding of poly-ethylene particles or poly-propylene particles on the inner surface of the tin plate cap; a curled edge and a rotating claw are formed by conducting punch forming on the edge of the opening of the tin plate cap with the poly-ethylene or poly-propylene cushion layer. The claw-type unscrew cap and the production technology have the advantages that the structure is simple; the production technology is relatively simple; the sanitary quality of each prepared bottle cap can reach the standard of food and drug safety; the sealing effect is high; the phenomena of fading and poisonous substance volatilization are avoided under a high-temperature condition; a preservative is not required to be added into a food or drug in a bottle sealed with the bottle cap, and can be preserved for a long time only through high-temperature sterilization.

Description

technical field [0001] The invention relates to a metal twist-off cap for a glass food packaging bottle, in particular to a claw-type twist-off cap with a PE or PP cushion layer and a production process thereof. Background technique [0002] In the food processing industry, for foods that need to be preserved for a long time, such as beverages, fruits and vegetables, condiments, etc., they are generally put into glass bottles, and then sealed with a twist-off cap, of which the claw-type twist-off cap is a A commonly used sealing cap for food glass packaging bottles. [0003] The existing commonly used claw type unscrewing cap adopts tinplate as the cover body, and stamps the cover claw on the edge of the cover mouth. Tinplate, also known as tin-plated iron, is a common name for electroplated tin-plated steel sheets, mainly referring to cold-rolled low-carbon thin steel sheets or steel strips coated with commercial pure tin on both sides. Therefore, tinplate is a material t...

AI Technical Summary

Problems solved by technology

[0004] The existing production process of tinplate claw-type unscrewed caps is to pre-press the tinplate first, that is, to use a roller coater to coat the inner and outer surfaces of the tinplate. The chemical action between the covers will cause pollution and prevent rust. The coated tinplate is sent to the dryer through the conveyor belt, and is cured at high temperature by the dryer under the driving of the circulating chain. The coating film is generally epoxy Phenolic, epoxy melamine or epoxy urea resin coatings; metal printing is carried out directly on the tinplate sheet after pre-press treatment, and the tinplate cover is formed directly after printing, and the cover claw is stamped on the edge of the tinplate cover body, and then injected into the cover body Glue, and drying to form a cover pad, the whole process is relatively cumbersome, the raw material for the injection of the tinplate claw-type twist-off cover produced by this process must use slurry, otherwise the injection layer cannot be formed on the inner surface of the tinplate, and most of the materials It is impossible to form a slurry, so the existing glue injection process for tinplate caps generally uses polyvinyl chloride (PVC) paste resin as the main raw material, and adds auxiliary materials such as plasticizers. The machine injects liquid glue into the bottle cap, the bottle cap is rotated at high speed, and then cured after being baked in an oven

Since polyvinyl chloride (PVC) contains a large amount of chloride ions and added plasticizers, when in contact with food, PVC sealing gaskets will cause many food safety problems due to the migration of plasticizers and free chloride ions ; and because polyvinyl chloride will volatilize a large amount of chloride ions at high temperature, the effect of high temperature sterilization of food in this kind of packaging is not very good, and its food shelf life cannot be guaranteed. In order to extend the shelf life of food, general food manufacturers , preservatives will be added to food, and the addition of preservatives will also affect the quality and safety of food; and because the sealing cushion layer formed on the inner wall of the bottle cap by injecting glue in the whole process must be dried at high temperature to make it solidify Only then can it be formed, so as to avoid the occurrence of glue breaking or degumming during high temperature sterilization, so the whole process is more complicated

[0005] In order to solve the defect that the existing bottle cap gaskets are not up to standard in sanitation and safety, some people have developed sealing gaskets of other materials, but most of them are a new material formed by mixing various materials, and their preparation methods and production processes are relatively Complicated; at present, polyethylene (PE) materials are also used as bottle cap gaskets. Since polyethylene cannot form slurry, the general method is to directly bond the prepared gasket with the molded bottle cap with glue, and its production efficiency is low. , and because the inner surface of the tinplate cover is coated, the PE material pad is easily separated from the cover body, and it is difficult to achieve a good sealing effect

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