Requirements of the most flammability and appearan

2022-08-08
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Performance and appearance requirements for sealing technology of beverage container lid

in recent years, with the continuous development of new beverage containers (such as various bottles, barrels and cans), the container lid is also innovating. Of course, although there are many types of container covers, their functions are to ensure the sealing of the container. At the same time, they should also have good opening performance and novel appearance design

the function of the container cover

tightness

the function of the cover is to ensure the sealing of the container, protect the contents of the container and prevent them from deterioration during the storage period. Therefore, various covers must have air tightness and sealing to ensure that the contents do not contact with the external environment and do not leak; For carbonated beverages and other aerated beverages, air tightness requirements are more stringent; At the same time, the containers cooled to form vacuum after hot charging shall be sealed without gas intrusion

ease of opening and resealing from the point of view of convenience for consumers to drink, various container covers should have ease of opening. With the development of large capacity bottles, especially fruit juice carbonated drinks, they should also have the function of re sealing after opening, that is, re sealing. In this case, it is required to keep the aroma or carbonated gas in the container

anti theft in some cases, container caps (mainly bottle caps) are required to have anti-theft function to prevent theft and resale. In addition to the structure of the cover itself, the container cover must also have sealing gasket or sealant. These materials should have certain elasticity to maintain the pressure sealing state. For unscrewing the cover, the gasket should also withstand the friction of the sealing surface and can be unscrewed at a certain torque

classification of container caps

some enterprises even directly promote and sell bottle caps by using graphite as graphene.

the caps used for sealing the glass bottle mouth include crown caps, screw caps, anti spiral caps and wide mouth caps

(1) crown cap. Crown cap is a commonly used sealing cap for glass bottles. The crown cap was invented by William painter of Baltimore and patented in 1892. At present, it is widely used as the sealing cap of small mouth bottles. The crown cover is made of ordinary tinplate, which is bonded or injected with gasket after stamping. Cork was first used as the backing material to play a considerable role in abs+gf materials. Later, rubber, aluminum foil, plastic and other materials were developed. At present, PVC and other plastic backing are widely used. The liner shall be flat and free of defects, firmly bonded to the bottle cap, and have certain elasticity and toughness. It shall be sealed without becoming a pollution source. The liner material is generally mainly natural rubber, and plastic material can also be used. These materials must be non-toxic and free of peculiar smell. The soaking solution shall not be colored or fluorescent. The bottle cap shall have good corrosion resistance and the paint film of the bottle cap shall have good wear resistance

at present, crown caps are widely used for sealing beverage bottles. Crown caps are used for disposable bottles, inflatable and non inflatable beverage bottles. The crown cap has good pressure tightness with cold storage effect, but it does not have re tightness and is poor in opening

(2) screw cap. Screw covers include three types of continuous screw covers: deep thread, shallow thread and general thread, as well as intermittent screw covers. Their dimensions and categories are marked with diameters (mm) and numbers representing corresponding features, such as general continuous screw covers with diameters of 28mm. Nominal diameter means the outside diameter near the top of the screw cap. However, all dimensions and nominal values are in inches

twist off the screw cover. There are discontinuous lines at the lower part of the screw cover, which divides the cover into two parts. It can be opened by twisting the scribed line. The lower part is left at the mouth of the bottle, leaving traces of opening, which cannot be restored. The broken remnant cover turns into an ordinary screw cover, so it is especially theft-proof and resealable. Screw caps can be made of tinplate, aluminum, plastic and other materials, depending on the bottle type and purpose. Like other types of covers, the reliability of screw covers also depends on the elasticity of the gasket and the flatness of the sealing surface of the container. The tightness of the screw cover shall maintain a proper unscrewing torque under the condition of ensuring the sealing, so that the consumer can easily open it

(3) stop screw cap. The cap is used for small mouth bottles and wide mouth bottles with threads. The flange of the cap is locked with the thread stop line of the bottle mouth thread. It is also called flange cap, bayonet cap and unscrew cap. The rotation stop line at the glass bottle mouth has a spiral angle, which changes gradually in the whole screw process, and becomes flat in the end. The distance between the sealing surface and the flat rotation stop line is very limited. Therefore, there are 4 lugs on the cap and 4 discontinuous thread lines on the glass bottle mouth. When opening the cap, the cap can be easily unscrewed after less than 1/4 turn. Therefore, it is commonly known as the four screw cap. Of course, according to the requirements, it can also be made into a six screw bottle cap

this screw cap is made of tinplate and other materials. There is PVC sealant on the sealing surface inside the cap. It can be sealed after tightening the cap. It has good re sealing performance and can be used repeatedly

no matter three piece cans or two piece cans, the can body and the can cover are connected by double crimping, and the inner side of the edge of the tank bottom cover is coated with sealing glue of ammonia glue, solvent glue and other materials, so a good sealing can be obtained after crimping. The tank cover is made by cutting plates, punching covers, rounding edges, injecting glue and drying. There is an expansion ring in the tank cover, because in the process of heating and sterilization after sealing, the tank cover expands when the pressure in the tank rises, and then recovers after cooling, so as to prevent distortion of the crimping part of the can. Most of the easy opening covers are used for carbonated drinks, wine and other beverage cans. The easy opening cover is characterized by a punching line (scribed line) at the opening part, which can be opened easily by pulling the punching line. According to the opening mode, the easy opening cover can be divided into pull ring type and button type. The pull ring type easy opening cover is widely used for inflatable beverage cans

easy opening lid requires high purity of materials. Generally, aluminum alloy is used. However, when aluminum Taijin easy opening lid is combined with iron anti can, it is easy to produce bimetallic corrosion, which is more serious to the content with high acidity. Therefore, tinplate can be used to replace aluminum alloy lid, and coating can also be applied to the contact part between aluminum alloy and can body

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