The seal formed by hooking the periphery of the tank cover with the flange crimping of the tank body is called crimping seal. Cylindrical metal cans widely used in canned food and beverage packaging adopt this sealing form. In order to prevent the joint part of the seal from leaking, glue (made of rubber or tree cooling material) is generally applied to the concave edge of the cover, and then it is clamped in the seam after crimping to enhance the air tightness.
2. gland seal
The seal formed by the ripple around the crown cap and the flange of the bottle mouth is called gland seal. In this kind of seal, an elastic gasket made of rubber or cork is lined between the bottle cap and the end face of the bottle mouth to seal. The gland is reliable and easy to unseal, which is a common sealing form when packing carbonated liquid drinks, such as beer, soda, alcohol and other glass bottles.
3. Plug sealing
The cork pressed into the bottle mouth forms a tight sealing way of the bottle mouth through its own elastic deformation, which is called plug sealing. Corks are often made of elastic materials such as cork, rubber and plastic, and their structures and shapes are different.
Bottle stopper seal can be used for direct seal or combined seal with bottle cap. Thereby improve that sealing performance of the product and prolon the storage period. Direct sealing is often used to seal bottled soy sauce, vinegar and other liquid foods, and combined sealing is often used to seal bottled high-grade wine, drugs and toxic products.
4. Rolling seal
The sealing method of rolling the thread with the same shape as the thread of the bottle mouth through the aluminum cover sleeved on the bottle mouth is called rolling sealing. When unsealing, the aluminum cover will break along the preformed indentation around the skirt, so the sealing cover is called a twist cover; And because the seal is easy to identify whether it is unsealed, it is named "anti-theft cover" abroad.
The twist-off bottle cap used for sealing has two forms in design: one is that the mark with a certain depth is only impressed in the circumferential direction of the skirt, and after sealing, as long as a certain rotating torque is applied in the direction opposite to the thread, the bottle cap will twist along the circumferential indentation, but the blank holder ring is still sleeved on the bottleneck, which is not convenient for recycling the bottle; Another newly designed aluminum cover has dents in the circumferential direction and axial direction of the skirt. After opening, the blank holder will automatically fall off along the circumferential direction and axial direction, which is convenient for recycling the old bottle.
Roller sealing not only has the advantages of tight and reliable sealing, convenient unsealing and beautiful packaging appearance, but also can identify whether the products in the bottle have been used, so it is especially suitable for sealing glass bottles filled with high-grade wines such as wine and brandy, and also commonly used for sealing plastic bottles of beverages such as Pepsi.