In the structure of the aluminum foil seal liner, the sealing surface is the sealing layer, and the other side is the backing. What is Backing of aluminum foil seal liner? It is a layer of material with a certain thickness that can be compressed.
Why backing used in the aluminum foil seal liner?
1. Used to fill the gap between the bottle mouth and the bottle cap. Due to the actual error of the injection mold, there will be a little gap between the bottle mouth and the cap after some bottles are screwed. The larger the bottle mouth, the greater the chance of this gap, and the larger the gap size. big. At this time, the backing is required to fill the gap so that the sealing layer can be in close contact with the bottle mouth during the sealing operation, thereby reducing the chance of poor sealing.
2. Increase the stiffness of aluminum foil. The thickness of the heat-sealing layer and the aluminum foil layer is usually still very thin, so it is easy to curl or deform. If the upper backing is recombined, the aluminum foil will become firm and not easily deformed.
3. Improve the efficiency of the aluminum foil seal liner into the cover. Whether it is using an automatic gasket capping machine to insert the aluminum foil seal liner into the cap, or manually inserting the cap, the operation efficiency of the aluminum foil gasket compounded with a backing and a certain thickness will be more efficient than that of the aluminum foil sealing film without a substrate. The lid operation efficiency is much higher.
The backing material of aluminum foil seal liner.
The backing used in the aluminum foil seal liner basically has two characteristics:
1. The material structure is relatively loose;
2. The material will be naturally straight under the condition of a certain thickness and a certain size. The materials suitable for aluminum foil gasket substrates that meet these two requirements are generally as follows:
1). Raw pulp paperboard, paperboard produced from raw wood pulp or fiber pulp. This material is relatively strong, can be compressed under a certain force, and has a good water absorption effect. It is mostly used in the structure of two-piece aluminum foil sealing gaskets.
2). Paper jam, such as coated white card or kraft card. This kind of material is relatively strong and can be compressed under a certain force, but the water absorption effect is not as good as that of virgin paper, and one side is smooth for printing, so it is mostly used in a one-piece aluminum foil sealing gasket structure.
3). EPE, foamed PE material (mostly low foamed PE material). This material is softer than virgin paperboard and is mostly used in the structure of one-piece aluminum foil sealing gaskets, but the material cost is slightly higher than that of virgin paperboard.
4). EPS, foamed PS material. The material of EPS is generally higher than the foaming ratio, so it is looser than EPE, and the material cost is lower than that of EPE. However, the gasket processing technology of EPS as the substrate will be more troublesome. The sealing gasket substrate of some Amway health products uses this material.
