Package lamination is a metal sheet manufacturing process.
Bundle lamination is a sheet metal manufacturing process used to produce multiple thin-film sheets at the same time. The process has several advantages, including not requiring the usual small roll sizes due to the increased initial thickness of the raw material “package”. This allows the use of conventional laminating equipment and has no negative effect on the finished product. The process typically produces aluminum foil for lithographic printing, food packaging, and electronics. Compacted laminate sheets have a distinctive look, with one side glossy and the other matte finish.
Sheet metal is produced by passing sheet metal ingots through rollers of progressively smaller tolerances. Once a suitable thickness is achieved, the sheets are passed through sheet mills to produce the required final thickness. Foil is classified as metal foil less than 0.0079 inches (200 µm) thick. The most common of these sheets is aluminum foil, which is widely used in a wide range of applications. Aluminum foil is often produced by an alternative process known as rolling.
This process has several advantages over more conventional sheet lamination techniques that require specialized equipment. These sheet metal mills are specially configured to produce the thinnest sheets and feature smaller, more expensive rolls. Single ply sheets produced on these machines are difficult to work with and are prone to tearing. The loose leaf laminating process is also quite slow. All of these issues are resolved by the packaging process.
Pack lamination involves feeding multiple sheets of paper through the roll at the same time. This effectively increases the initial thickness of the raw material and eliminates the need for small rolls. The extruded product is also stronger due to the increased thickness; It is also less prone to tearing, allowing for faster lamination speeds and better production rates. This process gives the laminated packaging foil its distinctive gloss on one side and matte on the other. This is because the surfaces in contact with the rollers are polished to a brilliant shine, while those in contact with the sheet remain dull.
Package lamination requires that the blank sheets be lubricated prior to lamination. For non-food industry blades, a kerosene-based lubricant is sprayed on the blades, while food industry blades are sprayed with an industry-approved lubricant. The sheets are hardened during rolling and are annealed or heated to soften after rolling. This heating burns off any excess lubricant from the blade and leaves a dry surface.