Swiss packaging company Bobst has released a new process AluBond, which claims to offer high metal adhesion and surface energy levels through vacuum metallization.
The company stated that traditional metallization techniques result in poor metal to polymer substrate bonding, even with plasma treatment. This produces de-lamination, which can lead to packaging failure and can result in product rejects.
According to Bobst, the problem is low surface energy on the metal side can contribute to poor lamination bonding. There is now good demand in the industry for high levels of metal adhesion on metallized film because of the need for more complex packaging structures that need lamination peel strength suitable for functional needs.
Bobst claims that it has created a new process which can address the issue in the packaging industry through its vacuum metallizers. Its new process AluBond is claimed to eliminate this need for chemically treated films.
High bonding strength can also be achieved on any substrate with Bobst’s AluBond’s unique metalizing process. This, claimed to be an advanced metal adhesion technology can achieve metal adhesion of up to 5N/15mm.
Bobst’s AluBond is an in-line hybrid coating technology which promotes chemical anchoring (chelation) of the first aluminium particles and create a metalizing seeding layer that offers high bond strength properties.
High adhesion is claimed to be achieved when there are direct chemical bonds between the aluminium coating and the polymer surface. Increased chemical bonding, created by the seeding layer can increase lamination bond strength and can lead to high performance during lamination, extrusion and coating processes, thus preventing failure of the packaging.
AluBond has shown that it can significantly increase metal bond strength and metal adhesion on the most commonly used substrates (PET, BOPP, CPP and PE) during aluminium vacuum metallization.
Additionally, it has also showed that it can increase dyne level retention that can translate to improved ink wettability during printing and enhances structure stability during lamination.
It can also generate added value by extending surface energy stability on metallized films over a long period of time and could eliminate the need for an additional surface treatment boost such as corona refresh prior to converting.
Image: Bobst introduces new metal adhesion process, AluBond. Photo: Courtesy of Bobst Mex SA.