Applications and Pros/Cons of Extrusion Lamination, Dry Lamination, and Solventless Lamination in the Packaging Industry

08 Apr Applications and Pros/Cons of Extrusion Lamination, Dry Lamination, and Solventless Lamination in the Packaging Industry

Extrusion Lamination:

Extrusion lamination involves the uniform extrusion of thin thermoplastic material (single or multi-layer) through a screw extruder from a flat head. This material is then continuously coated onto the surface of a base material or a base material containing an AC adhesive. The composite film is formed by pressure roller pressing and cooling roller cooling, resulting in two or more layers.

Advantages:

• Allows for the completion of multi-layer composite moulding in a single process.
• Environmentally friendly, as it can be performed without the use of solvents or with low solvent content.

Disadvantages:

• Requires skilled operation of the equipment.
• May exhibit limitations in composite properties such as stiffness and strength.
• Limited development and application of extruded composite plastics.
• Equipment costs are high, requiring significant investment.
• Operational speed may be moderate.

Dry Lamination:

In dry lamination, a solvent-based adhesive is diluted and coated onto a base film. The coated film is then subjected to hot drying in an oven, followed by the lamination of another layer of film to create a composite film.

Advantages:

• Suitable for various types of substrate films, providing flexibility in substrate selection.
• Lower equipment costs and faster entry into production.

Disadvantages:

• Residual solvent in the adhesive may pose environmental concerns.
• Machine speed is average, limiting production rates.
• Higher production costs associated with the use of solvents.

Solventless Lamination:

Solventless lamination involves the use of a single-component or two-component, 100% solid, solvent-free adhesive. The adhesive is applied to the base film after undergoing thermal softening, followed by the pressing of another layer of film to create a composite film, also known as reactive compounding.

Advantages:

• Suitable for a wide range of substrate films, offering flexibility in substrate selection.
• Environmentally friendly, as it does not leave behind any solvent residue.
• Fast machine speed, resulting in efficient production and lower costs.
• Affordable equipment that is easy to operate.

Disadvantages:

• The process is complex and requires high levels of skill and expertise.
• Adhesive improvements are necessary for specific structural requirements.

In conclusion, each lamination technique has its advantages and disadvantages. Extrusion lamination is suitable for multi-layer composite moulding but has limitations in composite properties. Dry lamination allows for various substrate choices but may have solvent residue and average machine speeds. Solventless lamination offers substrate flexibility, environmental friendliness, and cost efficiency but requires a more complex process and adhesive enhancements. Choosing the appropriate technique depends on specific requirements and considerations for a given packaging application.