Mica Corp.: Benefits of using primers in the extrusion lamination process

The flexible converting industry is growing due to consumer trends surrounding individually portioned packages, resealable pouches, and other packages that extend shelf-life and aid in food waste reduction.

Many flexible packaging applications require several layers of film and a combination of properties to meet consumer demands. To achieve packaging properties such as stiffness, aesthetics, and barrier, several different films can be laminated together in the extrusion lamination process, which joins two or more film substrates together in a wide web format, utilizing an extruded polymer as the adhesive. The finished structure can be compromised if the substrate doesn't adhere well to the extrudate, if the substrate and extrudate don't provide enough barrier properties, or if the line speed is too fast. Here's how adding primers into the extrusion lamination process can significantly improve adhesion and other properties, without slowing down the process.

1. Improved Product Quality

The use of primers in the extrusion lamination process can significantly reduce instances of delamination. The processing conditions used in extrusion lamination are complicated and play an important role in promoting adhesion. This is especially true for structures with low poly coat weights on paper. If the adhesion between substrates is too low, the poly can separate from the paper and wrap the chill roll causing downtime. Applying primers in these low adhesion situations can be the "insurance policy" needed to achieve the bonds required in these situations

2. Added Shelf Life and Product Protection

Adding primers in between the layers of a package can also help improve grease and/or water-resistance properties. This can help ensure a longer shelf-life and added protection to the product inside of the package.

3. Increased Output

The level of adhesion in the extrusion lamination process is greatly affected by the processing line speed. In general, the faster the line speed, the less effective adhesion is between the packaging layers. In many cases, line speeds must be kept low to produce a product with the desired adhesion level. The use of primers can improve adhesion and decrease chill roll wrap-ups by allowing the processing line speeds to be increased, thus increasing output significantly.