Extrusion Coating Bonding Success Improved with Surface Treating
Chances are you or someone you know has a secret family recipe for a great barbecue sauce, or chili or killer cheesecake. In each case, there’s probably a unique combination of ingredients that makes all the difference in the world.
As a professional in the extrusion industry, you can probably relate the family recipe analogy to the “secrets” your company employs to make the ultimate laminating bond. Many companies have found the combination of an ozone generator and corona treater to be an ideal combination when it comes to improving extrusion coating results.
In some cases, the treatment combination is required to produce complex multi-layer structures with significant bond and heat seal strength. In other cases, the right combination of treatment technologies can have a huge impact on operating efficiencies. You might also be interested to know that there is scientific documentation to support the benefits of combining ozone and corona.
Enercon co-authored a technical paper that studied the statistical effects of ozone adhesion in the extrusion coating process. In the study, the combination of ozone and corona significantly outperformed corona alone. It enabled converters to reduce air gaps, lower melting temperatures (which also reduces odor) and reduce coating weight which all translates into a faster, more efficient and more economical production line. Heat seal strength may also improve by using the combination of technologies.
| Figure 1 | |||
| Air Gap | Melt Temp | Coating Weight | |
| Corona Treatment | 24cm | 315°C | 15 g/m2 |
| Corona and Ozone Treatment | 19cm | 295°C | 13 g/m2 |
| Note: Variables tested for 95% probability of successful adhesion of LDPE with Natural Kraft Paper | |||
Treatment locations
Where should you locate your ozone generator and corona treaters for optimum performance? This picture shows a typical layout for a co-extrusion line with need for pre- and post-corona treatment.
Flame Treatment
It should be noted that Flame treatment is also used on extrusion coating applications using paper board. Flame treatment effectively burns off fibers on paper products prior to laminating. Fibers can cause pinholing in the lamination, which results in weaker bonding and unacceptable leaks.
Multiple Treatment Technologies from One Source
Enercon is pleased to be able to offer you a single source for all your extrusion treatment needs. We can help you evaluate if the use of ozone may be the secret ingredient in your extrusion coating recipe.
Contact us for more information.