Avoiding Delamination in Flexible Packaging
Intelligent blending and dispensing of adhesives is critical to proper film lamination.
November 22, 2010 By Ed Sullivan, for Inline Blending Solutions Inc.
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In the world of flexible packaging, it is critically important to control the adhesives used to bond laminates such as films and foils, which require meticulous accuracy of blending, dispensing and applying adhesives to substrate materials. Yet, the adhesive controls required for such accuracy are missing from nearly all systems, even though the consequences are quite serious—packaging failure, product loss, and significant downtime.
If not applied in the correct coat weight, whether too light or too heavy, the lamination bonding will fail, causing the overlay to bubble, blister or otherwise delaminate from the base material, a scenario that worsens as the problematic packaging travels farther down the distribution chain.
“The ultimate dilemma created by delaminated packaging is when it reaches the store shelf, which is a terrible situation for the product manufacturer and packaging supplier and could easily cost hundreds of thousands of dollars,” says Ray Mayes, a packaging controls specialist whose firm, Cereal City Electric (Battle Creek, MI), services the Midwestern food industry.
“And if you were to seal a food product into packaging material that later began to delaminate, you would then be wasting the product as well as the packaging,” he adds.
Even when delaminated packaging never leaves the plant, it normally takes adhesives about three days to cure. At that point, if there is a quality problem, the packaging producer has to go all the way back to reprinting the packaging, and then laminate it once again.
“This is a JIT world,” Mayes explains. “When you have a lamination error, it is almost impossible to really make up for it. You have to squeeze back in the production queue, which is very difficult. Schedules are always tight and the printer may be backed up. The printer or packaging house may be short of materials, and it can take considerable time to replenish them. In any event, it’s a very difficult and costly situation.”
The need for controls
Mayes attributes most delamination and other coatings problems to a lack of control with the blending, metering and dispensing of adhesives. Because most adhesive blending and dispensing equipment uses only single gauges to meter adhesive coat weight, if they use any at all, the process can slip out of control without the operator or system being aware of it.
“Unless the adhesive’s viscosity and flow rate are validated by a secondary metering system, you have no real control at all,” says Bruce Schuetz, who has worked in the metering and blending industry for over 30 years. “It is shocking to most controls experts that such a situation could exist in the flexible packaging industry, but it does.”
If not applied in the correct coat weight, whether too light or too heavy, the lamination bonding will fail, causing the overlay to bubble, blister or otherwise delaminate from the base material, a scenario that worsens as the problematic packaging travels farther down the distribution chain.
“The ultimate dilemma created by delaminated packaging is when it reaches the store shelf, which is a terrible situation for the product manufacturer and packaging supplier and could easily cost hundreds of thousands of dollars,” says Ray Mayes, a packaging controls specialist whose firm, Cereal City Electric (Battle Creek, MI), services the Midwestern food industry.
“And if you were to seal a food product into packaging material that later began to delaminate, you would then be wasting the product as well as the packaging,” he adds.
Even when delaminated packaging never leaves the plant, it normally takes adhesives about three days to cure. At that point, if there is a quality problem, the packaging producer has to go all the way back to reprinting the packaging, and then laminate it once again.
“This is a JIT world,” Mayes explains. “When you have a lamination error, it is almost impossible to really make up for it. You have to squeeze back in the production queue, which is very difficult. Schedules are always tight and the printer may be backed up. The printer or packaging house may be short of materials, and it can take considerable time to replenish them. In any event, it’s a very difficult and costly situation.”
The need for controls
Mayes attributes most delamination and other coatings problems to a lack of control with the blending, metering and dispensing of adhesives. Because most adhesive blending and dispensing equipment uses only single gauges to meter adhesive coat weight, if they use any at all, the process can slip out of control without the operator or system being aware of it.
“Unless the adhesive’s viscosity and flow rate are validated by a secondary metering system, you have no real control at all,” says Bruce Schuetz, who has worked in the metering and blending industry for over 30 years. “It is shocking to most controls experts that such a situation could exist in the flexible packaging industry, but it does.”
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