There are a number of factors that will affect thickness recovery of insulation after lamination and allow the insulation to perform with its stated R-values. Capital Steel Industries provides this information to aid in proper insulation application practices in steel buildings.

It is important to the insulation and steel building industries that regular testing of insulation products occurs to check for thickness, density and R-value characteristics. The “R” in R-value represents the resistance to heat flow and is a valuation of how effective the insulation will be once it is installed. The greater the R-value, the more the insulating power will be. There are minimal R-value grades which must be met.

There is a NAIMA (North American Insulation Manufacturer Association) certification program that provides laminators confidence in those insulating materials that undergo rigid testing procedures. The NAIMA identification stamp is on these products.

Thickness recovery in insulation performance is affected by three major influences.

• Inadequate ventilation that allows for excessive moisture in the product.
• Nip roller pressure which is excessive.
• Compression that is excessive during windup after lamination.

If the effects of these three influences are minimized thickness recovery will be improved.

Adhesives

Water based adhesives are strongly recommended for use in conjunction with lamination applications. Adhesive application rates must be consistent so the lamination process must be controlled within certain parameters. Moisture in the package must be allowed to dissipate as the adhesive cures so a ventilation path needs to be introduced by piercing the package ends. Finished product rolls need to be stacked on their sides to allow for evaporation and cross ventilation. To limit excessive nip pressure that tends to compress the insulation during lamination utilization of spacer blocks to limit nip roller height. Each different R-value should employ different spacer blocks. This lessens dust in the work environment and improves recovery by not breaking fibers and jeopardizing product integrity. The nip roller should be raised clear of the blanket when it is not being utilized.

Wind Compression Ratios

In general the windup compression ratio on insulation should not exceed 5.5:1. The range of optimal recovery is in the range of 4.5:1 to 5.0:1. The laminator and the brake tension on the facing control the compression ratio. So that it does not adversely affect the adhesive application rate great caution should be used when adjusting the brake pressure. There is an adjustable secondary compression roller that controls the amount of compression on some lamination equipment. Pressure on the windup mandrel can also control compression. Compression ratio calculations must be made using the appropriate formula.

Storage

Storage for extended periods of time at a project site or at the manufacturer’s location after lamination may adversely affect thickness recovery. 30 days or less is recommended as appropriate maximum shelf life. Material rolls on the bottom layers, if stacked, will crush with too much weight above them so the stack height of stored material should be limited.

Further questions about lamination process control and thickness recovery can be answered by Capital Steel Industries at 1-800-246-9640.

Read more about Capital Steel's building insulation recommendations