Inter-Ply Bond Measurement Standards in Recycled Paperboard Production
Inter-ply bond standards mandate TAPPI T 541 or ISO 16260 testing under strict ISO 187 conditioning to prevent converting delamination on recycled paperboard.
Blister Packaging Heat Sealing
Thermal Bonding
Adhesion of a thermoformed plastic blister to a coated paperboard card under controlled heat and pressure creates a secure, tamper-evident enclosure. This process of blister packaging heat sealing relies on the activation of a pre-applied heat-seal lacquer on the paperboard surface. The applied heat melts the polymer coating, which then fuses with the plastic dome as it cools down.
This bond ensures that the product remains protected from external environmental factors.
Process Parameter
Dwell time and seal pressure must be calibrated to match the thermal conductivity of the paperboard card. Thicker boards require more energy to transfer heat through to the adhesive layer, which can increase the necessary dwell time. However, excessive exposure to heat can scorch the paperboard fibers or distort the plastic blister.
Standard packaging lines optimize these variables to achieve maximum throughput without compromising the visual appearance of the card.
Package Integrity
Physical evaluation of the sealed package involves destructive fiber-tear testing to verify that the bond exceeds the internal strength of the paperboard itself. When the plastic blister is pulled away from the board, a successful heat seal must tear the paperboard fibers rather than peeling off cleanly. Peel failure indicates an inadequate thermal bond, which could lead to product contamination or theft.
To prevent this, operators measure the lacquer coat weight and maintain strict calibration of the sealing platens. This verification process is mandatory for pharmaceutical and retail packaging where barrier protection is required.