Underfill applications have always been difficult to achieve a good seal. Tape is often the preferred method as it requires less pressure to get a good seal with the use of light or soft touch tape heads. Hot melt is especially difficult as the lack of support from the underfill makes it extremely difficult to get a good bond between the minor and major flaps resulting in poorly sealed cases. This problem is compounded with the rising popularity of lighter gauge cases and increased use of recyclable content in corrugated.
One customer recently came to us with an application to pack shaving cream into their shippers. The box was to be packed with different sizes of bottles then sent into a Top only Hotmelt Case Sealer. This led to underfill for shorter height SKU’s. The customer was having difficulty reliably sealing these cases as the minor flap would get pushed down during the compression section.