Different processing methods will cause different fault manifestations, the following we mainly analyze the causes of paper thermit sealing delamination phenomenon under the gravure and solvent-free composite processing methods.

The YBB paper aluminum-plastic composite film standard does not specify the composite strength index of the paper aluminum layer in the paper aluminum-plastic composite film, usually we peel the paper layer apart, observe the transfer of paper fibers, if there is a layer of paper fibers left on the aluminum foil surface, it indicates that the composite strength is good at room temperature.

Paper aluminum delamination has many manifestations and different mechanisms. When paper aluminum plastic heat sealing, due to the poor heat transfer of paper, it is necessary to set a higher heat sealing temperature, and sometimes the heat is as high as 200℃, which is a greater test for the heat resistance of the rubber layer. In addition, under the action of heat above 200℃, the paper will lose water and produce a certain shrinkage stress, which will aggravate the phenomenon of thermal seal delamination.

The YBB paper aluminum-plastic composite film standard does not specify the composite strength index of the paper aluminum layer in the paper aluminum-plastic composite film, usually we peel the paper layer apart, observe the transfer of paper fibers, if there is a layer of paper fibers left on the aluminum foil surface, it indicates that the composite strength is good at room temperature.

Paper aluminum delamination has many manifestations and different mechanisms. When paper aluminum plastic heat sealing, due to the poor heat transfer of paper, it is necessary to set a higher heat sealing temperature, and sometimes the heat is as high as 200℃, which is a greater test for the heat resistance of the rubber layer. In addition, under the action of heat above 200℃, the paper will lose water and produce a certain shrinkage stress, which will aggravate the phenomenon of thermal seal delamination.

Delamination only appeared in the heat sealing part, and the strength of the parts without heat sealing was good

The heat of the hot sealing knife leads to the deterioration of the bonding fastness, which is generally separated from the internal delamination of the adhesive layer, which can be analyzed with PU dyeing agent.

Main factor: the heat resistance of the adhesive itself is not enough.

Countermeasure: The appropriate adhesive type number should be selected. The crosslinking curing of adhesives is inadequate.

Reason: the curing temperature time is not enough, the free water in the paper is too little. Countermeasure: Prolong the curing time and humidify the paper properly.

The composite strength of the heat-sealed part and the non-heat-sealed part is poor

The amount of glue layer left between the paper surface and the aluminum foil interface is too small

Possible factors: The paper absorbency is too strong, the coating amount is low.