Objective: this test is the first content of the solvent free composite technology. The purpose is to ensure that the ink and glue does not dissolve, which is the most important condition for the production of the composite. Now the solvent free glue is basically a polyurethane, a small number of ink solvent (such as a small number of acrylic resin printing ink) will react with the glue between the occurrence of mutual dissolution (sometimes referred to as penetration). Once this situation occurs, it will destroy the original printing pattern, affecting the appearance of the. All composite structures should be tested for this.

Method: a small amount of low speed compound can be made on the composite substrate (including printing film) and glue machine. Usually compound length is only a few tens of meters, composite after a short time (tens of minutes) can be found whether the compatibility.

Note: the type of printing ink and solvent must be adjusted when the mutual dissolution occurs. Sometimes the phenomenon of mutual dissolution is relatively slight, should pay attention to observation, and not easy to mass production.

Two, the appearance of quality inspection

Objective: the transparency of the inspection of composite membrane, and to observe whether there is orange peel, crystal, white spots, bubbles, through aluminum and tunnel defects. At the same time, but also to determine stiffness, flexibility of composite membrane. All composite structures are to be tested for this.

Methods: the actual production mainly by visual inspection or touch judge.

Note: once the defects mentioned above, according to the substrate, printing pattern, composite structure and other factors were targeted to solve.

Three, composite fastness (peel force) detection

Objective: to determine whether the composite membrane is satisfied with the most basic performance requirements. All composite structures are to be tested for this.

Methods: the sample test in accordance with GB/T8808-1988 or the stripping force standard requirements. For some of the requirements are not very strict products, can be judged by hand stripping.

Note: when the peeling force can not meet the use requirements, the visual conditions were solved by adjusting the proportion of the glue, replacing the glue brand, increasing the corona, or replacing the substrate.

Four, friction coefficient detection

Objective: the main inspection of composite film bag or filling sealing operation. In some solvent free composite products, especially PE composite structure (such as a thin layer composite), often appeared friction coefficient increases, effect of bag making and filling and sealing the opening. The composite coefficient of friction is also reduced. There is a big difference between this point and dry type composite.

Method: according to the relevant national standards.

Note: when the friction coefficient changed greatly, depending on the circumstances are solved by means of the method is as follows: to reduce the amount of glue, reduce the curing temperature, adjust the cash volume pressure or taper, replace glue grades, adjustment of PE film smooth agent proportion.

Five - transfer detection

Objective: this test is suitable for the composite film structure, in fact, it is an auxiliary detection of composite fastness. The reason is because the widely used alone made the film, and the composite fastness depends largely on aluminum transfer status.

Methods: generally use manual stripping.

Note: when the aluminized excessive transfer, depending on the circumstances taken to adjust the mixing ratio, replace glue brand, appropriate to reduce the curing temperature, replacement of the aluminized film etc. method to solve.

Six, other performance testing

Mainly include: the heat sealing strength detection, medium resistance detection, boiling resistance test, test etc..