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Lamination Bag Several Methods Of Testing Flexible Packaging
May 24, 2017

Flexible packaging bag has a good barrier, heat sealing, moisture resistance, and acid, alkali, wear, which is widely used in food packaging. With the people on the flexible packaging bag quality requirements of the growing, packaging enterprises on the flexible packaging bag quality inspection is also more and more attention. This article will combine practice, the compound bag product testing methods to do a summary, hope to help the peer.

    1. visual inspection of appearance

    Visual inspection includes the inspection of the Lamination Bag flatness, transparency and other items. Mainly used to detect the surface of the Lamination Bag with no obvious scratches and pinholes, sealing at any pollution. My company has a more complete appearance inspection method, as follows.

    (1) the compound bag placed in the center of the hand, aligned 40W fluorescent light gently shaking, through the Lamination Bag surface of the reflected light, you can clearly find the compound bag surface is scratched or traces, the industry is often referred to as " The If the drawing is serious should be based on the actual situation, find the fault, the impact will be reduced to the lowest point to ensure product quality. We found through the observation of the drawing phenomenon is mostly caused by the bag machine guide roller is not clean, so be sure to ensure that the guide roller clean. In addition, the guide roller does not rotate the same will make the Lamination Bag wire drawing failure. Guide roller does not rotate the cause of the bearing caused by lack of oil, so good lubrication is the fundamental condition of bearing rotation.

    (2) inspection of the compound bag flatness. The specific method is: take a few pieces of finished bag sample to "air to ground" to fall, let the natural landing (the location to be clean), observe the compound bag to the ground after the situation. If the Lamination Bag to the ground when the bend, outward Alice or inward arch, then the Lamination Bag flatness difference, otherwise it shows a good flatness.

    The reasons for poor flatness are generally the following: the bagging temperature is high, has damaged the inner layer of the composite stress stiffness; structural composition is unreasonable; material itself, uneven thickness. We note that when the total thickness of the composite of PET / PE and BOPP / PET / PE structures does not exceed 80 μm, the flatness tends to deteriorate.

    (3) visual inspection also includes inspection of transparency. Some products because of large area without pattern, transparency is particularly important. Transparency detection method is: to extract a finished bag, through the indoor indirect light source observation, if the blank at the "pitting", "ring", "mist" and other phenomena, then the transparency is poor, otherwise indicating good transparency The

    The reason for the poor transparency is multifaceted. For example, when the composite glue itself is yellow or reddish in color, the corresponding color shift will be affected by the transfer to the Lamination Bag. If the transparency of the material itself is poor , There are "mist", will also affect its transparency, so the material into the warehouse should be strict quality control, so that non-qualified raw materials Jincang. In addition, the transparency of different composite materials is also different, such as casting CPP transparency than blow molding co-extruded CPP transparency is much higher.

    2. Seal adhesion detection

    Sealing some subtle small cracks, in the visual inspection on a little negligence for the future leakage of food hidden danger, so the sealing bag sealing check is necessary. Commonly used method: a dye-added surfactant sprayed in the seal, to observe its through or not, if the dye color through the seal, then the seal performance is not good, on the contrary that meet the sealing quality requirements. In the actual work, we often use a long 20cm, width 5cm, 0.8mm thick and smooth, no burr of the small iron ruler on its seal close to push the top. If the light will have a drop off, perforation and other phenomena, then the seal performance is poor; if the seal still maintain the sealing size, then the seal performance is good.

    Resulting in poor sealing performance reasons are: sealing knife pressure is not enough or uneven, this situation as long as the pressure to adjust the seal spring can be resolved; low temperature will make the Lamination Bag seal adhesion deterioration. It is noted that when the total thickness of the composite material exceeds 80 μm, the problem of deterioration of adhesion tends to occur during bag making, and in particular, the structure of BOPP / OPP is most likely to occur. To ensure excellent product adhesion, there must be uniform and smooth sealing pressure and the appropriate temperature.