Did You Know The Reasons For The Poor Transparency Of The Flexible Packaging?
Transparency is an important indicator for determining the visibility and clarity of the packaged goods, and has a particularly strong relationship with the display effect of the products. Many plastic composite flexible packaging products are required to have high transparency, using a large area of blank base film BOPP and CPP composite, but in the dry composite process, sometimes the plastic composite flexible packaging has poor transparency or decline, failing to meet quality requirements, such as The finished product is “fog”, and there are phenomena such as “small pockmark”, “wave scales”, “silk pattern”, “mushroom umbrella cloud” and “drip splash”, which affects the transparency of the composite product. The composite finished product is scrapped. The possible reasons are as follows.
- The adhesive itself is too dark. Dark yellow, yellowish red, and sometimes even dark red like soy sauce, is also the corresponding color left on the film. Therefore, in the case where high transparency is required, a yellowish or even colorless highly transparent adhesive is used.
- The transparency of the substrate. When the apparent quality problems such as “shark skin”, “flow path marks”, and crystal spots appear on the surface of the inner substrate, the transparency of the composite product will be seriously affected. The fog-like ink smear that is transferred to the non-image portion during printing also significantly affects the transparency of the composite film.
- The problem with the glue. Inappropriate compounding procedures will result in insufficient mixing of the primary and curing agents, which may result in “glue”.
- The composite finished product has obvious appearance defects such as rubber spots.
- The drying tunnel temperature is not set properly. When the temperature enters the drying tunnel at the beginning, the temperature is too high, and the drying is too fast, so that the solvent on the surface of the glue layer evaporates rapidly, causing a local increase in the concentration of the surface layer glue, and the surface is crusted. When the heat penetrates into the interior of the glue layer, the film is formed. The following solvent vaporizes and breaks through the film to form a ring like a volcanic vent. One circle and one turn also makes the rubber layer uneven. It is also called “orange peel” (seeing with naked eyes, feeling the appearance of the composite film product) It is like the orange peel, which is called the orange peel. It causes opacity.
Therefore, the temperature of the drying tunnel should be gradually increased from the inlet to the outlet, from low to high, with a gradient to allow the solvent to continuously and continuously evaporate from the inside to the outside. In addition, when the amount of the glue is too large, the rubber layer is relatively easy to produce the above-mentioned rubber layer defects during the drying process.
Lanker Pack has been accumulated rich experience–from raw material development right through to production and quality control, we guarantee perfection in every product. Using state-of-the-art equipment, we create a wide range of products that includes pe-made pouches (stand up pouches, flat bottom pouches, coffee pouches, side gusset pouches, retort pouches, spout pouches, shaped pouches, etc) and stock (VFFS films, Lidding Films, etc.) Our factory is accredited to several widely accepted standards including BRC, ISO22000, GMP, HACCP and has also achieved U.S. Food and Drug Administration.
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