Why color packaging film is not bright
Data : 2016-06-23
Abst : 1. Temperature control is not suitable......
1. Temperature control is not suitable
When coating different substrates, the temperature of the electrically heated steel drum must be adjusted according to the product covered. Such as laminating substrate is gold cardboard, steel roller temperature control should be controlled at 70-80 ℃: If the cover 250g / m2 or 300g / m2 of gray paperboard, the temperature should be transferred to 80 ~ 90 ℃. Whiteboard paper in the placement process, its absorption of water far more than gold cardboard. Especially in rainy and winter, if the temperature is not adjusted properly, coated products no light. When the film is sometimes found on the silica gel roller obvious drops or steam, which is due to the paper after absorbing a large amount of water caused. Such product coating temperature must be raised some more. For a received product, bake temperature can be controlled at 50 ~ 60 ℃. To glue the film at the bake finger sticky test no trace of traces of stickiness can be a little sticky. If the film temperature is too high, it will blister. Therefore, when the film must be based on product characteristics control the temperature of heated steel drum.
2,Lack of pressure
According to the needs of customers, the thickness of the substrate material is inconsistent. In the film coating should be based on the thickness of the paper to adjust the silicone roller and steel drum pressure. If the pressure is too small, the membrane film products are not strong, not bright, easy to produce wrinkles: pressure is too large, wrinkles and paper will produce deformation.
3. The amount of plastic
When using a stretched polypropylene film coating. Must glue on the film. The amount of glue is applied to the moving film by a rotating steel belt mounted on a plastic box. The amount of glue is controlled by a steel blade that rests on the steel roll. Pressure light plastic volume: Pressure heavy plastic volume is small. The amount of glue to grasp how much, both fast and uniform, they can not produce crystal point. If the amount of plastic is too large, the product will be out of shiny gloss.
Special attention should be paid in the gluing process, it must be to prevent the gel solidified after the small particles and foreign bodies remain in the plastic plate. If retained, will be on the roll with rubber roller, stuck in the plastic blade, there will be a no plastic white. Therefore, the laminator after a long shutdown, before the film boot, use coated water or high boiling point kerosene cleaning gum pump and plastic bucket box to ensure that the glue on the rubber roller to the normal coating without the film Traces.
4. Keep the rollers clean.
After a long time under pressure, the steel drum in direct contact with the membrane, coupled with the temperature effect, some residues left on the steel drum above. Silicone roller and coated paper directly to the back of the product contact, coupled with the separation of paper separation, a lot of plastic directly onto the plastic roller hot and the accumulation of accumulation, which will affect the brightness of the products covered.
Serious when the product will also cover the folds. Therefore, we must keep the cylinder clean, stop down at any time to ensure the quality of the coating products.