Dry lamination is the process of using dry lamination equipment to bond two or more films together with an adhesive. In plastic composite flexible packaging, dry compounding is one of the most commonly used production methods. The quality of dry compound film is a key factor that affects product quality. Therefore, in the production process, each product in the production process must be carefully done. Details, to avoid compound failures, the common dry composite membrane problems in the process will be discussed with industry insiders.
Dry composite film curled edgethe reason:
( L ) The thickness of the dry composite film is inconsistent, resulting in different heat sealing temperatures and different shrinkage rates.
( 2 ) If the heat sealing temperature is too high or the time is too long, shrinkage and wrinkling will occur at the heat sealing part.
( 3 ) In the longitudinal heat sealing blade part, the running track of the composite film is not straight, causing shrinkage and wrinkling.
( 4 ) Insufficient cooling of the bag-making, especially after the bag-making is heat-sealed and then cooled and the heat-sealed part shrinks and wrinkles.
( 5 ) Insufficient aging time and excessive residual solvent will cause bubbles, delamination or curling of bag corners.
( 6 ) The surface substrate film has poor heat resistance and curls outward.
( 7 ) In the compounding process, the tension matching of the two substrates is not properly controlled, resulting in residual stress after curing and setting. Especially when the thickness of the composite film is thinner, such failures are more likely to occur, which is manifested as rolling out.
( 8 ) The shrinkage of the heat seal layer, especially the PE layer, is too large, causing inward curling.
( 9 ) The tension of the base material is inconsistent during compounding, which leads to shrinkage and curling, and which side of the tension is larger and the curling is biased to which side.
( 10 ) Too much residual solvent in the film causes outward curling.
( 11 ) The shrinkage ratio of the outer layer film is too different from the shrinkage ratio of the inner layer, causing outer roll. Conversely, internal curling occurs.
Countermeasure:
( 1 ) Adjust the tension and make the most appropriate pressure setting according to various substrates.
( 2 ) Adjust the drying temperature and pressure roller temperature.
( 3 ) Reduce the curing temperature and keep it at about 45 ℃.
( 4 ) Adjust the rewinding pressure to an appropriate range (set the thickness of the composite material and rewind after cooling).
Dry compound film odor
the reason:
( 1 ) Residual solvent odor. The residual solvent is caused by printing, and the glue will also be caused by improper process. The solvent residue caused by glue is mainly caused by the use of solvent and the concentration of working fluid. The low temperature of the compound packaging at room temperature can not smell, because the high temperature promotes the migration of residual solvents.
( 2 ) Film odor ( PE , CPP , EVA, etc.). Mainly because of the use of volatile additives with low boiling point and large odor during film manufacturing. In addition, the resin of the film itself is impure and unstable, and the presence of low molecular weight substances and improper manufacturing processes may cause it.
( 3 ) The smell of glue and ink. Ink odor removal is not good for ink solvent release, using high boiling point solvents and poor drying. In addition to the solvent, the odor caused by glue is also an important reason for the incomplete reaction of free monomers. For example , glues produced with 2,4-TDI and 8020TDI have very different amounts of free monomers.
Countermeasure:
( 1 ) Measure the residual solvent and confirm the drying conditions.
( 2 ) Check the film odor (invalid by gas chromatograph).
( 3 ) Confirm the drying conditions and select the appropriate ink and glue.
Dry composite membrane has bubbles
the reason:
1) The solvent is not completely volatilized due to uneven stirring when mixing;
2) The glue roller and hot roller have pits and lines;
3) The hot pressing roller is not compressed;
4) Too little glue is used and the concentration is thin.
Countermeasure:
All these problems should be paid attention to, preheating should be preheated in winter. The ambient temperature must not be too low.
Standard swing door cabinets is a model to your office.
They are made from high quality cold-rolled steel,all metal parts are phosphatised against rust and powder coated in different colors.
Full Height Swing Door Cupboard are suitable for general purpose in office, work places, home storage,keeping anything from office stationery to garage tools.
The standard feature of tall swing door cupboards are higed doors, 3-point locking system, and 2 to 4 adjustable shelves,and people also call them hinged door cabinets.
The external dimensions are usually in three sizes:Height 1850, 1200, 900 (mm)
Width 850, 900 (mm)
Depth 390, 400 (mm)
You always can get more choices in a manufacturer, sometimes two door storage cupboard with drawers are requested.
Black Metal Storage Cabinet,4 Shelf Metal Cabinet,Swing Cabinet for Sale
LUOYANG SHIDIU IMPORT AND EXPORT CO., LTD , https://www.shidiucabinetes.com