Industry news| 2021-12-13|admin
What points should be paid attention to in the process parameter design of paper plastic paper support composite:
① Selection of coating amount
Due to the fiber structure of the paper, the surface gap of the paper will absorb more glue, so when making paper plastic composite,Paper paddle moldingWhen the product is, increase the dry basis coating amount. However, the larger the coating amount, the better. The effective coating amount is the thickness of the adhesive layer stored between the paper surface and the aluminum foil interface after bonding. The glue liquid inhaled into the paper has no contribution to the composite fastness.
The coating amount is too large, the adhesive is not easy to cure, the surface is easy to produce "orange peel" phenomenon, and it may also lead to high hardness of waste products; If the coating amount is too small, the adhesion between paper and film decreases.
In addition, the smoothness of the paper is high, the fiber is tight, and the coating amount should be reduced; On the contrary, the smoothness of the paper is low, the fiber is loose, and the coating amount should be further increased.
Therefore, it is recommended that the gluing amount of customers should be more than 3.5g/m2, and the detailed gluing amount should be determined according to the material, equipment, process, product use, etc.
② Selection of gluing surface
Due to the fiber structure of the paper, the gap of the paper is larger and absorbs more glue. In serious cases, there will be lack of glue on the surface and delamination. When the paper is coated with glue, the coating amount needs to be increased to compensate for the glue absorbed by the paper. When the plastic film is coated with glue, the absorption of the paper to the glue solution can be reduced, and the coating amount can be reduced accordingly.
It is assumed that dry compounding process is used paper paddle molding or aluminum-plastic composite products, the adhesive is dissolved in the solvent, and if the paper is used for glue, the solvent has strong permeability to the paper, and a large number of adhesives will be brought into the paper. At this time, a large amount of glue will be required. It is difficult for our equipment to meet the requirements. Once the glue amount is not well controlled, it is easy to produce problems such as poor composite strength and glue infiltration, Therefore, we generally do not recommend that customers apply glue on paper. For example, when we consume BOPP / paper / PE, we first use BOPP glued composite paper, and then PE glued composite paper / BOPP.
③ Setting of tension
We mainly adjust the tension according to the membrane material. Due to the high tensile strength of paper, it is not easy to deform, so a large secondary unwinding tension or winding tension is required in the consumption process. The tension control of the film only needs to meet the small tension in the film compounding process. If the tension setting of the two films is unreasonable, the deformation of the two films may be different, resulting in problems such as wrinkle and curl.
④ Setting of drying channel temperature
When the plastic film is glued, the temperature transition of the drying channel of the laminating machine is too high, which is easy to form the tensile deformation of the plastic film. At the same time, the glue is monotonous and too fast, and the leveling property is poor; If the temperature transition is too low, the glue can not dry completely, which is easy to form the phenomenon of falling adhesion and fog.
⑤ Setting of pressure roller temperature and pressure
The pressure roller temperature is low, the adhesive can not fully penetrate and level the paper, and the bonding strength and gloss are low; If the temperature is too high, it is easy to deform and shrink the plastic film, which may lead to waste wrinkle.
The proper pressure will make the adhesive in viscous flow state penetrate into the interior of the paper fiber through the pressure of the pressure roller, and complete multiple bonding of the paper, such as physical machinery and chemical bonds. At the same time, under the pressure, the adhesive will be fully spread and leveled, and the color of the composite printing is bright.