First, the composite machining definition:
The so-called composite machining, is a combination of two or more mutually bonding film processing technology to achieve so that the strengths of the various films get to play, to make up for weaknesses purposes.
Second, the dry lamination method and extrusion processing combined processing method of comparison:
Dissimilarity:
①. Dry lamination process is to fit a variety of film together, and extrusion laminating process is the processing of the molten resin into one.
②. Dry lamination film processing method applies a large range of species, and extrusion laminating process is limited to PE, PP EVA infiltration of PE, and ionic polymers.
③. Extrusion lamination process with the adhesive surface of the molten resin is large, and therefore, the dry adhesive coating than less complex processing method.
Same point:
Dry lamination process in extrusion lamination process step is basically the same, consisting of the following four steps.
①. Coating
②. Drying
③. Adhesive
④. Maturation (only reactive adhesives)
Third, the complex processing steps:
. A) Coating Step:
For composite processing of the adhesive coating, the most important is the "uniform coating thickness is sufficient."
The following lists the coating amount is generally necessary:
◆ Dry machining complex (with packaging applications and change):
Dried 2--2.5 / m2 (dry weight)
Moisture 2.5--3g / m2 (dry weight)
Boil-2.5--3g / m2 (dry weight)
Cooking film sterilization was 3--4g / m2 (dry weight)
Aluminum retort sterilization was 4g / m2 (dry weight)
◆ When extrusion lamination process (the kind with the adhesive change):
Imine 0.01--0.05g / m2 (dry weight)
Titanium 0.1--0.2g / m2 (dry weight)
Carbamate-based 0.3--0.5g / m2 (dry weight)
. B) Drying step:
The solvent is completely removed.
Not only is the temperature, air volume is also an important parameter.
Dryer temperature gradient generally divided into three phases (such as 50-60-80 ℃).
◆ due to residual solvent brought ills:
Adverse ①. Bubbles and other places look
②. Curing inhibition
③. Odor
◆ residual solvents upper target: 5mg / m2 or less
. C) bonding the steps of:
At high temperatures, high pressure, improve their physical adhesion, it is very important.
◆ dry composite machining contact roller surface: 60--100 ℃, 10-20kg / m2
◆ extrusion lamination processing:
Resin temperature: 300--330 ℃
Aperture: 90--150mm
Pressure roller pressure: 10--15kg / cm
* Adhesive film on the wettability:
Dry lamination processing film, corona discharge treatment, must achieve more than 40 dyne.
When extrusion lamination process, to take advantage of Aperture oxidation. The degree of oxidation by the residence time of the resin temperature (squeeze exit) and slit width may be.
D). Curing step
Carbamate Department (isocyanate) adhesive is cured by a chemical reaction. The reaction requires a certain temperature and time. In addition, the isocyanate is reacted with water. Therefore, the proper temperature is essential.
Under dry lamination process, TDI-based two-component adhesive isocyanates, generally at 40 ℃, maturing within 48--72 hours.
Extrusion lamination process under, TDI-based two-component adhesive isocyanates, generally at 40 ℃, maturing within 24--48 hours.
Extrusion lamination process, the adhesive when using imine, no cooked necessary.
1. The ratio calculated adhesives
Example: AC-500A / AC-500B diluted to a solids content of 25%
| Ratio（g） | Solid content（%） | Solid content（g） | |
| AC-500A | 100 | 60 | 60 |
| AC-500B | 10 | 75 | 5.25 |
| Ethyl acetate | X |
2. Roller depth and the amount of coating applied to the adhesive when the relationship:
The coating amount (dried, g / m2) = 0.2x Roller depth (μ) x solids content (%) x specific gravity of the binder
Example: Roller depth 60μ, with a solids content of 25% of the adhesive coating, the required amount of coating:
The coating amount (dry, g / m2) = 0.2x60x25% x0.95 = 2.85
Curing temperature of the composite film processing
Isocyanate curing temperature
Described adhesive formulations (in AC500A / AC500B example)
All of the resin content (solid content) = (60 + 7.5) / (10 + 100 + 160) = 25 100
Conversely, when diluted to 25 percent,
Diluting solvent amount x can be calculated by the following formula
x = (60 + 7.5) / 25x100- (10 + 100) = 160