Compound packaging refers to the packaging materials of the printing ink film (such as BOPP, PET, etc.) that cannot be achieved by the physical and chemical protection properties of the substrate that is no longer adhered by the amount of adhesive and resin. It is generally used in food packaging. With the improvement of environmental safety awareness and the requirements of food packaging (color and taste preservation) in recent years, the quality control requirements for the amount of solvent residue in composite packaging bags have become stricter and stricter. Printing and packaging manufacturers and packaging customers All are looking for ways to reduce the amount of residual solvent. The general amount of solvent residue in the composite packaging is sampled immediately after printing. The detection method and standard are in accordance with the national standard document: GB / T10005-1998 biaxially oriented polypropylene / low density polyethylene composite film. The total amount of solvent residue is less than 10mg / m2, of which benzene Party class but less than 3mg / m2. Solvent residues in composite packaging are generally generated from inks, solvents, and production processes) The quality and performance of the ink, the drying speed of the diluted solvent, the performance of the machine, the environment, and the packaging structure all affect the amount of solvent residues). Since the current domestic composite packaging printing is mainly based on gravure rotary press printing, the ink is designed to contain benzene and ketones, and the solvent is evaporated to dry. The ink generally contains unequal amounts of toluene, methyl ethyl ketone, and ethyl ester. For different solvents, the molecular weight and boiling point of each solvent are different, and the volatilization rate is also different. This causes the residual amount of various solvents to be different. So, what are the factors that affect solvent residues? The following will analyze the structure of ink, solvent, environment, and composite packaging: 1. The compound ink generally contains chlorinated polyolefin and polyester resin as the main linking material. The higher the absorption residue of the resin molecules, the larger the solvent residue if the solvent release is poor. Generally speaking, the solvent release properties of polyester inks are better than polyolefin inks. 2. One of the biggest reasons for the solvent residue is the influence of the solvent performance. The quality of the solvent itself, the water content, the boiling point, the evaporation rate will be 10 million. If the solvent in the ink contains a high water release rate, or contains a high boiling point, it will be 10 million ink. The drying speed is reduced, which results in the detection of the quality of the solvent, so that there are tens of millions of quality problems. 3. The permanent residue is not a single cause. The temperature, air speed and air volume of the drying system of the printing machine often affect the solvent factor, but the air speed and air volume cannot keep up, and the solvent residue will be as large as the high-speed printing machine. In addition, the printing workshop environment and air flow will also have a certain impact. 4. In terms of packaging structure, there are many ways to reduce solvent residues. The Institute uses co-extruded films to focus on benzene-free composite inks or alcohol-soluble composite inks, choose environmentally friendly solvents, use solvent-free composite methods or extrusion composite methods, etc. . The compound packaging itself is more controlled on a more complicated printing process, and it can still control the residual solvent. Camera Bag,Camera And Lens Backpack,Camera Backpack,Camera Case Ningbo Fineweather International Trade Co., Ltd. , https://www.fwsbag.com