How to reduce the amount of solvent residue in food packaging printing?

Public date： 2018-3-22 10:31:13

Solvent residue problem has always been a difficult problem for ink companies. The state has already required the residual amount of benzene solvents to meet the hygiene requirements of BOPP/PE compound packaging, which must reach 3mg/m2 or less. Improve, how to reduce the solvent residue in the food packaging printing machine brush, has become a key issue for ink companies.
1. Among EVA-40W, MP-45 and CL-PP resins, CL-PP always has the highest residual solvent and EVA-40W has the least residual solvent, so it can guarantee the composite strength. Under the conditions, the content of CL-PP can be reduced appropriately and the content of EVA-40W can be increased.
2, choose the right CL-PP. The solvent residue caused by CL-PP of different manufacturers in the compound ink is very different. If the formula cost can be accepted, PP803MWS produced by Japanese paper can be used, and it can generally be reduced to 50% under the same amount of conditions.
3. When dissolving EVA-40W, MP-45 and CL-PP, adding a part of ethyl ester and residual solvent reducer can effectively reduce the residual amount of toluene solvent in the ink film.
4. Check whether the solvent used for the ink and the printer brush are pure. If there is a small amount of high-boiling solvent, it may cause the solvent residue to be too high, and even lead to serious odor in the printed matter.
5. Adjustments in the printing and compounding process:
1 Minimize the use of toluene solvent when preparing the dilution solvent, and use a mixed solvent of toluene, acetic acid and methyl ethyl ketone = 2:5:3;
2 in the printing process to improve the printing machine drying tunnel exhaust, appropriate to increase the temperature of the drying tunnel, if conditions permit, after the white ink is printed, open the drying tunnel for multiple drying;
3 The viscosity of the ink can be properly reduced during the printing process.