With the improvement of living standards,people puts forward higher requirements on food packaging.Ink as printed material,when it is used in food packaging,must abide by the principle of free transfer.Food packaging shall not use conventional printing ink,printing manufacturers must ensure that all after printing ink solvents in volatile,ink to cure thoroughly,and achieve the corresponding application industry standards.
In the current food plastic packaging printing,the most widely used benzene soluble chlorinated polypropylene ink.Manufacture and use of this kind of ink technology has been mature,mainly used in BOPP(two-way stretch polypropylene)printed materials,and adopts the intaglio printing method.Good though the ink printing eligibility and post-press processing performance is good,quick drying,but due to large(1)relative toxicity of toluene,print solvent residual values on the high side;(2)the poor thermal stability of chlorinated polypropylene,in the process of production and storage,easy to release of chlorine and hydrogen chloride formation,make the ink is strong acid,the print roll is produced in the production of heavy corrosion;(3)benzene soluble ink can damage the ozone layer,in use process will cause harm to workers'health and safety,and the remaining residues in packaging products,under certain conditions can cause to a certain extent to the packaging of food contamination.The ink is tend to be eliminated,in Europe and some developed countries have successively develop prohibited or control regulations on the use of the ink.
It is because of benzene soluble ink exist problems,environmental printing ink arises at the historic moment.Adopt environmental printing ink,neither to environmental pollution,and without causing physical harm to operators and also won't cause damage with food.
We have environmental printing ink:
Water-based ink was 1.
Water-based ink is the vast majority of flexo packaging printing house at home and abroad used in printing ink,it is mainly composed of water soluble resin,organic pigments,solvents and related auxiliary by the composite grinding processing.Water soluble resin is the nexus of water-based ink,often choose domestic water-soluble acrylic modified resin as a link of material,the heat resistance,weather resistance,chemical resistance,resistance to pollution and glossiness has significant advantages,such as whether directly disperse dissolved or synthetic polymer emulsion,all show the excellent performance,water-based ink does not contain volatile organic solvents,not only can reduce the printing quality of residual toxicity,and can prevent fire by static contact with flammable solvents.Water-based ink is not only a new type of"green"printing ink,and is the best product to replace benzene soluble ink.
The uv curing ink refers to under certain wavelengths of ultraviolet light,ink links within the crosslinking reaction between,to shift from liquid to solid finish curing inks,it before the link is dissolved,macromolecular prepolymer is firmly form ink film.The uv curing ink is mainly used for the flexible printing,soft base material it is made up of prepolymer,reaction diluent,pigments,additives,light initiator/composite.The choice of ink formulations of reactive diluent migration reaction influence;Additives on the performance of the ink,printing eligibility,printing ink of migrating,the wetting of the substrate,the friction coefficient,wear resistance,pigment dispersion and stability)and the smell of print to adjust;Requests the pigment to the ultraviolet absorption spectrum range as small as possible,an ideal pigment should have good dispersion,good flowing property,strong tinting strength,under the light irradiation of ultraviolet absorption of tiny,for the characteristics of the polymerization no harm.Should be paid attention to when using the uv curing ink printing polymerization inhibition,surface tension and wetting effect,and the correlation of the ink viscosity and humidity,the expansion of the print;Due to the printing ink adhesion of plastic is bad,so need to printing plastic flame treatment or corona discharge treatment,in order to improve the adhesion of the plastic surface.
3.The electron beam curing ink ink(EB)
Electron beam curing ink is refers to under the irradiation of high energy electron beam can quickly shift from liquid to solid ink,also known as EB ink.High energy electron beam,solids such as pigment and filler has a strong penetrating power,there will be no ink is absorbed by the pigment or filler block,the inside of the ink film drying not be affected.