Separate time and volatilization of the solvent evaporation is proportional to ink but with the time increase of volatile reduced to the complete evaporation takes a long time, this can be measured out, Wholesale Flags Suppliers the solvent in the ink film will be a long time the residual . In the use of slow volatile high-boiling point solvent, the problem of residual solvents in need of special attention. Residual solvents in the ink film since the role of the plasticizer, softening the ink film, and bring many other adverse effects.
Solvent evaporation drying type ink, easy to use, Swooper Flags with quick-drying, so it is widely used. The disadvantage is that excessive use will reduce the solvent resistance, heat resistance.
(2) response to the drying ink. Smaller molecular weight of the ink of the ink film formation, ie was the state of the prepolymer, and then oxidized in air, heat, light or reactive substances in a chemical reaction while the polymer, Wholesale Flags Suppliers the formation of the ink film. At this time in a cross-linking between the resin, the resin to form cross-linked structure, as shown in Figure 3-40. Cross-linked by its nature becomes stable, Wind Flags have better physical properties.
Figure 3-40 reactive ink cross-linking
The speed of chemical reaction, the higher the concentration of reactive substances, the faster, Also you can add the catalyst, as well as the role of the heat, light, accelerate the reaction rate. Reactive ink, heated for accelerated hardening effect. Not the type of heating can not be hardened. However, due to some material heating in the deformation and ink resins, Wholesale Flags Suppliers paint the heat of the strength of wood, when heated to pay attention to the temperature adjustment.
Evaporation drying ink, ink and dry ink film is a reversible reaction inks do not reversible.
The evaporation temperature of the solvent evaporation drying type ink, due to reactive forms. Ink changes are also different.
a. Oxidation of polymeric ink. Oxidation polymerization-type ink is oil-modified alkyd resin as a main component of the ink. The main reaction of this ink is part of the oil oxidation reaction of polymerization, Swooper Flags Wholesale Prices as the polymer. This reaction at normal temperature slowly, such as heating speed. Another amount of desiccant will also promote the reaction. This type of ink can be shiny of thick ink film products. Their adhesion is good, the ink film is tough. The defect is dry at room temperature is slow, at least 2 hours, 80 ° C heat drying takes half an hour, and stored in the ink surface is easy to produce the film. Advertising Flags Wholesale The ink used in the painting metal, hard plastic, wood products, paper, cloth.
b, heat curing type ink. Refers to the after the curing of the ink by the polycondensation reaction by heating can occur. This ink is also used in epoxy resin for the link material, but with two liquid epoxy ink, this ink is a liquid inks containing catalyst in the heating to curing. The advantage is a liquid type, solvent-free, Wholesale Flags Suppliers stable viscosity before heating the printed materials adhesion fastness and good resistance; drawback is that the energy consumption. The ink curing speed depends on the content and heating temperature of the catalyst. Without catalyst, ink curing, high temperature above 150 ° C in temperature will be able to curing the addition of catalyst, catalyst content, unfavorable ink saved. This ink hardening of various physical properties of the ink film is very good, mainly for the metal , also used for plastic .
(c) Two liquid reaction type ink. Refers to the main agent and curing agent were prepared by the of mixed use ink. Link more than expected in the main agent of epoxy resin, and limb-based resin composition, while curing polycondensation curing agent is added. The advantages of this ink is a solvent-free, with excellent adhesion on most materials; ink film gloss, strength and resistance to resistance. The drawback is that after the two components are mixed after the beginning of the Code poly, so the ink viscosity change over time. Blistering, but it also reduces the adhesion of the ink tackifier, not only cause the , Wholesale Flags Suppliers so the two-component mixture of ink should be controlled within the limit of using exhausted, or wasteful. Such inks slow drying at room temperature (20 ° C) Tack to two hours, curing 20 to 30 hours, 80 ° C, heating and drying takes 40 minutes, these weaknesses affect its widespread use.