Ink additives are auxiliary materials used to adjust ink to suit different printing conditions. There are many types of ink additives, commonly used ones include leveling agents, ink adjusting oils, driers, slow drying agents, thinners, abrasion resistance agents, varnishes, etc. Below is a brief introduction to the functions and usage methods of common ink additives.

1. Leveling Agent

A leveling agent is a functional additive that can improve the fluidity and surface smoothness of liquid materials after application. Its core function is to reduce surface defects of the coating, making the final film smooth and uniform, enhancing appearance quality and functional performance. Eliminate surface defects: by reducing the surface tension of the coating, it decreases issues such as pinholes and fisheyes caused by uneven tension. Promote spreading: enhances the wettability of the liquid on the substrate, allowing the coating to uniformly cover complex surfaces. Extend leveling time: delays surface drying speed, allowing the coating to flow fully before curing, reducing brush or roller marks. Balance fluidity: works synergistically with thixotropic agents to prevent sagging while avoiding excessive viscosity that hinders leveling.

2. Ink Adjusting Oil

  Ink adjusting oil is an essential auxiliary material used in offset printing inks. Commonly used ink adjusting oils are formulated from synthetic resins, drying vegetable oils, and high-boiling-point kerosene, mainly used to adjust the ink's fluidity and reduce its viscosity, generally used at about 3~5%. Adding ink adjusting oil does not affect the gloss or adhesion of the ink, nor does it significantly impact the drying properties of the ink.

3. Drier

Driers are one of the very important printing ink additives. Depending on printing conditions and the type of paper, the amount, type, and usage methods of driers vary. Common driers include red drier oil and white drier oil. Red drier oil dries from the outside in, while white drier oil dries simultaneously inside and outside. When printing, the type of drier oil should be selected according to the drying requirements and ink color of the print. Generally, the amount of drier oil used is 2%-3%; excessive amounts can have the opposite effect, slowing down the drying speed.

4. Slow Drying Agent

Anti-drying agents, also called antioxidants, are ink additives opposite to driers. During printing, various reasons often cause machine stoppages, and if the stoppage time is long, the ink on the machine will dry and peel. To solve this problem, an appropriate amount of anti-drying agent is usually added to the ink on the machine, and the machine is run a few times to prevent the ink from drying too quickly.

5. Thinner

In printing, due to excessive ink viscosity or poor paper quality, problems such as paper fuzzing and image loss often occur, affecting normal printing. At this time, in addition to adding an appropriate amount of viscosity reducer to lower the ink's viscosity, a small amount of thinner can also be added to reduce the ink's viscosity and ensure smooth printing. There are many types of thinners, generally low-viscosity No. 6 ink adjusting oil.

6. Abrasion Resistance Agent

Abrasion resistance agents, also called lubricants, are mostly wax-based substances. When printing inks have relatively coarse particles, such as white ink or metallic inks, adding an appropriate amount of abrasion resistance agent increases the abrasion resistance and smoothness of the printed product.

7. Varnish

High-end printed products such as trademarks and brochures usually undergo varnishing to achieve a high gloss effect. When using varnish, it can be mixed into the ink before printing or applied as a separate varnish layer after printing. However, varnished prints tend to yellow over time and have poor light resistance. Therefore, many new varnishes that can replace traditional varnish have been applied.