Flexographic Printing Inks

What is Flexographic Printing?

Flexographic printing is the most common printing type used in packaging production. This printing type uses nyloprint relief plates. Flexographic printing, which can be applied to uneven surfaces, is used on cardboard, kraft, corrugated board, PP, PE and other film-group materials. In flexographic printing, adequate colour coverage is achieved with a thin ink layer. By printing two different colours on top of each other, a third colour can be obtained. The thin ink layer also provides time savings with its quick-drying property.

Figure 1. Flexographic printing system

Flexographic Printing Inks

Varnish, composed of resins and solvents, disperses and wraps pigments from the ink. As a result, flexographic printing ink is formed. The advantages of flexographic printing inks are that they are fast-drying, low-cost and environmentally friendly. The formulation of flexographic printing inks is as follows:

Table 1. Flexographic printing ink formulation

Ethanol, isopropyl alcohol, n-propanol, ethyl acetate, methyl ethyl ketone, methoxypropanol, ethoxypropanol and monopropylene glycol are the main solvents used. • Drying Time Regulators: Methoxypropanol or ethoxypropanol (Retarder) Ethyl acetate (Accelerator) *The lower the evaporation index of the solvent, the more volatile it is and the faster the ink dries. • Thinning Method: 100% ethanol or 65% ethyl alcohol + 35% IPA There are 3 types of flexographic printing inks:

1. Solvent-Based

• Composed of 80-90% alcohols and 10-20% acetates, • Has lower surface tension compared to water-based inks, • Used in plastic shopping bags and industrial films.

2. Water-Based

• Essentially composed of water and pigment. Contains additives such as foam suppressants, • The ink type with the highest surface tension, • Used in the corrugated packaging industry.

3. UV-Resistant

• Composed of prepolymers, monomers, photoinitiators and pigments, • Dries when exposed to UV light, • Has high viscosity value, • Used in the food packaging industry. Öznur Kurt / Assistant Product and Service Development Specialist / Aleph Petrol ve Kimya Ürünleri San. Tic. A.Ş.

Sources 1. http://ambalajvekagit.blogspot.com/2010/06/ flekso-baski-nedir-nasil-yapilir.html 2. Matesan Makine Teknolojileri Sanayi 3. Ferkim Matbaa Mürekkepleri 4. www.brancher.com 5. www.gellnerindustrial.com 6. blog.luminite.com