Due to the unique chemistry associated with polyurethanes (PUs), it plays the role of an important constituent of different type of ink formulations except the conventional oil based Lithographic inks. Depending upon the formulation requirements, polyurethane can be made water soluble or dispersible, solvent soluble and/or radiation curable. In addition, in the ink formulation, polyurethane can be used as a pigment grinding resin, adhesion promoter resin and /or specific additives. However, the journey of polyurethane in the packaging industry does not restrict itself only to inks, but also to adhesives. Majority of adhesives used in packaging industry are based on polyurethanes. Similar to inks, adhesives can be of various types such as solvent-based, water-based and radiation curing adhesives. Other important area of polyurethane application is for foot-ware and foam industries.
As per the scope of this article, we will restrict our discussions towards polyurethanes for solvent borne printing inks. Within the solvent-base inks, the major segments where PU can be used are lamination inks and surface inks for both gravure and flexographic applications.
To understand the size of polyurethane business in solvent base, we need to understand the size of solvent-base ink business within important Asian regions. The scope of this section covers Chinese, Indian, SEA (South East Asia) and MEA (Middle East, Saudi Arabia and Africa) Ink Market
Except India, all the above other regions lamination inks are predominantly based on film forming polyurethane inks. Usually a 30% use of polyurethanes is common in these lamination inks. In India, currently 50 - 60% of lamination inks are typical toluene-based PVC-EVA based inks where the adhesion on BOPP substrate is negligible; therefore, strategic low cost polyurethanes can easily convert this market towards PU based inks.
Similarly for surface inks, plasticizing or semi-film forming PUs are used. Typically the percentage of this PUs for surface ink formulation is 15%. The solid content of these PUs are high and usually 70-80%. For these types of formulations, there is always a competition between polyamide, acrylics and PUs.
Considering the above factors, and based on our experience a fare estimation of the polyurethane consumption per annum has been provided in the following sections. In India, the current lamination ink type polyurethane volume demand is around 25000 metric tons and surface grade PU demand is around 4000 metric tons. Similarly, in China, the consumption of lamination grade PUs is highest in Asia and would be somewhere around 50000 metric tons; and the surface ink grade PU demand in China s similar to India. In SEA, the lamination ink type PU demand is also higher than India and estimated volume is around 40000 metric tons; and that of MEA region is around 10000 metric tons. However, the surface ink grade PU demand in both SEA and MEA regions are quite similar and nearly 2500 metric tons per annum.
By considering a flexible packaging growth rate of 12% in India, 14% in china, 13% in SEA and 5% in MEA; the PU demand for flexible packaging inks for the upcoming years are pretty lucrative and can attract much more business investment in this segment.