Gloss and hardness evaluation of water-based uv curable polyurethane acrylate film used in textile printing


Kalav B. , Baysal G., Karagüzel Kayaoğlu B.

Vlakna a Textil, cilt.25, ss.30-36, 2018 (Diğer Kurumların Hakemli Dergileri) identifier

  • Cilt numarası: 25 Konu: 3
  • Basım Tarihi: 2018
  • Dergi Adı: Vlakna a Textil
  • Sayfa Sayıları: ss.30-36

Özet

In the current study, it is aimed to evaluate the hardness and gloss properties of water-based UV curable polyurethane (PU) acrylate films by using two types of photoinitiators at different ratios. For this purpose, UV curable water-based unpigmented and pigmented formulations were prepared. Formulations were applied on glass plates and UV cured under gallium and mercury (Ga/Hg) lamps at three different power levels, i.e., 60, 90 and 120 W/cm. After UV curing process, gloss and hardness values of polymeric films were measured. The highest film hardness values implying the highest curing level was obtained with the formulation A1, including only Omnirad® 819 DW (former Irgacure® 819 DW) which is effective in deep curing, and formulation A3 including Omnirad® 819 DW and Omnirad® 500 (former Irgacure® 500) effective in surface and deep curing at 2:1 ratio, respectively. Among these two formulations, the highest gloss value was obtained with the formulation A3. GaHg lamp combination provided the highest gloss values while highest film hardness values were obtained with GaHg and GaGaHg lamp combinations. Compared to clear films, pigmented films rendered higher gloss values which was more prominent in single lamp (Ga, Hg) cured films. Results showed that photoinitiators (Omnirad® 819 DW and Omnirad® 500) provided better hardness and gloss values at 1:1, 1:2 and 2:1 ratios. Gloss values increased due to the increase in film hardness. The increase in the total applied energy resulted in an increase in the film hardness values of all clear and pigmented formulations. In terms of film hardness and gloss values, films prepared with Omnirad® 819 DW and Omnirad® 500 at 1:1 ratio and cured under GaHg lamp combination provided better results