Details

Autor(en) / Beteiligte

• Mesic, Beko
• Cairns, Mathew
• Järnstrom, Lars
• Joo Le Guen, Marie
• Parr, Robin

Titel

Film formation and barrier performance of latex based coating: Impact of drying temperature in a flexographic process

Ist Teil von

• Progress in organic coatings, 2019-04, Vol.129, p.43-51

Ort / Verlag

Lausanne: Elsevier B.V

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •Application of barrier dispersion to linerboard by the flexography was demonstrated.•Drying at temperature higher than 40 °C is required to improve barrier performance.•Insufficient drying creates cracks providing open pathways for moisture penetration.•DMTA shows that higher curing temperature improves film uniformity and stiffness. The post-application behaviour of aqueous dispersion barrier coatings is investigated. We have adapted a dispersion formulation initially optimised for rod coating, for application to linerboard by a flexographic press. The clay/talc/wax/poly(styrene-butadiene) latex dispersion coatings demonstrated a 60% reduction in water vapour transport rate across the barrier, and a 75% reduction in direct water uptake when the applied film was dried at 75 °C. Multi-layer coatings with a combined application rate of 7 g m−2 exhibited Cobb120 direct water uptake of 16.3 ± 3.7 g m−2 (120 s water contact duration) and a water vapour transport rate of 140 ± 12 g m−2 d−1 (23 °C, 50% RH). Investigation of the post-coating curing regime demonstrated a decrease in the prevalence of crack defects within the cured film, and corresponding improvement in barrier properties when higher drying temperatures were employed. Dynamic mechanical analysis of the cured films indicated improvements in homogeneity and a greater extent of intermolecular interactions in the coating formulations cured at elevated temperatures.