| Abstract [eng] |
With advancement of manufacturing technology and struggle to maintain the best adhesive quality, developers continuously make efforts to improve their production efficiency without hindering the quality of the adhesive. So, this research aims to incorporate the effect on quality of hot stamped periodical structures using different layer thicknesses and hot stamping regimes. Four adhesives which differ in concentration and viscosity were used during this research. Three of them are water based (S35.3197 and S35.3213 (Nolax, Switzerland), OPU746 (Lotto, Germany)) and one is the solvant based TC-03 (Centro Grafico DG S.p.A, Italy). All four adhesives were applied on multilayered polymer film with embossed periodical structures using rods with dfferent wire diameter (d = 4, 14, 24, 50 and 80 µm) under similar conditions. It was observed that adhesives Nolax S35.3197 and Lotto OPU746 followed linear dependence on coating thickness while the other two showed variable patterns due to low viscosity. To evaluate adhesive layer properties scratch test was conducted at five different loads, S = 260.86mN, 290.28mN, 309.89mN, 329.5mN and 358.92mN with all other parameters being same, on adhesive layers and it was found that adhesive Nolax S35.3197 had minimum variation of data in comparison to others and in general, the scratch width increased with the increasing load. Further, hot stamping was conducted on all samples for time, t = 1sec at constant load on substrate with grammage of 80g/m2. It was found that hot stamping quality depends on adhesivie layer nature, its thickness and hot stamping temperatue. Based on visual inspection, best quality of stamped structures were found in case of adhesive layer A1 (d=14µm, T=106ºC; d=24µm T=73º, 90º, 106ºC; d=50µm; T=73º, 90ºC) adhesive layer A2 (d=14µm, T=106ºC; d=24µm T=106ºC; d=50µm; T=90º, 106º C) and for adhesive A4 at rod diameter d=50µm and hot stamping temperature T=106º C. These structures were selected for final evaluation. For scratch testing of hot stamped periodical structures, same loads were used with similar conditions as those for adhesive layer properties evaluation. It was found that at smaller loads, S = 260.86 and 290.28 mN, there is very small or no deformation observed while in case of higher loads, S = 309.89, 329.5 and 358.92 mN, adhesive or cohesive failure was observed. |
