Testing the rolling tack of pressure-sensitive adhesive materials. Part II: Effect of adherend surface roughness

Abstract

A novel method and custom-made apparatus for testing the rolling tack of pressuresensitive adhesives (PSAs) and related materials were developed to measure bonding and debonding processes. The combined effects of adherend (probe) surface roughness, longitudinal load, and dwell time on bond-formation performance of ve different tacky materials chosen from various application areas were studied. These materials included synthetic PSAs (acrylic tape and the hydrocolloid dressing, Granu ex ® ), water-remoistenable adhesive (CENTRAL ® ), edible wheat our dough, and a static cling vinyl (PENSTIC ® ). Tack-rolling velocity curves were analyzed to study bonding and debondong processes. Each of the tested materials showed different tack behavior in response to varying probe roughness, external load, and velocity (dwell time). Surface wetting and mechanical interlocking were proposed as the mechanisms governing tack in most tested PSAs. Acrylic PSA tested on a smooth probe over a velocity range of 0.12-2.12 m / s showed higher tack values than on a rough one. A signi cant reduction in tack was due to restricted bond formation. Similarly, tack of Granu ex ® to a smooth model skin surface showed higher values than to a rough skin surface. CENTRAL ® showed typical cohesive failure when tested on silicone-coated paper. Interfacial failure and short-term bonding accounted for good tack performance on porous paper. Dough tested with aluminum probes showed cohesive failure similar to that of CENTRAL ® at velocities higher than 0.2 m/ s where the tack was independent of probe surface roughness. PENSTIC ® adhered only to smooth glass where the tack values tended to decrease with increased velocity. Bonding and debonding processes of the various tacky materials were clearly affected by adherend surface roughness, longitudinal load, and dwell time, and could be successfully analyzed using our novel proposed method and apparatus.

Skin surface model material as a substrate for adhesion-to-skin testing

“…The joint peel strength obtained for the smooth adherend was higher than that in the case of rough surface, which may be due to improved surface contact between the adhesive and adherend promoting bond formation. The last finding agrees with the results obtained by Ben-Zion and Nussinovich for acrylic pressure-sensitive adhesives applied on smooth and rough substrates [33].…”

Prepreg tack: A review of mechanisms, measurement, and manufacturing implication

“…[ 85 ] The latter aspect may be of importance for prepreg tack as the effect of the adherend surface roughness on the tackiness of soft adhesives has been demonstrated for PSA. [ 131,132 ] This may contribute to physical adhesion mechanisms such as mechanical interlocking. [ 133 ]…”

“…[85] The latter aspect may be of importance for prepreg tack as the effect of the adherend surface roughness on the tackiness of soft adhesives has been demonstrated for PSA. [131,132] This may contribute to physical adhesion mechanisms such as mechanical interlocking. [133] Previous considerations in combination with the influence of compaction force and dwell are the basis for the adhesive portion of bonding between prepreg resin and the substrate of interest.…”

The effects of substrate surface properties on tack performance of acrylic Pressure-Sensitive Adhesives (PSAs)

“…In contrast to the trends observed among all other classes of adhesives, the use of a rough substrate reduces the adhesion of a PSA to the substrate [7][8][9]. This effect results from the presence of asperities, which reduce the size of the real contact area with the polymer.…”