This paper is concerned with the fabrication of voided polyethylene microstructures by heat melding of plastic microcapillary films (MCFs) to form microcapillary monoliths (MCMs), which are consolidated layers of MCFs forming in two-dimensional arrays of microcapillaries. MCMs were manufactured by heat melding multiple layers of low-voidage MCFs or high-voidage MCFs. The optimal conditions for interface adhesion of the MCFs to create MCMs without compromising capillary integrity were investigated. The MCFs were processed from linear low-density polyethylene (LLDPE) and the melt rheology of the polymer was studied to provide theological parameters that could be used both to gain an understanding of the character of the polymer and for modeling of the MCM forming process. In particular, the temperature dependent nature of the rheology was investigated at the transition from viscous-dominated behavior to elastic-dominated behavior. Modeling of the melding process provided some additional information and confirmed issues in relation to the thermal bonding temperatures and mechanisms. (C) 2009 Elsevier Ltd. All rights reserved.