Manufacture of lightweight (structured cellular) polymeric parts

Abstract

Improving resource efficiency and effectiveness of materials is becoming very important in itself in the current economy. Though some of the manufacturing of structured components has been undertaken with polymeric materials, there has been little use of sheet polymeric materials in order to develop micro-channel devices. These micro-channel devices could, for example, be used in efficient heat exchangers and chemical reactors. The purpose of this master's thesis is to research selective diffusion bonding as part of the manufacturing process of these micro-channels in polymeric materials, in particular to further improve diffusion bonding and to find an effective way to inhibit bonding at predetermined places in order to achieve a selective bond.

In order to determine the quality of the bond a novel testing method was developed and verified using finite element modelling. The design of experiments methodology was used to determine the ideal bonding parameters, to test the effect of different surface modification techniques and to discover new stop-off substances. PMMA was used as a base material.

The results from strength tests showed that the following bonding parameters resulted in the best bond: 120 °C ' 0.31 MPa ' 60 min. Post-annealing did not improve bonding while polishing did show a noticeable improvement in repeatability. Chalk powder proved to be an excellent stop-off. The simulations of the strength test showed similar results as in the real-life experiments.