Influence of patterns in paper-based strips onmechanical properties

Sammanfattning: This project set out to determine, by experimentation, what changes could be made to the material properties of paper-based strips by making different patterns of incisions. The purpose of the project was to evaluate the possibilities of paper-based strips as tourniquets in clinical use for venepuncture, in which a hypodermic needle is inserted into a vein. A tourniquet is required, at a site closer to the heart than where the needle is inserted, to exert a pressure small enough to allowblood to continue being pumped through the arteries, but large enough to stop blood flowing backthrough the veins. In this way the veins become visible and enable a needle to be inserted into one of them. The paper-based strips were each 50mm by 27mm, and their properties to be examined  were the tearing strength and the extension under a range of forces. Thirty one patterns were tested, four times each. This project has aimed to use force/extension graphs to assess different pattern types for their potential use as tourniquets during venepuncture procedures.