Absorbency of biodegradable materials for MHM management in low-and-middle income countries

Four different kinds of natural biodegradable material namely (a) 100 % cotton terry cloth, (b) 100 % hemp cloth, (c) 100 % bamboo wadding and (d) 100 % linen were investigated in this study to find out their respective absorptivity index. All the fabrics are commercially available in bulk off the shelf and procured accordingly. The fabrics were cut by hand to give them a rectangular shape and stacked to 1 cm thickness. Together with that, the absorbency of a regular, store-bought sanitary pad (1 cm thick) was investigated as a comparison for the other materials. To ensure reproducibility of the results, all the experiments were triplicated. A gelatine solution was used to imitate the viscosity of menstrual fluid to provide a more realistic experiment. The typical volume of menstrual fluid lost during a monthly menstrual cycle is about 10-80 mL over eight days (average menstrual cycle). In present study, 20 mL of liquid (gelatine solution) was used to test the absorbency of these natural materials to ensure that the fabrics can retain more than one day’s worth of menstrual fluid. At first, 10 g of gelatine was added into 300 ml of water and heated (60 °C) with stirring until there were no remaining gelatine particles visible. The solution was then split up into 15 x 20 ml volumes for each fabric. The temperature of each solution was then checked to ensure the liquid was at room temperature (21°C) to maintain a constant gelatine solution viscosity, visually representative of menstrual fluid that could remain across each test fabric. Then each of the test fabrics was weighed in precision lab-scale, placed into the container of the same size and 20 ml of the gelatine solution was poured. After 60 seconds, the fabric was removed from the container and weighed again. The absorptivity index (ratio of absorbed mass to dry weight) was calculated. An absorptivity index was used to ensure that the results could be comparable, as each fabric has a different dry weight, and were hence incomparable. Parallax and reading errors were reduced by setting each measuring cylinder down on a flat surface and measuring the gelatine liquid from eye-level. Random cross checks were conducted by a lab assistant.