Improving Strength Properties of Paper Utilizing Mycelia Fungus

Abstract

Alternatives to the traditional sack grade of paper used for grocery bags was investigated for use in the commercial market. This project investigated the use of mycelium in conjunction with wood-based pulps to produce a structurally enhanced paper sheet. The study included creating and testing a fibrous sheet containing a network of mycelium. Three mycelium types were used: Reishi (Ganoderma Lucidum), Pearl (Pleurotus Ostreatus var. Columbus), and Enoki (Flammulina Velutipes). All three require similar growth conditions but have different growth patterns. Three major trials were run, providing the mycelium with different growth conditions and medium. The first was a simple inoculation. The second was an inoculation of filter paper that was then stored in petri dishes to help reduce the mold growth discovered in the first trial. And the third was an inoculation of pulp slurries that were left to grow before being converted into small sheets. The slurry samples were made with both bleached and unbleached pulp to see if the type of pulp affected the growth. The mechanical properties of the developed materials were evaluated and compared to control samples of each pulp medium. Testing of the mycelium sheets was minimal because of poor growth, mold buildup, and an insubstantial number of samples per trial. Visual inspection under a microscope with 2x magnification and low angle light revealed areas of shiny, hairlike tendrils, protruding off the surface. In some cases, the tendrils appeared to grow over dark mold spots. Under visual inspection only, Pearl had the most clear and substantial growth. After visual inspection, the sheets were tested mechanically in hopes of more sufficient data; the grammage and tensile strength were measured. Strength comparisons were separated based on the inoculation method--inoculated onto pre-formed sheets or added to pulp slurry. The collected data indicated that Reishi grown on bleached pulp was the strongest. In general, inoculated samples of pulp turned out stronger than the original or plain sheets for bleached pulp and weaker for unbleached pulp.