Physical and Surface Properties of Food Packaging Paper Coated by Thyme Oil

Abstract

Paper coated with natural materials has advantages over paper coated with fossil resources, including easy recycling, renewable components, and cost-effective formulation. Coating the paper surface with thyme oil has antibacterial and antioxidant properties and is known to improve packaging product quality. In the current study, the water resistance of the materials was measured by the Cobb30 values. The base paper, the starch-coated paper, and the thyme oil and starch-coated paper had Cobb30 values of 20, 17.5, and 15.7 g/m², respectively. The tensile strength index of uncoating and coating paper samples was, respectively (machine direction M.D.) 64.3 and 64.7, and (cross direction C.D.) 32.2 and 37.2. The bursting strength index results were 72.7 and 84.0. Hence, according to the tensile strength results, the treated paper burst strength values were higher than the base paper samples. The starch and thyme oil coatings formed a film layer on the paper surface, which may have helped impart better burst-strength properties. Besides, compared to the untreated base papers, the surface of the coated papers was denser and smoother, with a less porous structure, according to SEM results. In addition, resistance features of papers that are desired in the end-use of paper are shown in this work based on paper strength property tests.