Effect of starch on tissue waste/high density polyethylene/starch biocomposite for thermoforming process

Abstract

Tissue waste is a problem for the tissue paper industry because the drying process and transporting of this waste are expensive. As a result this waste landed in land fill. Addition of starch in tissue waste suggests a good way to overcome the problem. Three different types of starch were used, corn starch, rice starch, and tapioca starch. However, starch blended with tissue waste produces products with weaknesses in strength, water resistance and cannot be thermoformed. HDPE as binder was added to improve these properties and processability. Melt flow index (MFI) is used to determine the processability and differential scanning calorimetry (DSC) to determine thermal behavior of the most suitable starch to the purpose of thermoforming process. Compounding was done on two-roll mill to form sheet prior to the thermoforming process. Results showed corn starch was most suitable starch base on tensile and water absorption test. Apart of that, by using DSC, corn starch demonstrated better compatibility between components in blends as it showed one melting point. Unfortunately, this formulation has low values of MFI due to high viscosity. Generally, this biocomposite formulation has similar characteristics to the molded casing made using synthetic polymer.