Making Biodegradable Seedling Pots from Textile and Paper Waste—Part A: Factors Affecting Tensile Strength

Abstract

This study investigates the efficacy of using discarded textile (cotton and polycotton) and paper waste (newspaper and corrugated cardboard) as substrates to form sheets with optimum tensile strength. The effect of alkali treatment (sodium hydroxide (NaOH) and sodium bicarbonate (NaHCO3)), compressive loads (200 N and 500 N), and the use of binding agents (blackstrap molasses, sodium alginate, and cornstarch) were studied to optimize the tensile strength of homogeneous sheets. The alkali treatment using 5% NaOH for 5 h of soaking demonstrated the highest increase in tensile strength of 21% and 19% for cotton and newspaper, respectively. Increasing compressive load from 200 N to 500 N showed the highest increase in tensile strength of 37% and 42% for cotton and newspaper, respectively. Remarkably, among the binders, cornstarch at 20% concentration obtained an increase in tensile strength of 395%, 320%, 310%, and 185% for cotton, polycotton, corrugated cardboard, and newspaper sheets, respectively. The optimum results obtained from this study will be utilized to develop biodegradable seedling pots using discarded textile and paper waste.

Making Biodegradable Seedling Pots from Textile and Paper Waste—Part B: Development and Evaluation of Seedling Pots

“…Blending of paper substrates (newspaper and corrugated cardboard) with cotton and polycotton to form bio-composite sheets and determining the tensile and bending strengths are worthy to be investigated prior to making a biodegradable seedling pot [ 23 ]. The substrates used in this study include textile waste in the form of soiled towel (100% cotton), polycotton fabric (60% cotton/40% polyester), and paper waste in the form of used newspaper and corrugated cardboard.…”

“…The bio-composite sheet was formed using 5 cm × 2.5 cm and 12 cm × 2.5 cm molds for tensile strength and bending strength tests, respectively ( Figure 1 ). The compression method and instrumentation used to form sheets were common with Part A of this study [ 23 ]. After the compression, the bio-composite sheet was removed from the mold and dried for 5 h at 105 °C and kept in the desiccator prior to testing.…”

“…The addition of binder remarkably improved the tensile strength by 180–395%, while the alkali treatment (5% NaOH for 5 h soaking) increased the tensile strength by 14–21% only [ 23 ]. From these results, untreated bio-composite sheets for C blend 1 and PC blend 1 were considered as control treatments to compare the tensile and bending strengths with the treated bio-composite sheets.…”

“…A universal testing machine (LS5 Model, Lloyd Materials Testing, Lloyd Instrument Ltd., West Sussex, UK) equipped with 5 kN load cell was used to determine the tensile strength and bending strength of the prepared bio-composite sheets ( Figure 3 ). The method used to perform tensile strength was common with Part A of this study [ 23 ]. For bending strength, a three-point bending test was used.…”