wheat straw

Ingredients

wheat straw, Sodium hydroxide, sodium sulphite, copper sulphate penta-hydrate, ethylenediamine

Preparation Steps

Original Recipe Text

The pulp preparation involved cutting wheat straw to 2-3 cm lengths, followed by washing with filtered water. Mechanical pulping (p. 4) used heat treatment in an autoclave rotary digester at 165°C for 3 hours with a 1:5 solid-to-liquid ratio, followed by refining in a single-disc laboratory refiner. Chemical pulping (p. 5) employed the Kraft process with 16.5-17% active alkali (NaOH + Na2S) or the Soda process with 17-17.5% NaOH to produce 15 kappa pulps. Papermaking (p. 5) consisted of creating 70 ± 2 gsm hand-sheets using a British hand sheet former after disintegrating pulps at 3000 rpm for 10-15 minutes at 0.3% consistency.

Evidence

"The pulp is made from wheat straw harvested in western India. Cut the straw to a length of 2–3 cm with scissors."

Remarks

The study evaluates the effects of natural ageing (180 days at 15-25°C and 30-50% relative humidity) on wheat straw paper (p. 5). Ageing causes significant chemical and physical changes, notably an increase in carbonyl group content (measured by the copper number test) which serves as a degradation indicator (p. 6, 8). Mechanical pulp (MC) was particularly susceptible, showing a 25% reduction in folding endurance and a decrease in porosity by 6.25% (p. 7). FE-SEM imaging revealed that aged fibres develop a porous surface structure and exhibit increased deformation through kinking and curling (p. 14, 20). The yellowness observed in aged paper is attributed to lignin oxidation into low molecular weight chromophoric species (p. 2).