Evaluating the performance of hemp bast fibres in the production of packaging paper using different …
where ‘ Vwater ’ is the volume of water drained in a measuring cylinder. After beating for 37 min, a 20°SR beating degree of hemp bast fibre pulp was achieved. Preparation of wastepaper pulp For each blending, the required amount of wastepaper was weighted and torn from a 3-ply corrugated cardboard-type box into pieces measuring about 3 cm × 3 cm. To easily separate the box piece layers, the box pieces were then soaked for 5 min in a 1 L beaker filled with tap water. The paper layers were separated and kept in the same beaker for an additional 10 min to fully absorb the water. Finally, the wastepaper was disintegrated using a 3-blade rotor-type pulp disintegrator (L&W, model:5-1) at 1150 rpm for 20 min to obtain wastepaper pulp. Preparation of handsheets To prepare each blending stock suspension, the required amounts of beaten hemp bast fibre pulp (20°SR) and prepared wastepaper pulp were diluted with tap water. The pulp was subsequently disintegrated using a 2-blade rotor-type pulp disintegrator (Frank PT-I) at 1250 rpm for 20 min. Handsheets were made on a sheet former (Rapid- Köthen type) according to the TAPPI T-205 sp-02 standard [TAPPI T 205:2002]. Optical microscopy (OM) measurements To examine the morphology of the cooked and beaten hemp bast fibres (length, diameter and wall thickness) as well as manually quantify the size of the raw material, trinocular-type OM (SOIF, model: BK5000, software: MSHOT MicroShot v1.2 Image Processing System) was employed. A glycerine and water solution of 65% was prepared and used as a medium to distribute the overlapping fibres evenly on the slide. The diameter, wall thickness and length of the raw fibres were measured manually from the images taken. The repetition number was 75 for each size measurement type [Dutt et al. 2008]. Carbohydrate component, solubility and ash content tests of hemp bast fibre Carbohydrate components, solubility and ash content tests of hemp bast fibre as a raw material were conducted by the department of forest industry engineering at Karadeniz Teknik University. Table 2 lists common test types and standard operating methods. Hemp bast fibres were sampled and prepared for chemical component analysis using the TAPPI T257 cm-08:2012 test method [TAPPI T 257:2012]. The moisture content for hemp bast fibres was determined based on the TAPPI T210 cm-03:2003 test method [TAPPI T210:20 03]. Wise’s Chloride
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