Cellulose
The goal of this work is to increase the positive footprint of packaging products by designing ‘‘eco- effective’’ solutions according to the Cradle to Cradle design framework. Reutilization of two kinds of materials (waste paper and cereal bran) is proposed here in order to close the loop at the end of product life cycle. The aim was to design, manufacture and examine the degradation intensity of waste papers containing cereal bran with a special focus on the effect of the soil type. Both, paper sheets and paper pots were evaluated. It is expected that by understand- ing the degradation rate of the investigated products it will be possible to optimize paper pots manufacturing to assure sufficient mechanical resistance and the desired rate of degradation.
was defibred using a defibrator and formed into sheets of paper with a Rapid-Ko¨then device. Manufactured papers were made of pulp without and with 3% or 5% addition of wheat and rye bran. Both additives were by-product of the flour production and were provided by Gdan´skie Młyny i Spichlerze Dr Cordesmeyer Sp. z o.o. The fraction size of bran particles was below 0.4 mm. Details for the sample composition and labelling of investigated papers are summarized in Table 1.
Paper pots
Paper pots were manufactured in the laboratory from the same pulp as reference flat paper sheets and with identical additives configuration (Table 1). The cus- tom machine for forming pots was developed at University of Life Sciences in Poznan (grant number N30900831). The pot was formed directly in the container from water pulp solution with 2.5% dry mass concentration. 600 cm 3 of the pulp solution was used for manufacturing of each pot. The perforated mold was used to deposit a layer of fibres with additives, where water was removed from the cast by a vacuum pump. The formed pots were dried for 12 h at 50 Cin a climatic chamber. The final size of the manufactured pot was 6.0 9 6.0 9 5.5 cm (width 9 length 9 height, respectively). Degradation and characteriza- tion were performed on commercially available prod- ucts (pots manufactured with the addition of peat) in order to compare their overall performance with laboratory produced pots. Figure 1 presents images of pots manufactured in the laboratory and alternative commercially available products.
Materials and methods
Materials
Two forms of paper products were examined in this study including flat sheets of paper and paper pots. Five configurations were made for both products (Table 1). In case of paper sheets, 24 samples with dimension of 15 9 95 mm, were cut from each configuration of paper. Fifty pots were manufactured from individual paper type.
Paper sheets
Paper sheets were produced in the laboratory at University of Life Sciences in Poznan on the Rapid- Ko¨then apparatus from recycled pulp type D (card- board, paper, grey bags, corrugated board), weighing 100 ± 5 g m - 2 . The pulp was milled on the labora- tory mill PFI (till 28 ± 2 SR value). The wetness was measured with a Schopper-Riegler device. The pulp
Methods
Degradation in soil
The substrate used in this experiment was a natural soil sample collected close to Poznan (Poland). The soil was sieved to less than 2-mm particle size before degradation tests, and obvious plant material, stones, or other inert materials were removed. The degradation process was conducted in conditioned laboratory in 20 C and 65% RH. Three different types of soil (sandy, forest and agricultural) were selected as degradation environments for the investigated paper products. The pH of sandy soil was * 7.5 to 8.0.
Table 1 Summary of investigated samples composition
Sample code
Mass content of additives (%)
Wheat bran
Rye bran
WP
0
0
WP3W
3
0
WP5W
5
0
WP3R
0
3
WP5R
0
5
123
Made with FlippingBook - Online catalogs