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PEER-REVIEWED ARTICLE
where F w is specific surface (m 0 is average density of dry pine wood intended for chip manufacture (0.511 g/cm 3 ) (Mirski and Dziurka 2015), l is length (mm), w is width (mm), and t is thickness (mm). The symbol * denotes the theoretical (calculated) linear dimension of the chips worked out based on linear dimensions of at least 100 chips and average (of 10 repetitions) weight of 100 to 200 chips taken from each screen. Dimensions of EE chips were determined based on 850 chips taken at random from the batch intended for board pressing. Table 2. Conditions for OSB Pressing Resin content (%) MC Chips (%) Pressing Time (s/mm) Pressing Temperature (°C) Unit 2 /kg), ρ Pressure (N/mm 2 )
F ace
F ace 9.25
Core
Core 6.10
4
3
15
200
2.5
The conditions of board manufacture are presented in Table 2. The materials with the above-described properties were used to prepare three-layer 750×450 mm, 15 mm thick OSB panels with a density of 590 kg/m 3 and weight ratio of face/core layers 1:2. Three pieces were prepared for each experimental variant. The OSBs were then tested using relevant standards. The modulus of rigidity (MOR) and modulus of elasticity (MOE) were tested by EN 310 (1993). The internal bond (IB) was tested according to EN 319 (1993), and swelling in thickness (TS) after 24 h water soaking was tested according to EN 317 (1993). The properties of manufactured OSB boards were compared to industrial made OSB (Kronopol) and MFP (Pfleiderer). Determination of the longer and shorter axis was based on the orientation of chips in the core layer. It was assumed that for the longer axis, the chips in the core layer were oriented perpendicularly to the longer axis of a sample. Statistical analyses were performed using the Statistica 12 (StatSoft Inc., Tulsa, USA) and TableCurve 2D v. 5.01 software packages (Systat Software Inc., London, England). RESULTS AND DISCUSSION Dimensional characteristics of the experimental chips are presented in Table 3. The investigated types of chips differed mainly in their length and width, and only slightly in their thickness. Table 3. Dimensional Characteristics of Chips Used for External Layers of OSB Size AA BB CC DD EE - Mean Median Mean Median Mean Median Mean Median Mean Median l (mm) 4.15 4.06 10.15 9.83 15.07 13.95 49.69 46.35 96.79 102.2 w (mm) 0.54 0.55 1.10 1.10 1.46 1.42 3.38 3.35 12.76 11.85 t (mm) 0.17 0.17 0.45 0.42 0.61 0.57 0.61 0.61 0.61 0.59 λ (l/t) 24 24 23 23 25 24 81 76 159 173 κ (l/w) 8 7 9 9 10 10 15 14 8 9 φ (w/t) 3 3 2 3 2 2 6 5 21 20 F w (m 2 /kg) 1433.6 1421.1 819.2 868.3 614.4 647.8 512 502 435.2 458
8346
Mirski et al . (2016). “Non - strand chips OSB,” B io R esources 11(4), 8344-8354.
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