1 Introduction
1.1 Panel construction and manufacturing options
1.2 Objectives
2 Materials and methods
2.1 Experimental design
Factors | No. of levels | Levels |
---|---|---|
Veneer cutting method and thickness (veneer) | 4 | Peeled, 0.706 mm |
Peeled, 0.604 mm | ||
Sliced, 0.564 mm | ||
Sliced, 0.508 mm | ||
Veneer orientation | 2 | Tight-side out (TSO) |
Loose-side out (LSO) | ||
Core | 4 | Veneer (V) |
Medium density fibreboard (MDF) | ||
Combination core (CC) | ||
Particleboard (PB) | ||
Adhesive | 3 | Soy-based (Soy) |
Urea Formaldehyde (UF) | ||
Polyvinyl Acetate (PVA) |
Factors and factor combinations | No. of levels per factor or combination of factors | No. of observations for each combination in one block |
---|---|---|
Veneer | 4 | 24 |
Veneer orientation | 2 | 48 |
Core type | 4 | 24 |
Adhesive | 3 | 3a |
Veneer × core type | 16 | 6 |
Veneer × adhesive | 12 | 8 |
Veneer × veneer orientation | 8 | 12 |
Core × adhesive | 12 | 8 |
Core × veneer orientation | 8 | 12 |
Adhesive × veneer orientation | 6 | 16 |
Veneer × core × adhesive | 48 | 2 |
Veneer × core × veneer orientation | 32 | 3 |
Core × adhesive × veneer orientation | 24 | 4 |
Veneer × core × adhesive × veneer orientation | 96 | 1 |
2.2 Manufacturing and conditioning panels
2.3 Measuring check severity
2.4 Statistical analysis
3 Results
3.1 General observations
Rank | Veneer | Lathe checks | Core | Adhesive | Observed mean | No. panels with checks | Bootstrapped mean | 95% CI lower bound | 95% CI upper bound |
---|---|---|---|---|---|---|---|---|---|
1 | Peeled, 0.706 | LSO | PB | Soy | 0.000 | 0 | 0 | 0 | 0 |
2 | Peeled, 0.604 | TSO | MDF | PVA | 2.903 | 1 | 1.387 | 0 | 6.476 |
3 | Peeled, 0.604 | TSO | MDF | UF | 10.22 | 2 | 6.599 | 0 | 20.41 |
4 | Sliced, 0.508 | TSO | PB | UF | 7.107 | 1 | 6.907 | 0 | 37.92 |
5 | Peeled, 0.706 | LSO | MDF | PVA | 14.73 | 1 | 7.038 | 0 | 32.99 |
6 | Sliced, 0.564 | LSO | CC | PVA | 4.553 | 3 | 7.383 | 1.817 | 28.87 |
7 | Peeled, 0.604 | LSO | PB | UF | 8.703 | 1 | 9.208 | 0 | 43.80 |
8 | Peeled, 0.604 | LSO | Veneer | PVA | 26.49 | 3 | 14.83 | 0.651 | 83.15 |
9 | Peeled, 0.706 | TSO | PB | UF | 15.78 | 4 | 16.16 | 4.225 | 38.26 |
10 | Peeled, 0.706 | LSO | PB | PVA | 36.02 | 2 | 18.11 | 0 | 84.90 |
11 | Sliced, 0.564 | LSO | PB | UF | 22.27 | 4 | 18.69 | 4.762 | 57.02 |
12 | Sliced, 0.564 | TSO | PB | UF | 18.92 | 3 | 18.76 | 2.845 | 54.11 |
13 | Sliced, 0.508 | LSO | MDF | UF | 34.53 | 2 | 23.40 | 0 | 106.8 |
14 | Peeled, 0.706 | TSO | PB | PVA | 33.41 | 3 | 28.39 | 4.370 | 101.6 |
15 | Peeled, 0.604 | LSO | CC | UF | 34.26 | 5 | 28.74 | 6.237 | 108.0 |
16 | Peeled, 0.604 | LSO | PB | PVA | 32.71 | 4 | 35.29 | 13.51 | 96.59 |
17 | Peeled, 0.706 | TSO | MDF | PVA | 20.27 | 3 | 36.47 | 5.590 | 136.6 |
18 | Sliced, 0.508 | TSO | MDF | UF | 38.96 | 3 | 38.20 | 2.151 | 130.1 |
19 | Peeled, 0.706 | LSO | PB | UF | 58.41 | 3 | 40.76 | 3.185 | 185.0 |
20 | Sliced, 0.564 | TSO | PB | PVA | 83.67 | 2 | 41.64 | 0 | 194.0 |
21 | Sliced, 0.508 | TSO | PB | PVA | 57.45 | 4 | 43.14 | 14.70 | 117.6 |
22 | Peeled, 0.706 | LSO | CC | PVA | 24.63 | 3 | 43.71 | 0.798 | 161.0 |
23 | Peeled, 0.604 | TSO | CC | PVA | 53.00 | 3 | 47.73 | 9.339 | 162.6 |
24 | Sliced, 0.564 | LSO | MDF | UF | 48.62 | 5 | 51.67 | 13.20 | 131.7 |
25 | Sliced, 0.564 | TSO | MDF | UF | 62.32 | 3 | 53.14 | 8.349 | 142.1 |
26 | Sliced, 0.564 | LSO | MDF | PVA | 86.80 | 3 | 53.27 | 1.329 | 261.0 |
27 | Peeled, 0.604 | LSO | PB | Soy | 75.00 | 5 | 53.46 | 14.63 | 162.3 |
28 | Sliced, 0.564 | TSO | CC | PVA | 43.22 | 4 | 53.74 | 11.13 | 183.5 |
29 | Sliced, 0.564 | TSO | MDF | Soy | 59.83 | 5 | 53.85 | 8.191 | 233.5 |
30 | Peeled, 0.706 | TSO | Veneer | PVA | 47.28 | 3 | 60.36 | 11.35 | 228.0 |
31 | Sliced, 0.564 | LSO | PB | PVA | 42.85 | 4 | 60.41 | 15.99 | 196.9 |
32 | Peeled, 0.706 | TSO | MDF | UF | 95.90 | 4 | 64.55 | 8.466 | 187.6 |
33 | Peeled, 0.604 | LSO | MDF | Soy | 74.29 | 4 | 67.53 | 12.42 | 233.9 |
34 | Peeled, 0.604 | TSO | PB | PVA | 78.39 | 5 | 67.96 | 11.30 | 305.6 |
35 | Sliced, 0.564 | LSO | CC | UF | 49.12 | 5 | 68.69 | 19.55 | 147.5 |
36 | Sliced, 0.508 | TSO | CC | PVA | 58.69 | 5 | 70.46 | 21.28 | 209.1 |
37 | Peeled, 0.604 | TSO | PB | UF | 97.45 | 5 | 72.70 | 20.81 | 149.6 |
38 | Peeled, 0.706 | TSO | CC | UF | 72.12 | 5 | 74.20 | 16.46 | 218.1 |
39 | Sliced, 0.508 | LSO | PB | PVA | 103.7 | 6 | 77.91 | 16.57 | 307.8 |
40 | Sliced, 0.564 | LSO | Veneer | PVA | 95.03 | 4 | 84.10 | 15.46 | 281.8 |
41 | Sliced, 0.564 | TSO | PB | Soy | 129.7 | 3 | 87.20 | 13.43 | 423.3 |
42 | Peeled, 0.706 | LSO | MDF | UF | 38.63 | 4 | 90.92 | 7.095 | 416.8 |
43 | Sliced, 0.508 | LSO | CC | UF | 68.40 | 4 | 96.20 | 4.874 | 284.2 |
44 | Peeled, 0.706 | TSO | PB | Soy | 87.05 | 4 | 96.67 | 24.81 | 329.4 |
45 | Peeled, 0.706 | LSO | Veneer | PVA | 70.75 | 4 | 106.6 | 25.31 | 369.0 |
46 | Peeled, 0.604 | TSO | MDF | Soy | 79.72 | 7 | 110.2 | 44.31 | 275.6 |
47 | Sliced, 0.508 | LSO | MDF | Soy | 68.98 | 3 | 116.0 | 2.690 | 658.4 |
48 | Sliced, 0.564 | LSO | Veneer | Soy | 191.1 | 4 | 121.2 | 39.50 | 441.1 |
49 | Peeled, 0.604 | TSO | Veneer | Soy | 95.41 | 5 | 125.3 | 34.41 | 365.6 |
50 | Sliced, 0.564 | LSO | PB | Soy | 166.6 | 5 | 131.1 | 26.21 | 490.9 |
51 | Sliced, 0.508 | TSO | PB | Soy | 303.0 | 2 | 146.4 | 0 | 688.4 |
52 | Sliced, 0.508 | LSO | CC | Soy | 136.8 | 6 | 149.2 | 37.10 | 533.4 |
53 | Sliced, 0.564 | TSO | CC | Soy | 273.0 | 6 | 152.5 | 29.70 | 657.4 |
54 | Sliced, 0.564 | TSO | CC | UF | 203.1 | 6 | 152.6 | 51.07 | 373.7 |
55 | Peeled, 0.604 | TSO | PB | Soy | 186.9 | 4 | 152.9 | 6.390 | 875.1 |
56 | Sliced, 0.508 | LSO | MDF | PVA | 154.0 | 5 | 154.8 | 28.57 | 540.8 |
57 | Peeled, 0.706 | TSO | Veneer | UF | 134.5 | 8 | 154.9 | 71.76 | 313.3 |
58 | Peeled, 0.604 | TSO | CC | UF | 225.0 | 4 | 155.0 | 34.18 | 411.4 |
59 | Sliced, 0.564 | TSO | MDF | PVA | 98.66 | 3 | 158.8 | 18.10 | 754.1 |
60 | Sliced, 0.508 | LSO | PB | UF | 218.1 | 4 | 161.5 | 14.03 | 473.5 |
61 | Sliced, 0.508 | LSO | Veneer | PVA | 133.5 | 6 | 162.3 | 75.56 | 356.5 |
62 | Sliced, 0.564 | TSO | Veneer | UF | 154.7 | 6 | 172.8 | 60.59 | 329.9 |
63 | Peeled, 0.604 | TSO | CC | Soy | 84.91 | 7 | 183.6 | 80.08 | 614.6 |
64 | Peeled, 0.604 | LSO | MDF | PVA | 277.3 | 4 | 192.4 | 8.630 | 847.9 |
65 | Sliced, 0.508 | TSO | CC | UF | 357.4 | 5 | 196.8 | 17.46 | 930.7 |
66 | Sliced, 0.508 | TSO | MDF | Soy | 312.2 | 5 | 201.6 | 21.56 | 1015 |
67 | Peeled, 0.706 | LSO | MDF | Soy | 197.4 | 5 | 207.5 | 48.82 | 736.1 |
68 | Peeled, 0.604 | LSO | Veneer | Soy | 338.9 | 6 | 210.4 | 15.21 | 1109 |
69 | Peeled, 0.706 | LSO | Veneer | Soy | 269.9 | 6 | 215.8 | 46.62 | 884.8 |
70 | Peeled, 0.604 | LSO | CC | PVA | 145.6 | 7 | 224.1 | 101.3 | 450.6 |
71 | Sliced, 0.508 | TSO | MDF | PVA | 160.1 | 7 | 228.6 | 83.01 | 623.6 |
72 | Sliced, 0.564 | LSO | MDF | Soy | 183.6 | 5 | 231.6 | 64.88 | 688.7 |
73 | Peeled, 0.706 | TSO | MDF | Soy | 184.2 | 5 | 240.6 | 46.35 | 971.6 |
74 | Peeled, 0.604 | LSO | MDF | UF | 222.4 | 4 | 250.5 | 60.51 | 685.9 |
75 | Sliced, 0.564 | LSO | CC | Soy | 460.3 | 5 | 252.7 | 11.27 | 1429 |
76 | Sliced, 0.508 | TSO | Veneer | PVA | 133.9 | 3 | 258.8 | 66.21 | 932.3 |
77 | Peeled, 0.706 | TSO | CC | PVA | 155.0 | 4 | 268.0 | 104.5 | 787.9 |
78 | Sliced, 0.508 | TSO | CC | Soy | 510.7 | 4 | 292.0 | 12.72 | 1627 |
79 | Peeled, 0.706 | LSO | CC | Soy | 178.8 | 4 | 300.5 | 95.20 | 865.7 |
80 | Sliced, 0.564 | LSO | Veneer | UF | 553.3 | 7 | 311.0 | 112.6 | 884.5 |
81 | Sliced, 0.564 | TSO | Veneer | PVA | 359.9 | 5 | 314.9 | 18.14 | 1772 |
82 | Peeled, 0.706 | TSO | Veneer | Soy | 215.1 | 7 | 349.1 | 155.0 | 861.0 |
83 | Peeled, 0.604 | LSO | Veneer | UF | 297.0 | 8 | 374.7 | 159.9 | 750.4 |
84 | Peeled, 0.706 | LSO | Veneer | UF | 332.2 | 7 | 382.4 | 119.7 | 1244 |
85 | Peeled, 0.706 | LSO | CC | UF | 498.2 | 5 | 459.2 | 124.7 | 1172 |
86 | Sliced, 0.508 | LSO | PB | Soy | 368.1 | 7 | 481.1 | 172.7 | 1300 |
87 | Sliced, 0.508 | LSO | CC | PVA | 442.8 | 4 | 506.1 | 116.1 | 1740 |
88 | Sliced, 0.564 | TSO | Veneer | Soy | 935.5 | 5 | 509.2 | 21.18 | 2294 |
89 | Peeled, 0.604 | TSO | Veneer | UF | 354.7 | 6 | 540.2 | 132.7 | 1771 |
90 | Sliced, 0.508 | LSO | Veneer | Soy | 230.4 | 8 | 564.6 | 297.4 | 1625 |
91 | Sliced, 0.508 | LSO | Veneer | UF | 415.6 | 6 | 594.5 | 238.1 | 1182 |
92 | Peeled, 0.604 | TSO | Veneer | PVA | 548.8 | 4 | 748.9 | 216.7 | 2362 |
93 | Sliced, 0.508 | TSO | Veneer | UF | 769.9 | 8 | 784.4 | 336.9 | 1363 |
94 | Peeled, 0.706 | TSO | CC | Soy | 1005 | 5 | 908.9 | 158.7 | 2858 |
95 | Peeled, 0.604 | LSO | CC | Soy | 990.1 | 6 | 1236 | 115.0 | 4947 |
96 | Sliced, 0.508 | TSO | Veneer | Soy | 816.2 | 7 | 1343 | 232.6 | 6242 |
3.2 Data model and analysis
Parameter | Data model | Bootstrap value | Bootstrap 95% CI |
---|---|---|---|
Index | 1.58 | 1.58 | 1.58–1.60 |
Dispersion/residual variance | 17.2 | 17.2 | 16.2–20.3 |
Whole plot | 1.09 | 1.09 | 0.71–1.31 |
3.3 Effect of veneer
Veneer type | Quartile | |||
---|---|---|---|---|
1st (CD < 52 mm2/m2) (%) | 2nd (CD ≤ 121 mm2/m2) (%) | 3rd (CD ≤ 232 mm2/m2) (%) | 4th (CD ≤ 1343 mm2/m2) (%) | |
Peeled, 0.706 mm | 33 | 25 | 13 | 29 |
Peeled, 0.604 mm | 29 | 21 | 29 | 21 |
Sliced, 0.564 mm | 21 | 38 | 25 | 17 |
Sliced, 0.508 mm | 17 | 17 | 33 | 33 |
3.4 Effect of lathe check orientation
Lathe check orientation | Quartiles | |||
---|---|---|---|---|
1st (CD < 52 mm2/m2) (%) | 2nd (CD ≤ 121 mm2/m2) (%) | 3rd (CD ≤ 232 mm2/m2) (%) | 4th (CD ≤ 1343 mm2/m2) (%) | |
Tight-side out | 27 | 25 | 23 | 25 |
Loose-side out | 23 | 25 | 27 | 25 |
3.5 Effect of core material
Core type | Quartiles | |||
---|---|---|---|---|
1st (CD < 52 mm2/m2) (%) | 2nd (CD ≤ 121 mm2/m2) (%) | 3rd (CD ≤ 232 mm2/m2) (%) | 4th (CD ≤ 1343 mm2/m2) (%) | |
Combination core | 17 | 21 | 29 | 33 |
MDF | 29 | 33 | 29 | 8 |
Particleboard | 50 | 29 | 17 | 4 |
Veneer | 4 | 17 | 25 | 54 |
3.6 Effect of adhesive type
Adhesive type | Quartiles | |||
---|---|---|---|---|
1st (CD < 52 mm2/m2) (%) | 2nd (CD ≤ 121 mm2/m2) (%) | 3rd (CD ≤ 232 mm2/m2) (%) | 4th (CD ≤ 1343 mm2/m2) (%) | |
Polyvinyl acetate | 38 | 28 | 19 | 16 |
Soy | 3 | 25 | 38 | 34 |
Urea formaldehyde | 34 | 22 | 19 | 25 |