－目次－
第１章 木材乾燥の基礎
1 木材乾燥の必要性......................................................................................................

12 木材の性質................................................................................................................

22.1 木材の外観構造..................................................................................................

22.2 木材中の水分.....................................................................................................

32.3 密度..................................................................................................................

42.4 木材の収縮および膨張.........................................................................................

63 空気の温度・湿度と木材の平衡含水率...........................................................................

94 含水率の管理............................................................................................................

124.1 適正な仕上げ含水率............................................................................................

124.2 含水率基準........................................................................................................

144.3 含水率の測り方...................................................................................................

165 乾燥材の特徴............................................................................................................

225.1 寸法変化............................................................................................................

225.2 強度的性質........................................................................................................

22６ 乾燥速度と乾燥条件...................................................................................................

246.1 乾燥速度............................................................................................................

246.2 乾燥速度に及ぼす外周条件の影響........................................................................

266.3 乾燥速度に及ぼす木材条件の影響........................................................................

28７ 乾燥応力と損傷.........................................................................................................

297.1 乾燥経過と乾燥応力の発生...................................................................................

297.2 乾燥による損傷...................................................................................................

32第２章 乾燥設備および機器
1 木材乾燥の方式と種類................................................................................................

372 人工乾燥における温度、湿度、空気循環の役割..............................................................

372.1 温度 .................................................................................................................

382.2 湿度 .................................................................................................................

38

2.3 空気循環（風速） .................................................................................................

38

3 加熱、調湿、空気循環の方式.......................................................................................

38

3.1 加熱方式.............................................................................................................

39

3.2 調湿装置............................................................................................................

39

3.3 空気循環 ...........................................................................................................

40

4 人工乾燥装置の具備する条件......................................................................................

40

4.1 室内の風速、温度、湿度の分布..............................................................................

40

4.2 室内の温度、湿度の保持、調節..............................................................................

41

4.3 高温、高湿、酸性ガスに対する耐久性.....................................................................

41

4.4 乾燥室の気密性、壁体の保温力............................................................................

414.5 乾燥コスト...........................................................................................................

41

4.6 火災等に対する安全性.........................................................................................

414.7 装置の操作性.....................................................................................................

41

5 人工乾燥装置の方式と規模の選択................................................................................

41

5.1 乾燥方式............................................................................................................

41

5.2 乾燥室の規模.....................................................................................................

42

5.3 経済性...............................................................................................................

43

6 人工乾燥装置の自動制御............................................................................................

43

6.1 計測と制御..........................................................................................................

43

6.2 温湿度センサ......................................................................................................

44

6.3 調節計...............................................................................................................

45

7 蒸気式乾燥装置.........................................................................................................

457.1 概説..................................................................................................................

457.2 一般的仕様........................................................................................................

487.3 長所および短所...................................................................................................

51

8 除湿式乾燥装置.........................................................................................................

528.1 概説..................................................................................................................

52

8.2 一般的仕様........................................................................................................

53

8.3 長所および短所...................................................................................................

54

9 減圧乾燥装置............................................................................................................

55

9.1 概説...................................................................................................................

55

9.2 主な加熱方法.......................................................................................................

55

9.3一般的仕様...........................................................................................................

57

9.4 減圧式乾燥法の長所および短所.............................................................................

58

10 太陽熱利用乾燥装置.................................................................................................

5910.1概説...................................................................................................................

59

10.2 長所および短所..................................................................................................

60

11 高周波・蒸気複合加熱型乾燥装置...............................................................................

60

12 加圧・減圧乾燥装置..................................................................................................

6113 予備乾燥装置（プレドライヤ）.......................................................................................

6114 調湿装置.................................................................................................................

62

15 天然乾燥施設..........................................................................................................

62

16 狂いの抑制法...........................................................................................................

63

17 その他の品質管理機器..............................................................................................

64

18 エネルギー管理........................................................................................................

65

18.1 ボイラと燃料......................................................................................................

65

18.2 電気.................................................................................................................

67

18.3 乾燥装置の熱消費.............................................................................................

6719 乾燥設備費..............................................................................................................

68

20 乾燥機の点検（日常・始業点検）..................................................................................

70

21 乾燥設備の関連法規.................................................................................................

71

第３章 木材乾燥の実際
1 針葉樹材の乾燥特性..................................................................................................

732 天然乾燥の実務.........................................................................................................

762.1 天然乾燥の方法と留意点......................................................................................

762.2 天然乾燥の日数..................................................................................................

782.3 天然乾燥における材の損傷...................................................................................

792.4 板材および平割材の天然乾燥...............................................................................

792.5 角材の天然乾燥..................................................................................................

803 人工乾燥の実務.........................................................................................................

823.1 人工乾燥の方法..................................................................................................

823.2 乾燥スケジュールの基本型....................................................................................

83

3.3 蒸気式乾燥の実務...............................................................................................

87

4 除湿乾燥の実務.........................................................................................................

112

4.1 乾燥の原理と特徴................................................................................................ 112
4.2 除湿乾燥の乾燥経過...........................................................................................

113

4.3 板材および平割材の除湿乾燥...............................................................................

113

4.4 ヒノキ柱材の除湿乾燥........................................................................................... 114
4.5 スギ柱材の除湿乾燥............................................................................................

115

5 蒸気・高周波複合乾燥法の実務.................................................................................... 116
5.1 蒸気・高周波複合乾燥法の概要............................................................................. 116
5.2 蒸気・高周波複合乾燥法の運転手順......................................................................

117

6 蒸気・圧力併用型乾燥法の実務.................................................................................... 118
6.1 蒸気・圧力併用型乾燥法の概要............................................................................. 118
6.2 蒸気・圧力併用型乾燥法の運転手順......................................................................

119

7 高周波加熱減圧乾燥の実務......................................................................................... 120
7.1 高周波加熱減圧乾燥の概要.................................................................................. 1207.2 高周波加熱減圧乾燥の特徴.................................................................................. 121
7.3 高周波加熱減圧乾燥の留意点..............................................................................

1217.4 高周波加熱減圧乾燥による建築用材の乾燥............................................................

122

8 過熱蒸気乾燥法の実務...............................................................................................

124

8.1 過熱蒸気乾燥法の概要........................................................................................

124

8.2 過熱蒸気乾燥法の運転手順.................................................................................. 125
9 乾燥の前処理（乾燥性能を高める各方法と効果）.............................................................

1269.1 葉枯らし (本乾燥前の含水率の減少).....................................................................

126

9.2 丸太の予備的天然乾燥........................................................................................

127

9.3 燻煙熱処理 (成長応力の緩和による歩留まり向上と含水率の減少).............................

128

9.4 低温条件による予備乾燥（本乾燥前の予備乾燥）...................................................... 128
9.5 蒸煮・減圧処理（難乾燥材や心持ち材の予備的な水分除去）...................................... 129
9.6 高温セット処理＝高温低湿処理（心持ち材の材面割れ防止）......................................

130

9.7 過熱蒸気処理（心持ち材の材面割れ防止）..............................................................

131

9.8 局所爆砕処理 （難乾燥材や心持ち材の水分通導性の改善）.....................................

132

9.9 液相処理（心持ち材の材面割れ防止）..................................................................... 132

9.10 横圧縮処理（心持ち材の材面割れ防止）................................................................ 133
9.11 背割り加工・中空加工・インサイジング（心持ち材の材面割れ防止）............................. 133
9.12 乾燥前の選別.................................................................................................... 134
9.13 ヤニ処理（脱脂処理）..........................................................................................

135

10 乾燥操作.................................................................................................................

137

10.1 装置・機器の点検............................................................................................... 137
10.2 桟積み.............................................................................................................

137

10.3 試験材の取り方と置き方......................................................................................

139

10.4 乾燥装置への搬入.............................................................................................

141

10.5 安全点検..........................................................................................................

141

10.6 乾燥日誌の作成................................................................................................

14110.7 乾燥の進め方.................................................................................................... 143
10.8 乾燥終了時の操作.............................................................................................

144

11 乾燥に要する経費..................................................................................................... 144
11.1 設備費.............................................................................................................

144

11.2 エネルギーコスト................................................................................................

145

11.3 乾燥方法別、材種別乾燥経費.............................................................................. 145

第４章 木材乾燥技術の意義と近年の動向
1 木材乾燥技術とは....................................................................................................... 151
1.1 木材乾燥技術者の役割........................................................................................

151

1.2 木材乾燥の意義..................................................................................................

152

2 木材乾燥の方法概略..................................................................................................

152

2.1 木材乾燥の方式と種類.........................................................................................

152

2.2 最近の乾燥設備設置状況..................................................................................... 153
2.3 乾燥材の生産状況............................................................................................... 154
3 木材産業および住宅産業の現状と動向.......................................................................... 155
3.1 国内の木材需要と供給..........................................................................................

155

3.2 国産材の資源状況と利用......................................................................................

156

3.3 国内の住宅建築工法とプレカット............................................................................

157

3.4 建築用集成材の状況............................................................................................ 157
4 日本農林規格（JAS：Japanese Agricultural Standard）........................................................

159

5 製材品と木質材料の規格（JAS規格）.............................................................................. 159
6 含水率規格（JAS規格）................................................................................................

161

7 優良木質建材等認証（ＡＱ認証）...................................................................................

161

7.1 ＡＱ認証対象品目................................................................................................ 162
7.2 ＡＱ認証品目と針葉樹製材乾燥技術者研修終了者等について....................................

166

7.3 含水率計性能認定機種（第1章4.3項参照）..............................................................

167

8 日本産業規格（ＪＩＳ）....................................................................................................

167

9 規格および認証の表示マーク例.................................................................................... 168
付表（1）主要建築用針葉樹の、学名、一般呼称、ＪＡＳ名称.................................................... 169
付表（2）機械等級区分装置.............................................................................................. 170