{"id":8549,"date":"2009-03-24T02:08:00","date_gmt":"2009-03-23T19:08:00","guid":{"rendered":"http:\/\/vafs.gov.vn\/vn\/2009\/03\/xac-dinh-dac-diem-go-tram-bong-vang-lam-nguyen-lieu-tao-van-ghep-thanh\/"},"modified":"2019-09-25T10:30:39","modified_gmt":"2019-09-25T03:30:39","slug":"xac-dinh-dac-diem-go-tram-bong-vang-lam-nguyen-lieu-tao-van-ghep-thanh","status":"publish","type":"post","link":"https:\/\/vafs.gov.vn\/vn\/xac-dinh-dac-diem-go-tram-bong-vang-lam-nguyen-lieu-tao-van-ghep-thanh\/","title":{"rendered":"X\u00e1c \u0111\u1ecbnh \u0111\u1eb7c \u0111i\u1ec3m g\u1ed7 tr\u00e0m b\u00f4ng v\u00e0ng l\u00e0m nguy\u00ean li\u1ec7u t\u1ea1o v\u00e1n gh\u00e9p thanh"},"content":{"rendered":"<p>Nguy\u1ec5n Tr\u1ecdng Nh\u00e2n<\/p>\n<p>Vi\u1ec7n Khoa h\u1ecdc L\u00e2m nghi\u1ec7p Vi\u1ec7t Nam<\/p>\n<p>C\u00e2y tr\u00e0m b\u00f4ng v\u00e0ng (<em>Acacia auriculiformis<\/em>) \u0111\u00e3 \u0111\u01b0\u1ee3c tr\u1ed3ng \u1edf nhi\u1ec1u n\u01a1i. Trong t\u01b0\u01a1ng lai, g\u1ed7 tr\u00e0m b\u00f4ng v\u00e0ng s\u1ebd l\u00e0 ngu\u1ed3n nguy\u00ean li\u1ec7u quan tr\u1ecdng cho c\u00f4ng nghi\u1ec7p ch\u1ebf bi\u1ebfn g\u1ed7.<\/p>\n<p>\u0110\u1ec3 x\u00e1c \u0111\u1ecbnh kh\u1ea3 n\u0103ng s\u1eed d\u1ee5ng g\u1ed7 tr\u00e0m b\u00f4ng v\u00e0ng l\u00e0m v\u00e1n gh\u00e9p thanh, ngo\u00e0i t\u00ednh ch\u1ea5t b\u00e1m d\u00ednh, c\u1ea7n x\u00e1c \u0111\u1ecbnh c\u00e1c \u0111\u1eb7c \u0111i\u1ec3m bi\u1ebfn d\u1ea1ng, c\u00e1c khuy\u1ebft t\u1eadt, m\u1ea7u s\u1eafc&#8230;c\u1ee7a nguy\u00ean li\u1ec7u.<\/p>\n<p>B\u00e0i vi\u1ebft n\u00e0y n\u00eau k\u1ebft qu\u1ea3 x\u00e1c \u0111\u1ecbnh m\u1ee9c \u0111\u1ed9 bi\u1ebfn d\u1ea1ng thanh g\u1ed7 theo chi\u1ec1u d\u00e0i, ch\u1ea5t l\u01b0\u1ee3ng b\u1ec1 m\u1eb7t v\u00e1n gh\u00e9p v\u00e0 t\u1ef7 l\u1ec7 s\u1eed d\u1ee5ng g\u1ed7 l\u00e0m v\u00e1n gh\u00e9p.<\/p>\n<p>1. Ph\u01b0\u01a1ng ph\u00e1p v\u00e0 n\u1ed9i dung<\/p>\n<p>G\u1ed7 tr\u00e0m b\u00f4ng v\u00e0ng trong nghi\u00ean c\u1ee9u \u0111\u01b0\u1ee3c l\u1ea5y t\u1eeb L\u00f4 3 Ng\u1ecdc Quang thu\u1ed9c Trung t\u00e2m \u0110\u00f4ng B\u1eafc B\u1ed9 c\u00f3 \u0111\u1ed9 tu\u1ed5i 10 n\u0103m.<\/p>\n<p>Theo t\u00e0i li\u1ec7u c\u1ee7a P.\u0110. Bobinkop [1], \u0111\u1ec3 gi\u1ea3m thi\u1ec3u m\u1ee9c \u0111\u1ed9 cong v\u00eanh theo m\u1eb7t c\u1eaft, gi\u1eefa chi\u1ec1u d\u1ea7y v\u00e0 chi\u1ec1u r\u1ed9ng m\u1eb7t c\u1eaft c\u1ee7a thanh gh\u00e9p c\u1ea7n \u0111\u1ea3m b\u1ea3o t\u1ef7 l\u1ec7 1: 1,5 ho\u1eb7c 1: 2.<\/p>\n<p>Khi nghi\u00ean c\u1ee9u bi\u1ebfn d\u1ea1ng c\u1ee7a thanh gh\u00e9p, ch\u1ecdn chi\u1ec1u d\u1ea7y thanh gh\u00e9p s=&#8221;2&#8243; cm. Nh\u01b0 th\u1ebf, k\u00edch th\u01b0\u1edbc m\u1eb7t c\u1eaft c\u1ee7a thanh gh\u00e9p th\u00ed nghi\u1ec7m theo chi\u1ec1u d\u1ea7y v\u00e0 chi\u1ec1u r\u1ed9ng khi ch\u01b0a gia c\u00f4ng tinh s\u1ebd l\u00e0 2,4&#215;5 cm.<\/p>\n<p>V\u00e1n gh\u00e9p thanh \u0111\u01b0\u1ee3c t\u1ea1o b\u1eb1ng c\u00e1ch d\u00e1n c\u00e1c c\u1ea1nh ph\u1eb3ng, m\u1eb7t c\u1eaft c\u00e1c thanh gh\u00e9p c\u00f3 ph\u00e2n b\u1ed1 v\u00f2ng n\u0103m nh\u01b0 theo t\u00e0i li\u1ec7u c\u1ee7a N.A. Gontrarop [2] s\u1ebd t\u1ea1o t\u1ea5m v\u00e1n c\u00f3 bi\u1ebfn d\u1ea1ng nh\u1ecf nh\u1ea5t.<\/p>\n<p>Thanh g\u1ed7 m\u1eabu \u0111\u01b0\u1ee3c chia th\u00e0nh 2 lo\u1ea1i chi\u1ec1u d\u00e0i kh\u00e1c nhau, l=&#8221;100&#8243; cm v\u00e0 l=&#8221;50&#8243; cm, c\u00f3 \u0111\u1ed9 \u1ea9m W&lt;10% .<\/p>\n<p>\u0110\u1ec3 \u0111o \u0111\u1ed9 cong, c\u00e1c thanh gh\u00e9p \u0111\u01b0\u1ee3c \u0111\u1eb7t tr\u00ean m\u1eb7t ph\u1eb3ng chu\u1ea9n, \u0111o d\u00e2y cung v\u00e0 chi\u1ec1u cao \u0111i\u1ec3m cong nh\u1ea5t so v\u1edbi m\u1eb7t ph\u1eb3ng chu\u1ea9n.<\/p>\n<p>\u0110\u1ec3 x\u00e1c \u0111\u1ecbnh \u0111\u1eb7c \u0111i\u1ec3m v\u00e1n gh\u00e9p thanh g\u1ed7 tr\u00e0m b\u00f4ng v\u00e0ng, ti\u1ebfn h\u00e0nh t\u1ea1o t\u1ea5m v\u00e1n gh\u00e9p k\u00edch th\u01b0\u1edbc 1x2x0.02 m. C\u00e1c thanh gh\u00e9p c\u00f3 k\u00edch th\u01b0\u1edbc chi\u1ec1u d\u00e0i 50 cm, m\u1eb7t c\u1eaft chi\u1ec1u r\u1ed9ng 5 cm, chi\u1ec1u d\u1ea7y 2,4 cm khi ch\u01b0a gia c\u00f4ng tinh, \u0111\u1ed9 \u1ea9m thanh gh\u00e9p W &lt; 10%. C\u00e1c thanh gh\u00e9p \u0111\u01b0\u1ee3c d\u00e1n gh\u00e9p b\u1eb1ng keo PVAD, l\u1ef1c \u00e9p p=&#8221;3-4&#8243; kg\/cm<sup>2<\/sup>, l\u01b0\u1ee3ng keo g=&#8221;200&#8243; g\/m<sup>2<\/sup>, th\u1eddi gian \u00e9p t=&#8221;60&#8243; ph\u00fat.<\/p>\n<p>V\u00e1n \u0111\u01b0\u1ee3c theo d\u00f5i bi\u1ebfn d\u1ea1ng cong v\u00eanh theo th\u1eddi gian. \u0110\u1eb7c \u0111i\u1ec3m t\u1ea5m v\u00e1n \u0111\u01b0\u1ee3c \u0111\u00e1nh gi\u00e1 th\u00f4ng qua t\u1ef7 l\u1ec7 kh\u00e1c bi\u1ec7t gi\u1eefa gi\u00e1c, l\u00f5i v\u00e0 t\u1ef7 l\u1ec7 m\u1eaft tr\u00ean b\u1ec1 m\u1eb7t v\u00e1n.T\u1ef7 l\u1ec7 l\u00f5i, gi\u00e1c, m\u1eaft \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh th\u00f4ng qua \u0111\u01a1n v\u1ecb di\u1ec7n t\u00edch.<\/p>\n<p>T\u1ef7 l\u1ec7 x\u1ebb g\u1ed7 tr\u00f2n x\u1ebb th\u00e0nh h\u1ed9p ho\u1eb7c thanh \u0111\u01b0\u1ee3c t\u00ednh theo t\u1ef7 s\u1ed1 (%) th\u1ec3 t\u00edch g\u1ed7 h\u1ed9p, ho\u1eb7c th\u1ec3 t\u00edch thanh g\u1ed7 tr\u00ean th\u1ec3 t\u00edch g\u1ed7 tr\u00f2n.<\/p>\n<p>2. K\u1ebft qu\u1ea3 x\u00e1c \u0111\u1ecbnh<\/p>\n<p>M\u1ee9c \u0111\u1ed9 cong trung b\u00ecnh c\u1ee7a thanh gh\u00e9p lo\u1ea1i chi\u1ec1u d\u00e0i l=&#8221;100&#8243; cm khi d\u00e2y cung l= 67cm \u1edf m\u1ee9c \u0111\u1ed9 1.004 cm. V\u1edbi c\u00e1c thanh gh\u00e9p chi\u1ec1u d\u00e0i l=&#8221;50&#8243; cm g\u1ea7n nh\u01b0 kh\u00f4ng c\u00f3 hi\u1ec7n t\u01b0\u1ee3ng cong.<\/p>\n<p>K\u1ebft qu\u1ea3 x\u00e1c \u0111\u1ecbnh t\u1ef7 l\u1ec7 l\u00f5i, gi\u00e1c, m\u1eaft tr\u00ean b\u1ec1 m\u1eb7t t\u1ea5m v\u00e1n gh\u00e9p \u0111\u01b0\u1ee3c ghi trong b\u1ea3ng 1.<\/p>\n<p><em>B\u1ea3ng 1. \u0110\u1eb7c \u0111i\u1ec3m t\u1ea5m v\u00e1n gh\u00e9p<\/em><\/p>\n<table>\n<tbody>\n<tr>\n<td>TT<\/td>\n<td>N\u1ed9i dung<\/td>\n<td>\u0110\u01a1n v\u1ecb \u0111o<\/td>\n<td>S\u1ed1 \u0111o<\/td>\n<td>Ghi ch\u00fa<\/td>\n<\/tr>\n<tr>\n<td>1<\/td>\n<td>T\u1ef7 l\u1ec7 l\u00f5i<\/td>\n<td>%<\/td>\n<td>74,93<\/td>\n<td>Theo di\u1ec7n t\u00edch<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>T\u1ef7 l\u1ec7 gi\u00e1c<\/td>\n<td>%<\/td>\n<td>25,07<\/td>\n<td>Theo di\u1ec7n t\u00edch<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td>T\u1ef7 l\u1ec7 m\u1eaft<\/td>\n<td>%<\/td>\n<td>13.75<\/td>\n<td>Theo di\u1ec7n t\u00edch<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>K\u1ebft qu\u1ea3 x\u00e1c \u0111\u1ecbnh t\u1ef7 l\u1ec7 x\u1ebb g\u1ed7 tr\u00f2n th\u00e0nh h\u1ed9p v\u1edbi 2 lo\u1ea1i chi\u1ec1u d\u00e0i l=&#8221;100&#8243; v\u00e0 l=&#8221;50&#8243; cm \u0111\u01b0\u1ee3c ghi \u1edf b\u1ea3ng 2.<\/p>\n<p><em>B\u1ea3ng 2. T\u1ef7 l\u1ec7 x\u1ebb g\u1ed7 tr\u00f2n th\u00e0nh h\u1ed9p<\/em><\/p>\n<table>\n<tbody>\n<tr>\n<td>TT<\/td>\n<td>N\u1ed9i dung<\/td>\n<td>\u0110\u01a1n v\u1ecb<\/td>\n<td>l tr\u00f2n = 100 cm<\/td>\n<td>l tr\u00f2n = 50 cm<\/td>\n<\/tr>\n<tr>\n<td>1<\/td>\n<td>Th\u1ec3 t\u00edch g\u1ed7 h\u1ed9p<\/td>\n<td>m<sup>3<\/sup><\/td>\n<td>0.172<\/td>\n<td>0,053<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>Th\u1ec3 t\u00edch g\u1ed7 tr\u00f2n<\/td>\n<td>m<sup>3<\/sup><\/td>\n<td>0.508<\/td>\n<td>0,105<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td>Hi\u1ec7u xu\u1ea5t x\u1ebb<\/td>\n<td>%<\/td>\n<td>0.338<\/td>\n<td>0,503<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>K\u1ebft qu\u1ea3 x\u00e1c \u0111\u1ecbnh t\u1ef7 l\u1ec7 x\u1ebb g\u1ed7 tr\u00f2n th\u00e0nh thanh chi\u1ec1u d\u00e0i 50 cm \u0111\u01b0\u1ee3c ghi \u1edf b\u1ea3ng 3.<\/p>\n<p><em>B\u1ea3ng 3. T\u1ef7 l\u1ec7 x\u1ebb g\u1ed7 tr\u00f2n th\u00e0nh thanh<\/em><\/p>\n<table>\n<tbody>\n<tr>\n<td>TT<\/td>\n<td>N\u1ed9i dung<\/td>\n<td>\u0110\u01a1n v\u1ecb \u0111o<\/td>\n<td>S\u1ed1 \u0111o<\/td>\n<\/tr>\n<tr>\n<td>1<\/td>\n<td>Th\u1ec3 t\u00edch g\u1ed7 tr\u00f2n<\/td>\n<td>m<sup>3<\/sup><\/td>\n<td>0,105<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>Th\u1ec3 t\u00edch g\u1ed7 h\u1ed9p<\/td>\n<td>m<sup>3<\/sup><\/td>\n<td>0,053<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td>Th\u1ec3 t\u00edch thanh<\/td>\n<td>m<sup>3<\/sup><\/td>\n<td>0,038<\/td>\n<\/tr>\n<tr>\n<td>4<\/td>\n<td>T\u1ef7 l\u1ec7 Vthanh\/Vg\u1ed7 h\u1ed9p<\/td>\n<td>%<\/td>\n<td>70,580<\/td>\n<\/tr>\n<tr>\n<td>5<\/td>\n<td>T\u1ef7 l\u1ec7 Vthanh\/Vg\u1ed7 tr\u00f2n<\/td>\n<td>%<\/td>\n<td>35,540<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>3. K\u1ebft lu\u1eadn<\/p>\n<p>1. Khi x\u1ebb thanh l\u00e0m v\u00e1n chi\u1ec1u r\u1ed9ng g\u1ea5p 2 l\u1ea7n chi\u1ec1u d\u1ea7y s\u1ebd gi\u1ea3m \u0111\u1ed9 cong v\u00eanh m\u1eb7t c\u1eaft. Chi\u1ec1u d\u1ea7y th\u00f4ng d\u1ee5ng \u0111\u1ec3 s\u1ea3n xu\u1ea5t \u0111\u1ed3 m\u1ed9c s=&#8221;2&#8243; cm, v\u00ec v\u1eady, m\u1eb7t c\u1eaft thanh gh\u00e9p tr\u00e0m b\u00f4ng v\u00e0ng c\u00f3 k\u00edch th\u01b0\u1edbc t\u00ednh to\u00e1n 2,4&#215;5 cm theo chi\u1ec1u d\u1ea7y v\u00e0 chi\u1ec1u r\u1ed9ng.<\/p>\n<p>2. \u0110\u1ec3 gi\u1ea3m bi\u1ebfn d\u1ea1ng c\u1ee7a t\u1ea5m v\u00e1n gh\u00e9p, m\u1eb7t c\u1eaft thanh gh\u00e9p \u0111\u01b0\u1ee3c s\u1eafp x\u1ebfp trong t\u1ea5m v\u00e1n v\u1edbi v\u00f2ng n\u0103m theo theo ch\u1ec9 d\u1eabn c\u1ee7a N.A. Gontrarop [2].<\/p>\n<p>3. C\u00e1c thanh gh\u00e9p g\u1ed7 tr\u00e0m b\u00f4ng v\u00e0ng v\u1edbi chi\u1ec1u d\u00e0i l=&#8221;1&#8243; m, c\u00f3 m\u1ee9c \u0111\u1ed9 cong trung b\u00ecnh 1,004 cm v\u1edbi d\u00e2y cung 0,67 m. C\u00e1c thanh gh\u00e9p chi\u1ec1u d\u00e0i l = 0,5 m h\u1ea7u nh\u01b0 kh\u00f4ng b\u1ecb cong. Khi x\u1ebb thanh l\u00e0m v\u00e1n gh\u00e9p t\u1eeb g\u1ed7 tr\u00e0m b\u00f4ng v\u00e0ng chi\u1ec1u d\u00e0i thanh gh\u00e9p kh\u00f4ng v\u01b0\u1ee3t qu\u00e1 50 cm \u0111\u1ec3 tr\u00e1nh bi\u1ebfn d\u1ea1ng cong.<\/p>\n<p>4. Khi t\u1ea1o v\u00e1n gh\u00e9p thanh t\u1eeb g\u1ed7 tr\u00e0m b\u00f4ng v\u00e0ng, thanh gh\u00e9p chi\u1ec1u d\u00e0i l=&#8221;50&#8243; cm, m\u1eb7t c\u1eaft t\u00ednh to\u00e1n 2,4&#215;5 cm, ch\u1ea5t k\u1ebft d\u00ednh PVAD v\u1edbi c\u00e1c \u0111i\u1ec1u ki\u1ec7n d\u00e1n l\u1ef1c \u00e9p p=&#8221;3-4&#8243; kg\/cm<sup>2<\/sup>, l\u01b0\u1ee3ng keo g=&#8221;200&#8243; g\/m<sup>2<\/sup>, th\u1eddi gian \u00e9p t=&#8221;60&#8243; ph\u00fat, l\u1ef1c b\u00e1m d\u00ednh gi\u1eefa c\u00e1c thanh gh\u00e9p \u0111\u1ea1t 69,96-122,55 Kg\/cm<sup>2<\/sup>.<\/p>\n<p>5. V\u00e1n gh\u00e9p g\u1ed7 tr\u00e0m b\u00f4ng v\u00e0ng, do m\u1ea7u gi\u00e1c l\u00f5i ph\u00e2n bi\u1ec7t (gi\u00e1c m\u1ea7u tr\u1eafng, l\u00f5i m\u1ea7u s\u1eabm) n\u00ean tr\u00ean b\u1ec1 m\u1eb7t v\u00e1n s\u1ebd c\u00f3 m\u1ea7u s\u00e1ng t\u1ed1i ph\u00e2n bi\u1ec7t v\u1edbi t\u1ef7 l\u1ec7 l\u00f5i gi\u00e1c theo di\u1ec7n t\u00edch 74,93\/24,07 %. M\u1eb7t kh\u00e1c, tr\u00ean b\u1ec1 m\u1eb7t t\u1ea5m v\u00e1n chi\u1ebfm 13,75 % m\u1eaft g\u1ed7 t\u00ednh theo di\u1ec7n t\u00edch.<\/p>\n<p>6. Khi x\u1ebb g\u1ed7 tr\u00e0m b\u00f4ng v\u00e0ng l\u00e0m v\u00e1n gh\u00e9p thanh, v\u1edbi kh\u00fac g\u1ed7 tr\u00f2n chi\u1ec1u d\u00e0i l&gt;100cm, t\u1ef7 l\u1ec7 x\u1ebb h\u1ed9p d\u1ea7y 5 cm ch\u1ec9 \u0111\u1ea1t 33,34%. X\u1ebb kh\u00fac g\u1ed7 tr\u00f2n chi\u1ec1u d\u00e0i l=&#8221;50&#8243; cm, t\u1ef7 l\u1ec7 x\u1ebb h\u1ed9p d\u1ea7y 5 cm \u0111\u1ea1t 50,03%. Khi x\u1ebb thanh t\u1eeb g\u1ed7 g\u1ed7 tr\u00f2n chi\u1ec1u d\u00e0i l=&#8221;50&#8243; cm t\u1eeb g\u1ed7 h\u1ed9p d\u1ea7y 5 cm \u0111\u1ea1t t\u1ef7 l\u1ec7 35,54%.<\/p>\n<p>7. C\u00f3 th\u1ec3 s\u1eed d\u1ee5ng g\u1ed7 tr\u00e0m b\u00f4ng v\u00e0ng l\u00e0m nguy\u00ean li\u1ec7u t\u1ea1o v\u00e1n gh\u00e9p thanh t\u1ea5m l\u1edbn. T\u1eeb c\u00e1c t\u1ea5m v\u00e1n gh\u00e9p s\u1ea3n xu\u1ea5t c\u00e1c lo\u1ea1i \u0111\u1ed3 m\u1ed9c nh\u01b0 m\u1eb7t b\u00e0n, m\u1eb7t gh\u1ebf ho\u1eb7c c\u00e1c lo\u1ea1i \u0111\u1ed3 m\u1ed9c nh\u1ecf nh\u01b0 k\u1ec7 c\u00e1c lo\u1ea1i. \u0110\u1ec3 t\u0103ng gi\u00e1 tr\u1ecb s\u1ea3n ph\u1ea9m g\u1ed7 tr\u00e0m b\u00f4ng v\u00e0ng, b\u1ec1 m\u1eb7t s\u1ea3n ph\u1ea9m c\u1ea7n s\u1eed d\u1ee5ng lo\u1ea1i ch\u1ea5t ph\u1ee7 m\u1ea7u th\u1eabm ch\u1ea5t l\u01b0\u1ee3ng cao \u0111\u1ec3 che l\u1ea5p m\u1ea7u s\u1eafc l\u00f5i, gi\u00e1c ph\u00e2n bi\u1ec7t v\u00e0 m\u1eaft g\u1ed7.<\/p>\n<p><em>T\u00e0i li\u1ec7u tham kh\u1ea3o<\/em><\/p>\n<p>1.P.\u0110. Bobikop &#8211; S\u1ea3n xu\u1ea5t v\u1eadt li\u1ec7u d\u00e1n gh\u00e9p. Nh\u00e0 xu\u1ea5t b\u1ea3n ph\u1ed5 th\u00f4ng, Moscova, 1974.<\/p>\n<p>2. N.A. Gontrarop &#8211; C\u00f4ng ngh\u1ec7 t\u1ea1o c\u00e1c chi ti\u1ebft g\u1ed7. Nh\u00e0 xu\u1ea5t b\u1ea3n c\u00f4ng nghi\u1ec7p r\u1eebng, Moscova, 1990.<\/p>\n<p><strong>Determination on characteristics of<em> Acacia auriculiformis<\/em> wood as<\/strong><\/p>\n<p><strong>raw material for blockboard manufacture<\/strong><\/p>\n<p><em>Summary:<\/em>Wood of 10 year old <em>A.auriculiformis<\/em> trees is studied to supply raw material for manufacture of block board in furniture making. A woodblock with cross section 2.4x5cm, 100cm in length has a curving degree of 1.004cm, the chord in 67 cm. With the same cross-section the 50cm long block is not curved. When blocks 100cm long, cross-section 2.4x5cm are produced wood usage attains 33.66%, with those 50cm in length the wood used is 50.35%.<\/p>\n<p>Blockboard from <em>A.auriculiformis<\/em> wood is not uniform in colour, sap wood with light colour represents 25.07%, heartwood with dark colour represents 74.93% in area. On the blockboard surface wood knots represent 13.75% in area.<\/p>\n<p><em>A.auriculiformis<\/em>wood is a good raw material for blockboard manufacture when the blocks do not exceed 50cm in length. A dark coat must be applied to make the colour of the blockboard surface relatively uniform.<\/p>\n<p>****************************************<\/p>\n","protected":false},"excerpt":{"rendered":"<p>C&acirc;y tr&agrave;m b&ocirc;ng v&agrave;ng (Acacia auriculiformis) \u0111&atilde; \u0111\u01b0\u1ee3c tr\u1ed3ng \u1edf nhi\u1ec1u n\u01a1i. Trong t\u01b0\u01a1ng lai, g\u1ed7 tr&agrave;m b&ocirc;ng v&agrave;ng s\u1ebd l&agrave; ngu\u1ed3n nguy&ecirc;n li\u1ec7u quan tr\u1ecdng cho c&ocirc;ng nghi\u1ec7p ch\u1ebf bi\u1ebfn g\u1ed7. \u0110\u1ec3 x&aacute;c \u0111\u1ecbnh kh\u1ea3 n\u0103ng s\u1eed d\u1ee5ng g\u1ed7 tr&agrave;m b&ocirc;ng v&agrave;ng l&agrave;m v&aacute;n gh&eacute;p thanh, ngo&agrave;i t&iacute;nh ch\u1ea5t b&aacute;m d&iacute;nh, c\u1ea7n x&aacute;c \u0111\u1ecbnh c&aacute;c \u0111\u1eb7c \u0111i\u1ec3m bi\u1ebfn d\u1ea1ng, c&aacute;c khuy\u1ebft t\u1eadt, m\u1ea7u s\u1eafc&#8230;c\u1ee7a nguy&ecirc;n li\u1ec7u. <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[18],"tags":[],"_links":{"self":[{"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts\/8549"}],"collection":[{"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/comments?post=8549"}],"version-history":[{"count":2,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts\/8549\/revisions"}],"predecessor-version":[{"id":19347,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts\/8549\/revisions\/19347"}],"wp:attachment":[{"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/media?parent=8549"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/categories?post=8549"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/tags?post=8549"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}