:. !
IXlGHIEiXI CIJU CdlMG IMGHE sAlM XUAT vAlM DAIVI TU TRAU VA VUIM CHI X a DUA
Lam Tran V u \ Tran Thanh Cao^
TOM T A T
Trau va mun vun chi xo dua (MVCXD) la hai loai phe thai nong nghiep 1cm nhait b dong bing song Cim Long. Nghien ciru sir dung bieu qua hai nguon phd thai tren da duoc nhidu ngudi thuc hien, trong do co cac nha khoa hoc nhu: lam be tong nhe, lam van xi mang, citi trau, chat dot cho nhiet dien trau... song van chua mang lai ket qua kha quan. Tan dung hai phe pham tren de san xuat van dam la mot huong mcri cua dd tai nay. Vi la hai vat lieu mcri nen de san xuat van dam, de tai da tidn hanh dieu tra nguon nguyen lieu, nghien ciru xir ly nguyen lieu, chon keo, cong nghe san xuat van, tinh kinh td va trang sue be mat van dam trau-vun chi xo dua. De tai da thir nghiem xii' li trau bing ngam xut, axit, H.Oo; it ure, men vi sinh.
Ket qua cho thay: xir li ti'au bing ngam xut co tac dung nhat, song vuong mic nhat la viec xir ly moi tixrong nucjc ngam xut; khong san xuat dugc van dat tieu chuan 04TCN-1999 bing 100% trau khong xir ly.
Tuy nhien, neu trau dugc xir ly xiit (NaOH) thi van co the dat chuan, song lu'cjng keo ton gap ruoi so vcM van dam go, gia thanh vi vay cung cao bon van dam go ciing co khoang 20.000 dong/tim. Neu phoi tron trau khong xir ly xiit vcri vun chi xo dira theo ty le 6/4 voi ty le keo lop mat 15% va Icip loi la 12%, dugc ep d ap suat 20 kG/cm', nhiet dii 150"C trong thdi gian 17 phut (day 18 mm) tbi van dat dugc tieu chuan tren dung cho dd mcpc.
Tir khoa: Okal trau, van dam, vun chi xa dua. • r- i , , . • .
LDATVANDE
Vd triu chidm 20-26% khdi lugng hat thdc.
Rieng b ddng bing sdng Cim Long nudc ta nam 2009 vdi sin lugng Ida 19 trieu t i n / n a m thi lugng triu l i 4 trieu tin/nam. O mien Nam, do phin 1cm Ida la h i n g h o i (ngucM trdng lua thudng ban thdc minh lam ra v i mua gao ve an), viec xay xat lai thudng tap trung qui md vua va ldn nen lucmg triu tap trung vcii khdi lugng ldn lai it duge dung bdn rudng, chi mdt phin nhd dung lam chit ddt siy Ida he thu va nung gach, vi vay trau trd thinh vin nan ddi vcii cic chu Id xay xat vi khdng cd chd chua; mgt trong cie cich "xir li"
phd bien hien nay la dd triu xudng kenh rach. T r i u trdi ndi lenh benh tren sdng, kenh rach lim d nhidm mdi tmdng, tic ddng xau ddi vdi he sinh thai v i dac biet gay nguy hai ddi vdi ddi sdng ngudi dan. Sd lieu dieu tra cua ca quan mdi trudng duge cdng bd g i n day cho thiy, chi 25-30% lugng trau niy dugc sir dung, cdn lai khdng biet dung vio myc dich gi.
O Nam bd dira duge trdng d hau het cac tinh ven bien, tip trung nhidu n h i t b hai tinh Ben Tre v i T r i Vinh vdi dien tich 48.000 ha (Ben Tre 35.266 ha, Tra Vinh 12.880 ha, Nien giam Thdng ke, 2005), nam 2005 Ben Tre hien cd sin lugng dira khd 240 trieu qua. Khi q u i dua chin lugng vd chiem tir 33% den
Phan vien Co Dien NN va CNSTH phia Nam Phan vien Khoa hpc Lam nghiep Nam bg
35% khdi lugng qui. Trong dd chi xa dua chidm khoing 30%, gdm chi xa to dii (bristie fiber) khoing 12% v i chi x a ngin nhdi nem (maO;ress fiber) khoing 18%, phin cdn lai l i mun dira (coir dust) va chi ngin (short fiber) chiem khoang 70% khdi lugng vd. Hien trong tinh Ben Tre hang tram ea sd che bien chi x a dira thai ra mdi trudng g i n tram ngin tan myn vun chi x a dira mdi nam, gay d nhidm khdng khi v i ngudn nudc c i c sdng rach, inh hucmg den ddi sdng cita ngudi dan.
Trude day vin dam thudng dugc lim tir gd va phe lieu gd, g i n day nd cdn duge lam tir ba mia, ram ra... Qua nghien cim sa bg thiy trau v i vun chi xa dira (VCXD) cd the phdi trdn vdi nhau lim nguyen lieu sin xuat vin dam. Viec sin xuit van dam tu triu va vyn chi xa dira se gdp phin tao cdng an viec lim cho ngucM dan dia phuong, giam d nhidm mdi tmdng v i ban chd lang phi ngudn nguyen lieu. Do dd cin nghien eim thdng sd cdng nghe sin xuat van dam tir trau va vyn chi x a dira de tien tcM hoan thien cdng nghe s i n xuat.
II. NOI DUNG VA PHUONG PHAP NGHIEN CUU 1. Npi dung nghien ciiu
- Nghien cuu chpn keo, ty le keo v i chat phu gia; nghien ciiu ty le phdi trdn triu vcM VCXD;
nghien cuu che dp ep: nhiet dp, ap suit, thdi gian ep.
2. Vat lieu va phuong phip nghiSn ciru
32 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 1/2011
a. Vat lieu nghien cuu
-I- Vd triu thu tu nha may xay xat tai Long An, Ben Tre. Triu dugc nghidn tren may nghidn bua cd duong kinh Id thoat cua lucM li 6 mm thu dugc dam cd kich thude nhd hon 5 mm.
-I- Vyn chi xa dira thu tir nha may sin xuit chi xo dira d Ben Tre. Vyn chi xo dira la phd thii cita qui trinh sin xuit dit sach mun dua sau khi sang liy mun dira lam dit sach.
-I- Keo Urea-formaldehyde (UF), Cdng ty Dynea sin xuit, 50% chit khd, pH 8.
b. Phuong phap nghien ciru
Chgn phuong phip quy hoach thyc nghiem (QHTN) nhim kiem tra, dinh gii cac thdng sd cdng nghe sin xuit van dam tir triu vi vun chi xa dira.
Dya vao ket qua nghien cuu xay dung md hinh toan hpc va ung dung ly thuyet tdi uu dd giii cic bai toan tdi uu. Tmdc khi thye hien QHTN tien hanh thyc nghiem don yeu td de xic dinh lai tam vi khoing anh hucing cua cac thdng sd. Dung phuong phap quy hoach thyc nghiem bac 2 de phuc vu cho qua trinh nghien cim; phuong trinh tuong quan dang
Bang 1: Mirc va khoang bien thien cac yeu
tdng quat nhu sau:
Y:=b„ + f^b,x,+ f^b,^x,x,+f^b„x;
Trong dd:
Y- Yeu td diu ra nhu iing suit udn tinh; do dan nd ngam nudc; X,- Yeu td diu vio li cac thdng sd inh hudng (i=l, 2...); \ b„, b,j la cic he sd hdi quy cin xac dinh.
Sd thi nghiem: N = Nj -i- Na -i- NQ (n la sd yeu td phy thude).
- Phuong phap nghien cuu xac dinh tyle keo va chat ddng rin
Dam triu sau xii ly kieh thude bing nghien sang phan loai dugc dem phdi trdn vdi vun xa dira theo ti le 1:1. Ty le ket ciu van la 1:4:1; keo sit dung la Urea-formaldehyde. Nhiet do ep 180"C; thdi gian dp 15 phut; ap suit dp 18 kG/cm-; khdi lugng the tich 750 kg/m^; chidu day van la 18 mm. Trong dd, dam triu da dugc xii ly kich thude bing nghien va phan loai, cic Id thi nghiem ddu dugc lap lai 3 lin.
td nghien ciiu ty le keo va chat ddng ran Muc va
khoang bien thien Muc sao tren Muc tren Mirc ca sd Muc ducM Mirc sao ducM Khoang bien thien
Gia tri ma
-i-a
+ 1 0 -1 -a
£
Gia tri thuc cua cac thong sd X, (%)
Ty le keo Icip mat 17,36
16 14 12 10,64
2
X, (%) Ty le keo Icip loi
15,36 14 12 10 8,64
2
X3(%) NH.Cl
0,568 0,5 0,4 0,3 0,232
0,1 - Phuong phap nghien cdu tyle phdi trdn
Khi nghien cim cd dinh cic thdng sd: Keo UF vdi ty le keo mat, keo ldi va chit ddng rin NH4CI, theo ket qua nghien ciiu de xac dinh ty le keo vi chit ddng rin; khdi lugng the tich vin (KLTT) 800
kg/m^; ket ciu vin 3 Icip ty le mat ldi 1:4:1; kich thude danh nghla cua van mlu thi nghiem li 250 x 300 X 18 mm.
Cic thdng sd diu vio vi khoang bidn thien dugc the hien d cac bang 2, 3.
Bang 2: Miic vi khoang bien thien cac yeu td van dam 3 ldp trau - VCXD Muc va
khoang bien thien Mirc sao tren Muc tren Mirc ca sd Mirc dircVi IV: c sao ducTi 1 lang bien thien
Gia tri ma
-i-a
-Hi 0 -1 -a
8
Gia tri thuc cita cac t Xl (T) thcin gian
ep (phut) 15,36
14 12 10 8,64
9
X, (N) nhiet do ep (°C)
213,6 200 180 160 146,4
20
ldng sd
X3 (k) ty le dam VCXD (%)
60,23 50 35 20 9,77
15
- Phuong phap nghien cuv che dp ep
Khi nghien cuu cd dinh cac thdng sd: Keo IIF voi ty \i- keo mat, keo loi va chit ddng rin NH4CI, theo ket qua nghien cuu de xac dinh ty le keo va chat ddng ran.
Bing 3: Miic v i khoang bien thien c i c yeu td cua van dam
Khdi lugng the tich van (KLTT) 800 kg/in^; kdt ciu van 3 ldp ty le mat loi 1:4:1; ts' le phdi trdn triu/VCXD = 60/40 (tire 60% triu) cho c i ldp mat vi ldp loi; kich thude danh nghia cua vin mau tiii nghiem la 250 x 300 x 18 mm.
Muc va khoang bien thien Mirc sao tren Mirc tren Mirc CO sd Mirc dii'di Mirc sao dud-i Klioang bit'n ihien
Gia tri mri (a= 1,681)
+ a -Hi
0 -1 -a
E
Gia tri thyc cua cac thong sd X, (T) tbo-i gian
ep (phut) 19,4
18 16 14 12.6
2
X;, (P) ap suit ep (kG/cnr")
23,4 22 20 18 16,38
2
X., (N) nhiet dp i-p ( T ) 166,8
160 150 140 133,2
10 III. KET QUA VA THAO LUAN
1. Ket qua xac dinh ty le keo va chat ddng ran cho Icjp mat va Icip loi
Ket qua Ihi nghiem tint dugc va sau khi loai bo cic lic> sd hdi quy khdng d i m bao dp tin cay ra khdi md hinh da cho ])liu'cmg trinh hdi quy cd dang nhu
sau:
Y„„ = 8,99 - 0.083X1 + 0,093X2 - 0,405X3 + 0,155X2X3 + 0,391X12 + 0,189X22 -H 0,139X32 (1)
Y,„ =121,577 + 10,959X1 + 5,167X2 + 3,65X3
2 , 9 9 8 X 1 X 3 -H 3.688X2X3 -5,692X12 - 3,104X22 3,435X32 (2)
Bing 4: Ket qua linh toan tdi uu h i m mdt muc lieu cita van dam triu-vun xa dira
s^rr
1 2
Chi sd tdi uu Min (Y„„) = 8,52 Max (Y,„) = 130,92
Cic thdng sd tdi uu X,
0,106 0,703
k,„ (%) 14,2 15,06
X., -0,937
1,419
k, (%) 10,12 14,84
X, 1,68 0,897
k„, (%) 0,568 0,489 A'„ •' Ty li keo ldp mat: Ki: Ty le keo ldp loi; ty le
Ke-t q u i tinh toan tdi uu ham da muc tieu dfi xac dinh du'crc gii tri tdi uu d muc trong sd a = 0,6. Lfng vc)i a = 0,6 cac chi tieu tdi uu va thdng sd tdi uu dat dii'crc la:
Xl = 0,52 - Ty le keo lop mat K,„ = 15,04%
X, = 0,05 - Ty le keo lop loi K, = 12,1%
X;. = 0,05 - Ty le chit dong rin K,,, = 0,405%
Dd dan no cua vin nghien cuu Y,|„ = 7,6%
Ung suit udn tinh cua vim nghien cuu Y,„ = 142,5 KG/cm-
NH.Cl
2. Ket qua xac djnh ty le phdi trdn nguyen lieu Kdt q u i thi nghiem thu duoc vi sau khi loai bd cac he sd hdi quy khdng dam bio do tin cay ra khdi md hmh da cho phuong trinh hdi quy cd dang nhu sau:
Yi„ = 8,336 - 0,767X, - 0,792X2 + 0,315X:i -. . 0,384X,X:, + 0,584X,- + 0,356X.- + 0,814X3- (3)
Y„, = 141,222 + 12,712X, + 5,413X. + 8,383X3 - 5,488X,X, - 5,388X,X;j- 8,480Xf - 4,414X0-- 3,813X:,- (4)
Bang 5: Ket qua tinh toan tdi uu cua h i m mdt muc tieu STT
1 2
Chi sd tdi uu Mm (Yi.x) = 7,64 Max (Ytsrr) = 148,9 '.
Cic thdng sd tdi uu X,
0,64 0,35
T 13,29 12,70
X., 1,11 0,39
N 202 187
X3
-0,04 0,85
K 34,37 47,76
34
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 1/2011
Trgng sd a 0 0,1 0,2 0,3 0,4 0.5 0,6 0,7 0.8 0,9 1
X, 0,35 0,51 0,55 0,57 0,59 0,59 0,60 0,61 0,62 0,63 0,64
X, 0,39 0,42 0,51 0,60 0,69 0,77 0,85 0,92 0.99 1,05 1,11
X 0,85 0,48 0,32 0,21 0,14 0,09 0.05 0,02 -0,01 -0,03 -0.04
T (phut) 12,70 13,01 13,11 13,15 13,17 13,19 13,20 13,22 13,24 13,26 13,29
N ( C) 187,89 188,38 190,11 191,99 193,79 195,47 197,02 198,46 199,80 201,06 202,24
K (%) 47,76 42,27 39,74 38,20 37,13 36,31 35,74 35,27 34,90 34,60 34,37
Y,„
8,62 8,08 7,89 7,80 7,74 7,70 7,txS 7,66 7,65 7.64 7.61
Y,..
148,09 147,66 147,06 146,45 145,84 145,24 144,64 144,06 143,47 142,90 142,32 Qua bing 6 ta chpn dupe gia tri tdi im cho
nghic^n cuu cdng nghe sin xuat van dam 3 lop phdi Iron theo cac ti le khac nhau ttr dam trim va dam vun xcr dua vdi mite trpng sd (2 = 0,2, Ung vdi a = 0,2 cac chi tieu tdi uu va thdng sd tdi uu dat dupe la:
X, = 0,55 hay thdi gian ep la 13,11 phut; X_, = 0,51 hay nhiet dp ep la 190 C; X, = 0,32 hay ti le dam VCXD la 39,74% Oiy = 40%); dd dfin ncrcua van nghici-n cuu Y,|„ = 7,89%.
USUT cua van nghien cuu Y,„ = 147,06 KG/cm-.
3. Ket q u i xac dinh che dp dp
Ket qua thi nghiem sau khi xu It sd lieu, loai bd cac he sd hdi quy khdng dam bao clg tin cay ra khdi md hmh da cho phuong trinh hdi qu\' cd dang nhu sau:
Y,„ = 8,336 - 0,7(i7X, - 0,792X, -H 0,315X, - 0,3aiX,X.
-H 0,584X,--H 0 , 3 5 6 X , - -H 0,814X:r (5)
Y,„ = 139,707 -H 9,299X, -H 3,255X_, -H 3,951X:; - 3,638X,X, - 3,813X,X:, - 6,588X,- - 2,893X,- - 2,434Xr (6)
B i n g 7: Kdt q u i tinh toan tdi uu cua ham mdt muc tieu chd dp dp STT
1 2
Chi sd tdi mi Min (Ynv) = 7,64 Max (Y,sri) = 145,2
Cac thdng so toi uu X,
0,64 1,66
T 17,28 19,32
X., 1,11 0,56
P 22,2 17,78
X.
-0,04 -1,68
N 149 133,2 Bang 8: Kdt qua tinh toan tdi iru ham da muc tieu che dp dp vin d 150°C
Trpng sd a 0,4 0,5 0,6
X, 0,626 0,610 0,582
X,, 0,736 0,737 0,828
X;;
0,165 0,164 -0,047
T (phut)
17,25 17,22 17,16
P (Kg/cm-)
21,47 21,4 19,9
X (C) 151,65 151,22 149,53
Yr,.s 7,73 7,73 7,67
Y,, 143,5 143,5 143,6 Qua bing 8 ta chpn clugc gia tri tdi uu cho
nghit^n citu cdng nghe san xuat van dam trau -H
\'C.XD vdi mirc trgng sd or = 0,6. Tai do cic chi tieu va thdng sd tdi uu la:
X, = 0,582 hay thdi gian ep la 17,16 phut X_, = 0,828 hay ap suit ep la 19,9 kG/cm- X;i = -0,047 hay nhiet do ep la 149,53"C Dd dim nd cua van nghien cuu li Y„x = 7,67%
Ung suit udn tinh cua van nghien cuu la Y;^, = 143,6 KG/ciir
Kct qua sau xuat thu nghi(}m van triu - \'CXD
khd 1,22 X 2,44 x 0,018 ni cho thiy gia thanh van cao hon van dam gd cung co khoang 10 ngan ddng, chu yeu do tdn nhieu keo hon; tuy nhien van triu - VCXD cd uu diem hon ve kha nang each nhicj't, chdng chiy va cdn giup giim d nhiem mdi truong do thdi quen dd bd xudng sdng rach.
Mau van trcMi da diioe Trung lam 3 (QUATES3) kiem nghic^m dat ti(?ii chuan 04TCN-1999, cu the:
USUT = 20,4 Mpa; do no day ngam nude = 7,42%;
KLIT = 784 k g / m ' ; cuong do lien kdt trong = 0,2 Mi)a; lye bam dinh vit mat/canh van = 1,04/0,53.
QUI TRINH SAN X U A T VAN D A M T R A U - VUN CHI XCf DUA
I rau W= 13-18% am
Nahien luai 0 6 • Khrrbui • Kho lieu am ••
Sa\
W 3.0-5.5°'o
Sling phan loai
Khir biii
•Viin chi \ a dira
\ V - ! 3 - l S % a m
T
Ciil doan d< 1"" mm (hoac nshicn luOi 04)
icco mat HLK 45-52%
dam mat d =0.2-0.9mm
' '
Tron Ivco dam mat W y-ir/o
dam giua d =1-12mm
• "
1 ion keo dam giua \V 7-9%
keo giua HLK 45-52%
Trai tham dam VV 7.5-10%
w
1. - D d
Chci thich
- dci am -dai
~ diRtna kinh
~ dai
HLK - ham lirgng kht")
Ep nong
Hoan Ihanh
cha nham phang
I hanh pham
^ Thir pham
IV. KET LUAN VADE NGHI
1. Ket luan
- Loai keo hgp ly cho van dam trau-vun chi xa dira la UF vdi ty le cho ldp mat 15%, ldp ldi 12%, chit ddng rin NH4CI vdi ty le 0,4%.
- Ty le phdi trdn vin dam trau /vun chi xa dira la 6/4.
Hinh 1: Qui trinh san xuat vin dam trau - VCXD
- Che dp ep vin dam triu-VCXD vin day 18 mm: nhiet dp 150"C thdi gian dp li 17 phut; ip suit ep li 20 kG/cml
- Sin xuit vin dam tir vd triu-vun chi xa dira phii tdn keo vi thdi gian dp nhieu hon vin dam gd.
2. Kien nghi
36 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 1/2011
- Nghien cuu bd sung edng nghe va hoan thien thidt hi dd cd the img dung rdng rai vao sin xuit, gdp phin tang them thu nhap cua ndng dan va bio ve mdi trudng.
TAI UEU THAIVI KHAO
1. Pham Ngpc Nam-Nguydn Trpng Nhan (1999).
Chuyin giao ket qua nghien cuu sd dung cong dua nudc lam nguyen lieu san xuat van dam. Ky yeu hcpi thao chuyen giao khoa hpc cdng nghe trong ndng nghiep & phat trien ndng thdn, thang 10. Nxb. Ndng nghiep.
2. Trin Tuin Nghla (2001). Xay dung md hinh day chuyen thiet bi va cdng nghe san xuat van dam Bach dan phe lieu quy md nho. Thdng tin Khoa hpc Ky thuat Lam nghiep.
3. Nguydn Van Thiet (1993). Nghien ctru mpt sd yiu td cua cdng nghe san xuit van dam tu nguyen
heu tre a Viet Nam. Luan an phd tien sy khoa hpc k>' thuat. Vien Khoa hpc Lam nghiep Viet Nam.
4. Hoing Xuan Nien (2003). Dac diem ciu tao v i tinh chit cua xa dua. Tap chi Ndng nghiep & Phat trien ndng thdn, sd 02/2003.
5. Hoing Huu Nguyen, Hoing Xuan Nien (2003). Nghien cuu mpt sd yeu to chu yeu cdng nghe ip van dam xo dua. Tap chi Ndng nghiep &
Phit trien ndng thdn, sd 08/2003.
6. Pham Ngpc Nam (2006). Cong nghe san xuat van nhan tao. Nxb Ndng nghiep.
7. The tough new alternative to wood. Rice husk particle board technology from India (Vat lieu ben mdi thay the gd. Cdng nghe sin xuit van dam tir triu cua An Dp). Asia Pacific Tech. Monitor. 1992 Jul.- Aug.
STUDY ON TECHNOLOGY OF CHIPBOARD FROM RICE HUSK AND SHORT FIBERS OF COCONUT SHELL
Lam Tran Vu, Tran Thanh Cao Summary
Rice husk and short fiber of coconut shell are the biggest in volume of agricultural by-products in Mekong river delta, Vietnam. Many researchers and scientists paid much attention to using these by-products such as beton, cement board, firewood, electric generating..., but non of their work become feasible recently.
Using the by-products to make particle board is a new trend of this theme. Because of there are new materials for producing the particle board, the theme group smdied how to treat the materials and the particle board production process; the research result showed that: it is impossible to make 100% untreated rice husk particle board that met 04TCN-1999 standard. Ho'wever, the particle board made from 100% rice husk treated by natrium hydroxide (NaOH) may reach the standard but need 50% higher of glue and VND 20,000 more cost compared to of particle board made from wooden shavings for each the same size board.
If mix untreated rice husk and short coconut shell fiber with a radon of 6/4, adding glue of 15% for surface layers and 12% for the middle layer, pressed at 20 kG/cm', 150°C in 17 minutes (thick 18 mm) to make the particle board that meet standard for making furniture.
Keyword: Rice husk, short fiber of coconut shell, particle board, okal.
Ngudi phan bien: GS.TS. Ha Chu Chu
