CONG NGHIEP RLfNG
NGHIEN CU'U XAC DINH LU'gNG DU" GIA CONG CHO
K H A USAY CUA G 6 XE G 6 TRAM (MELALEUCA CAJUPUTI).
Bui Duy Ngoc Phong Nghien cuu Chi bidn Lam san Vign Khoa hgc Lam nghiep Viet Nam.
TOM T A T
Gd frim (Melaleuca cajuputi) la ngudn nguyen lieu tiem nang d vung ddng bing sdng Ciiu Long. Tuy nhien, go frim chua dugc sir dung nhu mgt ngudn nguyen lieu cho nginh cdng nghiep che bien gd. Phan ldn gd frim dugc sir dung lam "cir" (mgt loai cgc gia co nen mdng frong cic cdng trinh xay dyng), lam chit ddt, him than.. .v.v. Mdt vai nam gan day, gd frim dugc bim dim xuat khau sang cic nudc frong khu vyc dd lim nguyen lieu sin xuat giay. Lugng gd tram sir dyng lam gd xc rat thap, hau nhu khdng dang kc so vdi lugng khai thac hang nam. De nang cao gia tri cua rimg frim, cic nghien ciiu da dang hda sin pham cdng nghiep tir gd frim nhu tao van dam, vin MDF, gd xe lam do mdc, lim vin ghep thanh ...v..v. dang dugc xiic tien.
Sau khi say, gd xc gd trim bi co rut, bien dang cong vcnh rat ldn, do dd lugng du gia cdng cho khau say (LDKS) cao. Xic dinh dugc LDKS gd xe gd frim li rat can thiet lam ca sd de tinh toin lugng du gia cdng frong san xuat gd xc.
Ket qui xac dinh LDKS gd xe gd frim cho thay: theo cac phuong phap xe khic nhau gd xc gd frim cd LDKS rat ldn (han 10 %). So sinh vdi mdt sd loai gd rimg trdng khic, LDKS gd xc gd tram ldn gap 2 lan so vdi LDKS gd xe gd Keo lai, Keo l i frim hoac Keo tai tugng.
Tir khda: Lugng du khau say, Gd xe gd frim.
DAT VAN D t
Trong cdng nghiep san xuat gd xe va che bien dd mdc, xac dinh lugng du gia cdng la budc cdng vice can thiet nham sir dung nguyen lieu gd cd hieu qua. De tao ra dugc mdt chi tiet sin pham, nguyen lieu gd xe phai trii qua qua trinh say v i gia cdng cat got. Qua frinh nay lam tieu hao mdt lugng nguyen lieu gd tdi thieu. Lugng gd tieu hao dd cdn ggi la lugng du gia cdng. Lugng du gia cdng cho qua trinh cat ggt dugc hieu la lugng tieu hao nguyen lieu cho qua trinh cua, bio, danh nhin.v.v. thudng phy thudc vio dac tinh ky thuat cua may, khdng phu thudc vio loai gd nen dugc xac dinh dc dang.
Lugng du gia cdng cho khau siy (vidt tit la LDKS) la lugng nguyen lieu tieu hao do gd xe bi co rut, bien dang cong vcnh trong qua trinh say nham dat dugc kich thudc mong mudn cudi cimg cua chi tidt gd xc sau khi say. LDKS tiiy thudc vao mirc do co nit, bien dang cong vcnh cua gd sau say v i cd su bien ddng ldn giira cac loai gd. Lugng du gia cdng la thdng sd can xac dinh dc lam co sd tinh toin dugc kich thudc ban dau ciia phdi chi tiet can xe v i la can cir dc lap so do xc nham dat dugc ty le sir dyng gd cao nhat, tir do tiet kicra nguyen lieu gd.
Gd frim (Melaleuca cajuputi) la mdt frong cac loii cay frdng rimg chii yeu fren vimg dat phcn ddng bang sdng Cim Long. Cach sii dung tmycn thdng cua gd fram li lim cir, chat ddt, ham than.
Hien nay, gd tram cdn dugc bam dim dc xuat khau lim nguyen lieu giay. Nham da dang hda sin pham v i nang cao hieu qua sir dung gd frim, de tai
"Nghien ciiu sir dyng tdng hgp, cd hieu qua go trim" do Vien Khoa hgc Lam nghiep Viet Nam chu tri tien hanh nghien ciiu sir dyng gd tram lam van dam, vin ghep thanh va gd xc lam dd mdc. Trong khudn khd bai bio, chiing tdi gidi thieu ket qua xac dinh LDKS cua gd xc gd frim.
VAT Lieu, PHU'aNG P H A P NGHIEN CU'U Vat lieu va thiet bi
* Nguyen lieu go
- Gd fram (Melaleuca cajuputi) 10 nam tudi dugc khai thic tai phan trudng Sdng Trcm, Ci Mau.
*Thiethi
Cua vdng diing model: TF 700; cua cit miu da nang Model: LAB-300N cua Italia; tii siy thi nghiem Memmert cd quat thdng gio, cd thd dieu khien v i duy tri nhiet do (103 - 2)''C:, can dien tir Sartorius ky bieu BP 41 OS cd do c -h ^^j. ^^^
1126 TAP CHI KHOA HOC LAM NGHIEP £ 2009
0,001 (g); thudc kep dien tii Mitutoyo cd do chinh xic den 0,01 (mm).
Phirong phap nghien cihi
Mau thi nghiem cd kich thudc: 25x50x50 mm (diy X rdng x dii). Sd lugng miu cho mdi cdng thiic thi nghiem li: 9 mau.
Mau dugc lay tir cac that gd theo cic phuang phip xe: Xe xuyen tam (gdc x e a > 60°); Xe tiep tuyen (gdc xe a < 30°); Xc bin xuyen tam, ban tiep tuyen; (gdc xc 45° < a < 60°); Xe bd ddi (mach xc di qua tam khuc gd, gdc xe a = 180°);
Xe bao tam (gdc xc a = 360°). Tat ci cic mau gd thi nghiem ciing nhu that gd dugc bgc frong tiii nilon de ban che thoit am, dim bio cho cac mau thi nghiem trudc khi dua vao say cdn giii dugc do am ban diu tuong duong vdi do am khiic gd frdn khi mdi chit ha.
Cac mau thi nghiem dugc can, do xic dinh kich
Mau tru&c khi say
- Sd lieu dugc nap vao miy tinh va phan tich, xir ly sd lieu theo ly thuyet xac suit thdng ke. Cic sd lieu thyc nghiem dugc loai bd sai sd thd theo chuan studcn.
K^T QUA NGHIEN CLTU V A T H A O LUAN Gd trim 10 tudi cd dudng kinh nhd. Trong tdng sd 03 m' gd trdn thi nghiem, sd gd cd dudng kinh D
>l3cm chiem 15%; sd gd cd dudng kinh 8 <D
<l 3cm chidm 85%. Gd frdn dugc cat thdt bing cua vdng diing. Thdt gd cd chieu day la 50mm. Dudng
thudc chieu diy, chieu rdng v i khdi lugng ban dau cua miu, sau dd dua vio say tai nhiet do say
103±3°C den khi mau khd kict.
Xic dinh LDKS theo cdng thiic:
KTI KT2
LDKS = X 100 (%) KT2
Trong dd:
LDKS Lugng du do co nit, bien dang cong venh ciia mau thi nghiem sau khi say (%);
KTI Kich thudc mau gd xc thi nghiem frude khi say (chieu day DI, chieu rdng Rl, mm);
KT2 Kich thudc thyc cua mau thi nghiem sau khi say da loai bd phan gd bi co nit, bien dang cong vcnh (chieu day D2, chieu rdng R2, mm).
Xic dinh kich thudc mau frude v i sau khi say theo hinh ve sau:
Mdu sau khi say
kinh that phy thudc vao dudng kinh khiic gd trdn.
Miic do CO nit, bien dang cong vcnh cua gd xc cua mgt loai gd sau khi siy phy thudc rat nhieu vio vi tin cua gd xe tren mat cat ngang cua khiic gd.
Thdng thudng, gd frdn dugc xc theo 3 phuang phap li xe xuyen tam, xe tiep tuyen va xe bin xuyen tam - bin tidp tuydn. Ddi vdi gd tram, ngoai 3 phuang phap xe thdng thudng, do gd cd dudng kinh nhd, frong thi nghiem bd tri xc them 2 phuang phip li xe bo ddi va xc bao tam. Miu go thi nghiem dugc bd tri xe theo so dd sau:
Hinh 1. Sa do xe mau thi nghiem
TAP CHi KHOA HOC LAM NGHIEP SO 4 - 2009 1127
CONG NGHIEP RLfNG Trong dd:
1- Vin xe tiep tuydn
2- Vin xe bin xuyen tam-tiep tuyen 3- Vin xe bao tim
4- Vin xe xuyen tam
5- Vin xe bd ddi (mach xe di qua tam) Sd lieu xic dinh LDKS cua cac mlu thi nghiem tai cic vi tri (gdc xe) khac nhau fren mat cit ngang ciia cay go dugc ghi frong bing I
Bang 1. LDKS go xe go tram v&i cac phuang phap xe TT
1 2 3 4 5
Phirong phap x&
Xe tiep tuyen
Xe ban xuyen tam - bin tiep tuyen Xe bao tam
Xe xuyen tim
Xe bd ddi (mach xe di qua tam)
LDKS (%)
12.32 10.39 14.12 11.24 12.26
LDKS
16.00 -1 14.UU - 12.00 - i n nn - 8.00 - fi nn - 4 00 •
? nn • n nn -
"'1
• K |
Lu'O'ng dip khau say
Xuyen tam Ban xuyen tam Tiep tuydn Phipang phap xe
;- i^.K^iij'^^Si'K?:';
1 1
Bo doi Bao Tam
Bieu do 1. LDKS go xe go trdm vdi cdc phuang phdp xe
Qua sd lieu bing I v i bieu do I cho thay: LDKS gd xe gd fram deu ldn ban 10% d tat c i cic phuang phap xc. Cac mau gd xe d vi tri bin xuyen tam bin tiep tuyen cd LDKS thap nhat 10.39%, vdi phuang phap xc bao tam LDKS la cao nhit 14.12%. Mae dii xe tiep tuyen, xe bd ddi hoac xe bao tam cd LDKS cao (ldn han 12%) nhung frong thyc te ddi vdi gd frim do cd dudng kinh khuc gd nhd, nen de
nang cao ty le sir dung go xe thi 03 phuong xe nay vin thudng dugc ap dung.
Sd lieu so sinh LDKS gd xe gd fram vdi mdt sd loai gd rimg frdng khic dugc ghi frong bang 2
1128 TAP CHI KHOA HOC LAM NGHIEP SO 4 . 2009
Bang 2. LDKS go xd go tram so v&i mgt so loai go TT
1 2 3
Phuong phap xc Xe xuyen tam Xe tiep tuyen Xe bd ddi
Go tram 11.24 12.32 12.26
Go Keo lai^*' 4.81 5.41 4.91
LDKS(%)
Go Keo tai tugng'*' 5.88 6.38 5.90
Go Keo la tram'*' 5.51 5.88 5.40 (*) Nguon: Bdo cdo tong kit de muc Che bien thuoc de tdi KC0605.
LDKS ciia gd xe gd frim so vdi LDKS gd xe mdt sd loai gd rimg frdng khic dugc the hien qua cac bieu do dudi day:
1 9 C\f\ -
10.00 - H nn - (0
^ 6.00 •
_ j
4.00 •
2.00 •
u.uu •'
Lu'O'ng du' khau say (xe xuyen tam)
f
-
Go tram Keo lai Keo tai tugng Keo la tram Mot so loai go rOng trong
Bieu dd 2. LDKS go xe go trdm so v&i mgt so logi go.
Qua sd lieu bing 2 v i bieu dd 2 thay rang: theo cac phuang phip xe khic nhau, LDKS gd xe gd fram cao gip 2 iin so vdi LDKS gd xe gd Keo lai, Keo tai tugng vi Keo li fram. Sd di LDKS go fram cao nhu vay li do gd fram cd be sd co nit the tich (CRTT) rit ldn. Theo kdt qua phan tich tinh chit ca hoc cua gd frim so vdi mdt sd loai gd rimg frdng khac cho thiy: CRTT cua gd fram la 12.6 (%), frong khi dd CRTT ciia go Keo li fram li 0.41 (%), Keo lai li 0.39 (%) v i Keo tai tirgng la 0.46 (%).
Ngoai ra khi phan tich tinh chit co hgc cua gd fram va gd keo ciing cho thiy: go fram {Melaleuca preissiana) co riit theo chieu tiep tuyen li 23.2 (%), theo chidu xuyen tam li 11.2 (%). Cdn doi vdi gd keo {Acacia aff.Redolens) co nit theo chieu tiep
tuyen la 2.2 (%), theo chieu xuyen tam la 1.3 (%).
Nhiing ket qui phan tich tinh chat ca bgc cua gd frim va gd keo fren day da ly giai dugc tai sao LDKS cua gd xe theo phuang phap xc tiep tuyen cao ban khi xe xuyen tam v i LDKS ciia gd xe gd trim cao ban LDKS cua gd xe gd keo. Tir ket qui xic dinh LDKS cua gd xe gd fram dat ra van dc can tiSp tuc nghien ciiu cic bien phip xir ly dn dinh hinh dang, kich thudc cua gd xc gd fram dc giam thidu LDKS nham nang cao ty le sir dung gd frong qua trinh gia cdng che bien.
K^TLUAN VA KHUYEN NGH!
Ket luan
LDKS cua gd xe gd frim vdi cic phuang phap xc khac nhau da dugc xac dinh. LDLS cua gd xc
TAP CHf KHOA HOC L A M NGHIEP SO 4 - 2009 1129
CONG NGHIEP RLfNG
ban xuyen tam bin tiep tuyen dat thap nhat bign phap xvt ly nhim on dinh hinh dang va kich 10.39%, go xe xuyen tam dat 11.24%, go xe tidp thuoc go.
tuyendat 12.32%,gdxebdddid?t 12.26% vagdxe Khuyennghi
bao tam cao nhit li 14.12%. Khi sur dyng gd fram lira go xe nen cd bign phap LDKS cila go xd gd frim ldn hon gip 2 iin so xir ly go xe truoc khi say nham on dinh hinh dang, vdi LDKS go xe go Keo li fram, Keo lai, Keo toi kich thudc gd xd khi siy hoac nghien ciiu che dg tugng. De giim ihidu LDKS gd xd go frim can tidp siy hgp 1^ ddi vdi go fram de giim LDKS go xd go tuc nghien cuu xic dinh che do say hgp ly va cic fram.
TAI LIEU THAM KHAO
D6 Dinh Sam, 2006. Tong quan nganh cong nghiep c h i b i l n lam san a Viet Nam, Nha xuat ban Thong ke, Ha Noi.
Biii Duy Ngoc, 2008. Nghien ciiu sir dung t6ng hgp, c6 hieu qua go Tram, Bao cao so k6t (36 tai. Vien Khoa hoc Lam nghiep Vict Nam.
Nguyfin Quang Trung, 2006. Phan tich mot s6 dac tinh chu yeu cua go tram (Melaleuca cajuputi) va dinh huong sir dung trong san xuat van dam va van ghep thanh. Luan van thac sy khoa hoc ky thuat Dai hoc Lam nghiep.
N g u y i n Thi Bich Ngoc, 2005. Nghien ctiu cong nghe bao quan, che bien go rung trong Bao cao t6ng ket de tai Vien Khoa hoc lam nghiep Viet Nam.
RESEARCH ON DETERMINING PROCESSING SUPERFLUOUSNESS OF (MELALEUCA CAJUPUTYSA\N JmSER KILN DRYING
Bui Duy Ngoc
Forest Products Research Division Forest Science Institute of Viet Nam Summary
Melaleuca cajuputi saw timber is potential material in the Mekong Delta. However, this wood has not been utilized as a material for the wood product processing industry, with most of the Melaleuca cajuputi saw logs being made into "cu" (a type of pole is used for building), fiicl, coal, etc. In recent years, Melaleuca cajuputi wood has been exported to other countries to make paper The rate of Melaleuca cajuputi wood which is utilized as sawn timber was quite low in comparison with the rate of exploitation each year To enhance the Melaleuca cajuputi wood value, research on diversifying industrial products made from Melaleuca cajuputi wood such as Particle board, MDF, Fumiture, Laminated board.etc. are encouraging.
After kiln drying, Melaleuca cajuputi saw timber is distorted, and the deformation rate is quite high, so superfluousness of kiln drying process (SKDP) is high. Therefor determining the SKDP of Melaleuca cajuputi sawn timber is necessary for calculating sawn timber processes before drying.
The results of determining SKDP of Melaleuca cajuputi sawn timber show that according to different saw methods the Melaleuca cajuputi saw timber was highlydeformed (more than 10%).
In Comparison with other wood plantation species, SKDP of Melaleuca cajuputi sawn timber was twice as high as that of Acacia sawn timber.
Key words: Superfluousness of kiki drying process, Melaleuca cajuputi saw timber
1130 TAP CHI KHOA HOC LAM NGHIEP . 2009
