Cdng nghiep rung
J NGHIEN CUtJ ANH HtTOfNG CUA THONG SO CHE BO EP DEN CHAT LU'gfNG.GO GHEP KHOI DUNG LAM DAM CHIU L V C
Ph^m v a n Chu-ong*, Vu M a n h Tirong^, Ngnyen T r o n g K i e n ^ Le Ngoc Phuofc^
GS. TS. Tru&ng Dgi hoc Ldm nghiip TS. Tru&ng Dgi hoc Ldm nghiip IhS. Tru&ng Dgi hgc Ldm nghiip T O M T A T
Chat lugng van ghep khoi phu thupc vao rat nhieu cac yeu to cong nghe nhir: loai go, kich thuoc thanh co so, ket cau san pham, lo^ keo, lupng keo, ap suSt ep, thoi gian ep, iihi?t dp ep... Khi su dung keo dong ran ngupi, ap suat ep va thoi gian ep la hai tham so quan trpng cua che do ep anh huong dang ke den mpt so tinh chat co hpc ciia go ghep khoi. Anh hucmg ciia hai tham s6 nay d£n tinh chit co hpc cua van ghep khoi dung lam dim chiu lire, sao xuat tir go Tong qua su da qua xir ly on dinh kich thudc, xii Iy bao quan va xii Iy cham chay voi chat ket dinh PRF 1734/2734 da dupc tien hanh nghien cuu va xac dinh vdi ba muc ap suat ep (1,0 MPa, IJ2 MPa va 1,4 MPa) va ba miic thdi gian ep (180 phut, 210 phiit va 240 phiit). Kft qua nghien cuu cho thiy cac tinh chat co hpc co ban cua dim ghep khdi nhu dp ben uon tinh, mo dim dan hdi va kha nang bam dinh mang keo thay ddi khi thay doi ap suit va thdi gian ep (dieu kien ep ngudi, nhiet dp bing nhi?t dp moi trudng), anh hudng cua ap suit ep la ro net hem so vdi anh hudng ciia tfidi gian ep. San pham dam go ghep khdi dat cap chat lugng OLIO theo AS/NZS 1328.2 :I998 khi trj s6 ap suit ep 1,2 MPa va thdi gian ep la 210 phut.
Til khOii Ap suat ep, PRF 1734/2734, thdi gian ep, Tong qud su, vdn ghep khoL
I. D ^ T VAN DE
Theo Hiep hgi go va giay Hoa ky, d i m go cong nghifp la loai dam d u a c tao thanh tir cac
thanh go, phien go, van ep lop (dang LVL) ghep lai voi nhau nho keo dan va/hoac cac phu kien lien ket khac [2],
Hinh 1. Dam gd ghep khdi Tren thS gioi va a Viet Nam da co mot so
cong trinh nghien cmi ve anh huong ciia che do ep d8n c h i t lugng cua van go nhan tao noi chung va go ghep khoi noi rieng.
Denny Ohnesorge, Klaus Richter, Gero Becker (2010) da nghien cuu ctia cdu true va dieu kien dan ep den do ben dan dinh cua glulam tu go Beech (Fagus sylvatica). Tac gia da nghien cuu voi 4 loai ciu true (theo tidt dien ngang) khac nhau cua d i m chiu lire voi ap suat ep va thai gian ep thay doi. K^t qua nghien cthi cho t h i y c i u tnic van va che dp ep anh huong d^n h i u h i t cac tinh chit ctia glulam nhu: Do bong tach mang keo, dp ben keo tnrgt mang
keo, dp ben uon tinh...[5].
Dimitrios Tsalagkas va Vassilios Vassiliou (2010), da nghien cuu anh h u a n g cua thai gian ep den do ben uon tinh cua go ghep finger joint tu go Thong den (Pinud nigra) va go Van sam (Abies borisii regis). Ket qua ngliien ciiu da chi ra rang khi thay doi thoi gian ep van do ben uon tihh va mo dun dan hoi cua van ciing thay doi [6].
Ramazan Kurt, Kagan Asian, Vedat Cavus (2013), da nghien cuu anh huang cua ap suat ep den tinh chat ciia van ep khoi (dang Parallel strand lumber/PSL) su dyng keo Urea Formaldehyde (UF). Ket qua nghien cuu cho T A P CHI K H O A H Q C VA C O N G N G H E L . \ M N G H I E P SO 3-2015 85
Cong nghiep rimg
thay, khi ap suit tang tir 0,75 MPa len 1,50 MPa dp bSn u6n tinh (MOR) tang 77,78 %; mo dun dan il6i (MOE) tang 60,49% va do bto nen vuong goc voi bj mat van (CS) tang 19,86%.
Tir do tac gia cung khuySn nghi, tuy thupc vao yeu ciu chit luong san phim de xac dinh, lua chpn ap suat ep phu hpp [11].
Ramazan Kurt, Muhammet Cil (2012), da nghien ciiu anh hucmg ciia ap suit ep den chieu day mang keo va mot so tinh chit cua van ghep khdi (dang Laminated Veneer Lumber/LVL) vdi chit kSt dinh Phenol Formaldehyde (PF).
Nhom tac gia da nit ra ket luan: Vdi cac miic ap suit ep 0,25 - 0,50 - 0,75 - 1,00 - 1,25 MPa;
dp bSn u6n tinh (MOR) mong iing la 54,23 - 60,65 - 62,54 - 63,88 - 69,15 MPa; mo dun dan h6i (MOE) tuong ling la 5339,73 - 5496,22 - 5818,76 - 5946,67 - 6211,73 MPa.
Khi ap suit ep tang tat ca cac tinh chat vat 1^, tinh chit ca hpc deu thay doi theo hirong tinh cvc. Tuy nhien, khi tang ap suat ep se lam tang chi phi ve nguyen lieu, may ep yeu cau ap l\rc cao; do vay tuy thupc vao yeu cau ciia san pham hoac don dat hang de lira chp tri so ap suitephpply [12].
Apri H Iswanto, hawati Azhar, Supriyyato, Arida Susilowati (2014), da nghien ciiu anh huong cua lo^i keo, nhiet dp ep, thoi gian ep den mpt so tinh chat co hpc, vat ly ciia van dSm Iam tir ba mia. Ket qua nghien ciiu da chi ra ring: Khi thay doi loai keo (UF, PF, EPI), thay doi nhift dp ep tir: 120-130°C dSi voi keo UF, tit 170-180°C d6i voi keo PF va 150- 160°C d6i vdi keo EPI; tit ca cac tinh chit nhu: dp hiit nudc, dp truong no chiSu day, dp ben uon tTnh, dp ben keo vudng goc, md dun dan hdi ddu thay ddi [3].
U Vi?t Nam da co mpt sd cdng trinh nghien ciru ve anh hudng ciia chd dp ep (ap suit, nhiet
dp, thoi gian) den tinh chat vat lidu composite gd (van dan, van dam, van spi, glulam..).
Biii Van Ai, Nguyin Xuan Quyen, Pham Thi Thanh Midn (2011), da nghien ciin si dung vd hat Didu ket hpp vdi dam gd Bjch dan (Eucalyptus urophylla) de san xuit van dSn thdng dung. Tac gia da nghidn ciju anh hirong cua chd dp ep (nhidt do, ap suit, thdi gian) 6 mdt sd tinh chit ca ban ciia van dam. Kit qua nghien ciiu da khang dinh: thdng so che dg ep anh hudng tdi tit ca cac tinh chat cua van dam nhu khdi lupng the tich, dp truang nd chigu day, dp ben udn tmh, md dim dan hoi, dp bSn keo vudng gdc be mat van. Tir ket qua nghien Cliu tac gia de xuat tri sd ciia cac thdng so che dp ep: Ap suit 2,1 MPa, nhipt dp ep 18D°C,th6i gian ep 7 phut vdi chieu day van 16 mm [4].
Pham van chirong (2000), dS nghiSn cihi anh hudng ciia nhiet dp v4 thdi gian ep ldp m|l tdi chit lupfng san phim van ghep thanh tir go Keo tai tupfng va chat ket dinh UF. Tac gia da kdt luan: Nhiet dd va thdi gian ep anh huong ro net den dp truang nd chieu day (TS), dO ben udn tinh (MOR), md dun dJn hdi (MOE), dj bdn keo trupt mang keo (SS) ciia van gh^
khoi. Tri sd nhiet dp cp tdi uu la 120-125°C va thai gian ep la 2,8-3,2 phiit/mm chidu day sin
phim [8]. • • Pham Van Chucmg, Nguyen Trpng kien
(2013), da nghien ciiu anh hudng ciia ip sual dp, nhiet dp ep va thdi gian ep ddn tinh chat ca hoc cua san phim tre dp khdi su dung keo PF WG 6111. Nhdm nghien cihi dS kdt lujn: Khi tang nhidt dp ep tir 115°C ldn I35°C, cac tini chat nhu dp bdn udn tmh, md dun dan hoi deu tang, truong ndi chidu day giam; khi thai gian ep tang tir 12 gia ddn 16 gid, cac tinh chat nlw dp ben udn tinh, md dun dan hdi deu tSng.
tnrang nd chidu day giam; nhung khi thcri p^
dp tang tir 16 gid ddn 20 gia, cac tinh chit nh«
dp bdn udn tinh, md dun dan hdi deu gia*
86 TAP CHi KHOA HOC VA CONG NGHE LAM NGHIEP SO 3-2015
Cong nghiep rirng trucmg n o chieu day tang. Tir do tac gia dS xuat
tri so nhiet do ep va thoi gian ep den tinh chit c a hpc ciia san pham tre ep khm, su dung keo PF W G 6 1 I I : >fhiet do ep 135°C va thai gian ep 15 gicr [9].
Pham Van Chuang, Vu Manh Tuong, Nguyin v a n D i l n (2014), da nghi&n cuu anh buong ciia ap suat va thai gian ep d i n mot s6 tinh chat c a hpc cua go ghep khdi san xuit tir Keo la tram, chat k i t dinh la Synteko 1985/1993. Nhom tac gia da k i t luan: (1) dp ben uon tinh va mo dun dan h l i cua van ghep khoi d^u tang khi tang ap suit ep tir 1,0 - 2,0 MPa va thai gian ep tang tir 50 - 70 phiit; (2) Kha nang dan dinh gitta keo va g l , kha nang lien ket trong npi tai mang keo tang khi tang ap su3t ep va thai gian ep (dp bong tach mang keo giam va dp ben keo trupt mang keo tang);
(3) Ap suat ep anh huong ro net hon den cac Bang 1. Mpt so thong sd cua gd
chi tieu c a hpc ciia g6 ghep khoi so vai anh huang cua thai gian ep; (4) Tac gia khuyen nghi c h l dp ep khi tao van ghep khoi tir go keo la tram, chit kit dinh Synteko 1985/1993 san p h i m a dang thing, phang, dilu kien ep ngupi:
Ap suit ep tu 1,8 - 2,0 MPa, thai gian ep 60 phiit [10].
Trong nghien cuu nay, chiing toi sii dung keo PRF 1734/2734 la mot loai keo co kha nang dong ran ngupi. Vi vay, hai tham so chinh cua che dp ep dimg trong nghien ciiu la ap suat ep va thai gian ep.
ILVATUEUVAPHUttNGPHAPNGHBENCUtJ 2.1. V^t liSu nghlSn cuu
a) Go Tong qua su
Go Tong qua sii sau khi xii ly (6n dinh kich thuac, xu ly bao quan va xu ly ch^m chay) vai cac thong so dupc trinh bay trong bang 1.
Tdng qud su diing trong nghien cuu T T
1 2 3 4 5 6 7
Thdng s6 Khdi luprng the tich (g/cm^) He sd chdng truang nd (%) Hieu suat chdng hut nudc (%) Dp ben udn tinh (MPa) Dp bdn nen dpc thd (MPa) Md dun dan hdi (GPa) Dp Cling tinh (MPa) b) Chit kdt dinh (keo dan)
Bang 2. Mpt so thdng so ky thuat chu yeu vd T h o n g sd
Loai keo Trang thai Mau sac Dp nhdt
pH Ham lucmg
P R F 1734
Phenpl Resorcinol Formaldehyde Ldng
N a u d d 3000 - 9000 mPas, (Brookfield LVT, sp4, 12rpm, 25°C)
7,5-8,5 khd 54-58%
Thdi gian bao quan 20"(J 3U"(J 12 thang 6 thang
Tris6 0,72
29,13 17,53 104,45 45,30 75,15 81,60
i hirdng ddn su dung keo H a r d e n e r 2734 RF Hardener Bdt Nau NA
NA NA
20°C 30°C 12 thang 7 thang
T A P C H I K H O A H Q C VA C O N G N G H E L A M N G H I E P SO 3-2015 87
Cdng nghiep rung
ThoDg so P R F 1734 H a r d e n e r 2734
Dieu kien bao quan Nhiet dp tir 10-20''C, khi nhiet dp Nhiet dp tii 10-30**^, can phai d6 cao han 20''C, thai han su dung trong thimg kin, d i l u ki$n kho.
keo se giam.
Bap ling tieu chuan F Formaldehyde
Khoi luang"Ertich 1,150 g/cm^ ^:^ ,—, ______
Tinh chit mang keo Kha nang chiu nuac, chiu nhiet va chiu thai tiet tot. RF 1734/2734 la loai keo sau Idii dong r5n thupc Ioai WBP (weather and Boiling Proof) khi dan ep vai cac loai g l thong dung.
Mang keo dap iing duac trong d i l u kien thu de lanh va dun soi (tieu chuin JAS 1152).
Sudung Ap dung Nhiet dp ep
San xuat dam, cot; san xe tai,van ghep thanh, van ghep khoi Ep ngupi, ep cao tan
Khong thap hon 15°C Ty le phoi trpn
(phin khoi luang)
100:15, keo: chat dong ran
Nhiet do mang keo ( C) Thai gian ep (phiit) Thai gian ep 20
25 30 40 60 80
540 360 210 90
15 3 Ap suat ep
Luang keo trang
Dp amgd Chuan bi go Nhiet dp go Gia cong sau khi keo dong ran
Minimum 0,5 MPa doi vai go la kim Minimum 1,0 MPa doi vdi go la rpng 170-450 g/m^ trai 2 mat
G6 la rpng: 240-350 g/m^
Go la kim: 350-420 g/m^
10-15%, Khi ep cao tin: 12-15%
Go phai dupc trang keo trong vong 24h sau khi gia cong bl mat. Be mat ghep phai phang, nhin.
De dam bao chat luong mang keo va nang suit ep, nhiet dp go khong nho hon 15"C
2-3 ngay. Mang keo dat do ben dan dinh tit nhit sau 5-8 ngay 6 nhi?t dp 2D°C.
2. 2. Phirong phap nghign cihi a) Thiet kd thi nghiem (ma tran thi nghiem)
Theo thiet kd, san pham tao ra la van ghep khdi dang Glulam 3 ldp, vdi muc dich su dung Iam dim chiu luc. San phim cd kich thudc la: 1 x w x t = 3000x 120 x 6 0 mm.
Ap suat dp thuc nghiem vdi 03 miic khac nhau: l,OMpa; - l,2Mpa; - 1,4 Mpa.
Thdi gian dp 180 phut; - 210 phut; - 240 phiit.
Ma tran thi nghiem thidt kd theo bang 3.
Lin lap thi nghidm: 03
TAP C H i KHOA H Q C VA C O N G N G H E L A M N G H I E P SO 3-2015
Cong nghifp rirng
A p s u i t ep, MPa ThM gian ep, phut 180
BSng 3. Ma tran thinghi$m
1,0 1,2
210 240 180 210 240 180
1,4 210 240 b) Tieu c h u i n va phuang phap k i l m tra [1]
Tieu chuan kiim tra do ben udn: AS/NZS 1328.2:1998
+ Kich thuoc m i u : 600x50xt, mm + Cac b u a c tien hanh: mau dupc do bang thuoc kep va thuac Panme co dp chinh xac 0,01 mm. Sau do dua m i u thii len may thii van nang, mau d u a c ki6m tra theo phuang phap mpt diem dat Iuc.
Cong thiic xac dinh:
Trong do:
MOR - dp bSn uon tinh ciia go, MPa, Lg - khoang each giiia hai goi da, mm;
Pmax - lyc tac dung tai thai diem mau bi pha hiiy, N ;
h - kich thuac chilu day cua mau go, mm;
b - kich thu6c chilu rpng ciia mau go, mm.
Tieu chudn kiem tra mo dun dan hoi:
AS/NZS 1328,2:1998
+ Kich thuac m i u : 600 x 50 x t, mm + Cac b u a c tien hanh: mau dupc do b i n g thuac kep va Panme co do chinh xac 0,01 mm.
Mangl
Sau do dua m i u thii len may thii van nang, m i u duoc k i l m tra theo phuang phap mpt diem dat Iuc.
Cong thiic xac dinh:
P.Ll
MOE = I MPa
A.f.b.h^/
Trong do:
MOE - dp ben uon tinh cua go, MPa Lg khoang each giiia hai goi d o (1 = 360 mm)
P - luc tac dung len mau, N; P = Pmax/4 f- dp vong khi thu mau
h - kich thuac chieu day cua mau go, mm b - kich thuac chieu rpng cua mau go, mm Tiiu chudn kiim tra dp bin keo trugft mdng keo cua gd ghep khdi AS/NZS 1328.2:1998
Mau kiem tra dupc lay ngau nhien tir 16 san pham/lo mau thii. Dp am cua cac mau kiem tra tir 10 - 12%. Cac mau kiem tra la cac mau khong CO khuyet tat nhu mat go, lem canh, go sau, muc... Cat mau ki8m tra theo hmh 2 va hinh 3. Dung Iuong miu: 10 mau/serie
/ / ' (
•y^' :j^'/^
1 r
'z J^
1 r / \
Hinh 2. Cdt mau tir go ghep khdi
T/\P CHI KHOA HOC VA CONG NGHE LAM NGHIEP SO 3-2015 89
>_^
_
i.
^m
ffinh 3. ITinh dgng vd kich thu&c mdu thA do bin keo truat Cong thirc xac dinh:
Trong do:
t- chilu day thanh ghep ca so mm a- chieu dai mau thu: 25-55 mm b- chilu dai mau thii: 25-55 mm Phuang phap kilm tra:
Miu kilm tra dat tieu chuan dupc dua len thilt bi chuyen dimg (May AMSLER). M i u dupc lip thing diing, phuong gia luc song song vai b l mat mang keo; toe dp gia luc khong qua 9800 N/phiit.
Trong do:
P axb
P- luc pha huy mau, N;
{M?a)
a, b - dien tich mang keo, mml I I I . K E T QUA VA T H A O LUAN 3.1. A n h h u o n g cua ch@ do ^p den d3 b^n uon ti^nh
Nghien ciiu da tien hanh xac dinh dp bfin ufin tinh cho san pham glulam tic go Tong qua sii dS qua xii ly thuy nhiet va bien tinh cham chay bang MAP. Ket qua the hien trong bang 4.
Bang Dac trimg mau Ap suat ep, MPa Thdi gian ep, phut
X, MPa s m%
P%
C(«%)
4. Bo hen CDI
1,0 180 85,03
2,20 2,58 3,04 2,34
udn Hnh
CD2 1,2 180 89,30
4,00 4,48 5,01 2,55
cda ddm gd ghep
CDS 1,4 180 100,47
5,26 5,23 5,21 4,12
CD4 1,0 210 85,20
5,29 6,20 7,28 4,35
khdi vdi che do ep C h l do ep
CDS 1,2 210 110,38
9,60 8,70 7,88 3,21
CD6 1,4 210 82,89
6,21 7,49 9,03 3,67
khdcnhau
CD7 1,0 240 8 4 , 3 5 5,62 6,66 7,89 4,11
CDS 1,2 240 80,63
7,18 8,90 11,04 2,90
CB9 1,4 240 81,90 3,53 4,31 5,26 3,82
•* - gia tri trung binh cpng, s - sai tieu chuAn m a u , m % - h e so b i e n d p n g , P % - he so chinh xac, €(95%) - sai s l tuyet doi ciia u a c l u o n g
*180 5210
• 240
Ap suat ep, MPa
Hinb 4. Do bin udn tinh ctia ddm gd ghep khdi v&i cdc che dp ep khdc nhau 90 T ^ P CHf KHOA H O C VA C O N G N G H E L A M N G H I E P SO 3-2015
3.2. Anh hunng ciia che do ep den mo dun dan hoi
Bang 6. Md dun ddn hdi cua ddm go ghep khoi vdi cdc chedpep
Dac tnnig mau Ap suat ep, MPa Thai gian ep, phiit
r , MPa s m%
P%
C(95t4)
CDI CD2 CD3 1,0 1,2 1,4 180 180 180
Che dd ep CD4 CDS CD6
1,0 1,2 1,4 210 210 210
Cong nghiep rimg
1 khdc nhau
CD7 CDS CD9 1,0 1,2 1,4 240 240 240 8253,90 8831,67 9449,89 9688,38 10366.57 9846.23 9820.16 9143.56 8428,87
159,47 170,63 182,57 50,43 53,96 57,73 3,73 3,73 3.73 163,68 163,68 163,68
195,35 209,03 217,39 61,78 66,10 68,74 3,89 3,89 4,26 156,83 156,83 143,23
221,74 226,17 232,96 70,12 71,52 73,67 4,36 4,77 5,33 140,05 127,84 114,42
- 1 8 0
• 240
Apsuat ep, MPa
Hinh 5. Md dun ddn hoi cua dam go ghep khoi v&i cdc che dd dp khdc nhau 3.3. Anh hirong cua che d5 ep den dp ben keo trirgt mang keo
Bang 7. Dp bin keo truvt mdng keo cua ddm gd ghep khdi vdi chi dp ep khdc nhau Dac tnrng mau
Ap suat ep, MPa Thai gian ep. phut YTMPa
s m%
P%
C|g5",i
CDI 1,0 180 14,96 0,62 0,20 1,32 2.11
CD2 1,2 180 15,76 0,66 0,21 1,45 2,21
CD3 1,4 180 16,81 0,70 0,22 1,48 2,11
CD4 1,0 210 17,65 0,74 0,23 1,53 2,08
Che dQ ep CDS
1,2 210 16,05 0,67 0,21 1,46 2,19
CD6 1,4 210 16,35 0,68 0,22 1,56 2,28
CD7 1,0 240 15,76 0,66 0,21 1,61 2,45
CDS 1,2 240 15,09 0,63 0,20 1,73 2,75
CD9 1,4 240 14,96 0,62 0,20 1,32 2,11
TAP CHI KHOA HQC VA CONG NGHE LAM NGHIEP SO 3-2015
Cdng nghijp rung
- 1 8 0
= 210
• 2 4 0
Ap suat ep, MPa
Hinh 6. Dp bin keo truat mang keo cua dam gSghep khdi v&i cdc chi dp ep khdc nhau 3.4. Nhan x^t vk giai thich ket qua
Dam go ghep khoi la mot dang san pham composite go; ve cau true no gom 2 thanh phan vat Ii?u chii yeu: go va keo dan. Khi do ben dan dinh ciia mang keo nho, khi chiu uon mang keo se bi bong tach tnioc sau do pha buy mau.
Khi dO ben dan dinh cua mang keo lon, a trang thai chju uon lop go duai ciing (be mat chiu keo) s6 b} pha huy trudc. Do vay, nghien ciiu anh huong ciia che dp ep tdi chat lugng san pham dam go ghep khoi, thuc chat la nghien cuu anh huong ciia che do ep toi kha nang lien ket keo - go trong vat lieu.
Trong san xuat go ghep, ap suat ep khong nhung dong vai tro dinh hinh san pham ma con Iam tang kha nang tiep xiic giira bk mat vat dan. Theo ly thuyet dan dinh khi be mat vat dan phSng nhan, kha nang dan trai d8u ciia mang keo lon thi lire ep khong dang ke, trong th\rc te gia cong khong the thuc hien dugc d6n dp phang ly tuong. Vi vay, c4n phai chgn ra mgt trj so ap suat du lon, de lam tang kha nang tiep xiic giira cac bk mat thanh ghep la t6t nhit ma khong pha huy vat dan. Nhung ap suat do khong dugc qua lon se gay nen hien tugng tran keo ra ngoai Iam mit tinh lien tuc ciia mang keo, lugng keo trang khong dam bao anh
huong den chat lugng moi dan. Khi ap suit nho, kha nang tiep xiic giua cac hk mit tiSp xiic ciia cac thanh go ghep khong tot, lam cho chieu day mang keo khong deu do do dp ben dan dinh giam.
Tri so ap suat ep phu thugc vao rat nhieu thong so, chiing ta CO the bieu dien qua cong thiic:
Pmax= f (loai go, khoi lugng the tfch san pham, dp am vat dan, nhiet dp ep, dp map mo be mat vat dan...).
Tir ket qua nghien ciiu a bang 5, bang 6 va bang 7 cho tiiay ap suat ep phii hpp khi ep glulam dang khoi hop tir g6 Tong qua sii da xir ly bien tinh, chit kgt dinh PRF 1711/27341^ 1,2 MPa.
Thdi gian duy tri ap xuat max = f (loai go, dp am vat dan, loai keo, thdng so ky thuat ciia keo, nhiet dp ep...). Go m8m, nh? keo dl dong ran, thdi gian ep nhanh hon so vdi go ciing.
Phuang pbap ep nhiet do cao (ep nhiet), thoi gian ep ngan hon phuang phap ep nhiet dp thap (ep ngudi). Dp am thanh ghep ldn, keo khd ddng r5n, thdi gian ep dai han so vdi cac thanh cd dp am nhd.
Tir kk qua nghien ciru a bang 5, bang 6 va bang 7 thdi gian ep phu hgp khi ep glulam dang khdi hop tir gd Tong qua sii da xii ly bien tinh, chit kSt dinh PRF 1734/2734 la 210 phiit 92 TAP C H i KHOA H O C VA CONG N G H E L A M N G H I f P SO 3-2015
Cong nghiep rung
KETLUAJS
Tir ket qua nghien ciiu cho thay, ap suit ep va thdi gian ep cd anh hudng den mdt sd chi tieu chat lugng ciia dam go ghep khoi (dp ben udn tinh, md dun dan hdi va dp ben keo trugt mang keo).
O trj sd ap suat ep 1,0 MPa thdi gian ep anh hudng khdng dang k6 d6n dp b^n co hpc ciia dam go ghep khdi. Tuy nhien, anh hudng nay dugc the hien ro net d miic ap suit ep 1,2 MPa va 1,4 MPa.
Ket qua nghien ciiu ciing chi ra rang, khi ep van d che do ep ngudi (nhiet dp ep bang nhiet dp mdi trudng) ap suat ep cd anh hudng den tinh chat cua dam gd ghep khdi rd net hem so vdi thai gian ep (thdi gian ep trong pham vi nghien ciiu: 180 - 240 phiit).
Theo tieu chuin AS/NZS 1328.2 :1998 dk dat cip chit lugng GLIO, chiing tdi khuyen nghi ch6 dp ep khi tao dim go ghep khdi tir gd Tdng qua su, chit k^t dinh PRF 1734/2734 dilu kien ep ngudi: Ap suat ep tir 1,2 MPa, thdi gian ep 210 phiit.
Ldi cam on: NghiSn ciiu nay dugc tai trg bdi Bk tai "Nghien cihi cfing ngh8 vk thiet bi xur ly gS Tong qua su (Alnus nepalensis D. Don) d^ san xuat cau ki?n x3y dung nha ndng thon", ma sd: KC.07.15/11-15, thudc Chuang trinh khoa hpc va cdng nghe trpng dilm cip Nha nudc.
TAI Lif U THAM KHAO
1. AS/NZS 1328.2:1998, Glued laminated structural timber - Guidelines for AS/NZS 1328: Part 1 for the selection, production and installation of glued laminated structural timber.
2. AF-PA (1977), National Design Specification (NDS), American Forest and Paper Association,
American Wood council, Washington, DC.
3. Apri H Iswanto, Irawati Azhar, Supriyyato, Arida Susilowati (2014), Effect of resin type, pressing tenperature and time on particleboard properties made from sorghum bagass, Joumal of Agruculture, Forestry and Fisheries, No 3(2) pp 62-66
4. Biii Van Ai, Nguyen Xuan Quyen, Pham Th|
Thanh Mien (2010), nghien cuu su dung vo hat Dilu k^t bgp vol dam g6 Bach dan (Eucalyptus urophylla) dS san xuat van dam thong dung, Bao cao Khoa hoc, vien Khoa hpc Lam nghiep.
5. Denny Ohnesorge, Klaus Richter, Gero Becker (2010), Influence of wood properties and bonding parameters on bond durability of European Beech (Fagus sylvatica L.) glulams, Joumal of Forestry Science, No 67. pp 601-608.
6. Dimitrios Tsalagkas va Vassilios Vassiliou (2010), Effects of curing time on bending strength of the finger joined Black Pine and Macedonian Fir lumber. Joumal of Forestry Products, No 50 (10), pp 1375 - 1382
7. Pham Van Chuong, Nguyen Trpng Kien (2013), Keo ddn go, Nxb Nong nghiep. Ha Noi - 2013.
8. Pham Van Chuong (2000), Nghien cmi anh huong cua nhiet dp va thoi gian ep toi chat Iupng san pham van ghep thanh, Tgp chi Ldm nghidp, so 3 - 2000, pp 42-44.
9. Pham Van Chucmg, Nguyen Trpng Kien (2013), Anh huong ciia thong sd cong ngh^ den tinh chat co hpc, vat Iy ciia san pham tre ep khoi. Tap chi Khoa hoc vd Cong ngh^ Ldm nghiep, so 1 - 2013, pp 78-87.
10. Ph^m Van Chuong, Vu Manh Tuong, Nguyen Van Diln (2014), Anh huong ciia ap suat va thoi gian ep tdi mpt so tinh chat ca hpc ciia go ep khoi tCr go Keo la tram, Tgp cki Khoa hoc vd Cong nghe Ldm nghiep, so 1 - 2014, pp 48-55.
11. Ramazan Kurt, Kagan Asian, Vedat Cavus (2013), Influence of Press Pressure on the properties of Parallel Strand Lumber Glued with Urea Formaldehyde Adhesive, Joumal of Bioresources.com, No 8(3), pp 4029 - 4037.
12. Ramazan Kurt, Muhammet Cil (2012), Effects of Press Pressures on glue line thickness and properties of Laminated veneer lumber glued with phenol formaldehyde adhesive, Joumal of Bioresources.com, No 7{4),pp 5 3 4 6 - 5 3 5 4 .
T^P CHI KHOA HQC VA CONG NGHE LAM NGHIEP SO 3-2015
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94
THE EFFECTS OF PRESSING PARAMETERS ON THE QUALITIES OF STRUCTURAL GLUE LAMINATED BEAM
Pham Van Chuong, Vu Manh Tuong, Nguyen Trong Kien, Le Ngoc Phnoc SUMMARY
Press pressure and press time are two important parameters of press condition. The effects of press pressure and press time on the module of rupture (MOR), module of elastic (MOE) and bonding properties (BP) of stnictwal glue laminated beam manufactured from Anus nepalensis wood, that were treated dimensional stabilitv preservatives and fire-retardants with PRF 1734/2734 adhesives were determined. The beam were pressed for three different press pressure (1,0 MPa, 1,2 MPa and 1,4 MPa) and with three different press time (jgo minutes, 210 minutes and 240 minutes). The result was showed that MOR, MOE and BP values of structiml glue laminated beam were changed when press pressure and press time were changed (press temperature was at room temperature); the effect of press pressure was more significant than the effects of press time Product isa gradeGLlOaccording to A S / \ Z S 1328.2: 1998 when press pressure values is 1,2 MPa and press time is 210 minutes.
Keywords: Anus nepalensis, glue laminated timber, presspressue, press time, PRF 1734/2734
Ngudi phdn bien Ngay nbSn bai Ngay phan bien Ngay quyet dinh dang
PGS.TS. Cao Quoc An 26/8/2015
27/8/2015 15/9/2015
TAP CHi KHOA HOC VA CONG NGHE LAM NGHIEP SO 3-2015