KHOA HOC CONG NONE
A [ \ I H H U O I V G C U A THOIXIG S O C H E O O E P OEIV T i l V H C H A T C O H O C C U A V A T L I E U VAIV IVIDF P H U T A M
TRAIVG s u e LAIVIIIVATE
Le Xudn NgpcS Cao Qude An', Nguyen Tlii Minh Nguy^t^
T6MTAT
Trong nghien ciiu nay, phuang phap be mat dap iing (RSM) ket hgp voi mo hinh thiet ke thi nghi&m trung tam (CCD) dupe ap dung de mo hinh hoa. tdi uu hoa va xac dinh anh huong cua nhiet do ep (33 - 82"C) va thai gian ep (7 • 63 phiit) den do ben vat lieu duoc dan phii tu van soi khoi lupng neng trung binh (MDIO va tam laminate (HPL) sir dung chat ket dinh PVAc. K^t qua nghien ciru cho thay, nhiet dp va thoi gian ep deu CO anh huong d^n tinh chat ciia vat lieu trong do mirc dp anh huong cua nhipt dp ep la lon han. Do ben hk mat ty le thuSn voi nhiet dp va thai gian ep, do b^n u6n tinh ty le thuan vai thai gian ep va ty 1^ nghich voi nhiet dp ep. Gia tn dp b^n udn tinh dat tir 30.71 - 34.19 MPa. dp b^n be mat van MDF phii tam laminate dat tir 1,36 - 2,18 MPa. Thi nghifem da xay dung phuong trinh tuong quan va xac dinh duac che dp ep tdi uu de do b^n vat lieu dat k^t qua tdt nhfit la nhiet do ep T = 63*'C, thai gian ep Tg = 16 phiit.
Tu kh6a; /Vhiet do ep, thai gian ep, HPL, do ben udn tinh, do ben be mat phuong pbap be mat dap ung 1 . BAT VAN BE
Ngay nay, viec su dung vat heu gh (van cong nghiep: van MDF, van dam, van dan, van ghep thanh) thay the ngufln gfl tu nhien ngay cang khan hi^m !a xu huong tkX yeu. Vat lieu gfl co nhieu uu di^m so voi gfl nguyen nhu: co kich thuoc lon, it bi bien dang, ty le loi dung cao, d^ trang sue b ^ g cac vkt lieu dang tam...vat heu gfl duoc su dung ngay c ^ g nhi^u trong san xuat do go noi that. Nganh cflng nghe vat lieu phat tnen manh. vat lieu phu mat dirpc tgo ra ngay cang nhifeu, da dang vk chiing loai.
mau sac va co be mat, van tho' ino phong dupe hau het be m^t cac loai gfl. Su dung vat lieu gfl phu mat cho phep tao ra san pham nfli thSt hien dai. dap ung dupe yflu cau su dung vfl cflng nang va tham my.
Tam trang tri laminate (HPL - High pressure lammate) la mot ti'ong nhung vat lieu co dp ben cao va CO cac dac tinh vuot trfli ve chong nubc, hoa chat va cham chay dang rait diroc ua chuong. Tam laminate dupe cau tao tir nhieu lop giay n^n (giay kraff) kflt hpp voi keo nhiet ran, be mat tzim duoc phli lop giSy trang tri dupe tam keo va co lop b^ mat bao ve (overlay) b phia ngoai cimg. Duoi dieu kien nhi^t dp vao ap suat cao tao thanh mot vat lieu c6 tinh dong nhait va on dinh cao, co the sir dung nhieu loai keo va dan phti tren nhi^u b^ mat.
' Tnrong Dai hpc Liim nghi?p
Tinh chat cua vat li6u phu mat laminate phu thupc vao nhieu yeu td nhu loai van nen (van dam, van go dan, van IVIDF) loai keo dan (UF, PVAc, PUR, EVA), va cac thong so cua qua trinh dan phu (nhiet do ep, thoi gian ep, ap suat ep, luong keo trang...).
Lua chon dupe che dp ep phii hop se giiip han che ung suat ben trong lop keo dan giiJa tam lammate va van n^n, giam su co nit va pha huy hen ket trong qua trinh sir dung. Buyuksari va Umit (2012, 2013) da nghien ciru anh hudng ciia do bSn be mat va dp cung cua van MDF duoe trang siic bang van lang da qua xii ly nhiet. Thi nghiem sir dung keo UF voi cac thflng sfl thoi gian ep 8 phiit, nhifet dp ep (150 - 200''C) va ap suat ep (4 - 6 MPa). Ket qua cho thay nhiet dp ep anh huong dang ke den cuong dfl dan dinh va dfl b^n be mat ciia vat lieu, tinh chat ciia vat beu sau trang sire d^u cai thien ban so voi van doi chiing [6, 7]. Dimitar Angelski va cpng su da tien hanh nghien cuu anh huong ciia 4 loai keo trong do CO keo PVAc den cuong dfl dan dinh giira HPL va 2 vat lieu n^n la van (MDF va van dam). Ket qua cho tiiay cuong dp dan dinh giira HPL va van dam la thap hon so voi cuong dp dan dinh giiia HPL va van MDF dfli von t^t ca cac loai keo dan [5]. Pham Le Hoa (2013) da nghien ciiu xac dinh nhiei do ep thich hop khi dan phu van lang bi^n tinh TiO, dang NaNo len mpt so loai van nen va da Uen hanh sii dung keo PVAc 115A dan van lang biein Unh tren van MDF vai cac thflng so nhiet dp ep (4ii - 60 - SO"C). Immg k
104 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG S/aojn
KHOA HQC CONG NGHE
trang la 90 g/m^ luc ep 1,2 MPa. K^t qua cho tiiay nhiet dp ep tdi uu la eO^C, voi tri so' dfl b^n be mat cao nhat cho van lang gfl Gioi va be mat van MDF la 1,81 MPa [4]. Trong cac yeu to anh huong thi nhiet dp va thoi giau la 2 y^u td anh huong lon d^'n nang suat va chat lupng cflng doan dan dinh, day cung la cac yeu td co the khdng che trong di4u kien san xuat va thi nghiem [3]. Bai bao nay trinh bay ket qua nghien ciru anh huong cua nhiet do va thoi gian ep den dfl b4n vat lieu MDF duoc dan phii tam lammate bang keo PVAc thong qua moi quan he tuong quan giiia 2 yeu td nay va cac chi tieu chat lupng, lam co so cho viec lua chpn thong sd che do ep phit hpp voi timg muc dich su dung.
2 . VAT UEU VA PHUONG P H A P NGHIBU CUU 2.1. Vgt li^u, thi^t bi thi nghidm
Van MDF (PanelPlus - Thai Lan) voi cac thflng sd: chi^u day 17 mm; khdi lupng the tich 700 kg/m^, dfl am xac dmh tai thoi diem thi nghidm 9,4%.
Laminate HPL (Formica) voi cac thflng sd: nhom S (standard); hk mat san (texture); chieu day 0,5 mm; khdi luong th^ tich 1.440 kg/m^
Keo siia PVAc (KOATSU - Nhat Ban) voi cac thong sd: ma san pham KV52H; mau sdc trdng sira;
ham lupng kho 41,3%; dp nhdt 1540,8 MPa.s (may do BH, sd vong quay 10 rpm, nhiet do SCC; dp pH = 4,47.
Thidt bi thi nghiem thupc Tmng tam Thi nghiem va Phat trien cflng nghe, Vien Cong nghiep gfl va Npi that, Tniong Dai hpc Lam nghiep bao gdm:
+ May ep nhiet BYDllO voi cac thong sd: kich thuoe ban ep 800 x 800 mm; ap suat ep lon nhat 23.6 MPa; nhiet dp ep max SOO^C; khoang each tdi da giira 2 mat ban may 500 mm; sai sd nhiet dfl giCra 2 ban ep
±1''C.
+ May thir ca ly Qtest/25 (MTX, Elite).
2.2. Phuang phap nghifin ciiu
Phuang phap thuc nghiem da yeu td dua tren phuong phap bfl mat dap iing (RSM- response surface methodology) ket hop vol mo hinh thiet kd thi nghiem trung tam (Central composite designs - CCD) cua A Box-Wilson tren phan mem Minitab.
Cac bi^n ma hfla gdm co x, va Xa trong do bien Xj (thdi gian ep - T^); Xa (nhiet dp ep - T); Y (dp hen udn tinh, dp ben be mat van), cac thi nghiem duac bd tri ngdu nhien hoan toan, phuang trinh hfli quy tdng quat CO dang da thirc bac 2 nhu sau:
Y = b^-i-b^x^-\-b^x^+b^^x^x^^+b^^x^-t-b,y^xl ..., Mien quy hoach thuc nghiem duoc xay dung can cir vao ly thuyet, cac ket qua thuc nghiem tham dd va sai sd ciia thiet bi ep tai trung tam. Mifln quy hoach thuc nghiem xay dung tren phan mdm Minitab duoc trinh bay d-bang 1.
Bang
Yeu td Tg - Thoi gian ep (phiit) Xj T- Nhiet dp ep ("C) x.
. Mi^n quy hoach thuc nghidm theo phirong ka bac hai Cac miic
Diem sao dudi (-a)
7 33
Miic dudi (-1)
15 40
Miic cff scr (0) 35 58
Miic tren (+1)
55 75
Diem sao tren (+a)
63 82
Khoang bien thien fl)
20 18 Bang 2. C^c thflng sd chd dO kp cd dinh trong qua
trinh thi nghigm Thflng sd ep Luong keo Irang Sd mat trang keo Ap suat ep
Thoi gian de rao keo sau khi ep Thoi gian dn dinh de keo ddng rdn hoan toan
Tri sd
160 g/m^02 (van MDF va laminate)
0,94 MPa 4 phtit 24gio' Trong hai bao mien khao sat dupe xac dinh nhu sau: nhiet do ep (33"C - 82°C), thdi gian ep (7 phiit - 63 phut).
Ma tran thi nghiem dupe bd tri theo md hinh thiet ke thi nghiem trung tam sd thi nghiem duoe tinh theo cflng thtic:
N = 2^ + 2.k + Ho (2) Trong do: k - la sd bidn nghien ciru (k = 2); n^ - la
sd thi nghiem lap lai a tam (n,) - 5);
+ Sd thi nghiem d- muc co so- 2"^ = 2^ = 4;
+ Sd thi nghiem lap lai d- mirc diem sao ±a - 2k - 2.2 =4;
+ Sd thi nghiem cdn thuc hien trong mdi lan lap la; N= 2- + 2.2 -<- 5 = 13 tiii nghiem;
+ Tn sd canh tay don a= 1'''^ = 1,414.
KHOA HOC CdNG NGHt
Cac thflng sd che dp ep cb dinh duoc the hien tren bang 2.
2.3. Xac dinh dd b^n udn tinh va dp b^n b^ mat vdn
Sau qua trinh ep mdu va dn dinh, mdu duac cat theo TCVN7756 va thu ti-en may Qtest/25.
-JCac dinh dd ben udn tinh III + Tieu chuan kiem ti-a: TCVN 7756-6 :2007;
+ Kich thuoe mdu: Mdu thu hinh chii' nhat, chigu rpng (50 ± 1) mm, chieu dai 410 mm, chidu day 18 mm;
+ Sd lupng mau: 6 mau;
+ Do kich thuoe mau ldn hon chieu rflng giira 2 true may nen cdn su dung them bp ga rfli (hinh 1).
DO b^n udn tinh cua tam mdu thir la gia tn trung binh cflng dp ben udn tinh ctia tat ca cac mau thii lay
tir taim mdu thu do, ket qua Idy chinh xac ddn 0.001 Mpa.
- Xac dinh do ben be mat van 121 + Tieu chuan kiem tra: TCVN 7756-10 : 2007.
+ Kich thudc mdu: 50 x 50 x 18 mm, dupe khoet Id tron kich tiiudc (035,7 + 0,2) mm chidu sau bdng Idp lammate 0,6 mm vira du de cham vao lop van nen MDF.
+ Sd lupng mau: 8 mau.
+ Mdu thu sau khi dupe gia cflng theo tieu chuan duac dan vao ga thir hinh trdn co dudng kinh (35,6 + 0,1) mm bang keo Epoxy (Pionneer), mau sau khi boi keo dupe ep chat bdng day buoc va de dn dinh sau 24 gid trude khi tien hanh thir.
Dp bdn be mat cua tam mdu thii la gia tri trung binh cflng dfl ben be mat cua cac mdu thii lay tir tdm mdu lliir dd. Ket qua Idy chinh xac ddn 0,01 Mpa.
I'bnlnn lop Uminate Phi buy tai lap keo Epoxy Phi buy van nin MDF Pba hu\ lop keo dan PVAc Huih 1. Mflt sd hinh anh thuc nghidm vd mOt sd dang phd huy miu thii dd hkn hk mat 3 . KET QUA NGHBU CUU VA THAO LUAN
Tdt ca cac thi nghiem dupe bd tri lap lai 3 ldn. Sd lieu duac phan tich bdng phan mdm Minitabl6 (Minitab. Inc) de phan tich phuang sai. xac dinh muc dp y nghia va muc dfl anh hudiig ciia cdc \'eu td dau vao ddn ham muc tieu. Thong qua phan tich phirong Sill, so sanh cac chi sfl tuong quan voi gia tri p-value
<0,05 (dp chinh xac 95%) de xac dinh mfl hinh cd y nghia va cdc he so cd anh hudng den ham muc Ueu.
3.1. Anh huong cua nhi^t dp va thdi gian 6p d^n do hkn udn Snh cua vkt li^u
Cac gia tii ciia ham muc tieu duo, day la gia tri tiimg bmh cua mfli che dfl ep. Ket qua ihi hiem dup'c the hien d bang 3.
106
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG
KHOA HOC CONG NGHE
BSnp 3. K^t qua thi nf?hi6in anh huong caa nhi$t do, thoi gian ep tdi dO b^n u6n tinh cua vat U€u TT
1 2 3 4 5 6 7 8 9 10 11 12 13
Gia tri thijc Thai gian ep
CTg, phiit) 15,0 55,0 15,0 55,0 6,7 63,3 35,0 35,0 35,0 35,0 35,0 35,0 35,0
Nhiet do ep (T,°C)
40,0 40,0 75,0 75,0 57,5 57,5 32,8 82,2 57,5 57,5 57,5 57,5 57,5
Gia tri ma hoa Thai gian ep
X„ phiit -1,0
1,0 -1,0 1,0 -1,414 1,414 0,0 0,0 0,0 0,0 0,0 0,0 0,0
Nhiet dp ep (X2, »C)
•1,0 -1,0 1,0 1,0 0,0 0,0 -1,414
1,414 0,0 0,0 0,0 0,0 0,0
Ham muc tiSu YMOR, MPa
33,424 33,267 31,084 31,186 31,537 33,173 34,192 30,715 33,705 33,807 33,777 33,886 33,544
* Phan tich phirong sal va xac dinh miic do y nghia cua mo hmh Bang 4. K^t qua phan tich phirong sai cua md hinh Nguon bi^n thign
Mo hinh Sai s6 phan du Sir khong tuong thich Sai so thuan
Tong
Bac tudo 5 7 3 4 12 R' - 95,42%
Tong binh phuong
17,7823 0,8526 0,7859 0,0667 18,6349
Trung binh binh phuong
3,55646 0,12180 0,26196 0,01669 R^dudoan-69,45%
Gia tri F 29,20 15,70
Gia tri P 0,000 0,381
R' hieu chinh - 92,16%
Bang 4 cho thay mo hinh tuong quan (regression) co tri so |>value < 0,05 va he sd khong tuong thich CO p-value - 0,381 (p > 0,05) chiing to phuong sai la dong nhat, mo hinh thi nghiem hoan toan tuang thich voi thuc nghiem va y nghia thdng ke vai do tin cay 99,99%; he sd tuang quan boi (R-) Ciia mo hinh la 95,42% chi ra gia tn thiic nghiem chi CO sai khac 4,58% so vol gia tri du doan tir md hinh.
* Phan tich miic do anh huong ciia cac he so Bang 5 cho thay, chi co he sd hdi quy ( x . ' x j co gia tri p-value - 0,722 > 0,05 didu nay chiing td he sd nay khdng co anh hudng ham muc tieu, cac he sd cdn lai ddu cd anh hudng. Nhu vay phuang frinh tuang quan dang thuc cua md hinh cd dang:
YMOR - 27,797 + 0,132T, + 0,184T - 0,00181/
0,0022^ (3)
Bang 5. K^t qua phan tich miic dd anh huong dia cac h€ s6
Yeu td Phdndu Xl (thai gian ep) X2 (nhiet do ep) x,^
X,' x,*x.
He sd tuong quan 27,7976
0,1322 0,1845 -0,0018 -0,0022 0,0002
Sal so chuiin 1,80569 0,03737 0,05313 0,00033 0,00043 0,00050
Gia U-iP 0,000 0,010 0,010 0,001 0,001 0,722 Phuong trinh hdi quy (3) va hinh 2a, 2b cho thay nhiet dp va thdi gian ep cd anh hudng den do bin udn Bnh cua vat lieu. Khi tang nhiet dp va thdi gian dp thi giai doan dau do ben udn tinh ciia vat Ueu cd tang sau dd dan dn dinh. Neu tidp tuc tang nhiet dd (> 55°C) hoac thoi p a n dp (> 40 phiit) thi do ben udn tmh ciia vat lieu cd xu hudng giam nhanh. Trong
KHOA HOC CONG NGHl
phtim vi thi nghiem mirc dfl anh hudng cua nhiet dp ldn hon so voi thdi gian ep.
Ttagunqjiplim) Vl!!«d6qi(Tl
(a) (b) Hmh 2. Dd thi anh huong cua nhiet dfl, thdi gian ep
tdi dp bdn udn tinh
(a) Anh hudng cua thin gian ep tdi do bin udn tinh (tai nhiet do ep 58'C).
(b) Anh hudng cua nhiet dd ep tdi do bin udn tinh (tai thdi gian ep 35phut).
Didu nay co the duoc giai thich do do ben udn tinh cua vat heu anh hudng boi dfl ben udn finh ciia ban thdn van MDF va dfl ben cua hen kdt giira ldp
laminate va van ndn. Ca 2 yeu tfl nay deu c^
huong giam khi nhiet dfl tkng [3]. a giai doan dau nhiet dfl va thdi gian ep chua du de mang keo dong rdn hoan toan nhung van gdp phdn cdi thien do oen udn Gnh. Khi tiep tuc tang nhiet dfl va thai gian ep den thoi diem mdng keo dong rdn hoan toan tin do bdn udn tinh ciia vat lieu dn dinh sau dd co xu huong giam. Tdc do giam do ben udn tinh phu thuoc vao muc dp anh hudng cua nhiet dp va thoi gian ep va tflc dp lao hda cua mang keo PVAc (giam dp ben dan dinh). Dp ben udn linh cua vat heu se giam nhanh khi ca dfl ben dan dinh cua mang keo va dp ben udn tinh ciia van nen cimg giam.
3.2. Anh hudng cua nhiet dd va thai gian dp ddn dp bdn bd mat van
Cac gia tn cua ham muc beu dudi day la gia tn trung binh cua mfli che dp ep. Ket qua thi nghiem duoc the hien d bang 6.
Bang 6. K^t qua thi nghidm anh huong TT
1 2 3 4 5 6 7 8 9 10 11 12 13
Gia tn thuc Thdi gian dp
CTg, phiit) 15,0 55,0 15,0 55,0 6,7 63,3 35,0 35,0 35,0 35,0 35,0 35,0 35,0
Nhiet dp ep (T,»C)
40,0 40,0 75,0 75,0 57,5 57,5 32,8 82,2 57,5 57,5 57.5 57,5 57,5
cua nhidt do, thdi gian dp tdi dd b^n be m§t van Gia tri ma hda
Thdi gian dp (Xl, phiit)
-1,0 1,0 -1,0 1,0 -1,414
1.414 0.0 0,0 0,0 0,0 0,0 0.0 0.0
Nhiet dd dp (X2,°C)
-1,0 -1,0 1,0 1,0 0,0 0,0 -1,414
1,414 0,0 0,0 0,0 0,0 0,0
Ham muc tieu Yss, MPa
1,48 1,57 1,36 2,18 1,52 2,08 1,38 1,65 1,81 1,72 1,65 1,75
TTO
* Phan tich phuong sai m nniv do y ngfiia ctia nio hinh /^V
Bang 7 cho thjiy gia tri p-value ciia mo hmh tu(mg qu;m (regression) co hi so p-value < 0,05 va he
sd khdng tuong thich cd i>value . n.,-i;li i , 0,05 gia in J J S ^ S„ „(ji gja ^ d„ ^oan tu mo hinh
nhd han 0,05 (p < 0,0001) chimg to phuang sai la dong nhat, md hinh thi nghiem hoan loan tuong thich vol thuc nghiem va y nghia ihong ke vm a" ti cay 99,99%: he sd tuang quan b<.)i (R-) ^ 97,55% chi ra gia tri thuc nghiem chi cua mp hinh la
'"• sai khac
108
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG
KHOA HOC CONG NGHE
Bang 7. K^t qua phan tich phuang sai dia md hinh Ngudn bien thien
Md hinh Sai sd phan du Su khdng tuong thich Sal sd thudn
Tdng
Bac t u d o 5 7 3 4 12 R^ = 97,55%
Tdng binh phuong
0,679976 0,017063 0,003068 0,013995 0,697039
Trung binh binh phuong 0,135995 0,002438 0,001023 0,003499 R ' d u doan-93,73%
Gia tri F 55,79
0,29
Gia tri P 0,000 0,830
R' hieu chinh = 95,80*
* Phan ti'ch muc dd anh hudng cua cac hi sd Bang 8. Kdt qua phan tich mtrc dfl phu hpp ciia
cdchdsd Ydu to
Phan du X| (thdi gian ep) x^ (nhiet dd dp) x,"
x /
Xl X2
He SO tuong quan
0,999185 -0,025330 0,028108 0,000087 - 0,000349
0,000519 Sai sd chuan 0,255442 0,005286 0,007517 0,000047 0,000061 0,000071
Gia triP 0,006 0,002 0,007 0,106 0,001 0,000 Bang 8 cho thay he sd hdi quy bac 2 ciia thdi gian ep (x,^) cd he sd p-value = 0,106 > 0,05 chung td he sd nay khong cd y nghia va khflng anh hudng den ham muc tieu, cac he sd cdn lai cua mo hinh ddu co anh hudng. Nhu vay cd the xac dinh dupe phuong trinh tuang quan dang thirc cua mo hinh cd dang:
Yss = 0,9992 - 0,0253Tg + 0,0281T+ 0,000519Tg.T - 0,000349^ (4)
ddu tang. Neu tiep tuc tang nhiet do (> 75"C) thi dp ben udn tinh cua vat hSu cd xu hudng giara, trong khi tiep tuc tang thdi gian ep va giii nguyen nhiet dfl ep d muc 58''C thi dfl bdn be mat ty le thuan vdi thdi gian ep.
Dieu nay cd the dupe giai thich dp bdn be mat van duac quyet dinh bdi dp bdn hen ket giua van nen va tam laminate. Dfl bdn cua lien ket phu thudc chinh vao muc do ddng ran cua mang keo. Khi nhiet dp va tiidi gian ep tang lam tang tdc dp ddng rdn ciia keo.
Neu trong pham vi thi nghiem mdng keo dat muc dp ddng rdn hoan todn thi dfl ben be mat se tang ddn rfli dn dinh va se cd xu hudng giam neu nhu tiep tuc duy tri nhiet dp cao va thdi gian dp dai, do mang keo bi lao hda bdi nhiet dfl cao khoang SO^C. O miic nhiet dp tai tam la 58"C tdc dp lao hda cua mang keo cham nen trong pham vi thi nghiem chua nhan thdy su suy giam cua dp bdn be mat van hay thoi gian dp ty le thuan vdi dp bd mat [3].
3.3. Xac dinh chd dfl ep hpp ly
Can Cli vdo phuang trinh tuong quan anh hudng cua nhiet dfl va thdi gian ep den cdc chi tieu chat luong cua vat heu (3), (4), thflng qua phdn mem minitab xay dung dupe xu huong anh hudng dflng thdi cua 2 yeu td ddn ham muc tieu nhu hinh 4.
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(a) (b)
Hinh 3. Dd thi anh huong cua nhi^t do, thdi gian ep tdi dp bdn bd mat vdn
(a) Anh hudng cua thm gian ep tdi do ben bi matvin (tai nhiet do ep SffC).
(b) Anh hudng cua nhiit do ip tdi do bin be mat van (tai tlidi gian ep 35phut). Phuong trinh hdi quy (4) va hinh 3a, 3b cho thay nhiet dfl va tiidi gian ep CO anh hudng den dfl bdn be mat van. Khi tang nhiet do, thoi gian dp thi giai doan dau dfl ben bd miit van
(a) (b) Hmh 4. Dd thi anh hudng cua nhiet do vd thdi gian
dp tdi do bdn udn tinh va dO bdn bd mSt van (a) Anh hudng cua nhiet do va thdi gian ep den do bin udn tinh.
(b) Anh hudng cua nhiit do va thdi gian ep din do bin be mat van.
KHOA HOC CdNG N G H |
Didu kien bien de xay dung chd do dp tdi uu duoc xac dinh: nhiet dp ep trong khoang 30 - 70"C;
chi tieu chat lupng: tdi uu dp bdn udn tinh va dp bdn be mat cua vat heu; cac thong sd che dp ep khac theo hang 1.
Ket qua xii ly tdi uu qua phdn mdm thu duoc 84 phuong an tdi uu, trong dd phuong an tdi uu nhdt b muc nhiet dp 63"C va thai gian la 16 phiit vdi cdc thong sd chat lupng nhu sau: thai gian dp 16 phiit;
nhiet dfl ep eS^C; dfl ben udn tinh 32,405 MPa; dp ben be mat 1,52 MPa.
4.KEnUAN
Nhiet dfl ep va thoi gian ep co dnh hudng ddn dp hen udn tinh va dfl ben bd mat van cua vat heu van MDF duoc dan phu tam lammate bdng keo PVAc.
Trong didu kien tiii nghiem, gid tri do bdn udn tinh (MOR) dat tir 30,71 - 34,19 MPa tang 1,5 - 1,7 lan so vai gia tri cong bd cua nhd san xudt; gid tri dp ben bd m§t dat tir 1,36-2,18 MPa.
Nghien ciiu da xay dung dupe phuong trinh tuang quan giira nhiet dfl ep, tiidi gian ep ddi vdi dp ben udn tinh va do ben be mat van ddu la ham tuong quan bac 2. Qua dd da xac dinh duoc che dp ep tdi uu dp ben udn tinh va do ben be mat Id: thdi gian dp:
16 phut; nhiet dp dp: 63°C; lupng keo ti-dng: 160 g/m^; ap suat dp 0,94 MPa; thdi gian de rdo keo sau khi ep 4 phiit; thdi gian dn dinh de keo ddng rdn hoan toan 24 gid.
Ket qua gop phdn hoan thien ca sd khoa hoc cho viec xay dung che dp dan phu bd mat laminate bdng
keo PVAc tren van MDF diing trong san xuat do go nfli that.
TAI LIEU THAM KHAG
1. TCVN 7756 - 6 : 2007 (2007). Van gfl nhan tao - phuang phap thu - phdn 6: Xac dinh mo dun dan hfli khi udn tinh va dp bdn udn tinh.
2. TCVN 7756-7:2007 (2007). Van gfl nhan tao- phuong phap thu - phdn 7: Xac dinh dp ben keo vuflng gdc vdi mat van.
3. Pham Van Chuong va Nguydn Trpng Kien (2013). Keo dingd. Nxb Nong nghiep. Ha Nfli.
4. Pham Le Hoa va Cao Qude An (2013).
Nghien cuu xac dinh nhiet dp ep thich hpp khi dan van lang bien tuih TiOa dang Nano len mdt sd loai van nen (MDF, van dam, gd Keo Lai). Tap chi Khoa hpc vd Cflng nghe Lam nghiep. II (3), tr. 5.
5. Dimitar Angelski vd Vladimir Mihailov (2017). The influence of various types of adhesive on the adhesion strength between bonded HPL and furniture boards, tr. 5-10.
6. limit Buyiiksan (2012). Physical and mechanical properties of particleboard laminated with thermally compressed veneer. Vol. 7.
7. Umit Biiyiiksan (2013). Surface characteristics and hardness of MDF panels laminated with thermally compressed veneer. Vol.
44, 675-678.
8. LLC Minitab (2020). Analyze Response Surface Design. Minitab 16 Help file.
INFLUENCE OF PRESSING PARAMETER ON SOME MECHANICAL PROPERTIES OF MEDIUM DENSITY FIBERBOARD FACED BY LAMINATE PANEL
Le Xuan Ngoc, Cao Quoc An, Nguyen Tlii Minh Nguyet Summary
In this study, the apphcation of response surface methodology (l^M) and central composite design (CCD) for modeling regression model, optimization, and analysis of the influence of pressing temperature (32 - 82"C) and pressing lime (7 - 63 minutes) on performance of materials made from mrdmm density fiberboard (MDF) covered with high pressure laminate sheel (HPL) using PVAc adhesive. The results showed that, all factors affected the properties of the matenal, the pressing temperature has more influence than pressing time. The surface soundness is directly proportional to the temperature and pressing time while the static bending strength is proporUonal lo the pressing time and inversely proportional to the pressing temperature. The value of the static modulus of rupture (MOR) vaned from 30.71 to 34.19 MPa and the surface soundness reached Irom 1 34 to 2 IS MPa. The study was determined quadratic regression model for all factors and opUmized the pressing process for the highest bending strenfflh and surfa soundness: pressing temperature T = 63"C. pressing lime Tg = 16 mmutes.
Keywords: h-es^niii temperature, pre-^i^ing unic. HPL surface soundness.
metiwdology.
Ngudi phan bidn: GS.TS. Hd Chu Chu Ngdy nh$n bdi: 20/3/2020 Ngdy thflng qua phan bi$n: 21/4/2020 Ngdy duydt dang: :'S, 1/ I'O-'O
.MOH response surface
