KHOA HOC CONG NGHE
IMGHIEIXI CIJU X A C DIIXIH THOIVG 5 D COIXIG I%IGME CLIA Q U A TRilXIH E P T A O VAIV D A I U T U IXIGUYEIXI L I E U
DAIVl V O H A T D I E U V A D A I U G d
„ y Bui Van Ai'^
TOMTAT
V6 hat dieu (VHD) sau ep tan thu dau la ngudn phe lieu trong eong nghiep che bien hat dieu eua nuoc ta.
Voi thanh phan boa hoe ehiia ham lugng xenlulo xap xy 20% nen VHD duge danh gia co kha nang tan dung, phdi hgp voi dam gd bach dan Uro hoac tram cir de tao van dam. Bang nghien ciiu thuc nghiem da xae dinh duge thong sd cong nghe ciia qua trinh ep trong san xuat van dam 3 lop voi ap suat ep 2,1 Mpa, nhiet do ep 180°C, thai gian ep 7 phiit. San pham van dam dap iing dugc chi tieu chat lugng ciia van dam thong dung sir dung trong dieu kien kho.
Tir khoa: Van dam, dam vd hat dieu, vd hat dieu.
LDilTVAniDE
Van dara la loai hinh van nhan tao cd thi su dung da dang ngudn nguyfen lieu, tir gd tia thua dudng kinh nhd cho den gd canh nggn, bia bip, dau mau Do do, eae ea sd san xuat van dam quy md vira va nhd d nudc ta da tang nhanh vl sd lugng de sin xuit sin pham dap ung eae nhu eau sti dung van dam ciia xa hpi. Dl gdp phin giam bdt siie ep Ifen tai nguyfen rimg, cd nhilu cong trinh nghifen ciiu tan dung eac thti phe lieu dang xa spi trong ndng nghifep dl sin xuat van dam [3], [4], [5]. Ngudn thii heu cd khdi lupng ldn li vd hat dilu (VHD) duge tan thu trong qui trinh che biin hat dilu da dugc nghifen eiiu danh gia cd kha nang kit hpp tdt vdi dara gd bach dan Uro (Eucalyptus urophylla) va dara gd trara cir
(Melaleuca cajiputy) lara dam ldp loi dl tao van dam,»
Trong qua frinh tao van tan dung dam VHD, do nguyfen lieu dam khdng thuin nhit, dara VHD edn chiia mpt lupng nhd diu dilu va ldp be mat eiia vd hat ehiia nhilu cutin ed the gay anh hudng khdng tdt den mdi lifen kit dam - keo lira giam dp bin ca hpe ciia van dam. Sau khi da nghifen ciiu xie dinh ty lfe phdi trdn giiia dam VHD vi dam gd hpp ly [1], Vifen Khoa hpe Lam nghifep Viet Nam tiln hinh nghifen ciiu xae dinh eic thdng sd eiia chl dp ep gdra nhifet dd ep, ap suit ep va thdi gian ep phu hpp vdi dae diim nguyfen lieu dl tao van dip iing duge tieu ehuan chit lupng ciia van dam thdng dung.
IL VAT UEU VA PHUONG PHAP NGHIEN CUU
1. Vat lifeu
Vd hat Dilu sau ep tan thu diu: Thu mua tai ea sd ep dau Hii Phdng. Dam cua 2 loai gd rimg frdng dimg dl phdi hgp vdi dam vd hat dilu.
' TS. Vien Khoa hoc Lam nghiep Viet Nam
Gd Bach dan Eucalyptus urophyllas 6 tudi, khai thae tai Phu Thg; gd Tram eir Melaleuca cajiputy 5 tudi, khai thae tai Ca Mau; sii dung keo U-F cua hang DYNO, hara lugng khd 52 - 56, do nhdt 110 - 130s.
Cae thilt hi thi nghifem chinh: Thude kep difen tii CD-6"CS, do chinh xae 0,01 mra; can ky thuat 30 kg, do chinh xae 5 g, nhan hifeu EB30EDE-lour; can ky thuat 650 g, dd chinh xae 0,01 g, nhan hifeu Satorius;
raay ep van thi nghifem, kich thudc mat ban 400 x 400 mra; thilt bi xae dinh tinh chat ca hpc van STM 50KN United Stiite.
2. Phuang phap nghifen ciiu
a. Bd tri thuc nghiem dixie dinh thdng sd cdng nghe cua chi do ep
Yiu tdcddinh:
Van dam thi nghifem li van 3 ldp cd ty lfe kit eau giira ldp mat va ldp loi la 1: 3 : 1.
Ty le theo khdi lupng dara VHD va dara gd dl phdi frpn tao dam ldp l5i la 1:1.
Lupng keo su dung cho ldp mat la 12%, lupng keo diing cho ldp loi la 8%.
Khdi lupng thi tich van can dat 0,7 g/eml Kich thude van 1,6 x 35 x 35 (era).
Yeu tdbien dgng: Gdm cic thdng sd ehii ylu eua chl dp ep: Ap suit ep, nhifet dp ep, vi thdi gian ep.
Trong thue tl sin xuat van dam cd nguyfen lieu thuin li dara gd thi ap suit ep dao ddng trong khoang 2,0 - 2,5 Mpa; nhifet dd ep thdng thudng d 140''C. Song hien nay, xu hudng phat triln edng nghfe da dua nhifet dp Ip Ifen cao tdi 180°C va giira thdi gian ep tir 15 phut xudng edn 8 - 10 phut. Trfen ca sd khoang tri sd cic thdng sd chl dp ep van dam gd, trong ndi dung nghifen eiiu niy da bd tri cae raiic thi nghifem nhu sau (bang 1): '
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 11/2010 79
KHOA HOC CONG NGHE
5ang 1. Miic thi nghifem cua cac thong sd TT
1 2 3
Cac thong sd Ap suat ep (Mpa) Nhiet do ep fC) Thai gian ep (phiit)
chl dp ep Miic thi nghiem 2,1
140 7
2,3 160 10
2,5 180
13 Thdng sd dau ra: Chat lugng van dam eua eac cdng thuc thi nghifem thi hifen d eac tinh chit ca vat ly ehii ylu: Do am van W (%), khdi lugng thi tich V (g/cm^), dd dan nd ehilu day AS (%), do bin udn
tinh MOR (Mpa), do bin keo vudng gde eua van IB (Mpa): Xae dinh theo tifeu chuin 04TCN2-1999 Van dam (bang 2).
Chit lugng van dara thi nghiem duge ddi chie'u vdi eae cip chat lupng quy dinh tai bang phan loai van dara theo tifeu chuan TCVN 7754: 2007.
Van dam cd ehilu day 13 mra din 20 ram dugc phan eip chit lupng theo 7 Ioai ky hifeu tir PI dfe'n P7.
Bang 2. Phan cap chat lugng van dam theo tifeu ehuan TCVN 7754 : 2007
^ Cagchat luong
Ten chi tieu -.^^
1. Do ben udn tinh (MOR), MPa, khong nho hon
2. Do ben keo vuong goc (IB), MPa, khong nho hon
3. Do truang nd chieu day (AS) sau 24h, % khong lon ban
Chilu day van 13-20 mm PI
11,5 0,24
P2 13,0 0,35
P3 14,0 0,45 14
P4 15,0 0,35 15
P5 16,0 0,45 10
P6 18,0 0,50 14
P7 20,0 0,70 8 D l x a e dinh duge cae t h d n g sd chfe dd l p h p p ly
tao van d a m k i t h p p d a m V H D va dara gd, bd tri t h u c n g h i e m I p van vdi eac tri sd e p k h a e n h a u d u g c t h u e hifen trude d l xae dinh t h d n g sd ap s u i t ep h g p ly.
sau dd m d i t i l n h a n h t h u e nghifem x a e dinh tri sd nhifet do ep va thdi gian I p .
IIL KET QUA NGHIEN CUU
1. Xae dinh ap suit ep tao van dam kit hgp dam VHD va dam gd
Bang 3. Kit qua xae dinh cae tinh chat vat Iy, ea hge eiia van dam theo cac miic ap suit ep (Nhiet dp Ip 160°C va thdi gian ep 10 phut)
TT 1 2 3 4 5 6
Loai van
Dam VHD + dam gd tram
Dam VHD + dam go bach dan Uro
Ap suat ep P (MPa)
2,1 2,3 2,5 2,1 2,3 2,5
Tinh chat vat ly va ca hoc eua van W (%)
12,31 12,15 11,96 12,34 12,96 12,70
V (g/em^) 0,696 0,703 0,711 0,713 0,694 0,706
AS (%) 9,02 9,33 11,24 14,82 14,39 15,13
MOR OMPa) 11,60 11,58 11,78 11,57 11,54 11,68
IB (MPa) 0,309 0,348 0,341 0,301 0,318 0,298 Nhan xet kit qui thuc nghiem: Tix kit qui thuc
nghifem tai bang 3 cho thiy, khi tri sd ap suit ep thay ddi theo 3 rauc 2,1 Mpa, 2,3 Mpa va 2,5 Mpa, cae ehi tifeu ca ban vl tinh chit vat Iy va ea hpc cua 02 loai van dam kit hgp dam VHD va dam gd tram cu va bach dan Uro cd su chfenh lech khdng ldn. Dp im van d cae edng thtic thi nghiem diu dat xip xy 12%, ddi ehilu vdi yeu ciu vl dp am van dam thdng thudng trong khoang: 8 -12%, thi dp am van dam thi nghifem dat dugc nguong yeu cau. Khdi lugng the tich vin dam ciia eae cdng thiic thuc nghiim eiing dat xip xy 0,7 g/cm^ theo yfeu ciu dat ra.
Can eii theo tifeu ehuan Viet Nam TCVN 7754:2007 vl eae ehi tieu ca hpe eua van dam thdng dung su dung d dieu kifen khd (PI), eic loai van thi nghiera tai eac miie ap suit ep khae nhau diu ed chat
lupng thda man dp bin udn tinh > 11,5 Mpa, dp bin keo vudng goc > 0,24 Mpa. Kit qua kilra tra sir sai khae nhau vl gia tri trung binh eua tri sd dp bin udn tinh va dp ben keo vudng gde cila 2 loai van tai cac muc thi nghifem ve tri sd Ip theo tifeu ehuin Ttesst diu eho kit qua Ttest > 0,05. Nhu vay, su sai khie nhau khdng cd y nghia, va tri sd ap luc ep trong khoing tir 2,1 din 2,5 Mpa cd anh hudng khdng ldn dfe'n tinh chat ca hpc cila van.
Nhu vay, vdi yfeu eau tao van dam ed khdi lugng till tich 0,70 g/era^ tiii ap suit ep duge lira chpn tai raiie 2,1 Mpa vira dim bao eho chat lugng van va dim bio hifeu qui kinh tl cho qua trinh sin xuit.
2. Xae dinh nhifet do ep va thdi gian ep tao van dam kit hgp dam VHD va dam gd
80
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 11/2010
KHOA HOC CONG NGHE
Dfe xae dinh duge cac tihdng sd nhifet do ep va thdi gian Ip hgp ly, dl tai da tiln hanh thuc nghifem vdi 3 miic tri khae nhau (bang 4) vdi miic ap suit ep
Bang 4. Kit qua xae dinh tinh chat vat ly cua van dam theo cac miic nhifet do ep va thdi gian ep ed dinh la 2,1 Mpa. Kit qua danh gia chat lupng van dam thi nghiera thi hifen tai bang 4 va 5.
TT
1 2 3 4 5 6 7 8 9
Che do ep
rc
140 140 140 160 160 160 180 180 180
T (phiit)
13 10 7 13 10 7 13 10 7
Cac tinh chat vat ly ciia van W(%)
Van VHD-i- Tram cir
12,15 13,39 14,64 10,27 11,52 13,68 9,86 10,44 11,93
Van VHD-F Bach dan
12,96 13,38 15,60 11,05 12,78 13,42 10,54 11,15 11,68
V (g/cm') Van VHD -i-
Tram cir 0,703 0,707 0,715 0,688 0,690 0,684 0,694 0,701 0,705
Van VHD + Bach dan
0,694 0,699 0,688 0,683 0,691 0,680 0,687 0,714 0,691
AS (%) Van VHD +
Tram eir 9,33 11,39 14,64 10,27 10,50 12,78 9,23 10,54 10,78
Van VHD + Bach dan
14,39 14,60 16,86 11,65 12,82 14,92 8,85 10,34 11,06 Nhin xit ket qui thuc nghiem: Nhifet dp, thdi
gian ep va ap suit ep cd vai trd quan trpng frong qua trinh san xuat van dam. Chiie nang ea ban eua nhiet dd trong qua trinh ep van la cung cip nhifet dp cho keo ddng rin hoan toan trong rapt thdi gian nhit dinh va giam dp am van. Ap lue ep cd tae dung diy nhanh va nang eao su tilp xuc giiia keo va dam lara cho quang dudng di cua nhifet dp vao trong tara van ngin lai, ddng thdi lim mem dam giup cho qua trinh ep trd nfen dl dang hon. Tir sd lieu d bang 4 cho cac nhan xet nhu sau:
Vi do am vin (W): Trong cung dilu kifen thdi gian ep nhu nhau, khi nhifet dd lp cang tang thi dp am eua vin cang giara. Dp im cua van tang khi thdi gian Ip giara trong cung dilu kifen nhiet dp. Su diln hiln eiia dp ira van theo nhifet dp ep vi thdi gian ep hoin toin tuan theo quy luat trong sin xuit vin dara thuin nguyfen lieu gd.
Dp im ciia vin d eae chl dp ep khae nhau phin ldn diu dat yeu ciu dp am san pham van dam fhdng dung su dung frong dilu kifen khd la W < 15%. Tni chl dp ed nhifet dp ep t = 140''C, thdi gian ep T = 7 phut, dd am van dam VHD -i- dara gd bach din Uro dat 15,6% khdng dam bao yfeu eau.
Khdi lugng the ti'ch cua vin (V):Y^b\ lupng the Bang 5. Kit qua xae djnh tinh chat ea hpe eua
tich eiia van phu thudc chii ylu vao ap suit Ip. Do do, kit qua khao sat khdi lugng thi tich van theo cae miic nhifet dp va thdi gian ep kbac nhau khdng ed ed su sai khae dang kl va diu dat duge khdi lugng thi tieh cua van du kiln la 0,7 g/cm^ (Tj^sy > 0,05).
Do dan na chiiu diy cua vin (AS): La ehi tifeu danh gia quan trgng cua van dara, phin anh kha nang hut am cua vin dam. Bang 4 eho thay, d eac dilu kifen nhifet dp va thdi gian khae nhau, dp dan nd theo ehilu day eua van eung khae nhau. Nhiet dd lp cang eao thi ty lfe truong nd cang giam va dat gia tri thip nhit Idii nhifet dd 180''C va thdi gian Ip 13 phut eho ea hai loai van. Thdi gian Ip cang ldn thi ty lfe truong nd chilu day ciia van cang giam. Mac dii trong bang 4 vl ehi tifeu phan cap chit lugng van dara, ddi vdi van dara thdng dung su dung trong dilu kifen khd loai PI khdng quy dinh vl ehi tieu dp dan nd chilu diy. Song ddi chilu ehi tieu niy d cac cap chit lupng van cdn lai tir P3 den P7 diu cd quy dinh khdng vugt qua 15%. Vdi miic thi nghifem nhifet do Ip t = 140°C, thdi gian ep T = 7 phut, do dan nd ehieu diy eua van dara VHD + Bach din Ifen tdi 16,7%.
Nhu vay, tai chl do ep P = 2,1 Mpa, t = 140"C, T = 7 phut, dd ara van va do dan nd chilu day van dam khdng dam bao nguong quy dinh.
van dam theo cac miic nhifet do ep va thdi gian ep
TT
1 2 3
Che do ep
140 140 140
13 10 7
Tinh chat co Do ben udn ti'nh MOR (Mpa) Van VHD +
Tram cir 11,58 10,67 7,57
Van VHD-H Bach dan
11,54 10,06 7,41
hoc ciia van
Dp ben keo vuong goc IB (Mpa) Van VHD +
Tram cir 0,29 0,24 0,22
Van VHD + Bach dan
0,31 0,28 0,21
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 11/2010 81
KHOA HOC CONG NGHE
4 5 6 7 8 9
160 160 160 180 180 180
13 10 7 13 10 7
11,53 11,42 9,20 11,51 11,62 11,59
11,69 11,35 9,52 11,53 11,60 11,54
0,32 0,32 0,24 0,31 0,29 0,32
0,30 _ 0,35
___326____
0,33 0,32 0,29
Do ben udn tinh cua vin:
Kit qua thue nghiera da till hifen thai gian lp ed miie dp inh hudng ldn hon din dp bin udn tinh eua ca hai loai van dam so vdi inh hudng cila nhifet dp (Bing 5). Trong dilu kifen nhiet dd WO^C va 160°C, thdi gian ep cang ldn thi dp ben udn tinh eua van dam cang ldn, va chi dat chat lupng theo yeu ciu d miic thdi gian ep 13 phut. Khi nhifet dp ep tang len raiie 180''C, thdi gian ep ed anh hudng khdng ldn, dp bin udn tinh ciia van diu dat > 11,5 Mpa.
Do bin keo vudng gde cua vin dam kit hgp vo hatdiiu-gd:
Cudng dp keo vudng gde la chi tifeu danh gia kha nang lifen kit dara - dam trong tim van. Kit qua bang 5 cho thay, dp bin klo vudng gde cua van dam kit hpp dara VHD va dam gd thay ddi theo theo hudng tang Ifen khi tang miic thdi gian ep va nhiet dp ep. Dp bin keo -vudng gde eua van khdng dat tifeu chuan duy nhit d raiic thi nghifem nhifet dp lp 140°C, thdi gian ep 7 phut.
Nhu vay, tdng hpp kit qua nghifen eiiu thuc nghifem danh gii miic dp anh hudng eiia eac thdng sd nhiet dp Ip va thdi gian ep tdi tinh chat ea hpc ciia van dam kit hpp gitra dam VHD va dam gd bach dan Uro hoac dam gd tram cir ddng thdi ddi chilu vdi tifeu ehuan chat lupng eua van dam cin dat la loai PI cho van dam thdng dung sii dung trong dieu kifen khd da eho phep lua chpn tri sd nhiet dp ep li ISO^C, thdi gian ep 7 phut dl van dam dira bao chat lugng theo quy dinh.
IV. KET LUAN
1. Dam VHD hoan toan cd kha nang su dung va
kit hgp dam gd tram cir hoac dam gd bach dan Uro dl sin xuit van dara thdng dung.
2. Dl tao dugc van dam 3 ldp cd ty lfe kit eau vin 1 : 3 : 1 , trong dd dam ldp mat la dam gd fram eir hoac bach dan Uro, dam ldp loi dugc phdi hpp gitra dam VHD va dam gd tuong ling vdi ty lfe 1: 1 thi cac thdng sd ca ban cua chl dp ep duge lua chpn la: Ap suit ep 2,1 Mpa, nhifet dp ep 180°C, thdi gian Ip 7 phut Van dam duge sin xuat dap ling dii tifeu chuan eua van dara fhdng dung sii dung trong difeu kifen khd.
TAI UEU THAIVl KHAO
1. Bill Van Ai, Pham Thi Thanh Miin, Nguyfen Van Quyln (2009). Nghien cuu dinh gia kha nang su dung vo hat diiu di sin xua't vin dam. Tap chi Ndng nghifep & Phat friln ndng thdn sd 6 - 2009.
2. Nguyfen Trpng Nhan (2002). Bao cio dl tai cap Bd " Xic dinh tinh chat nguyen lieu gd rimg trong phuc vu cdng nghiep dim vi ghep thanh vdi Keo vi Bach dad'. Vifen Khoa hpe Lara nghifep Viet Nara, Ha Ndi.
3. Hoang Hiiu Nguyfen, Pham Van Chuong, Nguyin Van Thilt (1999). Hien trang cong nghe sin xuat cac vat lieu thay the gd phi lieu vi thu lieu lam nong nghiep.
4. Hoang Thi Thanh Huang (200i;. Nghien cm cdng nghe sin xua't vin tre 16 d, gd cao su kit hgp.
Luan an Tien sy ky thuat, Vifen Khoa hpc Lam nghiep Viet Nara.
5. Hoing Xuan Nifen (2004). Nghiin ctiu mgt sd yeu td cdng nghe sin xuat van dam tir nguyen lieu sa dua. Luan an Tiln sy ky thuat, Vifen Khoa hpe Lam nghiep Viet Nara.
RESEARCH ON DETERMINING THE TECHNIQUE PARAMEl^ERS OF PRESSING PROCESS TO MAKE PARTICLE BOARD FROM CASHEW NUT COVER AND WOOD CHIP
Bui Van Ai Cashew nut cover is a waste in cashew nut processing industry in our country. With a chemical component of an appropriate 20% content of cellulose, cashew nut cover has ability to use and mix with wooden chip of Eucalyptus urophylla or Melaleuca cajiputy to make particle board. This research determined the technique parameters of pressing process to make three layers particle board with presure 2.1 Mpa, temperature 180°C and time 7 minutus. Mainly mechanical properties of the product that meet standard of popular particle board used in dry condition.
Keywords: Particle board, cashew nut cover chip, cashew nut cover.
Ngudi phan bifen: GS.TS. Ha Chu Chu
