quy trinh san xuat gang tay cao su

8/4/2019 Quy trinh san xuat gang tay cao su

1/20

I.S lc v quy trnh sn xut

1 Quy trnh sn xut gng tay c bt

Bc 1. Lm sch khun s

- Ra bng nc, mt ca thay nc mt ln (c th thay sm hn nu nc

qu bn) (bn nc s 1)

- Phun tia nc

- Chi c ra (chi i di), lm sch cht bn. 1 ca thay nc 1 ln nc

chy trn.

Bc 2. Ra bng acid nitric (l mt cht oxide ha cc mnh) nng quy nh:0.2- 1.0, nhit : 50 60o C , c tc dng ty cht bn, bt cn bm chc trn

khun, thay hoc chm thm acid khi hm lng acid xung thp.

Bc 3. Lm sch khun s (bn nc s 2)

- Ra bng nc nng (70 80o C), ra cht bn v lng acid cn bm trn

khun.

- Chi c ra trn (chi i), lm sch cht bn. Mt ca thay nc 1 ln ncchy trn.

Bc 4. Lm sch khun s (bn nc ra cui)

- Ra bng nc nng (70 90o C), lm sch lng cht bn v d lng

acid cn li trn khun.

Bc 5.

- Nhng qua bn to ng

CaCO3: bt tch khun, ty tnh hnh thc t m iu chnh cho ph hp.

Ca(NO3)2 : cht to ng kt, iu chnh ty tnh hnh thc t.

Teric: cht phn tn, lm bng, iu chnh ty tnh hnh thc t.

1


2/20

Bc 6. Qua bn sy to ng (nhit quy nh 110 oC - 140o C), khun phi

c sy kh hon ton trc khi qua bn m, nhm trnh hin tng khun cha

kh qua bn m s to cc ng.

Bc 7. Nhng m

- Bn m phi duy tr n nh CTR : 3 3+, pH : 9 11

- Cc thng s khc ty tnh hnh thc t c th thay i.

Bc 8. Sy tin lu ha

- Sy kh bn thnh phm cho ro nc.

Bc 9. Qua bn tch chit 1& 2 (nhit quy nh 50o C 70o C)

- Loi b cc cht bn, mt s cc tp cht, cc protein trong cao su.

Bc 10. Se vin

Bc 11. Qua t sy lu ha, bt u qu trnh lu ha cao su

- T sy 1,2,4&5 nhit quy nh : 110o C 140o C

- T sy 3 nhit quy nh : 80o C 120o C

Ty tc chuyn v thi gian m m gi nhit cho thch hp, cc thng s

nhit i vi qu trnh lu ha l v cng quan trng, khi tng nhit s lm tng

lng lu hunh ha hp cng nh tng ng k tc lu ha. Khi s lu ha

cha ti mc hay lu ha qu mc u lm nh hng n cc tnh cht c l

ca sn phm (c bit nht l chu ko t v dn ko cng), ngoi ra cn

lm tui th sn phm b gim.

Bc 11. Qua cc bn tch chit 3&4 (nhit quy nh 60o

C 90o

C).Bc 12. Qua bn bt bp, vic nhng bn bt ny gip thnh phm khng b

dnh, cng nh gip vic mang gng d dng hn.

Bc 13. Qua t sy cui : sy kh.

2


3/20

2 Quy trnh sn xut gng tay khng bt

Tng t quy trnh sn xut gng tay c bt tuy nhin cng c vi im khc bit

Bc 1. Lm sch khun s

- Ra bng nc, mt ca thay nc mt ln (c th thay sm hn nu nc

qu bn) (bn nc s 1).

- Phun tia nc

Bc 3. Ra bng acid nitric (l mt cht oxide ha cc mnh) nng quy nh :

0.2- 1.0, nhit : 50 60oC , c tc dng ty cht bn, bt cn bm chc trn

khun, thay hoc chm thm acid khi hm lng acid xung thp.

Bc 3. Lm sch khun s (bn nc s 2)

- Ra bng nc nng (70 80o C), ra cht bn v lng acid cn bm trn

khun.

Bc 4. Bn kim ra khun, nhit t 45o C 65o C, nng KOH : 0.2% -

0.8%.

Lm sch bt, cht bn .Mt gi kim tra nhit 1 ln, 1 ca thay 1 ln. C tc

dng trung ho acid.

Bc 5.

- Chi c ra (chi i di), lm sch cht bn. Mt ca thay nc 1 ln nc

chy trn.

- Chi c ra trn (chi i), lm sch cht bn. Mt ca thay nc 1 ln nc

chy trn.

Bc 6. Lm sch khun s (bn nc ra 3+bn nc ra cui)

- Ra bng nc nng (60 80o C, pH: 6.0 8.0), lm sch lng cht bn

v d lng KOH cn li trn khun.

Bc 7.

3


4/20

- Nhng qua bn to ng.

CaCO3 : bt tch khun, ty tnh hnh thc t m iu chnh cho ph hp

Ca(NO3)2 : cht to ng kt, iu chnh ty tnh hnh thc t.

Teric: cht phn tn, lm bng, th iu chnh ty tnh hnh thc t.

Bc 8. Qua bn sy to ng (nhit quy nh 110 oC - 140o C), khun phi

c sy kh hon ton trc khi qua bn m, nhm trnh hin tng khun cha

kh qua bn m s to cc ng.

Bc 9. Nhng m

- Bn m phi duy tr n nh CTR: 3 3+, pH : 9 11.

- Cc thng s khc ty tnh hnh thc t c th thay i.

Bc 10. Sy tin lu ha

- Sy kh bn thnh phm cho ro nc

Bc 11. Qua bn tch chit 1& 2 (nhit quy nh 50o C 70o C).

- Loi b cc cht bn, mt s cc tp cht, cc protein trong cao su.

Bc 12. Se vin

Bc 13. Qua t sy lu ha 1, 2, 3&4, bt u qu trnh lu ha cao su, nhit

quy nh: 110o C 140o C. Ty tc chuyn v thi gian m m gi nhit

cho thch hp, cc thng s nhit i vi qu trnh lu ha l v cng quan trng,

khi tng nhit s lm tng lng lu hunh ha hp cng nh tng ng k tc

lu ha. Khi s lu ha cha ti mc hay lu ha qu mc u lm nh

hng n cc tnh cht c l ca sn phm (c bit nht l chu ko t v dn ko cng), ngoi ra cn lm tui th sn phm b gim.

Bc 14. Qua cc bn lm mt

- Bn lm mt s 1 : bng nc, nhit < 60oC

4


5/20



Cc bn lm mt gip nhit ca khun gim xung trc khi qua bn clo,

trnh vic khun qu nng lm bay hi clo bn clo.

Bc 15. Qua bn clo, ti y s din ra cng lc hai phn ng: phn ng clo ha

gy ra bi clo v phn ng cng hydracid vi HCl(sinh ra khi xc hlo vo

nc)lm tr b mt cao su gip chng dnh

Bc 16. Qua 2 bn dung dch

- Bn dung dch 1:cha nc chy trn, nhit : 30oC 50oC

- Bn dung dch 2:cha nc chy trn, nhit : 30oC 50oC

Bc 17. Bn tch chit 3&4

Bc 18. Qua t sy cui: sy kh

II.Cc li thng gp

5


6/20

STT Li Nguyn nhn Cch x l

1 Gng b dnh

v d dng b

mo m khi

thi

a.H s CHCl3 qu thp (thi

gian tin lu ha qu ngn)

b.Nhit lu ha thp (bao gm

nhit t sy, nhit bn

tch chit )

c. dy lp cao su to thnh

yu do hm lng Ca(NO3)2

qu thp hoc nhit bn

latex thp

-Kim tra li thi gian , nu th

cn tnh ton pha thm m c vo

-Tng nhit l sy, hoc cho gim

tc chy chuyn

- Kim tra hm lng Ca(NO3)2 tr

chuyn v nhit bn latex, i

chnh n khi t yu cu

2 Gng b dnh

dng dnh np

a.Nu dnh trong : hm lng

bt bp thp.Dnh ngoi : hm

lng CaCO3 thp

b.Trng hp dnh vng c

tay(thng thng l dnh

trong) : c th do cng nhn

MO x bt t bn bt phi

trn qu nhanh lm lng

dung dch trn b mt c hm

lng bt thp v nhit

gim. Nu dnh ngoi : trong

khi nhng chuyn, x thmnc vo bn to ng(trng

hp ny rt kh xy ra). Ngoi

ra cn c th do d lng cht

hot ng b mt

- Kim tra hm lng bt tr

chuyn ty thuc vo vic dn

trong hay ngoi m iu chnh ch

t yu cu

- Chm thm bt vo bn v hn

dn cng nhn MO trong vic x b

3 Gng c cc

im bn do

du

a.Bn to ng b nhim bn

do du m bi trn t dy

xch ri vo

-V sinh bn to ng, v sin

chuyn sn xut, kim sot ln

du m dng bi trn trn chuyn v

6


7/20

II.Tng quan v cch thc phi trn v cc loi ha cht s dng phi trn

phi trn

Vic phi trn ho cht cho sn xut gng tay cao su c bt gm ba cng vic nh

sau: phi trn cao su, phi trn ho cht lm ng, phi trn bt.i vi gng taykhng bt ch c phi trn cao su v phi trn ho cht lm ng.

1.Phi trn cao su

Cng vic phi trn cao su c tin hnh nh sau:

- Kim tra bn trc lc trn.

- Cho nc vo bn n mc quy nh v bt my khuy.

- Cho KOH ( pha long n nng t 15% n 25 %) vo theo s

lng quy nh v tip tc khuy.

- Chun b y s lng cht n bm vo bn trn.

- Mt n hai gi sau khi bm cht n tin hnh bm m.

- Chun b y ho cht lu ho v bm vo trn khi n gi trn.

- Cho thm nc n mc quy nh hoc bm thm m c nu c m ctn kho.

- Ghi phom v lu phng th nghim, phng th nghim kim tra mu

sau khi trn 02 ting.

- Chnh sa nu m khng t yu cu.

M cao su sau khi trn (sau khi bm cht lu ha ) c th s dng sau 22

ting. Thi gian s dng tt nht (20 ting - 40 ting ).Nu c s c xy ra m lng m s dng chm (thi gian qu 50 ting)

th m m ny khng s dng cho vic nhng chuyn m c xem nh m c v

c pha t (0%-10%) vo m mi. Lc ny s s dng m k tip.

Cc loi ha cht chnh s dng bn cao su

7


8/20

a)Latex HA

Bng yu cu k thut cao su ly tm (TCVN)

Tn ch tiu Lai HATng hm lng cht rn,%(m/m) khng nh

hn61.5

Hm lng cao su kh,% (m/m) khng nh

hn60.0

Cht khng cha cao su, (m/m), khng ln hn 2.0

kim NH3, % (m/m) , tnh theo khi lng

latex c c.

0.60

Tnh n nh c hc(s), khng nh hn 650

Hm lng cht ng kt(%m/m) khng ln

hn0.05

Hm lng ng, (mg/kg) tnh trn tng chtrn, khng ln hn

8

Hm lng mangan, mg/kg, tnh trn tng cht

rn, khng ln hn8

Hm lng cn, %(m/m), khng ln hn 0.10

Tr s axt bo bay hi (VFA), khng ln hn 0.020

Tr s KOH, khng ln hn 1.0

a.1. Ch tiu VFA (acid bo bay hi)

8


9/20

y l ch tiu hng u ca cao su ly tm, Acid bo bay hi (trng lng

phn t thp) c trong m nc vn cy l do tc ng ca vi sinh trn mt s

hydratcarbon c trong srum (cc acid ny thng l acid acetic, acid formic, acid

propionic. Ch s VFA cho ta thy c tnh trng bo qun m nc tt hay xu,cc acid ny lu li trong srum v sau khi ly tm mt phn ln chy ra theo skim,

phn cn li trong m ly tm s tip tc gia tng nhng chm hoc nhanh ty theo

s bo qun cao su ly tm. T l VFA khng c xc nh r rt, tuy nhin phi

di 0.02% (TCVN = 0.2%), v pha khch hng yu cu thng c s cao nht l

0.04%. Nh vy vic hnh thnh VFA c trong cao su ly tm cao hoc thp l do

mc nhim khun m nc vn cy v kh nng ly ra theo srum trong

qu trnh ch bin v vic bo qun cao su ly tm. Vi i ng k thut cng nhtrang thit b hin ti ca cng ty chng ta khng th kim tra cng nh x l nu

gp trng hp ch tiu ny khng t yu cu, mt d y l ch tiu quan trng

nht, c nh hng ln i vi thnh phm (c trung l mi hi chua).

a.2 Ch tiu DRC% v TSC%

- Ch tiu TSC%: ngi ta o hm lng tan b cht kh c trong mu, bao

gm hm lng cao su v phi cao su, ch tiu TSC% s dng trong kim sot qu

trnh dng hiu chnh ch tiu DRC%.Ch tiu TSC% trong kim tra cht lng

sn phm dng tr DRC% xc nh phi cao su, cn thng thng ch theo

mt ch tiu l DRC%.

- Ch tiu DRC%: tng hm lng cao su kh, dng xc nh cht lng

m latex ly tm.

a.3. Ch tiu phi cao su:

Ch tiu ny phi c kim sat trong khung TCVN, thng thng ch tiu

ny t yu cu, nhng trong mt s trng hp ch tiu ny vt khung (trng

hp cao su ly tm c phi cao su cao gn vt khung vi li tn kho qu lu).

9


10/20

Thng thng khi sn xut kim sat ch tiu ny phi < 1.7 hm lng nguyn

liu.

a.4. Ch tiu NH3

Ch tiu ny cn phi np y lng NH3 cn thit bng tnh tan qua

gi tr kim tra NH3 rt d dng, tuy nhin cn phi cung cp y v kp thi,

khi ly tm ra l phi cung ng ngay vi s lng tnh tan trc, v hnh ng

sm ny gip cho cc ch tiu khc nh MST v VFA.

.

a.5. Ch tiu MST

Khi cao su ly tm mi ly tm ra khi my c MST rt thp, sau tng dntheo thi gian lu kho, tuy nhin nu khng s dng x phng ha th MST s

khng t theo yu cu k thut, v vy ngay sau khi ly tm ra phi s dng mt

lng amonium laurat kch hat MST. S kch hat ny c gii thch nh

sau: S thay i ch tiu MST tng theo thi gian tn tr do phn ng thy phn

cc hp cht c trong m, v c ch c gii thch nh sau: Cc phospho lipid c

mt t nhin trong m b thy phn cho ra cc acid bo, ion phosphate v cc cht

kim hu c. Cc acid bo tm thy trong m cao su bao gm: oleic chuynlenic,

palmitic, stearic v arachitic, do s hp thu cc mui ammonium ca cc acid bo

trn b mt cc vi cu cao su, lm din tch b mt ca cc vi cu cao hn v do

lc y gia cc vi cu cao hn nn chng kh b ng t hn v nh vy s lm

tng MST. Theo cch gii thch ny th cao su ly tm c MST tng n cc i khi

c s cn bng ca s hp thu cc mui ammonium ca cc acid bo trn b mt

cc vi cu, th nghim cho thy cao su ly tm bo qun bng 0.02% NH 3 th MST

tng cho n 3 - 4 thng ngng khng tng na trong khi cao su ly tm khc c

bo qun bng NH3 cao hn vn tip tc tng MST. Nu MST tng t nhin th

rt chm v khng t yu cu, v vy mun tng nhanh ngi ta s dng liu

lng x phng (amonium laurat), vi HA t 0.02 n 0.04%. Lu x phng s

10


11/20

nh hng n ch s KOH.

a.6. Ch tiu KOH

Ch s KOH cho ta bit v s hin din ca cc gc acid kt hp vi

amoniac bn trong ca latex. Cc gc acid ny l do s thy phn ca cc protein,v vy khi cho amonium laurat ( acid bo c trong lng phn t cao) lm nh

hng n ch s KOH. Hn na ch s KOH bao gm tt c cc gc acid v c

cc gc acid bo bay hi (VFA). V mt tnh tan trong l thuyt ta d dng tnh

c phn trm KOH cn li trong cao su ly tm da theo t l phn trm TSC v

DRC m khng cn phi da vo kt qu o t.

V d: vi DRC = 28% v TSC = 31% sau khi ly tm c DRC = 60.3% v

TSC = 61.7% o t ch s KOH l 0.5 ta d dng tnh tan khi gim DRC = 24%

v TSC = 27%, s c ch s KOH d kin gim, nu thy ch s KOH gim cha

t yu cu th c th thay i DCR v TSC tnh tan li cho t yu cu.

a.7. Ch tiu Mg

Ch s Mg cc nh sn xut khng th xc nh c bi khng c iu

kin, do lng Mg cn li trong cao su ly tm qu nh thng thng i hi max

Mg = 50 ppm, do vic cn c s n nh v ch tiu Mg trong sut qu trnh cungcp sn phm cho khch hng nn nh sn xut c gng s dng DAP c tnh cht

sao cho Mg cn li trong cao su ly tm va t yu cu va phi n nh. iu ny

c gii thch rng m nc vn cy cha trong t nhin magie di dng ion

ha tr hai Mg2+ cng nh ln di dng anion HPO42-. S hin din ca magie

trong m ly tm th khng tt i vi ch tiu MST v ch s KOH, t rt lu

RRIM nghin cu cho thy t l t 50 n 80 ppm ti a c trong m sau khi

ly tm, nu vt qua s o ny phi x l thm x phng gia tng tnh n nh chc. Nu d tha magie trong m cng khng tt v s dn n s hnh thnh thy

tinh m iu ny s gy nhiu vn trm trng trong cng ngh sn phm nhng,

trc y mt s nc nh Thi Lan a ra th trng dng sn phm c magie

cao v tng MST h s dng thm lng x phng, lng m ny gy kh

11


12/20

khn trm trng do hnh thnh thy tinh v cha magi qu nhiu khi n tay

ngi tiu dng. Magi hin din trong m vn cy rt cao ( c th n 5000

ppm/TSC) thng thng phn ln n c bnh qun bi s hin din ca ca ln

(iu ny cng lm nh hng n MST) nhng khi phi hp vi magie th c thlm suy gim hm lng bng kt ta. T l magie/ln bin thin ty theo ging,

th nhng, nhng cng ty theo ch khai thc v ma, t l magie/ln > 2 nn

hu ht cc trng hp u cn tha magie trong m. V vy cn phi xc nh

tng trng hp c th, do tha magie nh vy phi thm ln di dng amonium

hygrogenphosphat (NH4)2HPO2 c vit di dng DAP hay DAHP. Vic thm ln

cn phi kim sat tt nu khng s gy nh hng n MST v KOH. Do phi

nm vng liu lng v cc k thut lai b magie ngy cng tr nn quantrng.

a.8 Ch tiu kim loi, cht ng kt

- Cht ng kt : Sau khi ly tm lai b cc cht rn ra khi, tuy nhin trn

thc t mt s ht nng nhng rt mn khng c lai b khi ly tm, v vy chng

c th lm ri lan mt s giai an v sau trong cng nghip. Do c d kin

phng php xc nh hm lng cht kt t, lm c iu ny phi ly tm rt

mnh. t l kt t ny i khi gia tng do vic cho thm phosphat vo m ly tm

(vic lm ny b nghim cm khng c s dng).

- Ch tiu cc kim lai: ng v mangan c bit nhm xc tc hat

ng ca oxy trn s xung cp ca chui polyisopren. S o ca hm lng ng

v mangan l nhm cho bit s hin din ca cc ion v do v ri ro c th c

ca s xung cp v sau trong cc sn phm cng nghip c gc l m latex. Cc

ch tiu phi nh n cc phng php quang k, chng khng cho php c lp ccdng hat ng so vi cc dng bt ng ca cc ion ny, do cc thng tin nhn

c s khng chnh xc. Cc gi tr o ny thng khng c thc hin trong

cc nh my sn xut, nu mun phi b sung thit b o t. Nhn thy tiu chun

12


13/20

i hi lng ti a l 8 ppm, nhng khch hng u cu ch c 3 ppm.

a.9. n nh ha hc

Ngi ta mun xem vi tc ng ca ha cht Calcium Nitrate, n vic

ng kt ca m ly tm, c ngha l nh hng ca vic ng kt vi ha cht cacao su ly tm.

Cch lm:

- Pha dung dch Calcium Nitrate chnh xc 10% (cho 25g Calcium Nitrate

vo bnh nh mc 250 ml, cho nc ct vo ngang vch lc u).

- Cn ng 20 gram m mu cho vo cc 100 ml.

- Nh 2 n 3 git dung dch Calcium Nitrate 10% vo mu, dng a thy

tinh khuy u cho ng kt.

- Ly phn m ng bm trn a thy tinh ra, vt cho sch ht srum vo li

trong mu.

- Tip tc nh 1 n 2 git dung dch calcium Nitrate 10% vo mu v tin

hnh tng t nh trn cho n khi ht m mu.

- Ly kt qu ghi vo biu mu, kt qu c gi tr t 2 n 4 l t yu cu.

Theo kin thc ca bn thn, dn nay vn cha hiu ch tiu ny c ngha

g?

b. Cht n CaCO3

b.1 Gii thiu chung v cht n CaCO3

* Tn khc: Carbonate calcium Craie Bt Bt vi Bt phn

* Thnh phn ha hc: ch yu l calcium carbonate, c ln mt s tp cht:

silica, calcium sulfate, oxide st, t st, calcium hydroxide, mangannese

hydroxide, .v.v

13


14/20

*Tnh cht: Bt mu trng, d: 2.7 nguyn cht: 90 99.5 %CaCO 3 ty theo

phm thng mi. Kch thc phn t thay i t 0.02 0.03 m

*Ch to v phn loi

- Calcium carbonate thin nhin chit rt t vi m, sau khi ra khi hm

, CaCO3 cha ti thiu l 15 20% nc, hong kh ngi ta lu kho v

nu sy l sy d nhit tng cht t cng s bin CaCO 3 thnh vi. Sau

c nghin bng my xay.

- Calcium carbonate trm hin (kt ta): bng phn ng phn gii gia cc

dung dch chlorua calcium v carbonate sodium hoc sc kh CO2 vo nc vi

trong. Loi ny thng cho ht c kch thc rt b+Tng qut c hai loi c phn hng nh sau:

Loi rt mn, c ht di 0.1 micron

Loi mn, c ht 0.1-1 micron

Loi trung bnh, c ht 1-3 micron

Loi th, c ht trn 3 micron

b.2. Cht n ang s dng

Tn thng mi: HITENXILE LX

*c tnh ha cht:

Canxi cacbonat l mt th nguyn cht ca vi uc nghin nh, bt mu trng,

khng mi v khng c hi.

*Thnh phn chnh:- vi CaCO3: 98.5 %

- MgCO3: 0.8

- Fe2O3: 0.02

14


15/20

- Thch anh (SiO2): 0.5

*Hnh dng bn ngoi

- Bt mu trng, hoc th st mu trng sa

- Trng lng ring: 2.7g/ ml

- tan trong nuc: 1.3mg/100g

- pH: t 8 - 10

L CaCO3 loi mn, c bc Acid Stearic gip cht n phn tn d

dng hn trong hn hp cao su. Cc ht CaCO3 bc acid stearic khng nhng lm

cho CaCO3 d phn tn trong cao su m lm cho sn phm c ngoi quan lng p

v kch thch nh s lu ho, khi s dng hm lng thch hp gip tng mt s

c tnh ca sn phm. Vic bc Stearic ny c tin hnh nh sau : ngi ta ho

cht n vo nc thnh mt th st sau ngi ta thm mui ca Na hay Ca vi

Acid Stearic, Acid Stearic s bc cc ht cht n thnh mt mng mng trn

lng.

Ngoi ra CaCO3 l cht ng vai tr quan trng gip gng tay c mu trng

sng.

c. Cht lu ha : A 118 thnh phn chnh bao gm

- Lu hunh (S)

- ZnO

- ZDBC

- ZDEC

- TiO2

- Cht chng oxi ha (cht phng lo)

*Tnh cht

15


16/20

c.1 Lu hunh:

+Khi qut :

- Tn khc : lu hong, dim sinh, sulfur . . .

- K hiu : S

+ Tnh cht

- Cht mu vng, d = 2.07, khng mi, khng v, khng tan trong nc, tan t

trong alcohol, eter, glycerine, tan nhiu trong Carbon disulfide, khi ma st pht

sinh in m. trng thi nguyn cht c phn ng trung tnh. dn in v dn

nhit km. Nng chy 119o C, thnh cht lng mu vng nht, trong, sm mu

160o C, ha nhy v nho 200 250o C, tr li lng 330o C v bc hi mu

nu 444,6o C. Nhit bc chy l 266o C, vi ngn la mu xanh lam v bc

khi anhydride sulfurous (SO2)

+Tc dng

- C tc dng lu ha bng cch thnh lp cu ni gia nhng phn t

hydrocarbon cao su dn n s pht trin mt cu trc mng li cht ch, lm

gim bt ti hn v do ca chng, hu qu l lm tng ln phn t khi,gim do, c bit l tnh khng tan trong dung mi. i vi trng hp ch

bin sn phm cao su lu ha t latex, lu hunh khng th ha trn trng thi

thng mi ban u m cn phi x l bin i thnh 1 trong 3 dng :

- Dng kh tm ha cht khc : (A118 v NR 118 thuc dng ny) lu

hunh thng mi em tn nghin kh chung vi cht phn tn ha v tm t

ha, hai cht c bit s dng cho latex ny s bao bc cc ht t lu hunh, to

cho chng trng thi c lp. Trn vo latex s khng kh khn.

- Dng th giao trng

- Dng khuch tn bn

c.2.Oxide km (ZnO)

16


17/20

+Tnh cht

- Bt mu trng, d= 5.57 5.6 trng thi v nh hnh hay hnh kim ty

theo iu kin oxide ha km, kch thc trung bnh thay i gia 0.1 09 m.

dn nhit 0.00166 CGS. trng thi nguyn chat61no1 tan trong nc vihm lng 0.005g/lit 25o C

+ Tc dng : i vi ngnh sn xut gng tay, ZnO c mt s tc dng sau

- Tng tr lu ha hay tng hot cho cht gia tc trc tip hoc qua s hnh

thnh savon km khi phi hp vi acid bo

- Nhit gel ha hay thu nhit ng c latex

- Nhum mu trng (i vi sn phm t hm lng ZnO trn 99% v hm

lng Pb v Cd khng qu 0.1 %)

Cn lu : ZnO c kh nng lm thay i nht v lm gim tnh n nh c

hc (gy ng c lc khuy trn) do c s phng thch ion Zn2+. V vy cn cho

xt hoc KOH vo latex sao cho pH t t 9 11 n nh c hc ca hn

hp c ZnO t ti a

c.3. ZDEC (Dietyl dithiocarbamate km)

+ Tnh cht

- Bt mu trng, d = 1.47, nhit nng chy : 171 178 oC, khng tan trong

nc, xng, alcohol, tan trong benzen, cloroform, CS2, tan t trong carbon

tetracloro aceton

+ Tc dng:

- Xc tin lu ha k t nhit 70 o C, tc dng cc nhanh nhit 90-

100o C cho n 160o C.Trong sn xut gng tay cao su nn s dng thm ZMBT

(Mercaptobenzothiazyle km) tng cng tnh n hi

- Khi s dng cht ny khng cn thit s dng ZnO v Acid Stearic, nhng

c th dng mt lng rt nho3d9e63 c tc dng hon ho hn

17


18/20

- i vi latex, c tnh an ton khi s dng do khng to hiu ng i, trnh

c vic lu ha qu mc ti ho

+c tnh ca hn hp cao su

- Khng lo ha tt

- Khng c mi v, khng c tnh nn c th dng cho cc sn phm tip

xc vi thc phm

- Khng bin mu hay dy mu

c.4. ZDBC (Dibutyl dithiocarbamate km)

+ Tnh cht:

- Dng bt trng, rt mn, mi v ng, d = 1.24. Nhit nng chy : 104o C,

khng tan trong nc, xng, alcohol, tan trong benzen, cloroform, CS2, tan t trong

carbon tetracloro aceton

+ Tc dng: tng t ZDEC nhng tc lu ha cao hn

+ c tnh ca hn hp cao su: tng t ZDEC

c.5 Oxide titanium (TiO2)- Lm trng, gip sn phm sng mu.

c.6. Cht chng oxide ha (cht phng lo)

- Cht phng lo cn gi l cht khng lo ha, c chc nng cn tr hay

gim thiu s h hng ca cao su lu ha.

- Theo cc yu t gy h hng cao su, cht phng lo c chia thnh 3

nhm chnh: khng oxygen, khng kim loi Cu v Mn, khng quang ha v ozone.

2. Phi trn to ng

Cho nc vo n mc quy nh.

18


19/20

Chun b bt tch khun, cho vo bn khuy, khuy u v bm vo bn

n lc ht.

Chun b cht to ng kt cho vo bn khuy v bm vo bn trn

n ht.

Chun b cht lm bng, pha long bng nc nng, cho vo m

trn.

Cho thm nc n mc quy nh.

Ghi li phom trn v lu phng th nghim.

Sau khi phng th nghim kim tra mu, nu khng t th phi khc phc.

M trn ny c th s dng ngay sau khi phng th nghim kim tra mu t.

* Cc loi ha cht s dng

a.To ng c bt

a.1.Dipcall : Cancium nitrate Ca(NO3)2 : cht to ng, khi cn thit c th

ng vai tr iu chnh trng lng gng

- Tan tt trong nc v ru, thm t tt, lp ph dy v u ( dy lp ph caosu c th ln n 0.42 mm)

- S ng kt cao su c th gii thch mt cch s lt nh sau : do ion Ca 2+ hnh

thnh khi khun i vo bn latex s lm ng t cc ht latex mang in m

a.2.Neolight : Cancium carbonate CaCO3 (50%) : cht chng dnh khun,

sau khi sn phm hnh thnh gip d dng tho sn phm ra khi khun,

a.3.Teric 320 gc Alcohol Ethoxylate(65%) : cht lm bng b mt, ngoi racn gi vai tr l cht phn tn, gip bt tch khun phn tn u trong dung dch

b.To ng khng bt

b.1.Dipcall : Canxi nitrat (77%) : cht to ng

19


20/20

b.2.Precarb (hoc GCC-MT05): Canxi cacbonat (98 %) : cht chng dnh

khun

b.3.CG-KH07: hn hp polymer t nhin (7%) : cht h tr chng dnh

khun, khi s dng ha cht ny vi mt hm lng nh c th gip gim hmlng bt precarb mt cch ng k, nhc im : nhanh lm bn khun

b.4.Teric 320 (65%) : cht lm bng b mt.

3.Phi trn bn bt chng dnh

- Cho nc vo bn n mc quy nh, bt my khuy.

- Chun b bt bin tnh chng dnh vo bn v cho tip tc khuy.

- Chun b v thm vo dung dch dit khun v ha cht h tr chng dnh.

- Thm nc vo n mc quy nh.

- Ghi li phom trn v lu phng th nghhim.

- Kim tra v khc phc nu kt qu kim tra ca bn t phng th nghim

khng t.

- M trn ny c th s dng ngay sau khi trn t kt qu.* Ha cht s dng

- Ho cht s dng: bt bin tnh, cht dit khun (Biocider), ha cht h tr

chng dnh (Porex 50).

- Trong : bt chng dnh (2% - 7%), cht dit khun v ha cht h tr

chng dnh c iu chnh tu theo yu cu ca gng tay.

20

quy trinh san xuat gang tay cao su

Documents