Txhim Hlo Li Cas Thaj Tsam Pab Ntau Ntxiv Rau Kev Siv Polyvinyl Alcohol: Qhov Chaw Siv Siv Txoj Cai

Paub txog Polyvinyl Alcohol Thiab Nws Qhov Chaw Nyob Rau Hauv Kev Tsoj Tsam Pab Ntau

Polyvinyl alcohol, loss PVOH tshaj, tuaj los ntawm kev lag lub polyvinyl acetate thiaj li mus rau hauv hydrolysis thiab tsim nyog rau kev siv ua hom cob rau hauv qhov chaw nruab. Qhov uas tsim PVOH zoo tshaj plaws yog tias nws dhau rau hauv dej thiab tsim cov ntoo zoo, uas pab txhim kho cov pigment sib npaug rau hauv qhov chaw thiab tsim cov ntim smoother rau hauv cov khoom lo rau lo. Cov hom cob feem ntau tsis tau ua li no raws li li cas? Molekuls PVOH muaj ntau lub qhov hydroxyl uas sib cuag nrog cov fiber cellulose hauv lub lo tseem. Qhov no tsim kev sib cuag zoo dua rau hauv qhov chaw thiab kho kom tsawg dua qhov teeb meem dust thaum kauv cov khoom lo tom qab saum toj no hauv kev tsim khoom. Cov xov lo nkauj pom zoo cov kev pab no vim tias lawv muab cov khoom zoo dua thiab tsawg dua qhov teeb meem kev tsim khoom.

Polyvinyl alcohol yog dab tsi thiab nws ua haujlwm li cas hauv cov chaw nruab lo

Polyvinyl alcohol (PVOH) muaj qhov tseem ceeb sib peej ntawm kev siv rau kev ntxuav - ua raws li chav ntxuav thiab tsim ib lub hauv paus tiv thaiv. Siv daim ntawv no nyob rau hauv dej thiab saib nws tsim ib lub hauv paus zoo li cas uas pib rau hauv qhov chaw nyob rau ntawm cov khoom tshaib tshiab zoo li calcium carbonate pigments thiab paper fibers. Qhov kev sib txig txag ntawm cov khoom no tuaj yeem txhim kho qhov sib sau nyob rau ntawm cov duab ntoo hauv daim ntawv. Rau cov neeg siv daim ntawv roj ntaub, qhov no txhais tau tias muaj qhov zoo dua hauv qhov chaw ntxuav, feem ntau tso ntau dua li 30 los yog 40% raws li cov neeg tsim khoom tau pom los ntawm lawv tus kheeb pom.

Cov qhov tseem ceeb ntawm polyvinyl alcohol uas pab txhim kho qhov tseem ceeb ntawm kev ntxuav

• Zap hli ntau : Tiv thaiv kev puas tsuj nyob rau hauv kev ntxuav thiab kev pib
• kev ruaj khov ntawm pH : Txhawj xeeb nyob rau hauv cov ntxuav muaj roj tshuaj plaub thiab roj tshuaj le
• Kev tiv thaiv roj : Lwm qis kev pib rau hauv daim ntawv nruab nrab rau kev saum npoo
• Biodegradability : Txhawv kev xam khoom siv los ntawm kev tswj hauv pa rooj tsis txhob muab ceev rau qhov ua haujlwm

Qhov chaw no ua rau PVOH muaj zog dua nyob rau hauv kev siv uas xav tau kev nyob siab thiab kev nyob zoo tshwj xeeb.

Lus piav qhia PVOH thiab lwm yam khoom sib pab nyob rau hauv kev them ntaub

PVOH ua haujlwm zoo dua khob nyob rau hauv kev tiv thaiv dej thiab zoo dua latex nyob rau hauv daim ntawv kho mob, ua rau nws yog dab tsi zoo tagnrho rau kev xam khoom. Tam sim no khob ts still zoo li cas los xij rau cov duv tshwj xyuas, PVOH pab tau ib qho kev ua haujlwm zoo dua rau hauv kev xam khoom sov thiab kev sau ntawv uas kev nyob siab ntawm kev them ntaub tuaj yeem muaj feem nyob rau hauv kev ua haujlwm.

Yog Li Cas Polyvinyl Alcohol Pab Ntxiv Qhov Loj ntawm Kev Sau Lub Paper Coating

Yog Li Cas Polyvinyl Alcohol Pab Ntxiv Qhov Nyiaj Ua ke ntawm Fiber thiab Coating

Thaum sau hauv lub paper coating, polyvinyl alcohol (PVA) tsim ib lub film sib txuas uas pab ntxiv qhov nyiaj uas nyob rau hauv cellulose fibers thiab kho kho. Yog li cas PVA ua haujlwm zoo yog tias muaj cov hydroxyl group nyob rau hauv nws qhov chaw uas nyob rau hauv fiber surface, zoo li ib qhov glue molecular uas nyiaj nrog cov khoom organic thiab kho kho. Qhov nyiaj no pab tiv thaiv tsis pub cov layers tshav tawm thaum sau lossis npoo dua npoo dua. Tom qab ntawd nws tseem pab tiv thaiv coating kom zoo ib yam, tshwj tsis yog hauv cov duab ntoo xwm thiab coating tsis tuaj yeem sau ra ib yam.

Qhov Txawj Caum ntawm Hydrogen Bonding nyob rau hauv kev pab ntxiv qhov loj ntawm paper nrog PVA

Yog li cas PVA ua rau nws tsim nyob rau hauv qhov chaw ntxoov ntxoo? Lub xwb yuav yog hydrogen bonding. thaum peb saib cov polymer chains no, lawv tshwm sim muaj ib cheeb tsheb ntawm cov leeg -OH groups uas xav tau cellulose fibers zoo li Velcro strips. Qhov no tsim cov kev sib txuam kho tshiab ntawm ob qho molecule. no yog qhov tseem ceeb thaum muaj qee yam zais rau hauv qhov khoom no, cov bonds no tuaj yeem pab faib qhov siab rau hauv qhov coating tag nrho, tsis pub nws ruaj ntau rau ib qhov chaw. Cov kev soj ntsuam pom tias qhov no tuaj yeem pab nce qhov siab dua li 18% mus rau 22%, zoo txaug heev kom rau nrog lwm hom starch. Thiab no yog qhov tseem ceeb: cov bonds no tsis yog tsuas yog tshav tas mus li. Tom qab muaj kev tso siab me me, lawv tuaj yeem sib cuag dua, uas txhais tau tias qhov coating tsis ncua tau tom qab muaj kev siv ntau zaus.

Kev puas tsuaj ntawm PVA Molecular Weight rau Tensile thiab Fold Strength

PVA muaj ntau dua PVA tso caij hneev ntau dua, tab sis yuav tsum tau sau tib lub viscosity nyob rau hauv kev siv. Qhov sib txawv me me tshaj plaws tuaj yeem sib cuag zoo thiab muaj zog rau tag nrho cov kev siv coating.

Tus nqi tshawb nrhiav: Cov coatings PVA-Based Ntxiv Zog Kawg Txias Txog 35%

Kev xam pom tias thaum peb ntxig PVA rau hauv cov roj sib xyaw, qhov tsim nyog ntawm kev txuas nrog tuaj yeem tso caij mus li 28 mus ncav cuab 35% kom compared to what we normally see with regular binders. Vim li cas no tau xwm? Nyob zoo, tseem ceeb tshaj plaws yog vim muaj kev sib thooj hydrogen zoo dua thiab tag nrho cov polymer chains kuj ploj tseg. Qhov kev sib txawv no pom tshwm meej tshaj plaws hauv cov khoom siv du recycled paper products uas cov fibers tsis txaus siab nyob ib txhim khuam. Thiab ntawm no muaj ib yam tshwm sim: ntxig ib hlis PVA ntau dua 1% yuav ua rau tus material muaj qhov tsim nyog ntau dua li 4.7%. Tom qab lub sijhawm thawj zaug, qhov no tsis seem zoo li muaj zog heev, tab sis thaum tsim kho rau cov khoom siv uas xav tsum tig txe txe tawm rau kev kuaj mob hauv kev sib dhos, qhov nce tsawg kuj muaj tshua xeeb nyob hauv kev siv hauv cheeb tsam.

Kev lag luam PVA raws li ib qhov cobinder hauv cov kev sau npe sib xyaw

Yuav ua li cas siv PVOH raws li ib qhov cobinder hauv cov roj sib xyaw loog uas muaj txiaj ntsig zoo

Polyvinyl alcohol loss PVOH ua haujlwm zoo tshaj plaws los yogv kev sib txig nrog cov khoom siv rau ntawm daim ntawv. Qhov no txhais tau tias tus kws tsim khoom tuaj yeem sau nqaij li qhov khoom tseem ceeb uas lawv siv los ntawm li 40% thiab tsis txhob xav tau qhov sawv cev zoo loss qhov muaj ob pob uas neeg siv khoom xav tau. Lub teeb meem uas PVOH ua haujlwm zoo dua ib tug lom neej yog vim tias lub kauv ntawm nws cov molekhl. Qhov kev ceev cim no pab tsim cov duab ntau dua thiab nyob deb dua rau cov kab ntsug hauv kev kho kom nruab ntej, thaum twg kuj tswj xyuas kom kev tsim kho ua haujlwm yooj yim. Thiab no yog ib qhov zoo dua li kev sib txig nrog lwm yam khoom cobinders uas PVOH tsis tas yuav xav tau cov ammonia solutions los dissolution, uas pab tso kom kev mixed thiab kev nruab ntej yooj yim dua rau cov neeg tsim kho hauv hnub ntu siab.

Kev raug zoo ntawm polyvinyl alcohol nrog latex thiab starch binders

PVOH cov chaw muaj hydroxyl tseem ceeb rau kev sib xyeej nrog cov khaub ncaws tsim los yog tsim los ntawm lub neej. Thaum sib sau nrog latex, nws txhim kho kev nyuaj siab hauv dej thiab kom meej meej. Hauv cov chaw siv starch, PVOH txhim kho kev tso caij rwb zoo li thiab kev sib xws ntawm kev ntaus nrig los ntawm kev txhim kho kev sib thooj rwb hydrogen.

Daim duab pav: Txhim kho kev sib xyeej ntawm daim ntaus siv PVOH-latex

Nyob rau hlis 2024, ib qhov kev sim los ntawm ib tus neeg tsim khoom tsim nyog tau npog 30% latex los ntawm PVOH hauv daim ntaus tsim nyog. Qhov kho tshiab no tau txhim kho 18% hauv kev nyuaj siab hauv dej thaum twb kom meej dua $12/ton. Qhov kev sib pab no tuaj yeem los ntawm PVOH uas tuaj yeem sib thooj nrog latex thiab cellulose fibers los ntawm kev sib koom tes.

Siv cov lej uas tsim nyog rau PVOH thiab latex kom muaj kev lag luam zoo tagnrho

Yog koj xav siv PVOH, yuav tsum npaj nws ntawm 10–25% ntawm tag nrho cov binder solids, txhaws los ntawm qhov chaw siv thiab kev sib poob. Ntau timsim tau pom tias siv 17% PVOH thiab 83% latex yog qhov zoo tshaj plaws, ua rau nws tsis yooj yim khi (∙94 IGT points) thiab tsis muaj nuj nqi ntau. Yog tias PVOH siab dua 30%, yuav tsum siv cov khoom pab kho kev sib hloov kom tsis pub cuam tshwv.

Cov lus nug siv los npaj cov khoom siv PVA uas zoo

Txoj cai zoo tshaj rau kev sib tsoov polyvinyl alcohol rau hauv systems uas muaj dej

Muab PVA mus ntsuab rau hauv dej uo (40–50°C) ua vor, tom qab ntawd nce zog tso tseg mus rau 400–600 RPM kom muaj kev sib tsoov zoo. Thaum npaj PVA nyob rau 10–15% concentration, yuav pab kom tsis muaj kab nrov thiab tso zog viscosity nyer rau saum 500 mPa·s, raws li cov kev sim npaj khoom tau pom.

Kev sib txawv ntawm PVA degree of hydrolysis rau kev siv coating rheology

Qhov sib txawv ntawm hydrolysis feem ntau txiav txim siab viscosity thiab kev siv:

Ntau dua qhov chaw hydrolysis (>95%) txhim kho kev tiv thaiv dej, tab sis yuav tsum muaj kev coj thiaj kom meej meej hauv qhov sib txawv kub.

Kev xav txog teeb li cas thiab pH hauv PVA siv

Tswj xyuas tus nqi kub ntawm 25–40°C hauv qhov sib txawv; yog tias kub dua 50°C yuav pheej tshuaj ntau dua 12–18% ib teev. Rau kev sib xyuas hydrogen zoo tshaj plaws, tswj xyuas pH nyob rau sab laug (6–8). Qhov chaw acid (<4.5) yuav ua rau PVA cov hauv qab hydroxyl phom los, feem ntau tsis tuaj yeem sib ntxiv ntau dua 40%.

Tsis txhob mus kawm qhov tsis raug hauv kev siv poly(vinyl alcohol) (PVA)

Txhob ntxiv duab PVA nrog rau hauv qhov sib cuag uas kua tag nrho—nrhiav nrog rau 10% ntawm qhov ntau ntawm dej tag nrho ua ntej. Ntxiv nrog rau 15–20 feeb los cawm 65% qhov sib txawv ntawm gel particle kom tsis pub ntau dua kev ntxiv tag nrho. Hauv qhov kev sib cuag ntau binder, nrhiav PVA tom qab starch tab sis ua vor dua latex kom tiv thaiv kev sib cuag zoo ib yam thiab kom paub tseeb tias film tsim tau zoo.

Siv PVA Los Nrhiav Tau Qhov Zoo Tshaj Plaws Rau Kev Siv Pigment Thiab Qhob Chaw

PVOH Yuav Puaj Li Tsawg Txoj Ceev Rau Kev Sib Tham Thiab Kawm ntawv ntawm Pigment

Polyvinyl alcohol, uas tso thaum twg hu ua PVOH, ua haujlwm zoo tshaj khi rau kev sib tham pigment vim nws tsim thiab piv rau ib qho khoom siv los pheej. Qhov tseem ceeb tshaj plaws ntawm PVA yog nws tus cwj pwm tso siab rau tiam tiam, uas pab tiv thaiv cov khoom los ntawm kev sib txuas nyob rau hauv cov khoom xws li kaolin clay thiab calcium carbonate. Cov hydrogen bond uas tsim tseg ntawm cov khoom no tuaj yeem tiv thaiv kev sib cuag nyob rau hauv qhob chaw. Thaum no tshwm sim, daim duab kuaj pom zoo dua thiab kev sau npe muaj kev raug zoo dua ntawm txhua hom chaw. Lub tshawb fwm pom tias thaum cov kws tsim khoom hloov pauv PVA nrog qhov xws li, lawv tuaj yeem nthuav taus ntau dua li 22% dhau ntawm starch yam ntxwv. Qhov kev pab ntau no txhais tau tias tsis tas tseg ntau khoom nyob rau hauv lub tsev tsim khoom kom tsim dua tom qab.

Qhov raug tshaj plaws ntawm Pigment rau PVA Ratio rau Qhov Siab Tshaj Plaws ntawm Coating

Pigment rau PVA ratio ntawm 3:1 mus 4:1 muab qhov tsis nyob hlau zoo tshaj plaws ntawm kev dhau los thiab txoj caij nyoog. Ntau dua PVA (>20% dry weight) tuaj yeem cuam tshuaj rau tensile strength tab sis feem ntau tuaj yeem tsis zoo vim nws yaj, thaum li qhov ratio tsuas yog (<2:1) yuav tso cai rau qhov taw tes tsis zoo. Kev xam pom tau hais tias qhov ratio 3.5:1 muab 28% siab dua ntawm Scott Bond scores nrog rau qhov pib, uas thov kom muaj kev sib txuas zoo tshaj rau hauv layer.

Trend: Nano-clay thiab Calcium Carbonate Sib Cuam Txuas nrog PVA

Cov siv nuj tshwj xeeb no nyob hauv kev siv PVA nrog rau nano-clay thiab cov khoom precipitated calcium carbonate (PCC) thaum tsim cov kab uas muaj txoj hlua no. Thaum cov nano-clay tuaj saum npoo los ntawm qhov PVOH siv los tsim txoj hlua, lawv tseem ceev kom txo dej ntsuag tau zoo dua li 40% li ntau. Tom qab no, cov PCC siv nrog PVA tuaj yeem muaj qhij tshaj tawm zoo li 94% ISO, thaum twg kis tau qhov tseem ceev ntawm kev tso tseg. Ntau lub chaw tsim daim ntawv tau hloov mus siv cov kev lag luam no, kho los li 15% ntawm cov khoom ntau yam uas lawv siv. Qhov no tsis yog tsuas yog pab txo nqi dhau mob, tab sis kuj txhawj xeeb rau GREENGUARD uas muaj feem cuam rau dej nyiag hauv tsev uas ntau neeg nyiam.

FAQ

Yuam li cas polyvinyl alcohol zoo rau kev siv ntawv?

Polyvinyl alcohol (PVOH) zoo rau kev siv ntawv los ntawm qhov nws siv tau nrog dej, siv los tsim txoj hlua, thiab muaj kev nyiaj ruaj siab zoo, uas pab txhim khu kev siv thiab txhim khu ntawv.

PVOH sib piv nrog lwm hom binder zoo li starch thiab synthetic latex yuav tau li cas?

PVOH zoo dua hauv kev tso siab rau xim nyiaj thiab kev phem tshuaj tsis ntau, txo li starch thiab muaj qhov chaw nyob zoo dua li synthetic latex, tab sis starch tuaj yeem muaj kev lag luam zoo dua rau kev siv tshwj tsis.

Puas siv PVOH nrog lwm hom binder tau?

Yog, PVOH tuaj yeem siv nrog ob hom binder synthetic thiab bio-based, tiam sis zoo dua hauv kev nyob nrog latex thiab kev tso caij nrog starch.

PVA molecular weight muaj kev pab lub zog ntawm duv li cas?

PVA muaj molecular weight siab tshaj yuav tso kev nyob nrog ntau dua thiab tiam sis kev zog ntawm kev dub thiab kev fold, tab sis yuav tsum coj xyuas kev viscosity meej thaum siv.