Table Of ContentGlass Science and Technology 6
The Manufacturing Technology
of Continuous Glass Fibres
Third, completely revised edition
K.L. LOEWENSTEIN, B.Sc., Ph.D., F.S.G.T.
Director, K.L. Loewenstein Ltd., CamberJey, Surrey, U.K.
ELSEVIER
Amsterdam - London - New York - Tokyo 1993
GLASS SCIENCE AND TECHNOLOGY
Volume 1. J. Stanek, Electric Melting at Glass
Volume 2. C.R. Bamford, Colour Generation and Control in Glass
Volume 3. H. Rawson, Properties and Applications of Glass
Volume 4. J. Hlavac, The Technology of Glass and Ceramics: An Introduction
Volume 5. I. Fanderlik, Optical Properties of Glass
Volume 6. K.L. Loewenstein, The Manufacturing TechnologyotContinuous Glass
Fibres
Volume 7. M.B. Volt, Chemical Approach to Glass
Volume 8. Z. Strnad, Glass-Ceramic Materials
Volume 9. M.B. Volf, Mathematical Approach to Glass
Volume 10. M.B. Volt, Technical Approach to Glass
Volume 11. I. Fanderlik, Silica Glass and its Application
Volume 12. J. Menbk, Strength and Fracture of Glass and Ceramics
ELSEVIER SCIENCE PUBLISHERS B.V.
Sara Burgerhartstraat 25
p.a. Box 211, 1000AE Amsterdam, The Netherlands
Library of Congress Cataloging-in·Publication Data
Loewenstein, K.L. (Klaus Leopold), 1923-
The manufacturing technology of continuous glass fibres /
K.L. Loewenstein. - 3rd. completely rev. ed.
p. cm. - (Glass science andtechnology: 6)
Includesbibliographical references and index.
ISBN 0-444-89346-6
1. Glassfibers. I. Title. 11. Series.
TP860.5.L6 1993
666'.157-dc20 92-39909
CIP
ISBN: 0 444 89346 6
©
1993, Elsevier Science Publishers B.V. All rights reserved
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._-_...__._-------._-~------._------
Preface to the Third Edition
This book clcab with glass fibres \\-hieh, to distinguish thelll from glass \voo!. arc
drawn as CCl1ltilJUOUS straight fihres. They IW1~' clld up ns chopped fihre:-;. may 1)('
chopped ('\TOll during the ntt('ll1wtion process itself hut.. <1:-: far a:-: the fi1H'ri:-;ing
f1lnlacc (bushing) i:-: cOllcC'l'lled (.}W fihre:-; an' drawn c01l1illUOlIsl~' by nl('Cha11ical
aUell1lation. This n'sults ill s1lch fihre:-: being characterised hy llilviug a spC'cific
diameter with ollly slllall variations front it. ,md by bcillg straight. Glass woo!. OIl
the other hand. although made to Cl specific av(~ragC' diallWU\L cOllsists of short
longths of fibre which have a IImch larger range ofdiameters: in additioll. the fi1)l"('S
an' c1lrled ,1l1d twisted m; they nre ronned.
AlthOllgh S01I1(' as]wcts or the 1l1,1I1Uract1lring tecl]]]ologies me silllilm. tll(' fihel'i
sation processes nrc diffcrellt and gOHTll the sLl'lIctll]"(' or t11(' fibres produced. For
co!1tinllolls fibres 1IH' att(\ll1lnlioll is 1I1(\chrlllical ,It (,olllroll('d speC'ds: ror glass wool.
it is by air hlast which ;-]l111S at forming short alld intertwil1(\(] lengths of fihre.
COlltinuolls film's ilre IlS('e! !llainly as rt'illi'Ol'('l'lll('IlI: with resins. t!wnuoplasiics.
hitllllH'n ,me! ("('llll'llt: glass wool is lIsee! rur heal ;-me! sOllnd ilIS1l!Cltioll.
The techllologies COV('rillg the two tyP('S of glass fi],]'(' tlms dil!"er sllflicie!ltl~' th;11
they require Se])arD(e tJ"('DtlllcnL Dnd t!ll' prodllcts llil\"(: separ"1(' Inrlrkt'(s. AllY
fmther refe]'('l1(,(' t.o glass fibrcs ill tbis hook will tlH'j'(\foj'{' imply gLlss fibres of 11J('
('ontillllolls kine!,
Hist()ri('rdl~'. tl1e glnss fibre indllst.ry is Jlilrt of Uw pbs1ics Dlld t('xtil(' indllslri('s,
COlllllH'rciallv. it is Illl\\' rimll,v cS(;lhlis!Jed il]SU ill 11l(\ hllilding r11ld lnmspurt,ltio!l
ml]"('
illdl1stries. Glass {';Ill he (,ollside]"('d ,IS <l rmv IWltlTi,d which. ill (,OlljllIlC! ion
with slIii;ll)]e pbst.ics, is llscd ill ill(' COIlStrllction o!' hO;lls, pmts of ilirnill"l. 1Ilo!or
\'ellicIe COlll])OIl(\Ilt.S. trallsl11ccl1t Dl1d ojl,\(j\[(' mo[ing s![('('1 ,11ld claddillg, hillll11i
1101lS l"O\)lillg 1"('lt, dOllJ('stic hOll.'-;(' roofing ill ~()]"t h i\nH'rica (Sllillgles). I"l)i-l!ll(,d PVC'
floorillg. sl';dS in plIhlic huildings. hllS('S. elc. Dn(' or ihe higges1 US('S is ill prillt('e!
circllil homds. As ,I sll('C('ssor to (I]'(lI)es ,11le! curlnillS glass fihre I"ahrics ,m' IW\\'
11s('d widl'l,\' ill \'(\rtic;l] IOllvers. Tec]lllologic,t!ly. the m,lllllf<lcl1In' of glrlSS Jihn's is
pm! of tll(' glilss industry hilt i.'-; linked dmYllstn',1ll1 to prO("('SSl'S whicll origillrlt('d
ill (he 1('xlile illdl1stry.
~'('ms
'I'll(' lirst. l'ditiOll. p]'('p;ln'd 2() ago. nl;\(le a si,Irl ill 1n'('S('llting (he gbss fibre
JIli\llll[",lc1llrillg pnH'('SS ;IS a hnlllclI or applied .'-;Ci('llC('. Tec]lllic,t! de\'('!()jllll<'IIt SillC('
VI P7'C.face to the Third Edition
then has been very considerable, and the fields of application, despite one or tN"O
setbacks; are increasing.
The industry has become very competitive. It may be a consequence of the need
for secrecy or reduction of expenditure that the number of patents published has
decreased significantly in the last decade: this has made it more difficult for the
outsider to keep himself informed of the likely trends of technological development.
The lay-out of the book has remained substantic\ll:y lIlH1ltered with the exception
that a short chapter on Health and Safety has been added. I felt that at the end
of the twentieth century no description of technology is complete without also
commenting on Health and Safety, not only for the benefit ofthe personnel involved
in manufacture, but also for the user.
Despite the secrecy surrounding this technology, this book could not have been
written or revised \vithout extensive discussions with many friends in the industry,
both from modern plants using advanced technology, and others. man.v in develop
ing countries, who are struggling to catch up.
I would like to thank individuals and companies who supplied photographs for
reproduction in the text. Thanks also to IV1r. Clifford rvIosey who prepared new
drawings, and the individuals who provided criticism and information for inclusion,
the inventors ofword proCt~ssorsand software without whom I could not. haw cmried
out the revision and, lastly, to the directors of :Messrs. Kabcl Teknik LtcL Altoll,
Hampshire, U.K., for providing me witb office space and conmll1nicatioll facilities.
K.L. Loewcnstcin
Cambcrlcy. S'Il'l'rcy
GU15 2BS. u.f{.
Contents
PREFACE V
CONTENTS VII
GLOSSARY OF GLASS FIBRE TERMS XI
SHORT CONVERSION TABLE XIV
CHAPTER 1. A BRIEF HISTORY 1
CHAPTER 2. GLASS AND GLASS FIBRES 5
References 12
CHAPTER 3. THE PRODUCTS AND THE MANUFACTURING PROCESSES 13
3.1. The products 13
3.1.1. Mats 13
3.1.2. Rovings 14
3.1.3. Roving cloth or woven roving fabrics 18
3.1.4. Combination mats 19
3.1.5. Yarns 19
3.1.6. Chopped strands 20
3.1.7. Milled fibres 21
3.2. An outline of the manufacturing processes 22
References 27
CHAPTER 4. GLASS MANUFACTURE 29
4.1. General
29
4.2. Glass compositions
30
4.3. Selection of raw materials for E glass manufacture
36
4.3.1. Raw material for introducing silica (Si02) 37
vii
vm Contents
4.3.2. Raw materials for introducing alumina (Ab03) 37
4.3.3. Raw materials for introducing boric oxide (BzO;}) 38
4.3.4. Raw materials for introducing magnesia (MgO) 39
4.3.5. Raw material for introducing calcium oxide (CaO) 40
4.3.6. Raw materials for introducing fluoride (F2) 41
4.3.7. Use ofsodium sulphate 41
4.3.8. Iron oxide (FeZ03) 42
4.3.9. The recycling of waste glass fibre 42
4.4. Handling, weighing, and mixing of raw materials into batch 44
4.5. Production of E glass 47
4.5.1. The characteristics of E glass from the point of view of glass melting 47
4.5.2. Production of E glass in a Unit Melter 48
4.5.3. Design parameters of unit melters for E glass 48
4.5.4. Special features 54
4.5.5. Design factors governing the campaign length of a unit meltcr
for E glass 59
4.5.6. Services and safety 61
4.5.7. Instrument.ation, controls and alarms 70
4.5.8. New developments covering furnaces for the manufactlll'c of E glass 73
4.5.9. Control of atmospheric pollution caused by a unit melior making
E glass 81
4.6. The forehearth or feeder 85
4.6.1. Forehearths for marbles manufacture 85
4.6.2. Forehearths for the direct melt operation 86
4.6.3. Electric heating of fo1'ehearths 101
4.7. Technical control of glass manufacture 103
4.7.1. The commissioning of a unit melter and foreheart.h for the
production of E glass 103
4.7.2. Operating the unit melte1' and forehearth 107
4.7.3. The commissioning and operation of a Pochet IIlcltcr and forcbearth 111
References 113
CHAPTER 5. THE CONVERSION OF GLASS INTO GLASS FIBRE 115
5.1. Marbles; quality control. Sorting and feeding of marbles to bushings 117
5.2. The fibre drawing furnace - the bushing 119
5.2.L The choice of platinum met.als and t.he alloys used 122
5.2.2. The nozzles 126
5.2.3. The construction of a bushing, its assembly and mounting in a frame 135
5.2.4. The design of larger bushings 141
5.2.5. Bushings without nozzles - the 'G' process 145
5.2.6. Nozzle shields and the stability of the fibre forming process 148
5.3. Bushings, heating and associated services, temperature control, and their
start-up and operation 152
5.3.1. Bushing electrics 152
5.3.2. Temperature control and temperature ramps 156
5.3.3. Power and control connections to the bushing, start-up and operat.ion 161
5.3.4. The behaviour of bushings as they age 163
..
Contents IX
5.3.5. The replacement of bushings 163
5.3.6. The repair and construction of bushings in the plant 164
5.4. Fibre size applicators 165
5.4.1. Types of applicators 166
5.5. Water sprays, gathering shoes or combs, and pull-down rollers 172
5.5.1. Water sprays 172
5.5.2. Gathering shoes and combs 173
5.5.3. Pull-down rollers 173
5.6. The mechanical attenuation of fibres: winders and other equipment, their
principles of operation and construction 175
5.6.1. Winders to make cakes 177
5.6.2. The direct-roving winder 190
5.6.3. The direct-wet. chopper 193
5.7. The fibre forming department 194
5.7.1. The geometry of a single bushing position 194
5.7.2. Principles of bushing position geometry 196
5.7.3. Services required in a fibre forming department. 201
5.7.4. Layout of a fibre forming depart.ment. 211
5.8. The handling of fibre cakes or direct-wound rovings 215
5.9. The drying of glass fibre cakes and direct.-wound rovings 219
5.9.1. Dielectric drying 221
5.10. Control of t.he fibre forming process 222
5.10.1. Fibre size - correct. type and quant.ity deposit.ed 223
5.10.2. Water cont.ent 224
5.10.3. Splitting efficiency 225
5.10.4. Cont.rol of tex (or count) 226
5.11. The commissioning of the direct-melt fibre forming process 230
References 234
CHAPTER 6. FIBRE SIZES FOR CONTINUOUS GLASS FlBRES 237
6.1. Fibre sizes for yarns and fabrics 238
6.2. Fibre sizes for glass fibres for the direct reinforcement of polymers 244
6.2.1. Propert.ies impart.ed by the fibre size which form a necessary part.
of the manufacturing process and/or properties of the composites 245
6.2.2. The nat.ure of glass surfaces and the problem of linking glass
fibl'e to polymers 248
6.2.3. Polymers for composites 248
6.2.4. Coupling agents (also known as keying agents) 249
6.2.5. The adhesive and film former 256
6.2.6. Plasticisers 262
6.2.7. Surfactallts 264
6.2.8. Lubricants 264
6.2.9. Emulsifying agents 266
6.2.10. Antistatic agents 266
6.2.11. Miscellaneous other materials 267
6.:3. Formulations of fibre sizes for the reinforceIncnt of plastics, etc. 268
6.3.1. Mixing equipment. 273
x Contents
6.3.2. Some examples of fibre size formulations for glass fibres that will
be chopped in subsequent operations 274
6.3.3. Compatible fibre sizes for yarns 280
6.3.4. Fibre size for t.he protection of E glass in Port.land cement. 281
6.3.5. Examples of fibre sizes for glass fibres which are used in
continuous lengt.hs 28]
6.3.6. Thixot.ropic fibre sizes 284
6.4. Factors governing adjustments to fibre size formulations 285
6.S. Fibre sizes for yarns and cords for the reinforcement. of rubber and clastomers 286
Appendix 6.1. Photometric test method for comparing rates of \Vet-out and
impregnation in resill of different film formers 288
Appendix 6.2. vVet-out test on glass fibre strands 288
References 289
CHAPTER 7. THE CONVERSION OF GLASS FIB11E STRAND INTO
SALEABLE PRODUCTS 293
7.1. The manufacture of chopped strand mats 293
7.1.1. The forming section 295
7.1.2. The biucler application section :304
7.1.3. The oven :306
7.1.4. Finishing section :307
7.1.5. Choppecl strand mat. - some general observatious 308
7.2. The manufacture of continuous stra.nd mat :30\)
7.3. The manufacture of t.issue or rooling mat 311
7.4. The manufacture of nwings 312
7.4.1. Ravings for chopping 317
7.4.2. Ravings for weaving :31D
7.4.3. Ravings for winding and pllltrusion 320
7.4.4. The directly-wound roving ;321
7.5. The manufactnre of woven roving fabric :322
7.6. The manufacture of chopped strands f!'OlIl cakes :325
7.7. The manufacture of yarns 325
7.8. The disposal of waste glass fibre strands and product.s :3:3]
References ;3:31
CHAPTER 8. HEALTH AND SAFETY 33.3
8.1. Health 333
8.2. Safety 337
References :3:38
NAl'vlE INDEX 339
SUBJECT INDEX 343
Glossary of glass fibre terms
'A' glass
Alkali-containg glass composition sometimes used for
fibre manufacture.
ARC or AR glass
Alkali-resistant glass composiban used in the form of
fibres for reinforcing cement.
Base plate see Orifice plate.
Basket
Perforated metal sheet fitted inside bushing to heat
Cl
glass and retain marbles (if used).
Batch
mended mixture of weighed raw materials in propor
tions calculated to give the desired glass composition
after fusion and melting.
Beater
sce Traverse.
Bushing
A small furnace usually made of platinum group metals
used for fiberising molten glass.
Bushing ears sce Bushing terminals.
Bushing frame
A metal frame containing the bushing within its reii'ac
tory insulation.
Bushing lugs sce Bushing terminals.
Bushing terminals
Thick flat pintos attached to the bushing at each end
which act as contact to the electricity supply.
Butterfly sce Traverse.
'C' glass
A chemically-resistant glnss composition used in fibre
mi:Lnufacture.
Primary pa,ckage of glass fibre strand wound onto the
collet of a winder.
Cemfil
Registered trade llame for one type of alkali-resistant
glass fibres used in the reinforcement of cement.
Chopped strands Chopped glass fibre strands.
Xl
