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TRICHLOROETHANE
FOR
ELECTRIC POWER UTILITIES
INLAND TECHNOLOGY INCORPORATED 2612 Pacific Hwy. East, Tacoma,. WA 98424
206-922-8932 800-552-3 100
Copyright 1992
INLAND TECH NOLOGY INCORPORATED 261 2 Pacific Highway East, Suite C - Tacoma, WA 9M24 (206) 922-8932
Inland Technology Incorporated is a highly specialized chemical design, manufacturing, and consulting firm, located in Tacoma, Washington.
Inland's principal business is working with large industrial facilities and military clients to design and manufacture less hazardous and less regulated chemicals to replace the hazardous chemicals that are commonly used.
A few past projects and clients are as follows:
U.S. Navy Submarine Base New London, Connecticut Replacement for Methylene Chloride
The Boeing Aircraft Company Seattle, Washington Replacement for M.E.K. and Toluene
Weyerhaeuser Company Federal Way, Washington Replacement for Stoddard Solvent and hazardous waste reduction
Hewlett Packard Fort Collins, Colorado Replacement for Trichloroethylene
San Diego Gas and Electric San Diego California Replacement for 1,1,1 Trichloroethane
- Some current ongoinp proiects are as follows:
Lawrence Livermore National Labs Livermore California Replacement for 1 , 1 , 1 Trichloroethane
The Boeing Military Aircraft Seattle, Washington
t TO DATE, THE SCIENTISTS AND ENGINEERS AT INLAND TECHNOLOGY INC. HAVE DEVELOPED SUCCESSFUL SUBSTITUTES FOR THE FOLLOWING PROBLEM SOLVENTS:
Methylene - Chloride
1,1,1 rrichloroethane
Paint stripping; cold tank soak;
Electronic & electrical
cleaning. Also, metal preparation
Both products are biodegradable; CITREX is not regulated by RCRA or SARA, Title 111.
CITRA SAFE is biodegradable; TEKSOL EP is not regulated by SARA, Title 111. Both are
low VOC and non-chlorinated
CITREX Both aie !oiir 'L'GC. resin rPmOVz! X-CALIBER
CITRA SAFE@ TEKSOL EP
SAFETY PREP CITRA SAFE TEKSOL EP
Surface preparation for
painting or welding
Methyl Ethyl Ketone (MEK)
SAFETY PREP, CITRA SAFE and TEKSOL EP are biodegradable;
all are low VOC's
Toluene / Xylene SAFETY PREP SAFETY PREP, CITRA SAFE and
Surface preparation for
painting or CITRA SAFE TEKSOL EP are biodegradable; welding TEKSOL EP all are low VOC's
Cleaning of fiberglass & epoxy resins
Z-STRIP CITREX Acetone Low VOC's & toxicity; High flash point;
CITREX is biodegradable
[t should be noted that performance needs vary fiom application to application and that none of these substitutes should be expected to be 100% cross over for all applications.
Stoddard Solvent / Mineral Spirits
Trichloroethylene
Also, the chemical behaviors of these substitutes (vapor pressures, dry time, etc.) may differ fiom solvents being replaced which may require changes in work practices in order for substitutes to be successful.
CITRA SAFE TEKSOL EP BREMTHROUGH is free fiom mosl
BREAKTHROUGH regulations, TEKSOL EP is low toxicity CITREX CITREX and CITRA SAFE are biodegradable,
TEKSOL EP low VOC. TEKSOL EP is non-chlorinated CITRA SAFE with low toxicity
Low VOC's; CITRA SAFE is biodegradable; Parts washing & paint clean up
Degreasing & resin removal
INLAND TECHNOLOGY INC. 1-800-552-3100 0 1990
Perchloroethylene
Ketone (MEK) Methyl Ethyl
'ITRA SAFE
BREAKTHROUGH
EP 921
Non-halogenated, low VOC's, easier disposal; low toxicity
Biodegradable, high flash point, low VOC, not regulated by RCRA or SARA Title 111
Degreasing ISO-PREP
Paint Gun Cleanup Vapor
Degreasing; Precision Cleaning Vapor
Degreasing; Precision Cleaning
! Freon 113
-1 1SJ Trichloroethane
'ITRA SAFE OR SKYSOL
WITH ULTRA FILTRATION
'ITRA SAFE OR SKYSOL
WITH ULTRA FILTRATION
CITRA SAFE biodegradable; SKYSOL is not regulated by RCRA or SARA Title 111, Section
3 13, both are low VOC's
CITRA SAFE is biodegradable; SKYSOL is not regulated by RCRA or SARA Title 111,
Section 3 13, both are low VOC's
% 1 CITRA SAFEs
INLAND TECHNOLOGY INCORPORATED 2612 Pacific Highway East, Suite C - Tacoma, WA 98424 (206) 922-8932
Developed for use in the aerospace industry, CITRA SAFE@ is a low-volatility substitute for Methyl Ethyl Ketone (MEK), 1, 1, 1 Trichloroethane, Toluene and blends of MEK and Toluene. CITRA SAFE@ is made especially for surface preparation, general solvent cleaning, and cleaning prior to sealing. It is literally a biodegradable solvent replacement for mineral spirits, thinners, and chlorinated solvents. The use of CITRA SAFE@ reduces risks of hazardous chemical spills, eliminates most hazardous waste disposal costs, and eliminates the health hazards associated with traditional solvents.
CITRA SAFE@ enjoys the following specifications:
BOEING AIRCRAFT COMPANY 0
AIRBUS INDUSTRY 0 SIL Number 20-006 - replace I, 1, 1 Trichloroethane and Methyl Ethyl Ketone for
general cleaning tasks
BAC 5504 cleaning prior to sealing in fuel cells BAC 5000 cleaning prior to general sealing BAC 5750 general solvent cleaning
ROCKETDYNE DIVISION ROCKWELL INT.
ADVANCED TECHNOLOGY LABORATORIES
NORTH ATLANTIC TREATY ORGANIZATION
RE302 10 - 028 cleaning fluid, low vapor pressure aliphatic.
ATL 23 10 - 0624 - 01
ATL 2301 - 0625 - 01
Replace 1, I , 1 Trichloroethane for general solvent cleaning Replace Freon 1 I3/IPA blend for cleaning crystal lattices
NATO 6850-66-137-6036
PHYSICAWCHEMICAL CHARACTERISTICS
Initial Boiling Point: 340F Vapor Pressure “ H g @ 25” C:<2 Vapor Density (air=l):>4 Evaporation Rate (N-Butyl=l): < . 1 Solubility: Not water soluble
Appearance & Odor: Clear with mild citrus odor Specific Gravity (H20=1): .84 Volatile by Volume: 100% Flash Point: 132F PMCC Surface Tension (dynes/cm) = 29.8
San Diego Gas and Electric has, like many utilities, been
engaged in a carefully structured search for a suitable
alternative for 1,1,1 Trichloroethane.
During their search they examined and tested over 24
different proposed substitutes. Only six materials made it
through initial screening to be subjected to the full batter
of tests.
Of the six materials, only one was deemed satisfactory in
terms of volatility, lack of residue, lack of damage to
components, and in terms of environmental and human safety.
The clear winner, according to these tests, was the product
CITRA SAFE, by Inland Technology Incorporated of Tacoma,
Washington.
The results of this testing were shared with the members
of the Western Underground Committee at their January 1991
meeting in Pleasanton, California.
San Diego Gas and Electric's test results are included in
the following pages.
- SDGZ San Diego Gas & Efeciric
INTERNAL CORRESPONDENCE
TO A . M. Archer CAT€ October 17, 1990
FROM
S. W. Hale FILE NO.
GAA 020
SUBJECT
1,1,1 TRICHLOROETHANE ALTERNATIVE SOLVENT S T U D Y
A s part of the Company's ongoing e f f o r t t o minimize the use of l,l,l trichloroethane, the Materials Analysis Laboratory received six samples of materials for evaluation as electrical cleaning solvents. The samples were identified as llTekusolv" , "Voltz" , "Citra-Safe'' , "EPA 2 0 0 0 " , ''Attack1t and "PF 3 2 " . The six samples, along with 1,1,1 trichloroethane (TCA) , were subjected to several tests and the results compared with the trichloroethane's performance. The test regimen is described below.
Test DescriDtion
Nine analyses were selected to evaluate the solvents as candidates for electrical components cleaning materials. Those tests were: Liquid Dielectric Value; Tracking, or Residue Dielectric Value; Flash Point; Volatile Evaporation Rate; Volatile/Non-Volatile Content; Solvent Absorption by PVC Cable Jacket; Effect on Seniconductor Adhesion to Insulation; Effect on Semiconductor Mechanical Strength and Effect on Semiconductor Volume Resistivity. The personnel safety aspect and the . environmental/disposal implications were previously evaluated by the Safety Department and the Environmental Department, respectively. Individual tests are described below with test results summarized in Attachment 1.
The Liquid Dielectric Value test measured the dielectric value of the solvent prior to any significant evaporation of volatiles (dielectric value is a measure of a material's ability to withstand electrical stress). Two electrodes, separated by a space of approximately 1/4", were immersed in approximately lOOml of solvent. until the circuit was completed by current crossing to the opposite electrode.
Increasing voltage was applied to one electrode
~ The Tracking, or Residue Dielectric Value test was performed on the non-volatile portion of the solvent (for this evaluation, non-volatiles were defined as the material remaining after 24 h o u r s of open dish evaporation in a fume hood). Electrodes,
t
A . M . A r c h e r -2 -
approximate ly 2 " a p a r t , w e r e p l a c e d i n t h e r e s i d u e . A s i n
~ t h e p r e v i o u s t e s t , v o l t a g e w a s a p p l i e d u n t i l t h e c i r c u i t was completed. The dielectr ic v a l u e of t h e r e s i d u e was compared t o t h e d i e l e c t r i c v a l u e of t h e d i s h b e f o r e s o l v e n t a d d i t i o n and subsequen t v o l a t i l e e v a p o r a t i o n . F i g u r e 1 is a g raph of t h e t e s t r e s u l t s , w i t h t h e d i e l e c t r i c v a l u e of t h e d i s h b e f o r e s o l v e n t a d d i t i o n normal ized t o 100%.
The Flash Point of a s o l v e n t is a measure of t h e m a t e r i a l ' s t endency t o f o m a flammable m i x t u r e wi th a i r . I t can i n d i c a t e t h e p o s s i b l e p re sence of h i g h l y v o l a t i l e and flainmable m a t e r i a l s i n a r e l a t i v e l y n o n v o l a t i l e o r nonflammable in ix tu re . T h e test w a s p e r f o r n e d by p l a c i n g a measured .anount of s o l v e n t i n a Pensky-Martens Closed Cup tes te r . AS t h e sample w a s h e a t e d , a s m a l l f l ame was. p e r i o d i c a l l y directed i n t o t h e cup. The f l a s h p o i n t was measured a s t h e lowes t t e n p e r a t u r e a t which t h e vapor was i g n i t e d by t h e f lame. F i g u r e 2 is a g r a p h of t h e f l a s h p o i n t t e s t r e s u l t s .
The Volatile Evaporation Rate t e s t w a s per formed by p l a c i n g 4 m l o f s o l v e n t i n a c u l t u r e d i s h , t h e n p l a c i n g t h e d i s h i n a fume hood t o a i d e v a p o r a t i o n . The d i s h was p e r i o d i c a l l y weighed d u r i n g a 24 hour p e r i o d . F i g u r e 3 i l l u s t r a t e s t h e e v a p o r a t i o n r a t e c u r v e s ( t o make t h e g raph
~ more e a s i l y r e a d a b l e , on ly t h e first 2 0 h o u r s o f e v a p o r a t i o n a r e p l o t t e d ) . For comparison, t h e e v a p o r a t i o n c u r v e of water is a l s o i l l u s t r a t e d . I n t h e
Oc tobe r 1 7 , 1 9 9 0
Residue Dielectric (Tracking) Dielectric chanc;e before solvent added
and after 24 hour evaporation period
% c h a w 8 In elelcctflc 1 4 0 % $-- I 100%
60%
60%
4 0 %
20%
0%
I eelore Solt-cnt Added 0 Non-Volatiles 1 b
i oos . no Ch.LF. FIGURE 1
Solvent Flash Point
Temperature ( d e g e e s F ) we:., 7 u h.. 00 1ll.h p e l n l ._ -- --__ _ _ _ 200
160
160 1 4 0
120
IC0 80
60 40
20
0
I
A 1.1. Archer - 3 -
t ab le i n Attachment 1, t h e v o l a t i l e e v a p o r a t i o n r a t e is
- e x p r e s s e d i n grams/hour .
T h e Vo l a t i 1 e /Non-Vo l a t i 1 e Con ten t w a s ineasured by comparing t h e sample weight a t t he s t a r t o f t h e above Evapora t ion R a t e t e s t with t h e we igh t o f t h e sample a t t h e end of t h e 2 4 hour Evaporation R a t e t e s t . ( A s p r e v i o u s l y ment ioned , f o r t h i s e v a l u a t i o n t h e n o n - v o l a t i l e c o n t e n t was d e f i n e d a s t h e i n a t e r i a l r ema in ing a f t e r 2 4 hours of open-d isn e v a p o r a t i o n ) . The we igh t -pe rcen t o f t h e v o l a t i l e s and n o n - v o l a t i l e s w a s t h e n ca lcu la ted . F igure 4 is a g r a p h i l l u s t r a t i n g t h e tes t r e s u l t s .
The s o l v e n t Absorp t ion by Czble J a c k e t w a s measured by p l a c i n g a pre-weighed 1" by. 1" coupon of PVC cable j a c k e t i n a s o l v e n t f o r 2 4 hour s . Upon r emova l , t h e c o u p o n ' s e x t e r i o r w a s d r i e d b e f o r e reweighing. '
The t w o w e i g h t s w e r e t hen coinpared. F i g u r e 5 i l l u s t r a t e s t h e t e s t r e s u l t s .
The E f f e c t on Semiconductor Adhesion w a s d e t e m i n e d by f i rs t measu r ing t h e adhes ion s t r e n g t h t o t h e i n s u l a t i o n on a sample of Ry2 c a b l e . The c a b l e sample w a s t h e n imersed i n a s o l v e n t f o r 1 hour . Fol lowing a 2 4 hour d r y i n g t i m e a t 90°C a n d a cool down period, t h e a d h e s i o n s t r e n g t h w a s a g a i n measured and t h e v a l u e compared t o t h e before- immersion value. F igu re 6 i l l u s t r a t e s the t e s t r e s u l t s .
The E f f e c t on Semiconductor Mechanica l S t r e n g t h w a s measured u s i n g t h e p u l l s t r i p s derived f r o m t h e above
O c t o b e r 1 7 , 1 9 9 0
Non-Volatiles Content 24 Hour Evaporation Time
FIGURE 4
Solvent Absorp t ion by Cable Jacket C h i n s e in Jzcket WeiSht a k e r Immersion
% Increase in J a c k e t IVeight
, 8% 7% 5.6% _____ 6 % 5% 4%
3% 2% 1% 0%
Solvent Effect on Semiconductor Adhesion Adhesion b e f o r e L af ter 1 hour so lvent immersion a n d 24 hour drying per iod
Chance in Aehesion 1 % ) 120% 11 I
100%
80%
60%
4 0 %
20%
1
A . 14- Archer - 4 - October 1 7 , 1990
semiconductor adhes ion t e s t . The semiconductor samples, a s t r i p b e f o r e s o l v e n t immersion and a n o t h e r s t r i p a f t e r d r y i n g , w e r e t es ted on a t e n s i l e t es te r a t a crosshead
- speed of 2 0 inches /minute .
A s o l v e n t ' s E f f e c t on Semiconductor Volume R e s i s t i v i t y w a s measured t o d e t e r m i n e i f t h e c o n d u c t a n c e / r e s i s t a n c e p r o p e r t i e s of t h e semiconductor w e r e changed by s o l v e n t exposure . T h i s was
Solvent Effect on Semicon Resistivity Resist iv i ly change before Q zfter 1 hour solvent immersion and drying s e q u e n c e
% chaw0 In t e ~ l I l l v i l y
_.____.- rn*
- - T U T . k u . 0 1 ~ V o l t ~ Clltr-3.1. EPk lC00 A I I s C k PF 32
eelore lmmerrion 0 M e r lmmeri icn
determined- by ineasuring t h e W O Z * no chaw.;. FIGURE 7 volume r e s i s t i v i t y both b e f o r e and i f t e r s o l v e n t immersion and a 2 4 hour d r y i n g pe r iod a t 9 0 ° C . F i g u r e 7 is a graph of t h e t e s t r e s u l t s , w i t h t h e volume r e s i s t i v i t y of t h e semiconductor b e f o r e s o l v e n t a d d i t i o n normal ized t o 100%.
Summarv
I t shou ld f i r s t be mentioned t h a t none of t h e a l t e r n a t i v e s o l v e n t s t e s t ed is a d i r e c t s u b s t i t u t e f o r i,i,i t r i c h l o r o e t h a n e ( T C A ) . These s o l v e n t s a r e chemica l ly d i f f e r e n t from TCA a n d t h u s o f t e n e x h i b i t d i f f e r e n t p r o p e r t i e s . T h i s s t u d y a t t e m p t e d t o e v a l u a t e t h o s e d i f f e r e n t p r o p e r t i e s i n t h e i r r e l a t i o n t o e lectr ical components c l ean ing .
With one e x c e p t i o n , no s i g n i f i c a n t d i f f e r e n c e s e x i s t between TCA a n d t h e t e s t e d s o l v e n t s from a l i qu id d i e l e c t r i c and r e s i d u e d ie lec t r ic s t a n d p o i n t . T h a t e x c e p t i o n is t h e I1Attack" s o l v e n t ( s e e At tachment 1 and F i g u r e 1). A s can be s e e n t h e Attachment, t h e l i q u i d d ie lectr ic va lue w a s 6KV (approx ima te ly 8 4 % less t h a n TCA) and t h e t r a c k i n g t e s t a l s o exhibited a s i g n i f i c a n t r e d u c t i o n i n d i e l e c t r i c - v a l u e . Because of t h e s e low v a l u e s , it is recommended t h a t t h i s s o l v e n t n o t b e c o n s i d e r e d f o r e lec t r ica l components c l e a n i n g .
None o f t h e s o l v e n t s e x h i b i t e d s i g n i f i c a n t effects on semiconduc to r a d h e s i o n and semiconductor mechan ica l s t r e n g t h . S.?e F i g u r e 6 a n d t h e Attachment.
t w p a r e d t o TCA, which has no f l a s h p o i n t , a l l t h e a l t e r n a t i v e s o l v e n t s e x h i b i t e d a s i g n i f i c a n t r e d u c t i o n i n f l a s h p o i n t t e m p e r a t u r e s (see t h e Attachment and F igure 2 ) . These c o m p a r a t i v e l y low f l a s h p o i n t t empera tu res , i . e . , approximate ly 120°F-1400F, w i l l probably n o t p r e s e n t a s a f e t y problem, however. (The S a f e t y D e p a r t m e n t should be c o n s u l t e d f o r t h e i r f i n a l
I
A. 14. Archer -5- October 18, 1990
approval in this area.)
None of the tested solvents caused significant change in the semiconductor volume resistivity (see Attachment 1 and Figure 7).
There were significant differences displayed in the volatile evaporation rate and the volatile/non-volatile content tests. TCA evaporated relatively quickly and left no measurable residue in this evaluation. The other solvents evaporated much more slowly and left measurable residues. using water as a reference, all the alternative solvents but one'(Citra-Safe) evaporated more slowly than water would when applied to a surface using the test conditions in this evaluation (see Attachment 1, Figures 3 and 4 and the applicable test discussions).
The Disposal Costs comments and Personnel Safety considerations comments in Attachment 1 were derived from evaluations by the Environmental Department and Safety Department, respectively.
Due to its relatively rapid evaporation rate as compared with the other alternative solvents, its low non-volatile content, minimal disposal costs and favorable dielectric quality, it is recommended that Citra-Safe be submitted to the Kearny Electric Shop for their evaluation. The Safety Department, however, should be specifically consulted about the relatively low flash point of this product (125'F in the S D G & E evaluation, 113'F according to the product's Material Safety Data Sheet).
S. W. Hale Extension 4995
Attachment
cc: B. I. Heramb G. E. Lehmann T. M. Reguly
I
ATTACHMENT 1
Liquid Oielectric Value ( K V )
X C h m y e in Dielectric on a Surface Due to Residue (Tracking)
F!ssh Point (degrees F)
':clatite Evaporation Rate ( g r m / h o u r )
Ccn-Volatile Content
Solvent Absorption by Jacket
Eiiec: on Semiconductor Adhesion
Effcct cn Semicocductor Hechanical Strength
if:'ec: on Semiconductor V o l a Resistivity
G i s F s a l Costs as Determined by the Environnenral Departmnc (S/dru-a)
icrscnnel Safety Considerations as determined by the Safety Oepartrrent
T U
>35
-3x
None
20.61
0:
8.2%
-S?:
s s z 5
note
ldrusolv V o l t z Citra-Safe €PA Zoo0 Attack PF 32
>3s 31 3s >35 6
- 13% -2x - 1% -2% '. -38%
135 1LO 125 .1LO 124
0.03 0.08 0.1G 0.09 0.10
65': sox 0.1% c 0% 17x
1.n 1 .F= 6.5% 1.n 5.6%
No significant effect displayed by any solvent
Ro significant effect disp(ayed by any solvent
-7K - OX +11% - 4 x - 4 x
S300 S300 EO.00' S300 so - 00'
note note ' note note note '
>35
+lox
124
0.11
11%
3.2%
- 5 %
S300
note
Since material pixports itself not to contain petroleum products, disposal in local landfill via regular trash cans should suffice for disposal.
' Personnel safety considerations for the tested solvents include the following:
A . For minimum exposure, all personnel required to wear goggles/safety glasses and nitrile gloves.
B. For moderate exposure, all personnel required to use a respirator with organic vapor cartridges, goggles/safety glasses, nitrile gloves, boots and a suit/apron.
C . Due to the relatively rapid evaporation rate of 1,1,1 trichloroethane, moderate to severe exposure levels could occur more quickly than the alternative solvents in the event of a large spill.
D. other controls required are moving air (natural or mechanical), no ignition sources and no contact with oxidizers- Additionally, Voltz and Tekusolv require a storage area with a temperature range of o0 - l o O o F.
No personnel safety information given due to absence of completed Product Approval Request.
The Elastimold Division of Eagle Industries is a manufacturer of
conductive connectors and components for the Electrical Power
Transmission Industry.
Elastimold conducted an extremely careful series of tests on
nearly twelve serious solvent substitution contenders for 1,1,1
Trichloroethane as it is used for component cleaning in their industry.
In all of these rigorous tests, the product identified as product
"B" performed better than any of the non-halogenated materials tested.
The accompanying letter from Elastimold identifies product "B" as CITRA
SAFE by Inland Technology Incorporated, Tacoma, Washington. The actual
test results are included following the letter from Elastimold.
December 18, 1990
Mr. Joe Lucas I n l a n d 2612 P a c i f i c Highway E a s t Tacoma, WA 98424
Oear Joe:
A s you reques ted , I am sending you with t h i s l e t t e r a copy of the p a p e r I de l ivered a t the 1389 TED Meet ing , in Ncw O r l e a n s , on t h e e f f e c t s o f Various s o l v e n t s on connec tor and cable s h i e l d n i a t c r i a l s . For Your information, C i t r a - S a f e i s s o l v e n t “0“ in T d b l e I on t h e second p a g e o f the paper.
A s I mentioned t o y o u , we have s i n c e t e s t e d a d d i t i o n a l s o l v e n t s a n d a r e now in t h e ’ p r o c e s s o f t e s t i n g molded p a r t s w i t h a n u m b e r o f s o l v e n t s . This occasioned my r e q u e s t f o r an a d d i t i o n a l g a l l o n o f C i t r a - S a f e .
I w i l l be p r e s e n t i n g o u r most recent r e s u l t s a t t h e Western Underground Meeting, on J a n u a r y 24 o r 2 5 , I n P leasanton , C a l i f o r n i a .
Thanks f o r your h e l p i n p r o v i d i n g the sample f o r our t e s t s .
S incere ly y o u r s ,
Donald D. Perry Manager Mater ia l S c i e n c e s
A t t ac hmen t
/peh
Presented t o t h e Western Underground Committee January 23-24, 1991
San Ramon, CA
E F F E C T OF DEGREASIt,tG SOLVENTS ON CONDUCTIVE AND SEMICONDUCTIVE
S H I E L D COMPOUNDS, AND ON THE ELECTRICAL P E R F O W C E OF ~ L D E D CONHECTORS
D.D. Perry and J.P. Bolcar E l a s t i m o l d D i v i s i o n , Eagle Industries H a c k e t t s t o w n , N. 3.
Most solvents t h a t a r e e f f e c t i v e i n c leaning and
degreasing cable and molded connectors a l s o tend t o .swel l
the EPDM and EPR rubber used in conductive j acke t s and
shields. (They have l i t t l e e f f e c t on po lye thylene) . This
-.. cwelling ac t ion tends t o d i s rup t the carbon chains t h a t
are respons ib le f o r the conduct ivi ty of t h e s e ma te r i a l s .
The degree t o which the conduct ivi ty i s reduced depends
on severa l f a c t o r s : ( 1 ) the time o f exposure t o the so lven t ,
( 2 ) the v o l a t i l i t y of the solvent , a n d the time e laps ing
a f t e r t he so lvent i s removed.
The
I ,
Solvent
A
B
C
0
E
F
C
H
I
J
Lfmonene
so lvents employed i n t h i s study a r e l i s t e d in Table
TABLE I PROPERTXT~~TOCYCKTS
Speci f fc Sravi ty
1.385
.860
. a 4 1
.760
.a01
N/A
. J J
.82
1.33
0.784
.a40
74-122
171
178
193-221
166
H/A
185-216
127
43
168-193
176
Flash Pt.(OF) Appearance. etc. Description
Hone Water k'hire 1 .l.l-trichlorethane/
150. Ye1 low-dmber ,9OX 1 imonene
122" Water Yhite ESSentfdl1y pure
144" Water Yhite Citrus-petroleum
perch1 oroethyl ene ( 7 5 / 2 S )
1 imonene
solvent blend
205" Orange C i trus-pe troleum
H/A Pale rellow Ci trus-petroleum
156.' Water White Hydrocarbon- terpene
dis tf 1 late
solvent blend
blend
blend 100- 105'". UI ter Yhi te A1 cohol- terpene
none Uater Y h l t e F luorocprbon 1.1.3
147" W a t e r Yhl te
12P' Clear, Water Naturdl terpene
C f t rus -pe t ro 1 em solvent blend
Yhl te
tleveland Open Cup
CI Closed cup (TAG) - Closed cup ( Penns k y - a r tens
- 2 -
along with t h e i r key p r o p e r t i e s and some d e s c r i p t i v e
information. Solvents A - F were included i n t h e o r i g i n a l
study, while G-J were eva lua ted l a t e r . Items of in te res t
a re the bo i l ing po in t s , which r e f l e c t r e l a t i v e v o l a t i l i t i e s ,
and f l a s h po in t s . All the hydrocarbons a r e r a t ed a s
"combustible" m a t e r i a l s ( f l a s h p o i n t s , 100-200°F) a s i s
solvent H . Thus, the low t o x i c i t y and environmental benef i t s
of these s o l v e n t s a r e paid f o r t o a c e r t a i n e x t e n t by the
f ac t t h a t they a r e a l l combustible mater ia l s .
O f the newer so lvents t e s t e d , G and J a r e
c i t rus-petroleum blends, H i s a blend of an alcohol and
a terpene d e r i v a t i v e , and I i s a Freon type
(chlorof luorocarbon) . A I though I i s non-flammable, r e l a t i v e l y
n o n - t o x i c , and a good c leaning so lvent , i t belongs t o t h a t
c l a s s o f m a t e r i a l s , the ~h lo ro f luo roca rbons , t h a t a r e being
heavily taxed and whose manufacture and use i s being phased
out world-wide due t o t h e i r damaging e f f ec t s on the ozone
layer .
6. Conductive S h i e l d Mater ia l s
T h e conduct ive j a c k e t compound used in t h e s l a b t e s t s
was a peroxide-cured EPDM. In add i t ion , two semiconductive
cable s h i e l d m a t e r i a l s were t e s t e d , an EPR j a c k e t from a
15kV 1/0 175 m i l s t randed aluminum cable , and an XLPE j a c k e t
from a s i m i l a r type of cable . These ma te r i a l s had r a t e d
maximum volume res i s t iv i t ies o f 5,000 ohm-cm under ambient
condi t ions .
- 3 -
1
C . Test Procedure
Volume r e s i s t i v i t y measurements were made by the
vol tage /cur ren t method using the arrangement shown i n Figures
1 a n d 2 . Samples o f conductive ma te r i a l s were c u t into
one-inch wide s t r i p s . The EPDM material was 40 mi ls t h i c k ,
while the E P R a n d XLPE cable sh i e lds were between 28 and
34 m i l s . As shown in Figure 2 , a cur ren t of 100 microamperes
was passed between two e lec t rodes cl ipped t o the sample
s t r i p three inches a p a r t . Voltage d r o p a c r o s s the sample
was measured between two f i n e krire e l e c t r o d e s a t t ached t o
the underside o f the sample one inch a p a r t . Volume
r e s i s t i v i t y was ca lcu la ted from the voltage d r o p , the known
c u r r e n t , a n d the sample dimensions. A one square- inch a rea
o f t h e conductive rubber s t r i p was enclosed by a l i q u i d - t i g h t
Teflon dam. Solvent ( 2 . 5 1 ~ 1 ) was placed inside t h e dam c a v i t y
a n d allowed t o remain i n contac t with the rubber f o r 15
minutes . Resistance measurements were made p r i o r t o add i t ion
of t h e s o l v e n t , then a f t e r addi t ion o f the s o l v e n t s , about
every f i v e minutes f o r the f i r s t 15 minutes , a f t e r which
measurement i n t e r v a l s were increased.
... : .&* .. . ‘ .A . ._ ;+-; ;; . . - .- .. - -. .-- -..: . . . . . . .
I I m 1 FIGURE 2
- 4 -
D. Resul ts of Tes t s on Slab Samples
The e f f e c t s of the var ious so lvents on t he connector
j acke t samples and two cable s h i e l d m a t e r i a l s a r e shown
i n Tables I 1 - IV and i n graphical form i n f i g u r e s 3 - 13.
The curves obtained on the EPDl.1 and E P R samples a l l show
the same general f ea tu re s : ( 1 ) an i n i t i a l r i s e i n volume
r e s i s t i v i t y a s the solvent pene t ra tes i n t o the rubber .
This r i s e cont inues even a f t e r removal o f the s o l v e n t ; ( 2 )
a decrease i n volume r e s i s t i v i t y a s the so lven t evapora t e s ,
a n d ( 3 ) a l eve l ing o f f a t some value which v a r i e s with
each type o f so lvent t e s t ed . I n many cases the f i n a l value
i s a t o r below the i n i t i a l level o f r e s i s t i v i t y . The only
except ion t o t h i s behavior was solvent I (Freon type ) which
does n o t swell the rubber a n d t he re fo re has l i t t l e e f f e c t
on i t s volume r e s i s t i v i t y .
I n the case of cross- l inked polyethylene, the so lven t s
g e n e r a l l y had l i t t l e e f f e c t on the volume r e s i s t i v i t y (F igures
11 - 13) . This i s because polyethylene, which i s a
semi-crys ta l 1 i ne polymer, i s not a t tacked by most s o l v e n t s .
Solvent J had somewhat more of an e f f e c t on the X L P E samples
than d i d the o t h e r so lven t s , b u t did not approach the changes
occur r ing w i t h EPDII and EPR.
I f we were t o r a t e these so lvents i n o r d e r o f t h e i r
i n c r e a s i n g e f f ec t s on the conduct iv i ty of the EPDM and E P R
m a t e r i a l s , they would be ranked as follows:
- 5 -
1
(1) Solvent A - Chlorinated so lven t .
T h i s so lvent exhib i ted the lowest maximum volume
r e s i s t i v i t y and more rap id a n d complete recovery o f
c o n d u c t i v i t y .
( 2 ) So lven t s B and C - E s s e n t i a l l y pure limonene.
These so lven t s showed a higher maximum volume r e s i s t i v i t y
and slower recovery, b u t eventua l ly re turned t o l e v e l s
o f conduc t iv i ty approximating the i n i t i a l va lues .
( 3 ) Solven t s 0, E , F , G a n d J - Ci t rus (or o t h e r t e rpene )
- petroleum blends.
These so lven t s showed considerable va r i a t ion i n behavior ,
which probably r e f l e c t s d i f f e rences i n t h e i r composition.
S o l v e n t s E , F and J took longer t o reach t h e i r maximum
r e s i s t i v i t y values and leveled o f f a t cons iderably
above t h e i r i n i t i a l values of volume r e s i s t i v i t y .
I t i s bel ieved t h a t these solvents c o n t a i n h igher
p r o p o r t i o n s o f h i g h bo i l i ng hydrocarbons than do 8 ,
C , 0 and G , so t h a t even a f t e r a cons ide rab le per iod
o f time, some so lvent i s s t i l l re ta ined i n the rubber.
This phase of the i n v e s t i g a t i o n showed the fol lowing:
. All t he so lvents t e s t e d a f fec ted the conduc t iv i ty
o f t h e rubber samples t o some degree, b u t had l i t t l e
e f f e c t on polyethylene.
-6-
I
. The so lvents varied i n the degree t o which they
decreased the conduct iv i ty of the rubber , a s shown
by the r e l a t i v e peak values of volume r e s i s t i v i t y ,
the recovery t imes, and the degree of recovery they
exhib i ted . I t should be noted, however, t h a t a t
no time did any sample become insu la t ing .
. Fina l ly , based on the t e s t s on s lab samples of sh i e ld
ma te r i a l s , i t can be concluded t h a t a l l of these
sol vents a re acceptable f o r use a s
c leaners /degreasers , i f properly used. This means
t h a t the following general procedure should be
followed:
(1) Parts should not be immersed in so lven t , and
so lvent should not be poured ins ide a connector.
( 2 ) Cable and connector i n t e r f a c e s should be cleaned
by wiping with a solvent-soaked c l o t h , then
wiped w i t h a clean c l o t h .
E. Tests on Molded Pa r t s
T h e next phase of the inves t iga t ion involved exposing molded
connec tors t o so lvents a n d eva lua t ing the r e s u l t a n t e f f e c t s
on t h e e l e c t r i c a l performance of the connectors . I t was
decided t o look a t t h ree pr inc ipa l a reas :
. The e f f e c t on the conduct iv i ty o f the s h i e l d ,
.
. The e f f e c t on the loadbreak mechanism.
The e f f e c t on connector i n t e r f aces (e .g . elbow-bushing),
-7-
I
11) Effec t on Shield Conduct iv i ty
T h i s was inves t iga ted using a small Elast imold s p l i c e .
Spl ices were immersed f o r 15 minutes i n the f ive
representa t ive so lvents . The s p l i c e ends were plugged
up t o prevent so ivent from ge t t i ng ins ide t h e Splice.
They were then t e s t ed in accordance with I E E E Standard
592. t4ost of the r e s i s t ance measurements were made
using a d i r e c t r e s i s t ance measurement, r a the r than
the current-vol tage measurement spec i f i ed i n I E E E 592.
This was done because of the complicat ions envisioned
i n clamping f o u r contac ts on the c y l i n d r i c a l s p l i c e .
However, a s a check, i n one case (Solvent B - limonene
type) the measurements were made by both methods.
These r e s u l t s a r e shown i n Table X . Although the r e s u l t s
obtained by the four wire (vol t age -cu r ren t ) method
were lower, the behavior in both cases was s i m i l a r ,
and the 5,000 ohm l i m i t was n o t even approached i n
e i t he r in s t ance . The r e s u l t s f o r the va r ious so lvents
a r e shown in Tables V - X . Although these so lvents
d i d cause a reduct ion in conduct iv i ty , i n no case d i d
the r e s i s t a n c e approach the maximum va lue of 5,000
ohms permit ted by the Standard.
Some p o i n t s of i n t e r e s t regarding these r e s u l t s
a r e as fo l lows:
- 8 -
. I n genera l , t he re was much l e s s of a n e f f e c t
on the sp l i ce sh ie ld t h a n on the 30-40 mil
s lab samples t e s t ed in the f i r s t p a r t of the
s tudy . This i s a t t r i b u t e d t o the much g r e a t e r .. _.
thickness of the sp l ice sh ie ld (approximately
125 m i l s ) . To confirm t h i s , a n experiment
was r u n i n which the s p l i c e was immersed i n
l , l , l - t r ich loroe thane f o r a n h o u r ins tead of
15 minutes. I n t h i s case , the r e s i s t a n c e rose
to 2,210 ohms, compared t o 1,800 ohms, and
i t took much longer to re turn t o the i n i t i a l
level o f 1,210 ohms. (1400 vs. 382 minutes
- Tables V and V I ) .
. Trichloroethane, due t o i t s h i g h v o l a t i l i t y ,
showed the most r a p i d recovery o f conduct iv i ty .
. While the o ther solvents (D, G and H ) did 'no t
increase the res i s tance any more t h a n d i d
t r ich loroe thane , the e f f e c t tended t o l a s t
much longer: 7202 minutes f o r Solvent G , f o r
example, vs. 382 minutes f o r t r i ch lo roe thane .
This r e f l e c t s the presence of h igher bo i l ing
components in these solvents .
( 2 ) F a u l t Current I n i t i a t i o n Test
The second p a r t of the t e s t of solvent e f f e c t s on s p l i c e s
involved measuring the a b i l i t y of the p a r t s t o i n i t i a t e
a f a u l t cur ren t . The r e s u l t s obtained a r e q u i t e
pre l iminary ,but may be ind ica t ive of t r e n d s t h a t a r e
worthy of f u r t h e r inves t iga t ion .
- 9 -
I
Fiv'e solvents were eva lua ted : A , B , D , G , and H. A n
untreated p a r t was used a s a cont ro l . The procedure
used was as fol lows:
Par t s were immersed i n solvent f o r 15 minutes, a s -
described above f o r the res i s tance measurements. The
. t e s t spec-iiiieii was theii iqiped o f f , assembled o n t o c a b l e ,
and subjected t o the f a u l t cur ren t i n i t i a t i o n t e s t .
The c i r c u i t condi t ions used d i f fe red from those specif ied
i n I E E E 592. Phase t o g round voltage was 5.0kV VS.
7.0kV specif ied i n the standard and the time allowed
t o take o u t the breaker was 10 cycles vs. 3 seconds
permitted in the s t a n d a r d . Under these condi t ions,
we obtained the following r e su l t s : .
(1) the untreated s p l i c e i n i t i a t e d a f a u l t twice,
as required,
the t r ich loroe thane soaked sp l i ce f a i l e d t o i n i t i a t e
a f a u l t ,
a l l the o the r s p l i c e s (soaked in flammable so lvents )
caught f i r e in the f i r s t t e s t .
( 2 )
( 3 )
These r e s u l t s cannot be considered t o mean t h a t the
p a r t s e i t h e r passed o r f a i l e d 592, b u t they do ind ica te
t h a t exposing connectors t o solvents i n the manner
described can c r e a t e problems by e i t h e r preventing
i n i t i a t i o n of f a u l t cu r ren t s o r causing p a r t s t o catch
f i r e . We intend t o inves t iga t e this matter f u r t h e r
by studying, f o r example, the e f f e c t of drying time
a f t e r solvent immersion and a l t e r i n g the c i r c u i t
condi t ions.
- 10 -
1 3 ) Effec t on Connector In t e r f aces
To evaluate how rep resen ta t ive so lven t s would a f f e c t
connector i n t e r f aces , 15kV loadbreak e l bows and bushing
i n s e r t s were ha l f submerged i n so lven t s A , B , and D
f o r 15 minutes. Four each of the mating p a r t s were
immersed i n each of the th ree so lven t s , then assembled
a n d tes ted a t 15k\r withstand l e v e l s . Subsequently,
two pa r t s from each so lven t group were t a k e n to
breakdown. The r e s u l t s a r e summarized i n Table X I .
A l l par t s passed b o t h impulse and Hi-Pot Withstand,
so i t i s apparent tha t th is degree of exposure t o solvent
does not have a negative e f f e c t on the i n t e r f a c e s in
terms o f e l e c t r i c a l performance.
r r r SUMMARY AND CONCLUSIONS
. A l l the so lvents t e s t e d , except f o r Solvent I ( a Freon type ) ,
s i g n i f i c a n t l y a f fec ted the conduct iv i ty of EPDM and E P R s l abs ,
b u t bad very l i t t l e e f f e c t on semiconductive X L P E sh ie ld
m a t e r i a l s .
. The s o l v e n t s d i f f e red in the e x t e n t of c o n d u c t i v i t y lo s s they
produced, and in the r a t e and degree of recovery o f conduct iv i ty
e x h i b i t e d a f t e r solvent removal.
. The more v o l a t i l e solvents permitted f a s t e r recovery of
c o n d u c t i v i t y and produced the l e a s t permanent damage t o
c o n d u c t i v i t y of the sh ie ld mater ia l s .
. S p l i c e s immersed i n solvents had r e s i s t a n c e s well below the
p e r m i s s i b l e 5,000 ohm maximum o f I E E E 592.
- 11 -
. Results o f , the n a i l t e s t were inconclusive, b u t indicated
t h a t solvent soaking i s p o t e n t i a l l y hazardous.
. 1 5 k V elbow-bushing assemblies, a f t e r par t s were sepa ra t e ly
exposed t o th ree typical so lven t s , passed b o t h AC Hi-Pot and ~~ ~
Impulse Tests .
. A l l t h e so lvents are considered t o be acceptable when properly
used.
The following should be avoided:
(1) immersing connectors in solvents
( 2 ) pouring solvents inside connectors
( 3 )
.
f a i l i n g t o wipe o f f excess solvent.
I V . PLANNED RlTURE GIORK
. Inves t iga t e e f f e c t of drying time a f t e r soaking on nai l t e s t
r e s u l t s .
. Inves t iga t e e f f e c t of solvents on loadbreak performance
(switching t e s t s ) .
. Perform r e s i s t a n c e measurements on sp l ices immersed i n so lvents ,
then aged f o r 504 hours a t 1 2 1 ° C .
DDP/g h h
- 12 -
TABLE I1 EFFECTS OF SOLVENTS ON VOLUME RESISTIVITY
OF PEROXIDE CURED CONDUCTIVE EPDM
Vol. R e s i s t i v i t y , ohmcm x of Time To Time To S o l v e n t I n i t i a l . -- Max. F i n a l Initial Value Max.Min. F i n a l Hrs. Remarks
A 140
B 235
C 228
D 2 9 1
E . 100
F 239
G 240
H 140
‘I 165
J 196
669
4499
4499
4653
1200
2062
2350
1000
210
21576
167
237
439
599
630
87 5
160
125
148
67 2
119
, 101
193
206
630
366
67
89
’ 90
343
75
120
110
217
900
399
3 10
145
38
420
21 A f t e r s t a n d i n g o v e r n i g h t
44
24 S t i l l d e c r e a s i n g a f t e r 24 hours
50
47 Maximum v a l u e e s t i m a t e d
138
30
2.4 Very l i t t l e e f f ec t
50
. .\ ?\.
..
*** , , .* .*
,
moo1
J.0001
001
01
0001
OOOOI
s a i n u ! ~ 'a w ! l 00 I 0001 01
0001
00001
.. ..
c
F a W a
w a W 05 03
"
N b w 05
w N rQ m
P -J w
i" 0 P
H
N a 03 0
03
0 0
"
N k-J 0 0
-J 0
ul
w ul 0
N W
G)
N W a3 0
w q
0 0 0
u
N -J 0 0
W 0
m
w 0 0
L . 7
(33 w
>
W W 4 cn
cn a3 ul U
.,
e U e ul
n n 0 3
w 0 N
N m
17 w n B -3
m 7 n m 0 -i 0 -rl
. . .
Figure 9 Volume Resistivity vs. Time - EPR Cable Shield
10 100 1000 Time, Minutes
10000
Figure IO Volume Resistivity vs. Time - EPR Cable Shied - Solvent J
1000 - 10 100 lo00
. Time, Minutes
Sol vent
A
B
C
D
E
F
J
TABLE I Y _ _ - - EFFECT OF SOLVENTS ON Y O L U M E RESISTIVITY
OF XLPE CABLE JACKETING
% o f Time To Yo1 ume Resistivity, ohm-m In i t i a1 Max. Final In? t i a l Va lue Max.Min.
1493 3064 1406 94 .2 50
412 602 383 94.9 111
928 1415 783 8 4 . 4 92
431 522 438 101.6 20
422 422 400 94 .8 5
693 699 67 0 96 .7 1 5
774 2 967 1601 * 206 .8 1 4 5 1
Time To Final Hrs.'
23
7 1
23
* 4
7
6
7 2
Figure I I Volume Resistivity vs.:Time - XLPE Cable Shield
I t 0 0
I06 10
-------- ----_ -- ---_ --
I 1 1 1 1 -
1 0 0 0 t o o
Tlms, Mlnutar
Figure 12 Volume Resistivity vs.'Time - XLPE Cable Shield
1 1 I 1 I l l , l I I I * I , l
IO I068 IO0
Time, Minutor
/ OooL
00001
TABLE V
Descri o t ion
I n i t i a l value Af te r immersion Max. value Final value
DescriDtion
I n i t i a l va lue Af t e r immersion Max. value Final value
EFFECT OF 1,1,1 TRICHLOROETHANE ON RESISTANCE OF SPLICE SHIELD -
15 MINUTE IMMERSION
Resistance, ohms
I , 170 1,800 1,800 1,060
TABLE VI
EFFECT OF 1,1,1 TRICHLOROETHANE
1 HOUR IMMERSION ON RESISTANCE OF SPLICE SHIELD -
Resistance, ohms
1,280 2,210 2,210 1,210
Time, min.
0 15 15
382
Time, m i n -
0 60 60
1,400
TABLE VI1
Descr ipt ion
EFFECT OF SOLVENT D ON RESISTANCE OF SPLICE SHIELD - 15 HINUTE IKHERSION
I n i t i a l value Af te r i mme rs i on Max. value F i n a l value
Descr ipt ion
I n i t i a l v a l ue Af te r immersion Max. value F i n a l value
Resistance, ohms
890 1,470 1,880
950
TABLE v r I r
EFFECT OF SOLVENT G ON RESISTANCE OF SPLICE SHIELD - 15 MINUTE IMMERSION
Resistance, ohms
970 1,530 1,610 1,070
Time. min.
0 15 22
9,800
Time. min.
0 15
7,202 28 5
TABLE I X
EFFECT OF SOLVENT H ON RESISTANCE ' OF SPLICE SHIELD - 15 MIHUTE..IH4ERSION
Des c ri p ti on
I n i t i a l value Af te r immersion Max. value F i n a l value
Resistance. ohms
1,450 1,790 1,790 1,080
Time, min .
0 15 15
7,150
.. . .TABLE X
EFFECT OF SOLVENT B ON RESISTANCE OF SPLICE SHIELD - 15 HINUTE ItMERSION
l e s c r i p t i o n Resistance, ohms ( a ) ( b )
[ n i t i a l value 830 6 20 I f t e r i mine r s i on 98 5 ,lax. value 1,605 1,110 Final value 990 87 5
1 , 585
( a ) D i r e c t measurement technique ( b ) Vol tage-cur ren t technique
0 0 15 15 56 3 30
2,837 2,730
. .
Solvent Pa r t #
1
2
3
4
i: 8
B
f 9
TABLE XI
EFFECT OF SOLVENTS OH BUSHIN6/ELBOW
IMPULSE AND AC HI-POT
Impulse w/stand AC Hi-Pot w/stand Impulse AC Hi-Pot 95kV +/- 34kV f o r 1 m i n . Breakdown Breakdown 3 sho t s ea. 3 s h o t s ea.
puncture b u s h i n g i n t e r f a c e
puncture bushing i n t e r f a c e
puncture b u s h i n g i n t e r f a c e
puncture i n t e s t cab le
puncture bushing i n t e r f a c e
0 puncture b u s h i n g i n t e r f a c e
P o l a r i t y
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass/Fai 1 Level Level 1 min.
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
t125, 1 s t shot
-110, 1 s t shot
ti /A
N/A
N/A
N / A
t150, 1 s t shot
-125, 1 s t shot
t130, 2nd shot
t130, 1st shot
Pass N/A
Pass N/A
Failure Mode AC H i Pot
3 puncture bushing i n t e r f a c e
4 puncture bushing i n t e r f a c e
5 puncture b u s h i n g i n t e r f a c e
6 puncture bushing i n t e r f a c e
11 puncture b u s h i n g i n t e r f a c e
12 puncture b u s h i n g i n t e r f a c e
N/A
N/A
70kV. 1 sec.
70kV 5 sec.
70kV 5 sec.
70kV 26 sec.
W A
N/A
N/A
N/A
60kV 15 sec.
60kV 20 sec.