p.1 

OAR Box 1413 

Prepped by Ollie Stewart 

Document Number: 

68) 11-1-68 

Docket Number: 

A-94-52 

Printed 7/9/2008 3:11:23 PM Sheet 68 of 114 
P.2 

2'f ~V 

RESI N AN D GEL COA T UPDAT E 

Faster, Cleaner, Stronger: 

A Resin and Gel Coat 

Development Update 

New resins may 

move the judgment 

about converting 

from open to closed 

molding toward 

larger parts and 

lower volumes. 

BY JOSEPH S. MCD1RMDTT~) 

C01^P0S.lTES-SERVl€ESXQaM)RAT}0N 

rn i^6\jd\ 

)*4. 

(JU <t%A—*-

T

he spirit behind the ad slogan" "not 

your father's car...," applies to resin 

systems today. Exactly fifty years 

after the commercialization of 

ambient-cure thermosets, the 

technology is still continually 

improving. A survey of producers 

reveals what they perceive the 

current market is looking for and how their 

R&D is responding. Processors who have 

not had a product review with their supplier 

recendy may wish to ask, literally, "what's 

cooking?" And what is not seen might be 

asked for. Here are highlights of recent 

product introdiicrinns and die issues they 

address. This survey focuses on unsaturated 

polyester developments since thermoplastics (June 1997), epoxy pre-pregs (March 

1997), phenolics (February 1997), and 

polyurethane (October 1996) have recendy 

been reviewed in Composites Fabrication. 

Cleaner for Laminators, Affordable for 

Press Molders 

What are the benefits to users of the new 

resin offerings? One major trend, lowpressure molding composite (LPMC), 

appeals to several customer groups. To the 

open-process contact molder requiring 

emission reduction, for either industrial 

hygiene limits or environmental permits, 

enabling resins for low-cost closed molding 

provide an option not available in the past. 

To existing compression molders who need 

a greater cost advantage against competing 

materials, LP.MC offers savings in cagital 

investment and operating p\pgnse 

compared to_pre\Ac 

•^.molding avmpound.-CSMC). 

One approach to low pressure systems 

was pioneered in England and is wellestablished dirough license in the U.S. A 

physical thickener-a solid, crystalline form 

of polyester-melts when processed in a 

heated mold, greatly reducing the viscosity 

ofthe compound. Thus it can be molded at 

lower pressure, but deliver surface finish, 

strength, and thermal requirements 

comparable to SMC. Molding at low 

pressure reduces the cost of the press, gives 

a variety of lower-cost tooling options, and 

saves operating energy costs. The second 

approach to die same benefits is through 

thickener chemistry, either by rheology 

modifiers, or finding ways to reduce filler 

loading through tweaking low profile 

additive chemistry. The result is a lowdensity, light SMC which can be produced 

on a standard compound-making machine. 

Low-density SMC reportedly can be 

molded at pressures as low as 1.4 MPa, 

when the processing temperature is at 

150°C (300°F). Other suppliers recommend a higher pressure, for example 2.1 

MPa, but offering a trade-off in temperature, down to 110 C°(240"F). In general, 

LPMC typically requires one quarter to 

one third the pressure of SMC molding, 

measured in pounds per square inch. This 

means the capability of compression 

molding in 330 ton to 500 ton presses, a 

fraction of the capital expense of milliondollar high-tonnage SMC equipment. The 

LPMC accommodation of aluminum, 

nickel shell, or even high-temperature 

epoxy tooling means a savings of at least 
P.3 

one diird on steel molds for SMC. 

Cost is not the only benefit of 

the new compression molding 

compounds. Part design capabilities are expanded. Kenworth's 

T2000 heavy truck was engineered 

with a roof cap, a 1501b. SMC 

charge with a 36-inch vertical 

draw. The size and configuration of 

this part would not have been 

possible with conventional SMC 

unless die processor upgraded his 

existing press. For resin transfer 

molders stepping up to LPMC, 

elimination of the dry preform, 

consistent Class "A" surface finish, 

and less waste are improvements 

over their present capabilities. For 

open-process molders, LPMC 

offers dramatic improvement in 

cycle time, more consistent quality, 

and less secondary trimming, in 

addition to environmental benefits. 

than one way to 

skin a 

That's why Reichhold Chemicals introduces the best way—Hydrex 100 

the latest innovation in marine laminating resins. When it comes to 

high-performance boats, you, and your 

customers have extremely high standards 

Fortunately, so does Hydrex 100. 

The unique formula of Hydrex 100 offers 

greater impact resistance, higher heat 

distortion temperatures, and unsurpassed 

protection against osmotic blistering. 

Plus, Hydrex 100 is the only 100% vinyl 

ester resin with the handling properties of a 

general purpose polyester or DCPD-blended 

product. It cures fast, works easily into fiberglass, and yields an amazing profile. 

Give us a call for more details on Hydrex 100. 

You'll find its benefits run more than just skin deep 

American Industries . 

uses:Hydrex 100 for the 

hulls on its Sonic USA 

Boats (from skin coat 

up to stringer placement) and on decks. 

tf 

REICHHOLD 

For more information, call us toll-free at 1-888-HYDREX-1 

Circle 4 1 on Reader Service Card 

Come visit us at COMPOSITES '97 at Booth » 313 

Are Environmental Issues 

Driving Resin Development? 

Not entirely, as evident from 

product development discussed 

later. But many in the FRP composites industry are discussing occupational health and environmental 

emission issues from the standpoint 

of resin reformulation. The openprocess molder able to phase out 

spray application and manual rollout of large resin surfaces exposed to 

air flow, will lower worker exposure 

to styrene below 20 parts per 

million (ppm) with ease if he adopts 

closed molding. While 50ppm is die 

current goal of industry's arrangement with OSHA, the threshold 

limit value is lower in most other 

countries, and 20ppm may soon 

appear on North America Material 

Safety Data Sheets as a result of 

recommendations under discussion 

within the American Conference of 

Governmental Industrial 

Hygienists. 

The conversion to closed 

molding would also tower a facility's 

environmental emissions of styrene 

by at least a third and in some cases 

by 90%. This will make Clean Air 

A a permits easier to acquire under 

generic volatile organic compound 

(VOC) control requirements and is 

likely to ease compliance with EPA's 

future Maximum Available Contro' 

Technology (MACT) standard foi 

controlling specific Hazardous Air 

Pollutants (HAPs). Unfortunately, 

conversion to closed molding will 

not be an industry-wide "silver 

bullet" which finishes off regulatory 

mandates. 

Processors and die specifying 

engineers who are their customers 

have many examples of essential 

FRP products which are simply too 

large, have too complex a threedimensional shape, or are not 

required in sufficient volume to 

ever make closed molding feasible. 

Even with the option of resin 

infusion under a vacuum bag, there 

will always be some assignments 

for which spray (or flow-coated) 

application and roll-out will be 

appropriate, according to these 

/producers. Resin suppliers~agree, 

although some mention diat the 

'line" between what is viable for !. 

*.\ closed molding is likely to drift to \ V, 

llarger pans and lower volumes. 'v\ 

All of this means that resin 

2 

10 Composites Fabrication!'August 1997 
r 

!«¥«'* Ji^T'fW fT-i^SWJf^-^'T 

P.4 

Normal gelcoat 

gelcoat droplet 

styrene 

Figure 1. Theory of 

environmental gel 

coat. 

*€> 

producers are working to improve the 

environmental resins diey developed 

to comply widi California Rule 

1162's compliance option of less than 

35% styrene content for general 

purpose resins. But there is a limit to 

taking the styrene out and continuing 

to have a produa which will crosslink into cured durable goods. 

Industry consensus is that the genius 

of composites is their versatility. Thus 

a range of formulations with various 

styrene contents will be needed to 

perform the numerous functions 

required of engineered materials. For 

this reason, resin suppliers may 

undertake to discuss widi EPA the 

implications of defining reinforced 

plastics industry MACT in a way 

similar to controls now in place for 

the paint and coating industry, 

namely by definitions of VOC 

content for broadly generic produas. 

Such an approach would inhibit the 

development of engineered resins in 

future generations, for example in 

civil engineering, energy transmission, and environmentally-desirable 

transportation equipment. 

The result is R&D work on 

resins which will make closed 

molding feasible and lower-emission 

resins for other cases. But there is 

ample evidence of product development in non-environmental areas. 

High productivity characteristics such 

as cure-on-demand resins; fire retardant systems; improved physicals 

such as toughness, weadierability, 

12 Composites Fabrication!'August 1997 

and masked print-dirough-all are still 

imponant in activity. Not to mention 

securing high performance at lower 

cost by substituting more available 

petrochemical building blocks. 

Laminating Resins: First, the 

Physicals 

Recreational boating may be one of 

FRP's most mature markets, but the 

technology never ceases to look for 

improvements. Modified vinylesters 

have been available as laminating 

resins for some time, but at least one 

100% vinylester has been introduced 

diis year. Such a produa is expected 

to have higher heat distortion 

temperature (HDT) and physical 

propenies. It is designed for the 

fabrication of small to large FRP 

structures with high production 

rates at room temperature. 

Boats builders find that such 

resins provide a low water absorption rate, high strength, and an 

improved profile. Benefits of these 

physical propenies include superior 

blister resistance, resistance to 

impact, and minimized printthrough to ensure smooth surfaces. 

Suppliers formulate such a resin 

so that it wets out reinforcements 

rapidly, which translates to 

minimized voids, while allowing 

users to easily maintain resin-toglass ratios. The high HDT allows 

the resin to retain its physical 

propenies at elevated temperatures. 

A stable gel time gives boat3 

builders consistent gel and cures 

with varying levels of catalyst. Since 

it is a thixotropic laminating resin, 

the product resists sagging and 

draining during lay-up. 

The goal in such development i. 

to have die performance of vinylester, 

but the user-friendly propenies of a 

DCPD or general-purpose polyester. 

Those benefits are of interest outside 

the marine molders, so the product 

can be successful in swimming pools 

and spa construction as well, 

Apan from vinylester, the same 

supplier is addressing his customers' 

goal of faster cure time. A nev 

hybrid RTM resin promises greater 

productivity through easier 

pumping, low resistance to flow in 

the mold, and improved wet-out of 

die reinforcement even when filled 

high 60% to 65% levels. 

Fire Resistance a Target 

Improvement in materials for the 

built environment is also a focus oi 

unsaturated polyester resin product 

development. One example is the 

response to fire safety standards for 

mass transit, which tend to be more 

stria in Europe. The first generation 

answer-high filler loadings to "fire 

harden" FRP components-make for 

ven' difficult molding conditions. By 

working widi a new grade of alumina 

trioxide and a new wetting andispersing agent, modified acrylii. 

resins have been formulated to very 

low viscosity, resulting in short cycle 

times for RTM molding. Rail car seat 

shells and interior panels are one 

successful application. The RTM 

resin development was cited for the 

Vinci Award at April's European 

composites trade fair in Paris. 

Combining flame retardance 

with resistance to corrosive environments is still another opportunity. 

Scrubbers, fans, and ductworkexposed to hot, acidic environments 

frequently need replacement, but 

less so as the industrial catalogues 

carr)' a wider range of performance 

FRP equipment. Antimony trioxide 

at 3% to 5% loadings can achieve a 

Class 1 flame spread rating below 15 

on the ASTM E-84 tunnel test, in a 

resin system which maintains high 

mechanical properties, and elongation in the range of 3.6% 

Another supplier has formulated a premium flame-retardant 

corrosion resin for cost savings by 

reducing antimony trioxide content 
P.5 

Products Cited in 

This Article 

CFA's policy of avoiding the appearance of commercial 

endorsement is balanced by recent reader feedback asking for 

supplier contact information. Trade names and suppliers 

listed below are listed in the sequence ofthe article's product 

discussion. Please note that suppliers not mentioned in this 

article may have analogous products and are well worth 

processors' contact. 

• Physically-thickened low pressure molding 

compound, patented as Crystic Impreg from Scott 

Bader Ltd., is available in the U.S. from National 

Composites Inc., South Bend, IN, (219) 289-4589. 

• The thickening agent and rheology modifier 

approach to low pressure SMC is represented by the 

Neulon® LoBarTM technology being developed by 

Union Carbide, Charleston, WV, (304) 747-5152. 

• Careful balance of resin chemistry, thickeners, and 

SMC formulation are behind the SMC LiteTM 

product available from Ashland Composite Polymers, 

Columbus, OH , (614)790-3333. 

• The low-pressure SMC formulated for deep draw 

sections is Ultryl low profile UPR from 

Alpha/Owens Corning, Collierville, TN, (901) 854-

2800. 

• High-performance laminating resin for marine, pool, 

and spa builders: Hydrex® 100, a 100% vinylester 

from Reichhold Chemicals, Inc., Research Triangle 

Park, NC,(919)990-7500. 

• Fire-resistant RTM compound with low viscosity 

incorporates alumina trihydrate designated ON-904 

from Martinswerk, Germany and BEVTC-W 996 

wetting agent from BYK ChemieUSA, (203) 265-

2086, in Ashland'sMODAR 835S resin from 

Ashland Composite Polymers, Columbus, OH , 

(614) 790-3333. : v 

• Flame retardant corrosion resins with 1.5% 

antimony trioxide, DION FR® 9300, are available 

through Reichhold's Corrosion Hotline at (800) 

752-0600. 

• Fast-cure hybrid RTM.resin, Polylite® 31507, are 

available from Reichhold's Closed; Molding team: at 

••: -(SOO). 431*1920:'

:

-

:

--;'.'-'r'Try 

'•''•• Fire retardance and corrosion resistance for hot, 

. ,acidic:enyirbnmentsareE.cprnbined in a new series of 

v resins, led by K299FR, from Alpha/Owens Corning, : 

.

 :Cplli?rvilie,. ^ : : • 

• Low styrene.emission gel Coats with both perfbr- ; .•*' 

mance and productivity advantages are available 

from, arriphg p.therS,: Neste Chemicals, which uses 

Neste LSE Gelcbat.as tirade name. Neste Polyester 

E Inc., Fon Smith, AR,.(501) 646-7865. ' ; 

to 1.5%, but still achieving the 

Class 1 flame spread rating. 

The faster cure objeaive is 

addressed in a new hybrid RTM 

resin. This produa is formulated 

for low viscosity, giving easy 

pumping results and good wetout of reinforcement even when 

filled at 60-65% levels. (See top 

photo onjiageJUGel Coats: Emission 

Reduction Brings Other 

Benefits 

The new generation of low-', 

styrene content gel coats has not; 

experienced sufficient years, of 

commercial use to allow a verdict.; 

But several gel coat formulators. i 

appear on dieir way to proving \ 

. "never say it can't be done." 

Styrene contents as low as 26% of 

the spray applied resin are being 

reponed for standard white gel 

coats. That is down from 37% 

only recendy and potentially a big 

help to processors bumping their 

head on a tons-per-year emission 

ceiling in their clean air permit. 

There is even a performance 

benefit iri better weathering, as 

one would expea, since there is 

less styrene available to cause 

yellowing. There is also better. 

retention of gloss on exposure to 

sunlight. Back in the shop, there 

is a benefit in less shrinkage ofthe 

gel coat layer and probably a 

smoother surface, widi faster cure 

time. Part of the emission reduction by overspray control of low 

emission gel-coat and spray application in general, lies in larger 

particle size (see Figure Ion page 

12). When gel coat is applied in 

many small droplets, the. greater 

surface area increases misting and 

die amount of emission from 

overspray. A larger transfer parti-: 

cie results in less styrene available 

for airborne discharge. 

.:".": Gel coat suppliers secure 

: credibility by not. guaranteeing 

specific emission reduction levels;. 

While reduaions of 30%, 50%, 

and in one case 90% are cited, a 

great pan of emission reduaion 

depends on operator training to 

maximize . transfer -efficiency. 

When good application 

technique is combined with die 

new' coating -materials, required 

film thickness can. be reached 

with less material and expense is 

saved (see "The Spray Operators' 

Anthem," Composites Fabrication, 

May 1997, pp.34-35). 

Gel coat suppliers contactefor. this article reported an 

impression, rather than an 

identifiable new produa series. 

Markets for ultra-clear and 

extremely weather-resistant 

products are showing signs of 

being willing to compensate the 

processor for upgrading raw 

materials. After some years of 

cost-cutting, anecdotes imph. 

there is a return to more aggressive use of neopentyl glycol to 

achieve extreme clarity, ultraviolet light stability, and flexural 

strength. This is good news, one 

source explains, for performance 

-. markets which will need a flexible; tough cosmetic surface to 

harmonize with upgraded 

vinylester laminates. 

That's Not All Folks! 

Stay tuned for new product 

Introductions at COMPOSITES '97 in October 1997. 

Several suppliers told us they are 

planning significant announcements related to dieir technology late this year and others 

• early next year. Gel coat produe 

ers, in particular, are working 

with new base resins and new 

ways to formulate existing 

products. There are also 

.improvements in pigments 

•i waiting to come on stage. In 

\ other cases, the high-margin 

i conditions of a few years ago 

'resulted in basic, research 

j programs with upstream, 

Ichemical intermediate suppliers* and several of these are 

soon to be revealed. A 

Joseph' McDermott,: a 

; Contributing Editor/: to, 

• Composites Fabrication, offers 

independent management 

consulting at Composites Services 

Corporation located in CresskiUj 

New Jersey.