APPLICATION INFORMATION
ADDITIVES FOR CASTING SYSTEMS LIKE CULTURED MARBLE, ONYX ANDPOLYMER CONCRETE BASED ON UNSATURATED POLYESTER

TS-A 1

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Additives for casting systems like cultured marble, onyx and polymer concrete based on unsaturated polyester

Contents
03 Introduction
04 Wetting and dispersing additives
06 Air release additives
07 Coupling agents

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Introduction
Artificial marble (calcium carbonate), onyx (ATH) and polymer concrete(silicate) are some examples of highly filled casting applications based onunsaturated polyester resins, which are differentiated according to thefiller used and the final product manufactured.
The most important properties of the end products can be not only an
attractive appearance but also a high filler content, low porosity, chemical
resistance and good mechanical properties.
This brochure shows you how BYK additives can help optimize theseproperties in your products.

For additional information
on additives and technical
topics please contact us:
Thermosets.BYK@altana.com
NoteTo ensure the best appearance
and full functionality, please
open in Adobe Acrobat.

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Additives for casting systems like cultured marble, onyx and polymer concrete based on unsaturated polyester

Wetting and dispersing additives
BYK-W 908 and BYK-W 909 are designed for cast polymer
application areas of cultured marble, cultured onyx, cultured
granite, solid surface (polyester and acrylic modified polyester)and polymer concrete. BYK-W 908 is the REACH registeredversion of BYK-W 909.
They exhibit high viscosity reducing effects in most highlyfilled compounds containing silica sand, ATH, and calcium
carbonate. Highly-filled application areas, such as polymer
concrete, show better wetting and therefore improved flow(see G. 02).

High viscosity reduction of a 75 %filled cultured marble formulation

By using 1 % BYK-W 908/BYK-W 909 (based on resin) it ispossible to reduce the amount of resin in the formulation
up to 10 %.
The additives are a water-clear liquid and have no effect oncolor, either initially or in the final cured part (see G. 03).
Also BYK-W 985 is suitable for highly-filled casting systems.

Lateral spread of polymer concrete compound

Viscosity (mPa·s)

Without additive

With 1 % BYK-W 908/BYK-W 909

300,000

200,000

100,000

0As measured on Brookfield RVT Viscometer with #4 spindle @ 5 rpm
for 1 minute (25 °C). All additive dosages are based on filler weight.

Control
0.5 % BYK-W 908/BYK-W 909
1.0 % BYK-W 908/BYK-W 909

G. 01

G. 02

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Additives for casting systems like cultured marble, onyx and polymer concrete based on unsaturated polyester

Physical testing
Thermal shock: Two vanity tops – one control without
additive at 26 % resin and another with BYK-W 908/BYK-W 909 at 22 % resin – were thermal shock tested up
to 1500 cycles at a certified lab. The results showed thatthe use of the additives at lower resin content had noeffects on the thermal cycles.
Impact: A certified lab tested the two vanity tops for impact
strength. Both, the control sample and the sample with
BYK-W 908/BYK-W 909, performed the same. This showedthat the use at a lower resin content had no effect on theimpact strength.

Dosage and incorporation
BYK-W 908/BYK-W 909 when used at higher dosages
will maximize the viscosity reduction. This will allow anoptimization of resin/filler ratio leading to lower costs.
The additives can also be used in lower dosages to improve
the filler wet-out, enhance flow and leveling, and help withdeaeration. In order to obtain the maximum air releaseproperties in any casting application and obtain a final partwith improved appearance and strength, it is recommended
that air release additives be used in conjunction with
BYK-W 908/BYK-W 909.

Reactivity: Tests in BYK laboratories have shown that
BYK-W 908 and BYK-W 909 have no effect on reactivityand do not influence gel or cure times.

Delta bOnyx: no color shift due to BYK-W 908/BYK-W 909
108642024 h48 hMeasured with BYK-Gardner color-guide after 24 h and 48 h exposure to UV light. Additive dosage based on filler weight.
Control
0.5 % BYK-W 908/BYK-W 909
1.0 % BYK-W 908/BYK-W 909

G. 03• For systems with up to 75 % filler:
0.5 %–1.5 % based on filler.
• For systems with more than 75 % filler:
1.0 %–2.0 % based on resin.
For best performance the additive should be mixed into theresin prior to the addition of filler.

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Additives for casting systems like cultured marble, onyx and polymer concrete based on unsaturated polyester

Air release additives
BYK-081is a medium active and transparent defoamer and has foodcontact approval.*
BYK-A 550
shows a high effectiveness with minimal haze and isrecommended for use in transparent castings andtranslucent cultured onyx parts and cultured marble.

Additives to improve defoaming
Product

Culturedmarble

Polymer
concrete

Solid surface
polyester

Solid surfaceCultured
polyester w/MMA onyx

Transparentcastings

BYK-081*BYK-A 550
BYK-A 555

BYK-A 555
shows the best air release effect and is recommended foruse in highly-filled casting applications such as cultured
marble and polymer concrete.
BYK-A 515
offers very good air release and is recommended for use
in polyester and acrylic modified polyester solid surface
applications.

BYK-A 515
First recommendation  

Second recommendation* For details on food contact use, please refer to the food contact sheet available on www.byk.com/en/service/regulatory-affairs/food-contact.

T. 02

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Additives for casting systems like cultured marble, onyx and polymer concrete based on unsaturated polyester

Coupling agents

BYK-C 8000 is a polymeric coupling agent that enhances
mechanical properties such as:• flexural strength• tensile strength• compressive strength• abrasion resistance• impact strengthin filled ambient curing resins. As a result, depending onsystems and usage, the thickness of the composites can be
reduced which is economically favorable.

65+ 55 %60+ 45 %

55504540350%

Your benefits• Improving mechanicalstrength up to +50 %• Improving flow properties
by reducing viscosity
up to 50 %• Easy-to-use – just add theadditive to the mixture
prior to curing!

0.1 %

0.2 %

BYK-C 8000 – Dosage (based on silica sand)G. 04

Increase of compressive strengthin polymer concreteStrength (N/mm²)

BYK-C 8000 strengthens the interface between filler
and resin by forming strong chemical bonds, resulting ina remarkable improvement of mechanical properties.

Strength (N/mm²)

Increase of flexural strength in polymer concrete

Filler is usually only mechanically embedded in the resin.
Under stress, filled parts break at the interface filler/resin.

1501301109070500.1 %0%
BYK-C 8000

G. 05

01/2022
TS-A 1BYK-Chemie GmbH
P.O. Box 10 02 4546462 Wesel
GermanyTel +49 281 670-0
Fax +49 281 65735

ADD-MAX®, ADD-VANCE®, ADJUST®, ADVITROL®, ANTI-TERRA®, AQUACER®, AQUAMAT®, AQUATIX®, BENTOLITE®, BYK®, BYK®-DYNWET®,
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info@byk.com
www.byk.com

The information herein is based on our present knowledge and experience. The information merely describes the properties of our products but noguarantee of properties in the legal sense shall be implied. We recommend testing our products as to their suitability for your envisaged purpose
prior to use. No warranties of any kind, either express or implied, including warranties of merchantability or fitness for a particular purpose, are maderegarding any products mentioned herein and data or information set forth, or that such products, data or information may be used without infringing
intellectual property rights of third parties. We reserve the right to make any changes according to technological progress or further developments.
This issue replaces all previous versions.