Kuraray Poval™ &Exceval™ –Temporary
Binder for Ceramics

Kuraray Poval™ / Exceval™

Temporary
Binder forCeramics
Kuraray Poval™ is used extensively across many ceramics applications ranging
from tiles and pottery to ferrite as a temporary binder of ceramic particles.
Kuraray Poval™ improves the mechanical green strength of green ceramic
bodies so they can pass through the production process easily before sintering without breakage. Kuraray offers “low ash” products to prevent residues
after sintering. Decomposition of Kuraray Poval™ proceeds slowly comparedwith other known binders which helps to prevent sudden generation of decomposition gas.

Kuraray Poval™ – Low Ash gradesViscosity1)

Degree ofNon-volatileAsh2)[mPa•s]hydrolysis [mol%]content [%]content [%]Kuraray Poval™ 5-74 LLA

4.6 - 5.4

72.5 - 74.5

97.5 ± 2.5≤ 0.1

5.0 - 7.0

Kuraray Poval™ 4-88 LA

3.4 - 4.5

86.7 - 88.7

97.5 ± 2.5≤ 0.094.5 - 7.0

Kuraray Poval™ 8-88 LA

7.0 - 9.0

86.7 - 88.7

97.5 ± 2.5≤ 0.094.5 - 7.0

Kuraray Poval™ 4-98 LA

4.0 - 5.0

98.0 - 98.8

97.5 ± 2.5≤ 0.094.5 - 7.0

Kuraray Poval™ 20-98 LA

18.5 - 21.5

98.0 - 98.8

97.5 ± 2.5≤ 0.094.5 - 7.0

Kuraray Poval™ 56-98 LA

52.0 - 60.0

98.0 - 98.8

97.5 ± 2.5≤ 0.094.5 - 7.0

Kuraray Poval™ 28-99 LA

26.0 - 30.0

99.0 - 99.8

97.5 ± 2.5≤ 0.094.5 - 7.0

Grade name1) of a 4 % aqueous solution at 20 °C DIN 53015 / JIS K 6726		2) calculated as Na 2OpHExceval™
for better green strength
Hydrophobically modified polyvinyl alcohol, Exceval™, provides the following
advantages when used as a binder offerrite bodies.
✓ Increased green strength✓ Improved moldability✓ Less crack after sintering which
result in yield improvement

Exceval™ grades for ceramics binderViscosity1)

Degree ofNon-volatileAsh2)[mPa•s]hydrolysis [mol%]content [%]content [%]Exceval™ RS-2117

25.0 - 30.0

97.5 - 99.0

97.5 ± 2.5≤ 0.4

5.0 - 7.0

Exceval™ AQ-4104

3.6 - 4.4

98.0 - 99.0

97.5 ± 2.5≤ 0.4

5.0 - 7.01) of a 4 % aqueous solution at 20 °C DIN 53015 / JIS K 6726		

Exceval™ contains a special hydrophobic group which enables alarger amount to be is adsorbed on ferrite particles compared withconventional polyvinyl alcohols as shown in Fig.1. Such ferrite particles combined with Exceval™/Kuraray Poval™ are usually spraydried and then moulded by dry press techniques. Due to the higher
adsorption of Exceval™ the system provides more uniform particles
which results in better flowability. This better flow is proven by lowerangle of repose as shown in Fig.2. (Repose is the steepest angle ofdescent from the horizontal plane to which a material can be piled
without slumping). Better flow of the ferrite body is a strong advantage in providing better distribution of the particles within the mouldin the dry press process. This allows pressure to be uniformly applied
to the mould preventing cracking after sintering and thus improves
the yield of the production process.

Fig.2 Angle of repose of spraydried ferrite particles
Angle of repose

Exceval™

Kuraray Poval™

pH2) calculated as Na 2OFig. 1 Adsorption of Exceval™ onferrite particles
Exceval™

Kuraray Poval™

6020°C50
Adsorption (mg / 10 g ferrite)

Grade name403020FE3O4/PVOH aq. = 5/50 (w/w)
10005000

10000

Exceval™ or Kuraray Poval™ concentration (ppm)

00.5
Moisture content (%)

1Adding value toyour products –worldwide
Kuraray Poval™, Exceval™, Elvanol™ and Mowiflex™ are the trademarks for polyvinyl alcohols
made by Kuraray. Their key characteristics — outstanding film-forming properties and high binding strength — add real value to your products. Our polymers are water-soluble, highly reactive,crosslinkable and foamable. They have high pigment binding capacity, protective colloid characteristics and thickening effects. The physical and chemical properties of Kuraray Poval™ makeit ideal for a wide variety of applications, ranging from adhesives through paper and ceramics
to packaging films. Many of our polymers are food contact-approved and thus suitable for foodapplications. Ecologically Kuraray Poval™ is advantageous due to its biodegradability and the factthat combustion does not generate residues. It is available in various particle sizes from granules
to fine powders.
Kuraray produces its wide range of Kuraray Poval™ grades in Japan, Singapore, Germany and theUSA. Kuraray’s global production and service network make us your partner of choice for innovative high-quality PVOH resins.
Kuraray – Here to Innovate.

Headquarters
Kuraray Co., Ltd.
Tokiwabashi Tower
2-6-4, Otemachi
Chiyoda-ku
Tokyo, Japan 100-0004
Phone: +81 3 67 01 1000
infopoval.jp@kuraray.com

Kuraray Poval™
product portfolio
Please contact your local
Kuraray office to discuss theright Kuraray product foryour needs.

Kuraray America, Inc.
2625 Bay Area Blvd.,
Suite 600 Houston, TX77058
United States of America
Phone: +1 800 423 9762

Kuraray Asia Pacific Pte., Ltd.
250 North Bridge Road
#10-01/02 Raffles City Tower
Singapore 179101
Phone: +65 6337 4123

info.kuraray-poval@kuraray.com

infopoval.sg@kuraray.com

Kuraray Europe GmbH
Philipp-Reis-Str. 465795 Hattersheim am Main,
Germany
Phone: +49 69 305 85 351

Kuraray China Co., Ltd.
Unit 2207, 2 Grand Gateway
3 Hongqiao Road, Xuhui District,
Shanghai 200030, China
Phone: +86 21 6119 8111

info.eu-poval@kuraray.com

infopoval.cn@kuraray.com

12_2021