H&K Ltd. TECHNICAL INFORMATIONISSUE 20201102-WI-10-8400A/8430B-20220418-P1/4***** Hei-cast 8400A/8430B *****
1. Overview
Hei-cast 8400A/8430B is a vacuum casting urethane material with the following characteristics.
(1) Due to its hardness of A94, low-density polyethylene and thermoplastic elastomer (olefin, styrene,vinyl chloride, polyester, and polyamide) products can be produced experimentally and applied as
small-lot products.
(2) It has good fluidity and fills the details of the mold with resin.
(3) It contains no plasticizers.

2. Basic characteristics
Item
Appearance

ValuesA Liquid

8400NA

Clear and colorless

8400A

Black

B Liquid 8430B
Product ColorNotes
Polyols(freezing at 15°C or below)

Clear and yellowish

Isocyanatesmilky white/black

Viscosity(mPa･s,25℃)

A Liquid

600

B Liquid

200

Specific gravity(25℃)

A Liquid

1.00

B Liquid

1.20

Mixing ratio

A:B

100:100

By weight

P o t

l i f e25℃

5-6 min.

Resin 100 g

Product specific gravity

25℃

1.15

JIS K-7112

BM type viscometerStandard pycnometer

NOTE) A component freezes at 15°C or below. Warm and melt and shake well before use.
Use of 8400A+8430B is recommended. The addition of 8400 C is not expected.

3. Basic physical properties
ItemValues
Type A

94

Type D

44Tensile strength

MPa

31

Elongation%

270

100% modulus

MPa

14

200% modulus

MPa

22

Tearing strength

N/mm

84

Shrinkage rate%H a r d n e s s

0.7
0.8Notes
JIS K-7215

JIS K-7312
Speed
500 mm/min
In-house standard (thickness 4mm)
Mating thickness
In-housestandard4(thickness 10mm)NOTE) Specimen curing conditions: Mold temperature 60°C 60°C x 60 min + 60°C x 24 h + 25°C x 24 hThis physical property value is representative of our measurements and is not a specification value.
The physical properties of the product vary depending on the shape and molding conditions. Please
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H&K Ltd. TECHNICAL INFORMATIONISSUE 20201102-WI-10-8400A/8430B-20220418-P2/4

use the product after thoroughly checking it.

4. Change in Hardness with TimeDemolding
1 hourHardness
Type A83

1 day2 days

3 days4 days7 days9394

959595NOTE) Specimen curing conditions: Mold temperature 60°C 60°C x 60 min + 25°C x days
This physical property value is representative of our measurements and is not a specification value.
The physical properties of the product vary depending on the shape and molding conditions. Please
use the product after thoroughly checking it.

5. Vacuum casting method(1) Pre-degassing
Perform preliminary degassing in the degassing chamber for about 5 minutes.
Be sure to degas only the amount used.
It is recommended to be degassed at 25 to 35°C of the liquid temperature.
Vacuum degassing at a liquid temperature of 50°C or higher for a long time may cause curing failure
due to volatilization reduction of the active ingredient.
(2) Resin temperature
Keep the liquid temperature at about 25°C to 35°C for both A component and B component during
casting.
If the liquid temperature is high, the pot life will be shortened, and if it is low, it will be longer.
(3) Mold temperature
Keep the silicone mold temperature between 60 and 70°C in advance.
If the mold temperature is low, curing failure may occur, resulting in deterioration of physicalproperties.
Also, the mold temperature affects the dimensions of the product, so please manage it thoroughly.
(4) CastingSet the container so that A component is added to B component.
Stir and defoam the solution B occasionally for about 5 to 10 minutes while the work room isevacuated.
Add A component to B component, stir for 30 to 40 seconds, and quickly pour and leak into thesilicone mold.
(5) Curing conditions
Placing it in a thermostatic chamber of 60-70°C, and then demolding it after 60 minutes of curing.
If necessary, perform secondary curing at 70°C to 80°C for 2 to 3 hours.

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2-19-6 Yanagibashi Taito-ku Tokyo Japan 111-0052 TEL 03-3865-3690 URL: http://www.heisengp.co.jp/

H&K Ltd. TECHNICAL INFORMATIONISSUE 20201102-WI-10-8400A/8430B-20220418-P3/4

6. Vacuum casting flow chart
A Liquid
Resin temperature: 25°C to 35°C

B Liquid
Resin temperature: 25°C to 35°C

Weighing
A:B=100:100

Weighing
A:B=100:100

Pre-degassing
5 min.

Pre-degassing
5 min.

Silicone type
Mold temperature: 60-70°C

Set resin temperature in the vacuum unit: 25 to 35°C
Vacuum degassing for 5 to 10 minutes
Mixing30-40 sec.
casting/leakCuring
60°C x 60 min.
De-molding

7. Handling precautions(1) A component and B component dislike moisture. Do not allow them to come into contact withmoisture for long periods of time, as well as mixtures. Always seal them after use.
(2) If moisture gets into A component, many bubbles will be generated in the cured product.
In such cases, use a separately sold dehydrating agent (DH PASTE).
(3) A component freezes at 15°C or below. Warm at 40 to 50°C and shake well before use.
(4) Vacuum degassing of A component at 50℃ or higher for 20 minutes or more may cause poor curing
due to volatilization of the active ingredient.
(5) B component may react with moisture and become cloudy or hardened.
Do not use the material that are extremely transparent or hardened, as they may deteriorate physicalproperties.
(6) If B component is heated at 50°C or above for a long period of time, it may deteriorate and thecontainer may swell at the internal pressure.
Store the product at room temperature.
8. Safety and health precautions(1)B component contains 1% or more of 4,4'-diphenylmethane diisocyanate. Provide a local exhaust
ventilation system in the work area and be careful of ventilation.
(2)Be careful not to touch the ingredients directly with your hands or skin. In case of contact, wash themoff immediately with soapy water. Leaving it in contact for a long time may cause rash.
(3)If the ingredients get into the eyes, immediately wash the eyes with running water for 15 minutes andconsult an ophthalmologist.
H&K Ltd.

2-19-6 Yanagibashi Taito-ku Tokyo Japan 111-0052 TEL 03-3865-3690 URL: http://www.heisengp.co.jp/

H&K Ltd. TECHNICAL INFORMATIONISSUE 20201102-WI-10-8400A/8430B-20220418-P4/4(4)Provide a duct so that exhaust air from the vacuum pump is discharged outdoors without fail.
9. Fire Defense Law Hazardous Materials Classification
Liquid A: Hazardous substances Class 4 Petroleum Class 3 Hazardous Class III
Liquid B: Hazardous substances Class 4 Petroleum Class 4 Hazardous Class III
10. Packing formLiquid A: 8400 NA, 8400A 1kg royal canLiquid B: 8430B 1 kg royal can

When using our products on the basis of this technical document, it is your company's liability to decide whether this product is suitable for youruse or not after thorough consideration. We are not responsible for the accuracy of this technical material, the results of its use, or the infringementof patents by a third party, as the uses and conditions of use of our products are outside the scope of our control.

H&K Ltd.

2-19-6 Yanagibashi Taito-ku Tokyo Japan 111-0052 TEL 03-3865-3690 URL: http://www.heisengp.co.jp/