EMKAY PLASTICS LTD
Unit 11 Charles watling Way
Barnard Road
Bowthorpe Business Park
Norwich
Norfolk
NR5 9JH
Tel: +44 (0) 1603 746 000
Fax: +44 (0) 1603 746 001
info@emkayplastics.co.uk
      
Subcategory: Composite Core Material; Polymer; Polymethacrylimide; Thermoset
Material Notes:
ROHACELL 31 is the lowest density grade and a very high strength:weight ratio.
General ROHACELL Information: ROHACELL is a closed-cell rigid expanded plastic material for lightweight sandwich construction. It has excellent mechanical properties, high dimensional stability under heat, solvent resistance and, particularly at low temperature, a low thermal conductivity. The strength and moduli values are the highest for any foamed plastic in its density range. ROHACELL is manufactured by hot forming of methacrylic acid/methacrylonitrile copolymer sheets. During foaming this copolymer is converted to polymethacrylimide.
 
 
Physical Properties
Metric
English
Comments
Density
0.032 g/cc
0.00116 lb/in_
ASTM D 1622-63
Water Absorption
19.5 %
19.5 %
Equilibrium at 98% RH
Moisture Absorption at Equilibrium
1.5 %
1.5 %
15% RH
Moisture Absorption at Equilibrium
2.9 %
2.9 %
30% RH
Moisture Absorption at Equilibrium
4.7 %
4.7 %
50% RH
Moisture Absorption at Equilibrium
6 %
6 %
65% RH
Water Absorption at Saturation
13 %
13 %
Volume %; 50 days immersion at 20イ.
Moisture Expansion
Max 1 %
Max 1 %
50 days immersion at 20イ.
Mechanical Properties
Tensile Strength, Ultimate
0.979 MPa
142 psi
ASTM D 638-68
Elongation @ break
3.5 %
3.5 %
ASTM D 638-68
Modulus of Elasticity
0.0353 GPa
5.12 ksi
ASTM D 638-68
Flexural Yield Strength
0.786 MPa
114 psi
ASTM D 790-66
Compressive Yield Strength
0.393 MPa
57 psi
ASTM D 1621-64
Shear Modulus
0.0128 GPa
1.85 ksi
ASTM C 273-61
Shear Modulus
0.0137 GPa
1.99 ksi
ASTM D 2236-69
Shear Strength
0.393 MPa
57 psi
ASTM C 273-61
Electrical Properties
Dielectric Constant
1.05
1.05
5.0 GHz
Dielectric Constant
1.05
1.05
10.0 GHz
Dielectric Constant
1.06
1.06
26.0 GHz
Dielectric Constant
1.08
1.08
2.0 GHz
Dissipation Factor
0.0001
0.0001
2.0 GHz
Dissipation Factor
0.0004
0.0004
5.0 GHz
Dissipation Factor
0.0008
0.0008
10.0 GHz
Dissipation Factor
0.0034
0.0034
26.0 GHz
Surface Resistance
2E+13 ohm
2E+13 ohm
Thermal Properties
CTE, linear -100イ
25 ｵm/m-イ
13.9 ｵin/in-ェ
CTE, linear 20イ
37 ｵm/m-イ
20.6 ｵin/in-ェ
ASTM D 696-70
Thermal Conductivity
0.031 W/m-K
0.215 BTU-in/hr-ft_-ェ
ASTM C 177-63
Maximum Service Temperature, Air
180 イ
356 ェ
Dimensional stability per DIN 53424
Oxygen Index
19 - 20 %
19 - 20 %
Descriptive Properties
Colour
White
 
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