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 71 is a low 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
0.0753 g/cc
0.00272 lb/in_
ASTM D 1622-63
Water Absorption
15.5 %
15.5 %
Equilibrium at 98% RH
Moisture Absorption at Equilibrium
1.2 %
1.2 %
15% RH
Moisture Absorption at Equilibrium
2.4 %
2.4 %
30% RH
Moisture Absorption at Equilibrium
3.6 %
3.6 %
50% RH
Moisture Absorption at Equilibrium
4.3 %
4.3 %
65% RH
Water Absorption at Saturation
16 %
16 %
Volume %; 50 days immersion at 20イ.
Moisture Expansion
Max 3 %
Max 3 %
50 days immersion at 20イ.
Mechanical Properties
Tensile Strength, Ultimate
2.74 MPa
398 psi
ASTM D 638-68
Elongation @ break
4.5 %
4.5 %
ASTM D 638-68
Modulus of Elasticity
0.0903 GPa
13.1 ksi
ASTM D 638-68
Flexural Yield Strength
2.45 MPa
356 psi
ASTM D 790-66
Compressive Yield Strength
1.47 MPa
213 psi
ASTM D 1621-64
Shear Modulus
0.0284 GPa
4.12 ksi
ASTM C 273-61
Shear Modulus
0.0294 GPa
4.27 ksi
ASTM D 2236-69
Shear Strength
1.28 MPa
185 psi
ASTM C 273-61
Electrical Properties
Dielectric Constant
1.08
1.08
2.0 GHz
Dielectric Constant
1.1
1.1
26.0 GHz
Dielectric Constant
1.11
1.11
5.0 GHz
Dielectric Constant
1.13
1.13
10.0 GHz
Dissipation Factor
0.0003
0.0003
2.0 GHz
Dissipation Factor
0.0007
0.0007
5.0 GHz
Dissipation Factor
0.0018
0.0018
10.0 GHz
Dissipation Factor
0.0076
0.0076
26.0 GHz
Surface Resistance
5.5E+12 ohm
5.5E+12 ohm
Thermal Properties
CTE, linear -100イ
30 ｵm/m-イ
16.7 ｵin/in-ェ
CTE, linear 20イ
35 ｵm/m-イ
19.4 ｵin/in-ェ
ASTM D 696-70
Thermal Conductivity
0.03 W/m-K
0.208 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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