Epoxy Matrix

By using epoxy rather than polyester resin as the matrix in DuFLEX, a reduction of laminate thickness is achieved while improving damage tolerance.  Epoxy exhibits better moisture and fatigue resistance, and has superior strain capabilities which provides DuFLEX laminates with greater impact resistance than polyester / E-glass laminates that are up to 3 times thicker.

Tensile Modulus3.650 MPa(0.53E+6psi)
Tensile Strength83.3 MPa(12,800psi)
Tensile Elongation9.8%
Compressive Strength(yield)98 MPa(14,210psi)
Compressive Strength(ultimate)130 MPa(18,850psi)
Izod Impact0.598 notch

Skin Mechanical Properties

DuFLEX Standard Panel

Skin laminates are constructed using stitched biaxial E-glass manufactured to our exacting specifications.  The material provides excellent properties in both warp and fill directions, surpassing American Bureau of Shipping (ABS) requirement for balanced laminates.

Compared to the ABS minimum tensile strength for basic laminate, DuFLEX skin laminates show far superior performance.

ABS Basic LaminateTensile StrengthTensile Modulus
Warp (0°)124.1 MPa (18,000 psi)6,890 Mpa (1.0E+6 psi)
Fill (90°)99.28 (14,400 psi)6,890 MPa (1.0E+6 psi)
DuFLEX Skin LaminateTensile Strength ASTM D3039Tensile Modulus ASTM D3039
Biaxial-Warp(0°)371.9 MPa (53,900 psi)21.27 GPa (3.08E+6 psi)
Biaxial-Fill(90°)327.6 MPa (47,500 psi)18.22 GPa (2.64E+6 psi)
Laminate thickness0.53mm per 600gsm (0.021* per 18oz)
Fibre fraction62-64% weight fraction
Poisson’s ratio0.10

Compressive values have been extrapolated from sandwich flexural tests (ASTM C-273) conducted at the University of Southampton, UK in which skin bending was negligible.

DuFLEX Skin LaminateCompressive StrengthCompressive Modulus
Biaxial-Warp(0°)293.8 MPa (42,600 psi)21.27 GPa (3.08E+6 psi)
Biaxial-Fill(90°)255.5 MPa (37,000 psi)18.22 GPa (2.64E+6 psi)
DuFLEX Skin LaminateIncrease Over ABS
Biaxial-Warp(0°) Tensile Strength+300%
Biaxial-Fill(90°) Tensile Strength+300%

DuFLEX Strip

A stitched uni-directional is used as the backbone to the DuFLEX strip system.  The ability to place a large percentage of the reinforcement mass during planking has obvious benefits.

Laminate TypeTensile Strength ASTM D3039Tensile Modulus ASTM D3039
Unidirectional @ (0°)585.6 MPa (84,900 psi)34.73 GPa (5.04E + 6 psi)
Unidirectional @ (90°)23.00 MPa (3,330 psi)8.295 GPa (1.20E + 6 psi)
Laminate thickness0.88mm per 800gsm (0.035* per 23.5oz)
Fibre Fraction62-64% weight fraction
Poisson’s ratio0.26


Particularly in strength critical applications the Z-Joint must be given adequate consideration. It can be considered analogous to a weld in aluminium, as a strength reduction exists.

DuFLEX Skin LaminateTensile Strength ASTM D3039Strength Reduction
Biaxial-Warp (0°)298.6 MPa (43,310 psi)19.8%
Biaxial-Fill (90°)262.9 MPa (38,130 psi)19.8%
Unidirectional – Warp (0°)488.6 MPa (70,870 psi)16.6%
Unidirectional – Fill (90°)23.0 MPa (3,330 psi)0.00%

No reduction in modulus was recorded, resulting in continuity of panel stiffness and fairness during formation. The majority of marine applications are stiffness critical and therefore a strength reduction in the laminate due to the joints presence is normally of little consequence. A weft unidirectional tape can be used in situations where strength continuity is desired.