Semitron® ESd 225

Semitron® ESd 225 is a static dissipative acetal designed for use where electrical discharge in operation is a problem.  It is commonly used for sensitive electronic components including: integrated circuits, hard disk drives and circuit boards.  It is also an excellent choice for material handling applications, and components in high speed electronic printing and reproducing equipment.

Semitron® ESd 225 is dissipative and electrically stable.  Static electricity is dissipated through this product as readily as it is dissipated along the surface. Semitron® ESd 225 is ideal for fixtures used in the manufacturing of hard disk drives or for handling in-process silicon wafers.  It is tan in color.

Specification Test Value Units
Specific Gravity, 73°F  D792  1.33
Tensile Strength @ Yield, 73°F  D638  5,400 psi
Tensile Modulus of Elasticity, 73°F  D638  200,000 psi
Tensile Elongation (at break), 73°F  D638  15 %
Flexural Strength, 73°F  D790  7,300 psi
Flexural Modulus of Elasticity  D790  220,000 psi
Shear Strength, 73°F  D732  6,000 psi
Compressive Strength – Ultimate psi
Compressive Strength at 2% Deformation psi
Compressive Strength at 10% Deformation  D695  8,000 psi
Deformation Under Load %
Compressive Modulus of Elasticity, 73°F  D695  175,000
Compressive Strength ⊥ to Laminate (Modulus) psi
Compressive Strength ⊥ to Laminate (Yield) psi
Compressive Strength ⊥ to Laminate (Ultimate) psi
Hardness, Durometer (Shore “D” scale)  D2240     –
Hardness, Rockwell (Scale as noted)  D785  M50 (R108) Rockwell M
Izod Impact, Notched @ 73°F  D256 Type “A”  1.5 ft.lbs/in. of notch
Coefficient of Friction (Dry vs Steel) Static  0.30
Coefficient of Friction (Dry vs Steel) Dynamic  PTM55007  0.29
Maximum Static Bearing Load (P)  1,000 psi
Maximum Unlubricated No Load Bearing Velocity (V)  50 ft/minute
Maximum Limiting PV (Unlubricated)  PTM55007  2,000 psi x ft/min.
Wear Factor “K” x 10-10  PTM55010  30 Cubic in.-min/
Sand Wheel Wear/Abrasion Test  50 UHMW=100
Minimum Mating Surface Hardness Rockwell (Brinnell)
Coefficient of Linear Thermal Expansion  E-831 (TMA)  9.3 in/in/°F x 10-5
Coefficient of Thermal Expansion // to Laminates  9.3 in/in/°F x 10-5
Coefficient of Thermal Expansion I to Laminates  9.3 in/in/°F x 10-5
Softening Point °F
Heat Deflection Temperature 264 psi  D648  225 °F
Embrittlement Temperature °F Min.
Continuous Service Temperature in Air  180 °F Max.
Short Term Service Temperature  200 °F Max.
Tg-Glass Transition (Amorphous)  D3418  N/A °F
Melting Point (Crystalline) Peak  D3418  320 °F
Thermal Conductivity  F433     – BTU-in/(hr/ft F)
Dielectric Strength Short Term  D149     – Volts/mil
Surface Resistivity  D257  109 -1010 ohm/cm
Volume Resistivity ohm/cm
Dielectric Constant, 106 Hz  D150  4.31
Dissipation Factor, 106 Hz  D150  .036
Flammability @ 3.1mm(1/8 in.) UL94  UL 94  HB
Arc Resistance seconds
Water Absorption, Immersion 24 Hours  D570 (2)  2.0 %
Water Absorption, Immersion Saturation  D570 (2)  8.0 %
Machinability Rating  1 1=easy, 10=difficult
Rod Diameter Availability (Off the Shelf)  .250-6.0 inches
Sheet Thickness Availability (Off the Shelf)  .250-2.0 inches
Characteristics / Attributes  Static Dissipative / Easily Machined / Wear Resistant