Static Dissipative Polyurethane Material

Cast polyurethane elastomers are generally thought of as excellent electrical insulators.  The excellent abrasion resistance of polyurethanes is the reason they are generally found in applications such as material handling, where charge accumulation can become an issue.

Applications occasionally require the polyurethane be a non-insulator in order to avoid detrimental or dangerous electrical discharges.

Conductive materials are materials that have a surface resistance of 1 x 10⁵  ohms/square or less.

Static Dissipative materials have a surface resistance of more than 1 x 10⁵ ohms/square but not greater than 1 x 10⁹ ohms/square.

Anti-Static or Resistive materials have a surface resistance of more than 1 x 10⁹ ohms/square but less than 1 x 10¹² ohms/squre.

Insulative materials have a surface resistance of greater than 1 x 10¹²  ohms/square.

1.  Metal salts:  this creates a top surface that attracts moisuture which makes the top surface good, but the interior of the part may not be as conductive.

2.  Carbon Black & Carbon Fiber:  both materials require high loading of the filler and can leave marks.  The anti-static properties can have hot and cold spots throughout the part.

3.  Cataphor:  is a reactive chemical that is limited in what formulations and durometers it can produce.  In addition, it also lowers the physical properties of the urethane.

4.  Carbon Nanotubes:  is a non-reactive material that does not change the physical properties of polyurethane, nor does it mark materials it comes into contact with.  It should also be noted that in most cases, there is an improvement in physical and mechanical properties.  Very small amounts are needed and conductivity is uniform throughout the part, even if it abrades.  This is the process that PSI Urethanes integrates into our formulations.