Friday, March 31, 2006 Radiation treatment of engineering plastics Steritech has been exploring the concept of using Gamma Irradiation to upgrade the properties of engineering plastics.
There are many potential benefits of Gamma Irradiation for plastics -mainly nylons.
Here is some information on our project:
*Radiation crosslinkable Polyamides* Crosslinking booster masterbatches are available for PA6, PA6.6, PA11, PA12 Stabiliser masterbatch tailored for radiation crosslinking -UL listing of materials with RTI Elec. up to 150°C -Best HWI (hot wire ignition) values of all non-fire-retardant-modified PA grades, i.e. maximum fire resistance -Dramatic improvement in chemical resistance -Elimination of stress crack sensitivity, e.g. to zinc chloride
*Radiation crosslinking can improve* -Heat Deflection Temperature (HDT) -Mechanical Properties -Thermal Properties -Tracking Resistance -Chemical Resistance
*Improvements in Mechanical Properties* Radiation crosslinking can confer on certain plastics (PA, PE, but not PBT for example) improved mechanical characteristics, without any dimensional change. The following changes can thus be observed: -increasing hardness -increasing stress at break and increasing modulus -improved impact resistance -improved creep resistance -improved resistance to stress cracking and to abrasion
*Improvements in Thermal Properties* Of all properties, the thermal properties are affected most strongly after radiation crosslinking. In particular, significant improvements can be observed in: -dimensional stability (in all cases) -heat distortion temperature (HDT) -creep -glow wire resistance -flame resistance
*Improvements in Chemical Properties* Generally, radiation crosslinked plastics present an improved resistance to: -their usual solvents (for example, acids in the case of polyamids, organic derivates in the case of polyethylene or elastomers) -hydrolysis resistance (in the case of polyamides 6 and 6-6, for example) and to chemical aggressive agents, like salt haze, grease, oil, for example less swelling and dimensional change.
*Additional Advantages* -ionizing radiation can crosslink finished parts through their thickness processing without depalletizing (ie. performed directly in complete pallets or big bags -lends itself to mass production
