TR-90™ • THE SPECIAL RESIN

Grilamid TR^® At a Glance

Compared to the known semi-crystalline polyamides, crystallization of the macromolecules is prevented by carefully selecting the monomers, resulting in polymers with amorphous structure which brings a strikingly high level of transparency.

Grilamid TR® grades combine the properties of semi-crystalline polyamides whith those of amorphous polymers in a unique way, currently not achieved by any other trasparent thermo-plastics.

In addition to transparency, other outstanding properties include excellent flexural fatigue strength, which facilitates applications under dynamic loading, and high resistance to chemicals, resulting in low susceptability to stress cracking when in contact with media.

The well known tendency of amorphous thermo plastics to suffer from stress cracking, which is very often at the root of component failure, is a rare phenomenon in the case of Grilamid TR®.

The cycloaliphatic Grilamid TR® grades also offer excellent weathering and UV resistance.

Properties of Grilamid TR^®

• High transparency, even with thick walled components...
• Clear and light inherent colour...
• Resistance to chemicals and stress cracking...
• Very high flexural fatigue strength...
• Very good toughness, even at low temperatures...
• Dimensional stability and dynamic strength...
• Light weight due to low density...
• Low water absorbsion compared to standard polyamides...
• High heat deflection temperature thanks to high glass transition and temperatures...
• Low and mainly isotropic shrinkage...
• Easy processing...
• Easy colourable.

Grilamid TR^® Nomenclature  ●  Classes

The Grilamid TR® product family is composed of amorphous polyamides that differ from each other in their chemical structure.

These are designated with numbers:

In the table below, these sectors are marked in red, as we offer eyewear made from this polymer.

SUB-CLASSES  (Described in detail in the Table below)

Building on these basic polymers, variants have been developed which offer additional properties...

These are designated with letters:

• LX   Improved resistance to alcohol...
• LY   Improved resistance to stress cracking...
• LZ   Improved resistance to stress cracking + high strength...
• LS   Easy demoulding...
• UV   Resistant to weathering...
• NZ    Very high impact strength...
• TRV   Reinforced with fibers, maximum dimentional stability.

Grilamid TR^®  ●  Fatigue strength 

Grilamid TR is characterized by its impressive dynamic loading capacity, which results in extemely high fatigue strength. This unique property allows the use of transparent polymers even in safety critical applications such as water filter housings in sanitary installations.

     Resistance to stress cracking

The formation of stress cracks (also known as environmental stress cracking) is the most common cause of damage to plastic components and is particularly critical in the case of trasparent plastic materials.

It involves the formation of cracks due to the effects of contact media on plastic components under stress. The resistance to stress cracking of trasparent materials is tested using the Bent Strip Method.

The diagram below shows the values of flexural stress, in MPa, at which the stress cracks are visibly apparent after one minute of contact with the liquid medium. Isolated incidents of clouding which occur are not recorded in the diagram.

Thanks to its chemical structure, Grilamid TR exhibits excellent resistance to stress cracking compared with other transparent plastic materials in both polar media (e.g. ethanol, isopropanol) and non-polar media (petrol, hexane).

In order to provide a clear overview, only flexural stress up to 60 MPa is shown, although it may sometimes be considerably higher.