Terms of use

Mechanical characteristics

We have selected and presented the essential mechanical characteristics required by the design offices. The values ​​announced are the result of measurements made according to the standards in ideal laboratory conditions. It will therefore be necessary to apply in use the coefficients of safety of use.

Electrical properties

The electrical properties are related to the molecular structure. The presence of fillers, additives, moisture absorption and morphology in the study of these properties should be taken into account. The complexity of electrical and electromagnetic phenomena will often require real experimentation where the environment of the plastic part will then intervene.

Thermal properties

The thermal properties should rather be called "thermomechanical" because there is a correlation between the mechanical properties and the temperature. A thermoplastic has a glass transition temperature (Tg) where before it behaves like vitreous, rigid and brittle. After this Tg, it goes to the plasto-elastomeric state which causes a drop in mechanical properties to the melting temperature.

A thermostable material (high performance polymer) has a highly rigid molecular structure (binding energy) which results in good heat behavior. Thermosets have a three-dimensional structure and do not have a glass transition, but the drop in mechanical properties will depend on the degradation of the materials at high temperatures.

Chemical components

We have retained the most commonly used chemical components to give you reference points on the behavior of the various plastic families. For safety reasons, full-scale tests (chemical, dilution, temperature, duration) on representative samples will be essential before any qualification.

In addition, for manufacturing tolerances, it is necessary to take into account the NFT 58-000 standard which defines 4 levels: N = normal, R = reduced, P = accuracy and TGP = very high precision (exceptional use). Tolerance levels will be obtained through rigorous monitoring of the manufacturing process, the means used (machines, molds) and the processed material (TP / TD). In addition, it is necessary to take into account the morphology of the part, the shrinkage and post-shrinkage of the retained polymer as well as its moisture uptake.

Chemical components

Chemical components Legend

Finally, the withdrawals indicated are only indicative because they are a function of the position of the injection point and thus of the macromolecular orientation (flow direction and perpendicular direction) but also of the material as a function of its crystallinity, its reinforcements and the thermal of the mold. Exchanges with our engineers are therefore essential to finalize the design of parts that we can validate with our simulation software filling and deformed.


DEMGY provides its information database for information only and subject to use according to its purpose, and declines all responsibility for any errors and misuse of this information. This technical information is indeed likely to be modified, adapted or rectified according to the evolution of the technical means set up for the creation of this database.

Any use of this information by a user therefore remains the sole responsibility of the user and must be confirmed by the competent services of our company which, without this request for verification, can not be held responsible for any errors on our database.