TECHNICAL DATA SHEET OF A COMPOUND WHAT IS,WHAT REPORTS AND HOW
Technical data sheet (or TDS for short) is the basic, informative document released by manufacturer of a material (whether it is a raw material or a semi-finished product such as a compound, intended as a material composed by a polymeric matrix to which additives and reinforcements of various kinds have been added).
The TDS basically reports the values of a series of properties of a material, described in statistical terms: that is, the reported values are the average values of the properties of the material.
These values are obtained by testing the material (several times, to obtain statistically significant average values) according to international test standards (or methods) (such as ISO and ASTM).
The test methods, as well as the specific test conditions, in case the method admits different ones, as well as, clearly, measurement units must always be indicated to allow understanding how the values have been obtained and to be able to properly compare TDS of different materials or manufacturers.
In fact, based on the application for which the material could be considered and used, a (technical) preselection of the material in general is based exactly on a comparison of TDS of materials from different suppliers.
The properties reported can be of many types
The most common are:
- Physical
- Mechanical
- Thermal (including the fire resistance properties for flame retardant materials)
Depending on material type and its possible applications, some specific properties may be reported (e.g. thermal or electrical conductivity or some mechanical properties, such as impact resistance, evaluated at temperatures below ambient).
The values of the properties, reported on the TDS, being average values, are not to be understood as punctual values, valid for each specific batch of material.
The specific values of some properties, relating to each batch of material, are in fact reported on another document, associated with each individual batch, called Certificate of Analysis (or CoA for short).
In general, the CoA reports the values of the properties that are measured for each single batch of material and which are the most important to define the constancy (quality) and / or processability of the material.
The property values, reported on the TDS, are not even comparable to product specifications: specifications in fact indicate the variability limits of the properties of a material (since each batch is not totally identical to other batches of the same material) that the manufacturer guarantees.
These limits are often also indicated on the CoA to demonstrate the conformity of the single batch of material to the defined specifications.
Currently, a lot of property databases (TDS) of materials from many manufacturers are available on the net, which allow to check and compare the values of the materials of interest.
Some databases can be found at the following links:
www.ulprospector.com (linked to US certification body UL94)
www.campusplastics.com/ the database is also downloadable for offline use with the ability to update it when connected).
www.materialdatacenter.com/ms/
The TDS of a compound, in addition to property values, also reports
- Commercial name of the material
- General description (qualitative) of the material
In general terms there are also:
- indications on the process of transformation and handling of the material
- indications on safety issues with references to the material safety data sheet (or MSDS for short: this is the other basic document concerning safety, which must always be provided by material manufacturer).
Often there are also:
- compliances to specific laws or regulations
. graphs of specific performance (e.g. stress strain graphs for tensile tests conducted at different temperatures).
Many material manufacturers report the TDS data of various products on a single summary document (such as a brochure or product catalogue).
The interpretation of the property values reported on the TDS (and sometimes of the properties themselves) is not always immediate as well as it is not easy to possibly verify them.
In RDLab137 we can support in the interpretation and general evaluation of TDS as well as in the verification of the values of the properties reported on a TDS. We can support also in the determination of properties of specific interest for a material, not reported on the TDS.
Ing. Luca Ciceri - RDLAB137 srl
Last revision: 12/11/2020
