Know more

Our use of cookies

Cookies are a set of data stored on a user’s device when the user browses a web site. The data is in a file containing an ID number, the name of the server which deposited it and, in some cases, an expiry date. We use cookies to record information about your visit, language of preference, and other parameters on the site in order to optimise your next visit and make the site even more useful to you.

To improve your experience, we use cookies to store certain browsing information and provide secure navigation, and to collect statistics with a view to improve the site’s features. For a complete list of the cookies we use, download “Ghostery”, a free plug-in for browsers which can detect, and, in some cases, block cookies.

Ghostery is available here for free:

You can also visit the CNIL web site for instructions on how to configure your browser to manage cookie storage on your device.

In the case of third-party advertising cookies, you can also visit the following site:, offered by digital advertising professionals within the European Digital Advertising Alliance (EDAA). From the site, you can deny or accept the cookies used by advertising professionals who are members.

It is also possible to block certain third-party cookies directly via publishers:

Cookie type

Means of blocking

Analytical and performance cookies

Google Analytics

Targeted advertising cookies


The following types of cookies may be used on our websites:

Mandatory cookies

Functional cookies

Social media and advertising cookies

These cookies are needed to ensure the proper functioning of the site and cannot be disabled. They help ensure a secure connection and the basic availability of our website.

These cookies allow us to analyse site use in order to measure and optimise performance. They allow us to store your sign-in information and display the different components of our website in a more coherent way.

These cookies are used by advertising agencies such as Google and by social media sites such as LinkedIn and Facebook. Among other things, they allow pages to be shared on social media, the posting of comments, and the publication (on our site or elsewhere) of ads that reflect your centres of interest.

Our EZPublish content management system (CMS) uses CAS and PHP session cookies and the New Relic cookie for monitoring purposes (IP, response times).

These cookies are deleted at the end of the browsing session (when you log off or close your browser window)

Our EZPublish content management system (CMS) uses the XiTi cookie to measure traffic. Our service provider is AT Internet. This company stores data (IPs, date and time of access, length of the visit and pages viewed) for six months.

Our EZPublish content management system (CMS) does not use this type of cookie.

For more information about the cookies we use, contact INRA’s Data Protection Officer by email at or by post at:

24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

Menu Logo Principal Logo BIA

Home page

Flax, an asset for eco-materials

Fibres de lin modifiées mécaniquement : impact des procédés de broyage sur leur morphologie

As part of an international collaboration, we have recently shown the impact of grinding processes on fibre morphology and on the mechanical properties of the composites formed.
The flax stems are a source of fibre. Long fibres are suitable for textiles. Short fibres are incorporated into other polymers to make composites. Short fibres, which are the valorisation of intermediate quality batches, are produced by grinding processes to obtain the desired size for each industrial application. Depending on the parameters of the process used, this grinding also produces a greater or lesser proportion of very fine particles (called 'fines').
As part of an international collaboration, we have recently shown the impact of grinding processes on the morphology of the fibres and the mechanical properties of the composites formed.  Thus, we have shown that 'fines' are 6 times less efficient than calibrated short fibres for the mechanical reinforcement of composites. Thus, the grinding process, which determines the particle size and shape, must be adapted according to the desired use of the short flax fibres (i) for their mechanical reinforcement properties of the composites or (ii) for their economical filling function (in the case of 'fines').
Flax fibres

Mechanically modified flax fibres: impact of grinding processes on their morphology © Inra, Bourmaud/Beaugrand/Mayer-Laigle

In addition, by comparing different grinding processes, we have shown that the grinding of fibres also induces changes in the polysaccharides contained in these fibres. In particular, the content and crystallinity of cellulose is affected by the grinding intensity, opening up new perspectives for the conversion of polysaccharides into bioenergy.
This research opens many perspectives on the understanding of composition-structure-mechanical property relationships. In the future, the investigations will be extended to other biomasses, in particular those of the French hemp industry.

This study was carried out by the INRA BIA and IATE units in collaboration with the University of Southern Brittany - IRDL, INSA Rouen, and the Centre for Natural Material Innovation, University of Cambridge UK.