The thimble is used for supporting the sample. So, as long as the sample debris do not flow down the flask you can avoid using the thimble.

That's what I thought me too

Thank you for your answer.

In order to avoid the celulose thimbles we used to use the Gooch Type Filtering Crucibles.

I would keep an eye on the instrument while it works.

If the polymer swells it might clog the overflow tube.

We can use a Soxhlet extractor for a solid polymer without using cellulose extraction thimbles, because this latest is used in the case where samples are in the form of powder

Thank you all for your answers

# Agnieszka Piegat # I didn't understand the idea that you have told me, can you give me a brief description of the mounting system. we put the Gooch Type Filtering Crucibles inside the soxhlet ?

I searched Sigma-Aldrich using the term "thimble", and found extraction thimbles made of glass fibre from Supelco and Whatman.

We regularly used Whatman glass fibre pads for filtering solutions of polyethylene in hot xylene.

Definitely the powdered systems need thimble. During soxhletion powder may break away and removal of each solid sample at the end of experiment is cumbersome task. These difficulties are avoided by using thimbles.

you can use good quality whatmann paper and wrap you polymer in it. Preweigh it and weigh it  (dry) after soxhlet  extraction. This will hold true only if whatmann paper is of good quality and should be of sufficient size to prevent its going into the collecting flask

AS suggested by Lochab, Whatman filter paper is a good alternative. you can fold it and use stapler pins to ensure that polymer stays inside. 

Thank you again for your answers

So I must use Whatman filter paper even if my polymer is solid, because I tried it without thimble and I think it works well

Thank you for all of your answers and good advices. Could you please tell me which type of filter paper would be suitable for a good alternative to cellulose thimbles ? Because I assume that Whatman filter paper Grade 1 (such as https://www.sigmaaldrich.com/catalog/product/ALDRICH/WHA1001917?lang=fr®ion=BE&gclid=EAIaIQobChMIgrC5jJP_4QIVhZztCh0w4QBaEAAYASAAEgKlofD_BwE ) won't be enough ? (thimble thickness is approx. 1,5 mm , and the porosity is different...).

Many thanks !