[If I had the whole sentence, unless this is a title, I'd probably be able to be more precise.]

When a viscoelastic material is treated so that it starts to deform - during vulcanization - it is 'jerked' (pulled fast and hard), and it will retrun to a more rubbery state.

ballotare v.tr. (sballotare) to toss; to jerk
[source La Biblioteca di Republica's l'Enciclopedia Dizionario di Italian-Inglese]

[in vulcanization work, 'jerk' not 'toss' is used]

jerk n. 1. a quick, sharp, sudden movement 2. v. move or raise with a jerk
[source OED]

This is a property of some non-Newtonian liquids/plasmas.

I translated 'sacco' as 'sack' but usually this is done in a vat (recipiente ampio)

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Note added at 41 mins (2010-07-17 11:49:14 GMT)
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The syntax could be changed to:

nonbonding rubber jerked from the sack - depending on the somplete phrase.

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Note added at 43 mins (2010-07-17 11:51:07 GMT)
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Typos

"...and it will retrun to a more rubbery state." - should be 'return'

"depending on the somplete phrase." - should be 'complete'


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Note added at 1 hr (2010-07-17 12:31:41 GMT)
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Preposition da

The preposition da really has me thinking. Based on context, it could be:

1. ...from the sack;
2. ...at the sack; or
3. ...by the sack.

I obviously went with the more common 'from'.