This page contains a Flash digital edition of a book.
advertorial PP Processing Degradation


4.6 4.4 4.2 4


3.8 3.6


0 1 Pass Number


Contamination As most plastics are incompatible great care should be taken not to mix material types.


It is therefore essential that no purgings, or scrap product resulting from material changes are recycled and it is vital that machinery is thoroughly cleaned between material types. Other sources of contamination include: -


• Oil • Dirt / Rubbish • Masterbatch


All contaminated material should be eliminated from any recycling process and disposed of. Failure to do so will result in the contamination of more material and further scrap.


Dust


The mechanical abrasion that constitutes the regrind process tends to result in dust. Ideally this should be removed and disposed of. In the case of some polymers dust will significantly affect the physical properties of the end product.


Fibre Fillers


The mechanical abrasion that takes place in the regrind process dramatically affects the physical properties of plastics that contain glass, carbon or other fiber reinforcement.


In addition to reducing the length of the fibers, any chemical coupling agent (size) will also be affected, and since the fibres depend upon their interface with the plastic that surrounds them the grinding process can dramatically reduce physical properties.


Food and 2


Medical Applications


In both these cases special consideration should be given to the use of regrind. Normally in medical applications regrind is not used. In the case of food packaging careful evaluation must be undertaken to ensure that compliance with required standards are maintained as well as overall suitability for any given application.


It is strongly advised that if there is any cause for concern about the use of regrind then further advice should be sought from the material supplier. Where it is not desirable to use regrind the scrap can be sold to specialists companies who will recycle the waste.


Plastribution is the UK’s leading distributor of plastics raw materials, delivering reliability, know-how and true business partnership to the world’s best polymer suppliers and our UK customers.


In the event that you require further information about the shrinkage of polymers, please do not hesitate to contact a member of the Plastribution team for further information by emailing sales@plastribution.co.uk or phone 0845 3454560


© Plastribution Limited. All rights reserved. 2012


MFR g/10min


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68
Produced with Yudu - www.yudu.com