This page contains a Flash digital edition of a book.
Melt fi ltration | machinery feature


Peter Mapleston reports on how the latest melt fi ltration systems are being developed to handle higher throughputs and greater contamination levels


Cleaning out the contaminants


The latest advances in melt fi ltration systems confi rm a continuing trend towards increased throughputs, improved fl ow to reduce dead spots and material degradation, lower back pressure for improved energy effi ciency, and longer lifetimes. Many of the develop- ments have recycling operations principally in mind. Italian company Fimic, which produces what it says


is a new generation of self-cleaning melt fi lters, continues to refi ne its products. It recently added laser-drilled screens to its range of punched stainless steel types. Laser technology makes it possible to obtain smaller holes on a thicker screen so that, Fimic says, there is the correct balance between the level of fi ltration, the hole diameters, the strength of the screen, and the open area. “This new addition enhances the capability of the


fi lter to treat the most different materials and to obtain pellets that can be used in the most varied applications,” claims the company’s head of marketing, Erica Canaia. The fi nest fi ltration that Fimic can now supply is 150


microns (100 mesh). In addition, the thickness of the sheet makes it possible to clean the screens in an oven several times for reuse. Fimic is now well advanced with the testing of even fi ner fi lters, at 100 microns. “The trials have been exceedingly satisfying,” Canaia


www.compoundingworld.com


says. The new fi lters should be commercialised before the end of the year. Fimic fi lters with coarser meshes can treat urban


solid waste with the resulting material suitable for moulding applications, while less contaminated materials can be fi nely fi ltered for use in the production of fi lm. Filters can handle a wide range of melt fl ow indices; Canaia cites as examples of the two extremes an 80-MFI PP and a 0.01-MFI HDPE. A control probe sends a signal to the PLC when


pressure reaches a pre-set level, putting a scraper into motion. Canaia says that the scraping technology simplifi es the process compared to back-fl ush technol- ogy and enables the fi lter to process materials with higher levels of contaminants as well as more aggres- sive contamination. “In fact, the wear that can be caused by, for example, sand, metal or glass or any other contamination would only cause a higher wear on the screen and would not affect any of the other fi lter parts,” she says. “Considering the cost of the screen is considerably lower that most of the competitors, the advantages are obvious.” The units store the contaminants from up to six


scrapings (which may take place as frequently as once every few minutes in applications involving dirty reclaim


July 2015 | COMPOUNDING WORLD 57


Fimic’s latest designs offer


fi ner fi ltration and can work at lower


pressures


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  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88