TECHNOLOGY | MACHINERY MELT FILTRATION Melt filter helps film maker recycle scrap
German packaging film manufacturer Oldenburg has retrofitted a Gneuss RSFgenius 175 melt filter, to help deal with its production waste. Oldenburg makes polyethylene (PE)
packaging such as bubble film, stretch and foam sheet. Film waste generated during production is collected and re-pelletised on a central recycling extruder. However, the conventional screen changer on the line was not able to filter very fine material. This meant that the recyclate could not be used in thinner film gauges. This central recycling extruder was equipped with a conventional screen changer, which was not able to filter sufficiently finely. If the recycled material
PRINTING
Making plates with
no solvent DuPont has installed a solvent-free thermal platemaking system at Comexi’s technical centre in Girona, Spain. The Cyrel Fast 2000 TD system combines thermal processors and a variety of photopolymer printing plates for flexible packag- ing and other applications. It offers high productivity and performance and can reduce processing costs and environmental impact compared to solvent- based methods.
“It enables a workflow
from file to plate in less than an hour,” said Jan Scharfenberg, business leader for DuPont Cyrel Solutions East. �
www.dupont.com �
www.comexi.com
46 MIXING
Cooling mixer avoids degradation problems
Promix Solutions says that its P1 cooling mixer prevents typical product degradation that is caused by long residence times. At the same time, it avoids deposits or temperature peaks during the tempera- ture control process. Forced guidance and constant product mixing leads to short residence times combined with a narrow residence time distribution, it says. Static mixers such as the
Promix SMB Plus can homogenise melts and liquids – which minimises temperature differences or temperature peaks. Also, variations in the material composition – such as additive concentrations – can be equalised. This
FILM & SHEET EXTRUSION | July/August 2021
was not filtered finely enough, the simple, discontinuous screen changers on the blown film lines would block up quickly. Simple, discontinuous screen changers also tended to block up quickly. After running several trials, the company installed a Gneuss RSFgenius with self-cleaning system. It can now filter sufficiently finely (to 75 microns) so that pellets made from the scrap can be fed back into the blown film extruder. Its efficient operation means that filter elements do not need frequent replace- ment – and the amount of material lost to back-flushing is minimised. �
www.gneuss.de
leads to a uniform product in terms of composition and temperature distribution. Based on the SMB mixer
structure, the P1 cooling mixer combines the functions of a static mixer and a heat exchanger in one compo- nent. A heat transfer fluid flows through both the mixing elements inside the P1 cooling mixer and the double jacket. This leads to a
effective heat exchange in a small space. This uniform flow prevents deposits and product degradation. Even very high-viscosity liquids that lead to a high pressure drop in the cooler can be processed without problems. P1 cooling mixers are
appropriate for hourly throughputs ranging from a few kg to several tonnes. �
www.promix-solutions.com
www.filmandsheet.com
IMAGE: GNEUSS
IMAGE: PROMIX SOLUTIONS
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
