Extrusion International 4-2024

21 Extrusion International 4/2024 Servomotor-Driven Edge Trimming System for Sheet and Film Extrusion  Hellweg Maschinenbau’s new, individually controllable R 200/20 Servo edge trimming system brings flexibility to the shredding of ex- trusion edge strips. Touchscreen control enables processors to adapt this step to production conditions and so optimize it for the specific application. Jointly developed with BREYER Extrusion, this newmachine complements the extensive range of systems, also known as guillo- tines or chippers, from this global manufacturer of digitally controlled shredding machines for effective, energy-saving plastics recycling. Designed for a working width of 200 mm and cutting thickness of up to 20 mm, the R 200/20 Servo con- tinuously pre-shreds one or two edge strips from film or sheet pro- duction. A downstream granulator then processes the resulting chips, which are several centimeters in size, into regrind or flakes in the millimeter range as required. These can then be fed straight back into the recycling loop. Thanks to a servo geared motor, cutting cycle times can be freely set using the associated touchscreen dis - play. As a result, the cutting frequen- cy of the R 200/20 Servo and thus also the length of the edge strip chips can be selected at a constant cut - ting speed and so optimized for the output of the respective extrusion system and for input to the down- stream granulators. Numerous, short chips relieve the load on lower power granulators, while the longer pieces possible when using powerful granulators relieve the load on the chipper. In both cases, electronically controlled edge trimming cuts down on wear and energy consumption. In addition, the high chopping speed permitted by the servomotor results in a smoother process because the permanently advancing film web only runs over the stationary blade for a very short time. This minimizes any counter-thrust and associated lifting of the entire edge strip. Extrusion requires uninterrupted operation, and this is exactly what the R 200/20 Servo is designed for, just like all of Hellweg’s other gran- ulator systems. Users can be confi- dent that these granulators with their unsurpassed endurance and minimal maintenance requirements will not be the cause of downtime. The durable special guides and the hardened, low-wear blade support and eccentric roller are further fac - tors backing up this confidence. As a manufacturer of granula - tors for any plastics application, Hellweg is expanding its portfolio in step with changing customer requirements. In addition to edge trimming systems, this portfo - lio ranges from small machine- side granulators for sprues up to high-performance systems for solid parts, film and sheet with a throughput of five metric tons per hour and above. The digital Smart Control System, featured by all the granulators, captures parameters such as power consumption, mo- tor speed and bearing tempera - tures, as well as blade, screen and V belt status. By continuously opti- mizing the ratio of engine load to throughput, it ensures particularly economical operation with minimal operator effort. For example, the MDSi 340/150 Smart Control machine-side granu- lator, the most powerful model in the series with drive powers from 1.5 kW to 4 kW, achieves granula- tion outputs of 10 kg/h to 80 kg/h. The 300 series central granula- tors, which are as compact as they are powerful, shred thick-walled moldings, sheets, sprue cakes, pipes, and profiles. And the MDSGi 1500/600 wet granulator equipped with a forced feed system, which was premiered at Fakuma 2023, of- fers an unprecedentedly good ratio of throughput to energy consump - tion. It produces flakes of consis- tently optimum quality, as well as a particle size distribution and ge - ometry that are perfect for further processing. Hellweg Maschinenbau GmbH & Co. KG www.hellweg-maschinenbau.de The touchscreen on Hellweg’s R 200/20 edge trimming system, which is equipped with a servo geared motor, allows cycle times to be freely set. This means that the size and number of individual chips can be optimized for further processing independently of extrusion system output (© Hellweg Maschinenbau)