Underwater- pelletizing systems - Extrusion Auxiliary

1 Underwater- pelletizing systems2 Our companyBKG was founded in 1994 with the aim of pelle-tizing under water, the new technical plasticmaterials such as PET, PA6 and PBT. Severalhundreds of Underwater- pelletizing machineshave been supplied world-wide (with through-puts of 2 kg/h) witnessing our addition to supplying parts for ourown Underwater- pelletizing and dryingsystems, we also offer die plates, bla-des and cutter hubs for other manufac-turers pelletizers. BKG Underwater- pelletizing systemsare not only suitable for thermoplasticsbut also for all materials, which behavelike thermoplastics. LLDPE, LDPE, HDPE, PP, EPDM Polyvinyl PVC-P (Soft-PVC) Styrene PS, SAN, ABS Acrylic PMMA POM PC Polyester PET, PBT, PEN PA 6, PA , PA 11, PA 12 Polymerblends Thermoplastic TPE-S, TPE-O, TPE-E, TPE-A Polyurethane Hot Melt EVA-based, APAO-based, PA-based Natural Chewing gum Synthetic Epoxy resin3 Our productsCustomers need for high quality throughoutbecomes more and more important.

2 BKG s com-pany strategy is focused consequently on twoaims: to offer our customers first class productsand service at favourable prices, while enablingour employees to be motivated, work success-fully and be satisfied with their work. The modern quality management system DIN ENISO 9001: 2000 is an important part of our com-pany concept. It confirms our quality and provesthat we are mastering all internal processes. Furthermore the desire for quality and the knowhow of all employees (made up by careful trai-ning and further education) play a central role inour company. The fulfilment of the customers orders within our internal quality standards is ofhighest priority. Our customers can rely on our quality, fast andpunctual delivery, reliable operation, systems ,machines and services and their long life-timeeven with intensive use.

3 This is made possible by precise work, from theconstruction of standard models through to indi-vidual special solutions. We are our customers partner in every field of plastics processing. And yet our principle is quite simple: solid prac-tical solutions simple in handling, precise androbust in use and at the same time economicalin performance. Master Series 300, 1000, 20004-5 Diverter valves Bypass piping6 PelletizersAH 2000AH 4000AH D2507 Tempered water systemsmodular construction8-9 Combi-line10 Opti-line11 Wear-protectedsystems12 Special solutions13 Technical dataAccessories14-164 BKG Master pelletizersThe Master series covers a wide output rangefrom 2 up to 2000 kg/h. Because of the integra-ted know-how the BKG system convinces byeasy handling and compact design. A hand-wheel allows fine-adjustment of the contactpressure of the cutter head to give optimal pro-duct processing , whatever the requirement.

4 TheMaster series can be installed in the minimum ofspace and easily relocated at any time. Further advantages in particular for compoundand master batch production: flexibility with respect to the granulated mate-rial flexibility with respect to new materials andcolours flexibility with respect to the production ofvarious pellet sizes, thanks to fast exchangeable perforated plates easy and fast cleaning of the system compo-nents production of micro granulatesA new design of perforated plates permits pro-cessing of not only all the customary plasticssuch as PE, PP, AB etc. but also products asPA 6, PA , PBT, PET and PPO. A furtherimportant step towards the processing of criticalhigh-temperature products. Total system Master 3005 Easy clean centrifugal dryerAfter being cut the pellets are separated from thetransport water in the centrifugal dryer and driedin the counter-air flow.

5 Residual moisture lessthan 0,05%, depending on the material type, canbe realised. Thorough cleaning is made easy bytwo large doors and a removable one piece rotorscreen essential when producing colour com-pounds and master A 300 and A 2000 The micro-metric adjustment of the pelletizerguarantees precise control of the blades againstthe die plate. This ensures long blade and dieplate life. The quick exchange die plate can beexchanged within only 10 minutes. Various holediameters can be used ( 0,3 mm 4,2 mm).23 Agglomerate Ejection (optional)Any agglomerates are automatically detected asthey break the light beam of a photo-eye .When clumps of pellets are detected theagglomerate gate automatically opens and anyoversized material is ejectedbefore it enters the clean water tankThe master water tank (heating optional) pro-vides the water flow of the pelletizing system ,which cools down the pellets directly after leav-ing the perforated plates.

6 Any fines are collectedon a large woven wire mesh screen in the mesh screen and the tank can be cleanedwithin a very short time to avoid cross contami-nation between colour batches. 1123455 Control panelThe master system is delivered with a compactcontrol panel. The operator friendly panel showsall process data as well as graphs. The on-screen help function assures easy handling. 46 Polymer Diverter ValveThe polymer diverter valve consists of a heatedhousing and hydraulically movable piston. Byhydraulic actuation of the piston the melt flowcan be diverted e. g. towards the floor or direc-ted towards the die diversion is necessary because the desiredoptimal melt flow per die plate hole can not begenerated instantaneously, by the precedingequipment (e. g. extruder), at start-up. The polymer diverter valve also separates thepelletizing process from the preceding process( extruder) so that both of them can be shutdown separately in case of minor faults or chan-ges made at the pelletizing side.

7 Polymer diver-ter valve before the screen changer and theextruder pipingThe bypass means the piping around the cuttingchamber. The process water entry into the cut-ting chamber can be exactly timed by thisbypass piping and the two 2/2 way valves, the3/2 way valve (all valves incl. final position indi-cator) and the related SPS avoids a freeze-off (blocking) of the die plateholes if the process water enters too early and,furthermore, agglomeration of the pellets if theprocess water enters the cutting chamber toolate. Also a high loss of process water is avoidedwhen the pelletizer is electrical equipment is pre-wired on a biggerterminal box where the plugs for the polymerdiverter valve, the die plate heating and the pel-letizer are connected for easy and quick electri-cal and mechanical disassembling of theseunits, e.

8 G. if extraction of the extruder screws isnecessary. Diverter valve in front of the screen changer and theextruder connectionPelletizer AH 2000 with direct connection to the continu-ous screen changer and bypass pipingThe BKG pelletizing systems are consisting mainly of the following three mechanical aggregates: Polymer Diverter Valve Pelletizer Tempered Watersystem7 Pelletizers for 2 kg/hThe pelletizer cuts the polymer strands into pel-lets in the cutting chamber, which is completelyfilled with water, immediately after they havepassed the die of the high temperature difference bet-ween melt and water, the cut polymer drops soli-dify immediately into the characteristic sphericalform of Underwater- cut pellets (spherical formdepends on the product viscosity). The different types of BKG pelletizers work witha throughput of 2 - kg/h.

9 The "small"Master covers the output range from 2 - 500kg/h, the A and AH types with the "big" AH D250reach throughputs of up to 15 t/h which aremainly demanded by the polymer industry in thecontinuous polymerisation and polycondensa-tion lines in the field of PA, PET, PBT as well asSAN and PS. Cutting chamber with die plateThe die plate consists of the die plate collar withcartridge heaters and die plate insert with dieholes. The nose cone mounted on the die plateinsert avoids dead space and directs the poly-mer flow to the radially arranged die holes. In thecutting chamber filled with process water thestrands leaving the die holes are cut directly intopellets. The die plate collar and cutting chamberare bolted directly onto the preceding equipment(Polymer diverter valve or adapter). The two-piece design of the die plate enables a quickchange of the die plate insert within 10 minutes.

10 Hydraulic control fully automates the forwardfeed of the cutter shaft (higher force during start-up and step-by-step reduction down to mini-mum force during regular production). This assu-res a constant production because the optimumapplication pressure is reproducible. Also the blades at the die plate can be re-groundto predefined values to level the blade wearoccurring during production, thus ensuring con-tact between blades and tungsten-carbide cut-ting face of the die plate. The flexible head of the cutter shaft, on whichthe cutter hub is mounted, gives the tolerancesof the axial alignment between cutter hub anddie plate are compensated. Automatic connection of the pelletizer to thecutting chamberPelletizer AH D250 for throughputs of up kg/h8 Tempered water system inmodular design To meet customers requirements, BKG is nowdelivering their systems in modular format.