Profitable Recycling and Upcycling with ZSK Extruders

Auro­ra Kun­st­stoffe, a com­pa­ny locat­ed in Neuen­stein and since end of 2019 mem­ber of MOL Group, is demon­strat­ing how plas­tic proces­sors’ pro­duc­tion waste can be recy­cled and upcy­cled prof­itably. This pro­duc­er of recom­pounds uses reject­ed parts accu­mu­lat­ed from plas­tic com­po­nents man­u­fac­tur­ing as pri­ma­ry raw mate­r­i­al and process­es it into recy­cled, new-prod­uct-qual­i­ty plas­tic com­pounds. After a major fire in their pro­duc­tion area in 2017, Auro­ra Kun­st­stoffe decid­ed once again to rely on ZSK twin screw extrud­ers from Cope­ri­on. Those three ZSK 45 Mc¹⁸ twin screw extrud­ers have been in suc­cess­ful oper­a­tion since ear­ly 2019, and with their high through­puts and their reli­a­bil­i­ty, they have ful­filled every require­ment that Auro­ra Kun­st­stoffe needs for their inno­v­a­tive busi­ness plan.

Technology for First-Rate Compounds

In man­u­fac­tur­ing tech­ni­cal plas­tic parts, typ­i­cal­ly there is approx­i­mate­ly a five per­cent rejec­tion rate. Auro­ra Kun­st­stoffe pur­chas­es this pro­duc­tion waste, then exam­ines the pre­cise com­po­si­tion and vari­etal puri­ty. Once they pass qual­i­ty con­trol, the sin­gle-vari­ety plas­tic parts are ground, fed into the com­pound­ing process and pel­letized. The result is pel­lets main­ly based on PA6, PA66, PA11, PA12, POM, PP, PC, and PC-ABS. To accom­plish this, Auro­ra Kun­st­stoff relies on Cope­ri­on ZSK tech­nol­o­gy. With­in the ZSK twin screw extrud­ers, the ground mate­r­i­al is reli­ably homog­e­nized with addi­tives, fillers and rein­forc­ing mate­ri­als and devolatilized. To this end, Cope­ri­on designed each of these three ZSK 45 extrud­ers indi­vid­u­al­ly for Auro­ra Kunststoffe’s require­ments, equip­ping them with ZS-EG twin screw side devolatiliza­tion units and spe­cial wear pro­tec­tion for prod­uct-con­tact parts. Fol­low­ing melt dis­charge from the die head at the end of the extruder’s process sec­tion, plas­tic strands are tak­en over by semi­au­to­mat­ic SCP 200 strand con­vey­ing sys­tems from Cope­ri­on Pel­letiz­ing Tech­nol­o­gy. They are auto­mat­i­cal­ly con­veyed via a cool­ing water chute and a con­vey­or belt to the strand pelletizer’s feed mech­a­nism, where they are cut to com­pounds whose qual­i­ty cor­re­sponds to that of new mate­r­i­al. Not­ed Nor­bert Büter, Cope­ri­on Sales Man­ag­er, “When recy­cling plas­tics, it is nec­es­sary to adapt the process para­me­ters and recipes to the var­i­ous raw mate­ri­als. With their flex­i­bil­i­ty and high torques, ZSK twin screw extrud­ers are opti­mal­ly suit­ed for pro­cess­ing even the most dif­fi­cult raw mate­ri­als to very good prod­uct qual­i­ty – and they do it at through­puts that are eco­nom­i­cal. By devolatiliz­ing using ZS-EGs, not only are unwant­ed gas­es removed; oper­a­tional safe­ty of the entire vac­u­um sys­tem is increased. This applies espe­cial­ly to even very volatile viscosities.”

Rebuilding Production

In 2017, a large fire at Auro­ra Kun­st­stoffe destroyed the entire pro­duc­tion area. Auro­ra Kun­st­stoffe held fast to its suc­cess­ful sus­tain­abil­i­ty con­cept, even expand­ing it after the fire. New twin screw extrud­ers began oper­a­tion in a new, larg­er space in 2019. In meet­ing such a tight dead­line, Auro­ra Kun­st­stoffe relied on close col­lab­o­ra­tion with their sup­pli­ers. Alexan­der Schwein­le, Head of Pro­duc­tion at Auro­ra Kun­st­stoffe, is par­tic­u­lar­ly proud of this: “Cope­ri­on deliv­ered not just three ZSK 45 extrud­ers that were indi­vid­u­al­ly designed for us, and the appro­pri­ate strand pel­letiz­ers, but they also sup­port­ed us with the engi­neer­ing nec­es­sary for the entire pro­duc­tion. I would like to empha­size the real­ly good col­lab­o­ra­tion between our two com­pa­nies: Cope­ri­on con­sis­tent­ly reacts to our inquiries quick­ly and knowl­edge­ably, which was key dur­ing our production’s rebuild­ing phase.”

Successful Recycling Concept

Pro­duc­tion waste from indus­tri­al plas­tics man­u­fac­tur­ing is becom­ing more and more valu­able in times of ris­ing raw mate­ri­als prices and increased envi­ron­men­tal pol­lu­tion. Auro­ra Kun­st­stoffe buys these indus­tri­al by-prod­ucts and turns them into high-qual­i­ty raw mate­ri­als that are used in the auto­mo­tive, con­struc­tion, fur­ni­ture and elec­tron­ics industries.

Plas­tic waste comes to Auro­ra as part of its unique Auro­ra-Lean-Logis­tics con­cept, con­sist­ing of Aurora’s own fleet of about 60 semi-trail­ers and a box con­cept for per­fect­ing sin­gle-ori­gin col­lec­tion. At Auro­ra, mate­ri­als are ground and processed into recom­pounds by means of extru­sion. With this process, Auro­ra Kun­st­stoffe achieves through­puts of up to 650 kg/h on their ZSK 45 twin screw extrud­ers. Per day, Auro­ra Kun­st­stoffe pro­duces over 50 tons of com­pounds. For the future, Auro­ra antic­i­pates increas­ing demand. “I am cer­tain that soon­er or lat­er, there will be a legal­ly man­dat­ed recy­cling quo­ta”, said Schweinle.

Jochen Schofer, Busi­ness Seg­ment Man­ag­er, Recy­cling & Direct Extru­sion at Cope­ri­on added: “We’re con­vinced that becom­ing cir­cu­lar is unavoid­able for the plas­tics indus­try.” To that end, there is still plen­ty of room for improve­ment. In Ger­many, the share of recy­clate used in plas­tics pro­cess­ing in 2017 only achieved a bit more than 12%. Auro­ra Kun­st­stoffe, in con­trast, is tak­ing an absolute­ly lead­ing role for us; their com­pa­ny con­cept is not only prof­itable, it’s sus­tain­able too! We’re proud to sup­port Auro­ra Kun­st­stoffe with our com­pound­ing and engi­neer­ing know-how!”