7 , ▁while ▁a ▁process ▁for ▁the ▁recovery ▁of ▁carbon ▁dis ul ph ide ▁in ▁the ▁ray on ▁st ap le ▁plant ▁was ▁developed . ▁ ▁During ▁World ▁War ▁II ▁Gl anz stoff ▁Ober bru ch ▁went ▁through ▁its ▁most ▁difficult ▁years . ▁Until ▁September ▁ 1 9 4 4 ▁the ▁factory ▁continued ▁to ▁operate ▁without ▁severe ▁dis ru ptions . ▁On ▁September ▁ 1 9 , ▁the ▁ 4 5 th ▁anni versary ▁of ▁the ▁works , ▁all ▁machines ▁had ▁to ▁be ▁stopped . ▁Ober bru ch ▁was ▁now ▁on ▁the ▁front ▁line . ▁ ▁In ▁February ▁ 1 9 4 7 ▁Al lied ▁forces ▁allowed ▁production ▁to ▁res ume . ▁At ▁the ▁end ▁of ▁ 1 9 4 8 , ▁Gl anz stoff ' s ▁work force ▁had ▁grown ▁to ▁ 3 , 4 0 0 . ▁In ▁December ▁ 1 9 5 1 , ▁the ▁first ▁machine ▁for ▁continuous ▁vis c ose ▁spin ning ▁was ▁set ▁up ▁to ▁replace ▁the ▁glass - roller ▁spin ning ▁process . ▁In ▁ 1 9 5 3 , ▁the ▁last ▁glass - roller ▁spin ning ▁machine ▁was ▁turned ▁off . ▁ ▁Per lon ▁▁ ▁A part ▁from ▁text ile ▁and ▁technical ▁ray on ▁(" C orden ka “ ), ▁which ▁due ▁to ▁its ▁raw ▁material ▁was ▁considered ▁a ▁natural ▁fi ber , ▁Ober bru ch ▁entered ▁the ▁world ▁of ▁fully ▁synth etic ▁fib ers ▁and ▁introduced ▁Per lon ▁( poly am ide , ▁PA 6 ). ▁The ▁fast - g row ing ▁synth esis