Kuwomba akamawomba, komwe kumadziwikanso kuti hollow blowing, ndi njira yopangira pulasitiki yomwe ikukula mwachangu.Njira yopangira zida zankhondo Pankhondo yachiŵiri ya padziko lonse, mawilo opangidwa ndi mphepo ankagwiritsidwa ntchito popanga mbiya za polyethylene zosalimba kwambiri.Chakumapeto kwa zaka za m'ma 1950, ndi kubadwa kwa poly-density poly ...
Werengani zambiri