Worldwide 3D printer shipments will reach 455,772 units in 2016, more than doubling the 219,168 units shipped in 2015, market research firm Gartner said on Thursday.The 3D printing is now experiencing widespread acceptance in specialist industries and is used to create prototypes, augment manufacturing processes and produce finished products. Gartner predicts that Greater China, emerging Asia/Pacific and mature Asia/Pacific regions will experience a combination of high 3D printer shipments and high growth rates through 2020. "The evolution of hardware and software along with an ever-expanding collection of usable materials has driven growth in both the consumer and enterprise 3D printing markets," said Pete Basiliere, Research Vice President at Gartner.According to Gartner, the increase in 3D printer shipments over the next four years will total more than 6.7 million.Military organisations, whose equipment often has very long lives, are working with defence contractors to evaluate 3D printing of replacement and modified components on shore and at sea, added Basiliere.