Japanese companies have built what they call the world's first 3D-printed train station, a compact white curved-roof structure installed in a rural western region.

Producing Hatsushima Station's foundations and exterior took just seven days, according to Serendix Corporation, which worked with West Japan Railway Company (JR West) on the project.

The parts were reinforced with steel and a concrete cleat filling and then assembled on site, JR West said in a March statement.

Using conventional methods, "it takes a month or two to build a roof and walls," JR West's Naohiro Ohashi said.

"We were able to install them in about two hours -- so there is an advantage in terms of speed," he told reporters last month.

The assembly process began after the last train left the station in Arita in Wakayama region around midnight, and everything was done before the first train arrived at around 5 am.

Now the interior needs to be finished and ticket gates put in before the station can open.

The structure is 2.6 metres (8.5 feet) high and 6.3 meters wide. Embossed on its side is a circular design meant to look like a mikan orange, a local speciality.

Serendix said it used a "special mortar" to build the station using a construction-grade 3D printer with a robotic arm.