Foxconn, the primary manufacturer for Apple Inc. (NASDAQ:AAPL), is reportedly in its final stages of preparing for iPhone 6 production. Reports from China indicate that Foxconn is performing iPhone 6 "product validation tests" at its factory in Zhengzhou to ensure that its manufacturing processes runs smoothly when the real production begins.

The PVT stage entails Foxconn running trials on its assembly line and producing a limited amount of iPhone 6 handsets, Telecom expert Xiang Ligang recently detailed on the Chinese social network Weibo. Xiang believes the iPhone 6 is right on track for a September launch. And recent reports suggest that Apple will host a media event on Sept. 9 to unveil the iPhone 6; the device will likely hit stores Sept. 19.

Prior reports suggested that the iPhone 6 had already gone into mass production in mid-July; however, those reports were never confirmed. Reports about the iPhone’s current production status have also not been confirmed. Regardless, Apple has reportedly ordered between 70 million and 80 million units of the iPhone 6 -- and possibly also another iPhone model -- to be produced by its suppliers by the end of the year. With rumors for the iPhone 6 suggesting the device will include a much larger 4.7-inch display, anticipation for the device is especially high. Morgan Stanley analyst Katy Huberty expects the new larger iPhone could increase Apple’s smartphone sales by 20 percent.

In addition to being larger, Apple may implement sapphire glass into the iPhone 6 display. Internally, Apple’s 64-bit A8 chip for the iPhone 6 is rumored to be a dual-core processor running at 2GHz or more. And the device may include a more powerful battery, between 1800mAh and 2100 mAh. As for software, the iPhone 6 probably will run Apple’s iOS8 operating system, which was first showcased at the Worldwide Developers Conference in June.