The overseas land empire that the Mongols created allowed for the largest, and final, flowering of the Silk Road, but this system of trade routes was not particularly new.  It was expanded and improved upon thanks to the greater degree of political unity brought by the Mongols, but it was only a difference of degree.

In terms of technology transfer, the biggest difference is that by the 1300's Europe had states worth mentioning, and people who could read - a much different situation than during the flowering of the Silk Road under the Tang in the 700's, or under the Han around 0 AD.  During the Mongol period, Europe was developed enough to be receptive to advanced technologies that it had ignored in the past.  One example is the Moldboard Plow, which was in use in China in the Han dynasty, but only adopted by the Europeans in the later Middle Ages.

The other thing I was responding to was the idea that the Mongols turned China into an export manufacturing center.  China was always an export manufacturing center - the Mongols just encouraged those exports to follow the Silk Road, as these exports had in the past under the Tang, but had not during the Southern Song, which was isolated from Central Asia and much more focused on the sea trade with East and Southeast Asia.