They started with sketches, motors, spare parts, and whatever materials they could find. They would search through second‑hand markets for alternative parts. If something did not work, they went right back to the drawing board.

The early prototypes were rough. Some opened too slowly. Others shut too quickly or jammed altogether. But with every failed attempt, the design improved.

Before long, an opportunity presented itself. The university was putting up a new teaching building and needed doors accessible for people with disabilities. Wang and Zhang were asked to put their idea to the test.

They strengthened the design, improved the sensors, and installed their first working automatic door.

Seeing it open smoothly as people approached changed the way they looked at what they had built. This was no longer just an experiment. It was something people could actually use.

That realization eventually led to a much bigger decision. In the early 1990s, as more people were leaving secure jobs to start businesses of their own, Wang and Zhang chose to do the same. They left the university and opened a small automatic door factory.

The early years were anything but easy. They worked out of rented premises with basic equipment and limited funds. Days were spent meeting customers and installing doors. Evenings were spent back at the workshop, refining designs and fixing whatever had gone wrong. They were founders, engineers, installers, salesmen, and repair technicians all at once.

One winter, an early batch of doors began failing in low temperatures. Complaints came in, and the two founders spent several freezing days on site until they found the cause and solved the problem. It was a lesson they never forgot: an idea can be developed at one’s own pace, but once it becomes a product, you are responsible for the people who rely on it.

They renamed the company PAD: P for Power, A for Automatic, and D for Door.