An integrated production system: a commitment to manufacturing that pays attention to even a single screw

YKK AP's products consist of various parts such as aluminum and plastic frames, glass, screens, and functional parts. All of these manufacturing processes are done in an integrated manner at our own manufacturing locations.

Glass used for products such as windows—our mainstay products—is purchased in sheets of rough glass, then processed in-house into Low-E glass and triple-glazed glass. In addition, we process everything in-house, from melting ore for aluminum materials and blending raw materials for plastic materials.

For components that are arguably vital for our products, we produce metal and plastic functional parts—such as door rollers, screws, and screen netting—based on our technological development capabilities, including elemental technologies. There are also various testing and assessment functions which we perform for further quality assurance.

In addition, the development and manufacturing of specialized equipment for production is handled by our own department, called Machinery & Engineering. The seamless and rapid collaboration between Machinery & Engineering and the development and manufacturing divisions make our technological competitiveness even greater.

We believe that our commitment to integrated production enables speedy technological development, cost adjustment throughout the supply chain, and reliable quality assurance.

YKK AP's commitment to monozukuri, with its integrated production system, permeates down to a single screw. This is embodied in the improvements we made in 2016 to the wood screws used to install window frames in the building frames of wooden houses. By reviewing the depth of the recessed area in the top of a Phillips head screw, as well as the shape of the thread on the screw tip, we improved the screw's grip on a screwdriver bit, as well as its ability to bite into wood. This made it possible to reduce time spent fastening screws by 30% (according to our own research).

(Sudo) Regarding these improvements to wood screws, when we were developing the APSWORD NEO aluminum-vinyl composite window, our core product which launched in April 2017, in an effort to give the screws an advantage as one of the product's many selling points, we improved them by moving to wood screws which would be easier to work with than existing ones.

To begin with, the screws are in accordance with JIS, and meeting these standards guarantees a certain level of quality. However, when we thought whether that was really all there was to it, we decided not to be satisfied with JIS, but to start working on improvements with the desire to create a better product.

First, we thoroughly investigated factors such as the screw thread shape, the state of the paint, and the sharpness of the tip. Development and manufacturing brought together knowledge and technology to improve the screw.

Furthermore, YKK AP has all kinds of specialized departments within the company—including the Value Verification Center, which handles the evaluation and verification that is essential for product development and the provision of new product value—and a department specializing in studies and analysis. With the cooperation of these departments, we were able to bring the improvements to fruition in a short period of about three months before mass production began. We believe that we were able to proceed with such speed because of the environment in which a variety of in-house experts—from departments such as development, manufacturing, quality, evaluation and verification, and studies and analysis—were able to work together in close proximity. I believe that would not have been the case if we had gone through an external vendor.

(Shibata) We are also pursuing thorough quality at the manufacturing site. The Screw Line, which is solely responsible for manufacturing screws for YKK AP, manufactures and ships as many as 600 million screws over the course of a year. When manufacturing such huge quantities of screws, spot checks are common. However, starting in 2017, we introduced 100% inspections at YKK AP, with a strong desire not to produce a single defective product. This inspection consists of image inspection of screws using high-speed cameras and automated bagging. In addition to removing defects, we can also prevent the mixing of screws with different part numbers by conducting inspections of every screw and bagging them in a consolidated way.

There were many people involved in the design stage of the screw, and a great deal of technology was packed into its design. The introduction of this 100% inspection system was made possible by the desire of our employees to "focus on each and every screw, so as not to waste this technology."

This device can be used in ways such as obtaining data from defective products, which also allows us to check phenomena which cause defects and leads to improvements.