CNC-Controlled Pressing of Aluminum Windows and Doors

Article from "De Schrijnwerk"

The production of PVC windows and doors has been largely automated for many years in most joinery workshops. In contrast, automation in aluminum joinery production has typically been limited to sawing and machining centers. However, it is clear that even after these initial steps, there are numerous opportunities to further optimize and automate the production process. In this respect, the possibilities and advantages of a CNC-controlled corner press are particularly noteworthy. For this technology, Tryma has long been the exclusive partner of the French manufacturer MTI Machines.

Single-Head Corner Press

Traditionally, the corner joints of aluminum windows and doors are pressed with a conventional single-head corner press. This requires the operator to position, clamp, and press each corner individually. In addition, when switching to a different profile type, the operator usually needs to manually change the set of press knives. These steps are not only time-consuming but also require substantial expertise.

Now, manufacturers have the option of upgrading to a CNC-controlled single-head corner press. Different profile types are pre-programmed into the machine. The operator simply selects the profile number on the machine’s screen, after which the press knives automatically adjust to the correct positions for corner pressing. Thanks to this fully automatic knife positioning, operators no longer need to change press knives manually. As a result, multiple profile types and series can be processed consecutively without manual adjustments.

All profile types are pressed with the same set of knives. Clamping and pressing are initiated by the operator using dual thumb buttons and a foot pedal. This ensures absolute operator safety and represents a major advantage compared to conventional corner presses.

Four-Head Corner Press

Productivity can be significantly increased with a four-head corner press. This system consists of an automatic feed table, the four-head corner press itself, and an automatic output table. Each window is assigned a specific barcode which, once scanned, ensures that the feed table automatically adjusts to the correct dimensions. After assembling the element, the operator places it against a stop on the feed table, after which the element is automatically transported to the corner press by powered conveyor belts.

Simultaneous Corner Pressing

The window is then transported into the press, where all four corners are pressed simultaneously by the four press heads. A key advantage is that this process is profile-independent. Two knives are CNC-configured for both height and depth, allowing different profile types to be pressed consecutively using the same tools. As a result, the operator no longer needs to manually change press knives when switching profiles. The average cycle time is 60 seconds per pressed window.

While the machine is pressing automatically, the operator can already prepare the next element, as no further adjustments are required. After pressing, the element is transported to an automatic output table, where the corners of the frame remain exposed for easy cleaning. Optionally, the window can then be automatically transferred to a gasket insertion machine or to a buffer and sorting system.