Have you ever wondered how the football shapes got into a sheet of plywood? When the knots in a tree fall out when the tree is turned into veneer sheets, there is a hole that is left behind. That hole in the veneer sheet is then patched with the football shaped patches. InterConnecting Automation Inc. was recently brought in to help automate a machine that patches the veneer at a plywood facility. Until this point in time, the process of patching the veneer was all manual and required operators to stand at a manual patcher and patch all of the holes in a sheet. This was extremely labor intensive and a slow process.
A machine was developed that automated this process. Essentially, there is a feed belt. The veneer sheet is feed down this belt. When coming down the belt, the sheet goes through a scanner. There, the scanner will report the coordinates for all of the holes in the sheet. The veneer then reaches the main patching table. The patching table has a total of 9 servos that controls it. The sheet come into the middle section. It is then either sent to the right or the left based on which side is open. From there the sheet is patched at that respective side. While it is being patched, the Center X,Y,Z housing returns to the center and grabs the next piece and takes it to the other side.
After the veneer sheet is all patched, the sheet is then feed out to a stacker system. Here, there is an X,Y,Z servo driven sheet stacker. It will stack the patched veneer sheets into different stacks depending on there grade and available stacking room. When the stack is full, the operator will remove it with a forklift and sensors will detect that the stack is removed and allow sheets to be dumped there again.
To do this system, a total of 12 Sure Servo systems were utilized for each of the XYZ systems. To run the servo systems, the BRX PLC was chosen. It was chosen because of its motion capabilities, remote IO, and because of stage programming. The BRX easily handled the motion for the 12 servo drives, and all of the encoder feedback. Next, instead of running multiconductor cables all over the machine, the Domore remote IO was utilized to reduce wiring and keep the system neat. Finally, the use a stage programming made the programming a "no brainer". The machine was programmed and debugged in no time because the flow chart of the machine was easily converted to stage programs. In the end the machine functioned better than expected and was able to handle the patching that normally took a few employees to complete.