In 2013 Sun entered into a new market segment, the Dental industry. The products we manufacture for the Dental industry are orthodontic spring clips for a brace bracket. A full set of braces consists of 17 unique clips produced with interchangeable progressive dies. Due to the difficulty in forming the customer specified raw material, the small size of this component, and the tight tolerances, it was decided by our design team and agreed to by our customer that we should utilize a laser measuring device to improve the reliability of the most significant dimensional feature of these products.
This micro-stamping has a very tight tolerance on the gap of the clip which is the most critical dimension. To ensure this dimension is met Sun's Engineering department investigated the best options available for a Laser Profilometer and then designed, built and programed the laser measuring machine to present each part to the laser profilometer for 100% inspection. Not only does this machine perform accept and reject functions but it also has a closed loop feedback system to a tuning station immediately before the laser measurement takes place. With this system when the laser detects the feature becoming too close to upper or lower limits it provides feedback to a servo-motor which then adjusts how much this feature is tuned bringing the dimension closer to nominal again. This was all done in house with the support of our customer and engineering team. This was Sun's first use of a laser measuring device.
This program is run 100% inline and the product is feed through the press on a strip or a carrier. The reel goes from the stamping die through the measuring station, the laser closes on part as it is feed through and measures both sides, then determines if part is bad and or good due to the data it has collected. This laser measuring device is very accurate it measures within .2 microns. It not only measures the part it also records and analysis the data it collects and adjusts the tool accordingly based on this data. When the laser inspection machine measures a part good that part is sequenced further down to a cut-off station. If however a part is measured out of specification the part is not cut out of the strip but remains on to be cut-off with the parts carrier scrap.
While this machine measures the most critical feature of all parts we continue to perform Quality personnel visual and dimensional inspections. Since the implementation of this machine we have not identified a single part out of specification. Since the success with this program we have been awarded another program that also requires us to design, build and program another laser measuring machine for a second set of braces.
Here is a Breakdown or the Laser Measuring Device 5 main functions;
• Measure the gaps critical dimension
• Records and analysis the data
• Adjust the tool based on the data
• Cuts the good parts off the strip
• Leaves the bad parts on the strip to be scraped