Is your current thermoforming line not keeping pace with production demand or your newer equipment? Are you looking for ways to increase speed and accuracy to improve output? This was a scenario we recently faced in our foam plant. After years of use our Commodore 730-28 thermoformer was starting to lose pace with the newer machines on our production floor. We were facing a decision to either replace the aging equipment or perform a complete system upgrade to get it producing to a similar level as the other machines. We recognized this as a challenge for us, but more importantly a real world challenge for our customers as well. We took a practical approach by replacing some equipment with new, but opted to upgrade several lines, thereby better managing our capital spend. Here are the 5 upgrades that we did to increase the output of this machine:
In the case of our 730-28 we were looking for increased control of heat distribution on the sheet in order to, improve quality and reduce scrap. We integrated additional Calrod heaters into the existing oven and configured them for additional zones of heating, allowing us to more accurately control temperature of the sheet before reaching the thermoforming station.
Due to the age of our 730-28 we were finding it increasingly difficult to find replacement components for the electrical controls. Replacing the control system made finding new components easier, more cost effective, and with the expanded control capability we were able to implement new sensors for better machine operations. The older components that were removed provided spare inventory for the machines that have yet to be upgraded. Part of the upgrade was an improved operator interface and the ability to access the machine remotely.
We implemented smaller yet faster hydraulic forming cylinders to the form station. Through years of testing on our servo machines we found that historical forming force requirements have been unnecessarily excessive. By experimenting with different size bore cylinders in our foam plant we have proven that the smaller cylinders can create the required pressure to make a quality product with the added benefit of a 20% increase in linear velocity. Additionally, the hydraulic unit does not work as hard as before, therefore decreasing stress on the system and increasing the unit life.
Trim Press Upgrades
With increased forming cycles per minute (CPM) the trim press had to improve in order to take advantage of the upgrade. As trim press cycles increased vibration from the reciprocating motion of the treadle was causing issues with trim accuracy. By replacing the treadle support structure with a stiffer "A-frame" design we were able to increase the speed of the machine while maintaining accuracy Additionally, we switched out the chain drive for a timing belt drive on the trim press. The dampening effect of a timing belt allowed for slightly faster run speeds without impacting trim accuracy, while simplifying machine maintenance as it does not require lubrication and is more cost effective to change out. Continued trials of different frame designs and Finite Element Analysis have helped incrementally improve our run rates by as much as 100 CPM.
Photo Eye Sensors
The 730-28 had older sensors that were measuring the underside of the sheet looking at the inside slope of the foam trays which was not very accurate for trimming and indexing. We replaced the sensors with a new photo eye sensor and relocated to scan the top side of the sheet for the break in material providing more accurate indexing and trimming. The system required no additional programming and was quickly mounted and adjusted to the machine.
So, when we completed these upgrades we started up the machine and set it off running. Most of the upgrades ran concurrently so we had minimal down time. Our plant manager is seeing a 20-25% increase in the output of the machine after the initial adjustment period. These upgrades allowed us to save money over an equipment replacement and they are paying for themselves with the increased productivity. We will continue to share our experience with the machine and future upgrades as we continue to look for ways to increase productivity in our foam plant.