You have seen it before but maybe didn’t know what it was. I’m talking about plastic, dimensional lumber. The lumber is extruded first in sheet form and then ripped to size depending on the size lumber needed. It is the ripping process with a multi-blade rip saw that was causing problems for our customer. Basically, the blades would heat up to a point where they would melt the plastic instead of making a nice sharp cut.
The customer was having to stop the ripping process every ten minutes or so to allow the blades to cool down enough to continue for a while longer. The customer was using a simple nozzle, blowing onto the blades and the arbor to achieve the cooling more quickly. They noticed this did have a positive effect and so they thought that colder air would be better. So, they invested in (2) Model 3725 Adjustable Spot Coolers for the cold air source. Then, the Adjustable Spot Coolers were mounted to a 1-1/4″ PVC pipe with many holes drilled along its length. The purpose of the PVC pipe is to act as a manifold to distribute the cold air from the two Adjustable Spot Coolers mounted at each end. The pipe was 4 ft. long to cover the full width of the cutting area. In this way, the blades could be at any number, up to 14 and in any position and still receive the cooling flow during the cutting process.
This idea worked so well for the customer, they were able to achieve approximately a 25% productivity gain just by not having to stop all the time to allow for cooling. They are still evaluating whether they can go longer than the usual 3 weeks between sharpening of the blades due to cooler cutting conditions which keep the blades sharper longer.