A frequent question shops ask is whether they should spin their chips to send to a recycler, or if they should briquette. They ask questions like:
Assessing the Situation
There are many shops that use a centrifuge to spin fluid from chips as opposed to using a briquetter to compact the chips into pucks. But, when it comes to lose scrap and pucks, the pucks are easier to store, leave little residual oil, and can bring more money than loose chips. So why despite the benefits of a briquetter, are some shops just spinning?
Unfortunately, the answer is not that simple. The answer to that question depends on the answer to a few other questions including:
A look at Spinning Vs Briquetting
When we take a look at cutting oils we know that it can easily cost $20 or more per gallon (10-20 times the cost of water-soluble cutting fluids. For heavy users like Swiss-style CNC shops and screw machine houses, this can quickly add up to high costs. For example, recycling a ton of brass chips that has just 5% oil could mean a loss of $5000. Similarly, shops that generate a dumpster full of aluminum chips per week could lose about the same amounts of money in water-based cutting fluid.
So most typically, when the shop’s goal is solely reclaiming and saving on cutting fluid, a wringer is the answer. Centrifuge systems are the metal equivalent of salad spinners, quickly turning wet chips into dry ones. Some shops keep it simple: fill up the chip carts on a regular schedule, pull them over to a standalone centrifuge, dump them in the hopper, and push the button. There’s some manual labor involved to this approach, but it’s minimal.
When saving on cutting fluid is not the main goal, but volume of scrap is high and transportation cost is an issue due to hauling longer distances, then minimizing the size of the machining waste through briquetting would bring maximum value. Depending on the briquetter manufacturer, the average aluminum puck weighs around 125 lb./cu. ft. (dependent on the size of the briquette and density of material before briquetting). This is nearly ten times denser than loose chips, saving substantial amounts of storage- optimizing container fill.