We are going to discuss the differences between steel BX and aluminum BX, also known as MC cable. There are various terms used, but these are the most common. We process these cables in two different ways, although they go through similar equipment, not all steps are the same.
Traditionally, the method was to place the cable in a vise and pull the wire out manually. We used to do this a lot in the early days, but it is not scalable for large quantities. While most of this material is still exported, a few people in the U.S. process it.
You might think aluminum BX is easier to process, but we have found that steel BX is simpler. For steel BX, we start with a shredder, then move to a granulator. After that, we use a magnet to separate the steel from the insulated wire. The insulated wire then goes into another granulator to chop it down further, making sure there is no un-scalped copper, meaning no copper still encased in plastic. And as a final step, we use an air separation table.
For the granulator, we use a staggered cut rather than a scissor cut. The scissor cut involves angled blades that meet at a point, which concentrates the cutting force but causes blades to wear down faster when dealing with abrasive materials like steel. In contrast, the staggered cut uses straight bed blades and staggered teeth on the rotor, allowing the same cutting force to be applied more evenly and extending blade life.
When processing aluminum BX, we make a few adjustments. We typically use a larger screen in the granulator, about 1/2 inch, and follow a similar process: first shredder, then granulator, and then an air separation table to separate the aluminum from the insulated wire. The insulated wire then goes through another granulator and air separation table. The main difference here is that instead of using a magnet after the first granulator, we rely on air separation.
That is the basic process we use. There are many ways to approach this, but we have found this method works best for us.
If you do it differently or have any questions, please reach out to us.
