April 4, 2014
KW Plastics of Troy, Alabama is the largest plastics recycler in the world. The company started by recycling automobile batteries over thirty years ago. In those days the casings were made of Bakelite, so the company’s activity was in lead recycling. The company went into plastics recycling when battery casings were changed to plastic.
Since that time, the company has focused on most all types of polypropylene and polyethylene.
Vincent’s involvement with KW Plastics is in a project involving recycling used bulk bags. These bags, made of woven polypropylene, are recycled in the normal manner, starting with shredding followed by metal separation and washing. Next comes dewatering and drying before the plastic is extruded into pellets. These resin pellets are the raw material for plastic extrusion machines.
Vincent’s involvement in the project is unusual in that our screw presses are used in dewatering the washed plastic. Our other installations in the plastic recycling industry involve dewatering wash tank sludge, a much easier application.
What we found the most interesting is something that has nothing to do with our bulk bag project. KW Plastics has taken-over of the paint can market. The next time you see a 1-gallon pail of paint, turn it upside down and take a look. Chances are you will see that the pail is made of black plastic, and the KW logo is molded in the bottom. It was not long ago that all 1-gallon paint cans were made of steel. Today steel cans are hard to find.
The advantage of plastic pails is that they resist denting. Furthermore, the lips (and lids) are treated with chlorine gas so that paint will not stick to them. This is a great advantage: the lids seal tighter, preventing paint from drying out in the pail.
Kenny Campbell, founder of KW plastics, holds numerous patents which position his firm as the sole supplier of the plastic pails. A key part of the technology he developed involves installing the lip at the top of the pail. The lip must be sealed perfectly to the rest of the pail; it must be strong enough to hold up when the lid is pried loose; it must be flexible to seal against the lid; and it must accept both plastic and tin lids.
Today huge quantities of these pails are injection molded and assembled in one of the many Troy factories. At the same time, in order to reduce shipping expense, satellite factories have been erected adjacent to several major paint producing factories.
This technology has been a fascinating thing to see.