A SIMPLE switch to a polymer bearing in place of stainless steel has saved lead acid battery recycler, Frys Metals, tens of thousands of rands in maintenance costs and much more in preventing lost production time.
Due to the aggressive, acid environment of the Germiston-based recycler, the company had grown accustomed to losing up to four full days of production per month due to premature failure of a critical conveyor idler bearing. That is until plant engineer, Erasmus Smit, revisited the requirement for a stainless-steel bearing and tried other options to prolong the period between changes.
Having experimented with various stainless-steel types and ruled out other materials he decided to turn to polymer bearing manufacturer, igus, to find a solution. With the assistance of igus product specialists, Juan-Eric Davidtz and Kabelo Maimane. The team determined that an igubal JEM insert bearing would be the ideal substitution due to its high load handling ability, abrasion and chemical resistance.
Saving time and money
“Ultimately when the last stainless-steel bearing failed we stopped the conveyor and split the belt to get access to the bearing and shaft that would invariably be damaged and in need of refurbishing due to the slow failure and abrasion. Once the shaft was replaced and the bearing inserted into the existing steel housing we had a specialist resplice the belt and restarted the process… that was five months ago and we have not changed it since.
“While the part cost just over R200 it has saved us a fortune in downtime prevention and improved the overall productivity of the plant substantially. Its success has also led to us seeking other areas of improvement where we can use igus bearings and other motion plastics solutions to replace steel throughout the plant.
“We have already identified a number of applications that will benefit from these wonder-materials including bearings, bushing and cable management solutions. Considering that our whole business is built around the smashing and recycling of batteries containing aggressive acids it is needless to say that only the toughest materials will do,” says Smit.
Treasure from scrap
Frys Metals process includes the collection of car, truck and similar lead acid batteries which are stockpiled and loaded into a chute using front-end loaders which usually leads to substantial damage of the casings and starts the process. The chute releases the mostly broken batteries onto the incline conveyor in question and these make their way up to a specially adapted hammer mill leaking all the way.
With an acidity pH of approximately 3, the acid spills over the conveyor and persists throughout the rest of the process. The batteries are further pulverised and the lead is extracted. Several other processes are applied which leads to the plastic being recycled and the lead smelted and both materials are made ready for resale to battery manufacturers.
The entire process is demanding and requires high levels of safety and environmental management to prevent accidents and damage to the environment. By reducing the amount of human intervention these more efficient engineered materials contribute to an all-round improvement of the entire process.
igus is the world’s preeminent manufacturer of motion plastics. Its wide range of iglidur polymers are specially formulated to meet a wide array of applications in the harshest of environments. With extensive resources made available annually for further research and development, the company can adapt and customise its solutions for specific applications.