When the USA-based industrial lead-acid battery manufacturer, Battery Builders LLC, decided to upgrade its facility, it seemed like an obvious choice to include its six-station cast-on-strap machine in those upgrades. MEPCA found out how the company worked with robotic integrator MAC Engineering to install a Kawasaki large-payload robot with a robotic cell consisting of six process stations.
To automate the cast-on-strap machine (COS), a robot solution needed to have a high payload and high repeatability in order to lift and align the battery plates accurately. BBI also needed to be able to rely on the robot and peripheral equipment to meet production goals of 1,000 battery cells per day – more than double the current daily production.
BBI had also been plagued by frequent machine breakdowns from its manually run COS machine, which it had used for over 25 years. The antiquated machine was causing costly delays in production, and BBI was experiencing four to five hours of downtime a week.
Plus, the process of manually stacking battery plates and loading plates into jars generated more airborne lead dust, which posed a greater risk for exposure, than if the process was automated. The older machine also required employees to lift heavier loads, resulting in a greater risk of injury. For BBI, it was important to see the positive impact of automation reflected in its work environment – not just on its bottom line.
In order to properly create its lead-acid batteries, BBI had to install a workhorse precise enough to consistently align 300 lbs. of battery plates up to 500 times per day. The robot also needed to be able to brush off the end connectors on the batteries, dip them into molten lead, and package them in a plastic jar. In order to accomplish this diverse list of detailed tasks, a versatile robot was required.
Almost immediately after the automated solution had been installed, Battery Builders saw the advantages delivered by the Kawasaki robot reflected in the quality of its end product.
The number of labourers needed to man the process went down from seven to five. The robot steps in after the battery plates have been manually slid onto the conveyor to align the plates and ensure they are even and flush. During this new process, operators no longer had to lift the plates from the ground – they moved the plates laterally onto a conveyor, which is more ergonomically friendly.
From here, the robot picks up the plates and runs them over a large bristle brush to remove any lingering debris from the end connectors, called lugs. Next, the robot runs the product through a flux process. The lugs are then dipped into tin, and dipped again into molten lead. Last comes the case-out process, where the robot places the battery plates into their plastic casing.
Although Kawasaki’s ZX300S robots are capable of carrying payloads of up to 300 kg, they combine a long reach arm with a minimal amount of dead space for a wide work envelope. They also have a high repeatability of ±0.3 mm, making them ideal for applications that require precision and heavy lifting. When combined, these features created the perfect solution for BBI’s setup, which required the robot to be able to reach multiple machines at varying heights.
Since replacing the old, breakdown-prone COS machine, BBI has seen a better, more consistent product quality using fewer man-hours, and created a significantly safer work environment. The employees who used to operate the old machine are now working in the battery assembly department – allowing BBI to put more man hours towards the final stages of battery assembly and ultimately improving the overall quality of the batteries. Once all of the integration is complete, the company will be able to increase production from 400 to 1,000 battery cells per day – more than double the output it saw prior to automation.