Of all the factors that impact ergonomics on an industrial cart or rack, casters are the most crucial part of that equation. The amount of push-pull force exerted to start and continue rolling, as well as turn and maneuver, are ergonomic issues that can be reduced by utilizing the proper ergonomic caster.
Since everything is riding on the wheels, conventional thinking is the harder the wheel material, the easier it is to push. While the hardness does make it easier to roll, it might not be the best fit for your application to switch all your wheels to steel or phenolic, as this would cause several other issues.
One of these concerns is added noise. You will have carts that are easy to use, but they would also be very loud. OSHA guidelines state that an increase of 5 decibels db(A) reduces an operator’s allowed time of exposure by half.
Also, a phenolic or plastic wheel will accumulate debris in the rolling surface of the wheel. Even if you have a clean factory floor, you will still collect a certain amount of debris which has an adverse effect on the life of your wheel.
And merely increasing wheel size might not be enough. While in theory, increasing wheel diameter (for example to 12 inches) with a smaller width (for example 1.5 inches) will give you better ergonomics, many carts have size limitations on the wheels that they can accommodate.
This is where the advantages of a polyurethane wheel come in. New polyurethane wheel tread formulations achieve a return of energy, hence reducing the amount of push-pull force required. They are some of the most ergonomic wheels available and provide less resistance than other wheels. When thinking about caster ergonomics, the wheel’s bearings also come into play.
Generally, ergonomic casters use a ball bearing, so you should select precision bearings that are sealed and are maintenance-free. Bearings that require maintenance can become dirty or contaminated with debris. If these bearings are not properly maintained, the lubricant can break down which causes the rolling resistance to increase quickly.
The caster rigs can also have a significant impact on ergonomics, especially when turning, or when starting to roll when the wheels are not parallel. The longer the swivel lead (distance between the center of the swivel section and the center of the wheel), the easier it is to turn or start rolling when the wheels are not all parallel.
Maintenance-free TWERGO® wheels were developed to ensure that all the wheels rotate independently of each other. They can rotate in either direction and at any rate with a minimum of rolling resistance. Because less force is required to move heavy loads, the risk of injury decreases. This makes TWERGO® casters and wheels perfect for applications like production racks (power transported, manually handled and mobile fixtures); parts bins, conveyor systems, and other applications where maintenance-free casters and ergonomics are concerns.
When it comes to reducing worker injury in material handling applications, safety and savings usually go hand in hand. Which is why proper ergonomics can have a substantial impact on an organization’s bottom line. Between reducing the risk of injury, creating higher quality and increasing productivity, ergonomics can benefit the health and well-being of everyone involved.