To work at most mattress plants, workers definitely need a good night's sleep. The manual work of lifting, moving and positioning mattresses that weigh 100 to 200 pounds takes a lot out of anyone.

But as Imperial Bedding discovered, it doesn't have to be that way. By using a range of conveyors in places where they had never been used before, workers now manufacture high-quality mattresses and box springs and then load over-the-road trucks more ergonomically and with less physical effort than ever before. Also, a bar code tracking system maximizes delivery truck loading efficiency. In the end, the cycle time of mattress production has fallen, trimming costs and labor hours.

According to Ron Rowe, president of Huntington, W. Va.-based Imperial, this is the only mattress plant in America that uses conveyors so extensively, especially in the shipping department. And while instrumental in the development of the materials handling system, Rowe is the first to say his inspiration did not come from within.

Instead, an inspector from OSHA visited Imperial. 'The inspector told me that loading our trucks manually was a danger to our employees and that I needed to find another method,' says Rowe. 'I was lost as to where to look for a solution, but knew I had to find one.'

OSHA made sure of that by fining the company and demanding follow-up to the problem. Rowe set to work looking for a solution to this ergonomic issue that required employees to pick up and move mattresses and box springs that weigh as much as 200 pounds.

'The guys lifting the mattresses could suffer from nerve and back injuries,' he says. 'Not only that, but they were going home exhausted from such heavy work.'

Furthermore, Rowe and his workers were not getting any younger. Many of them had been at Imperial nearly as long as he has - more than 30 years.

In a typical day, the staff of 85 at Imperial produces between 700 and 1,000 pieces on one shift. Every piece is shipped the same day to customers in the retail and hotel industries.

Rowe began looking for answers by consulting with a physical therapist, who helped train employees on proper lifting techniques to help minimize injury potential. It was a starting point, but Rowe knew it wasn't going to satisfy OSHA.

With a background in electronics and as a mechanic, Rowe applied his skills to create some sort of equipment that could help load his mattresses onto trucks. Using rough sketches, Rowe came up with the concept of a specialized conveyor. Then he attended a bedding trade show where he found an extendible conveyor (Stewart Glapat Corp., www.adjustoveyor.com ) that could be adapted to the shipping department.

But Rowe didn't stop there. Even though the OSHA inspector had focused on the shipping department, Rowe took this opportunity to improve mattress handling ergonomics throughout the plant.

Imperial runs a near just-in-time operation, building daily to customer orders. But the production sequence is driven by the shipping operations. Mattresses are assembled in the order that they are required for loading onto delivery trucks.

The process begins in the build-up department where workers collect materials for a particular mattress model. Lift trucks and dollies bring mattress spring assemblies, foam, pads, tops and other components to the build-up tables. There, workers loosely assemble the mattress before sliding it onto a takeaway conveyor for delivery to the tape-edge machine.

This 300-foot long belt conveyor automatically feeds the mattress to the tape-edge workstation where it is automatically flipped to sew all four sides. As the mattress comes off the machine, it moves onto an on-edge conveyor (see photo) which carries it the length of the building, about 400 feet, to the wrapping machine.

As the mattress is wrapped, a bar code printer runs a shipping label. This tracks the mattress while it is staged in an overhead conveyor bay prior to truck loading.

A fixed scanner reads the label and determines where the mattress needs to go in the staging area. 'When the mattress is scanned, if it's due to be loaded, a trap door will open at the right point and set the mattress onto another conveyor line that takes it down for loading,' explains Rowe. If the shipping department is not yet ready for the mattress, it will stay in the staging area until needed. In either case, 'the conveyor system moves the bedding onto the trailer in the exact order needed for smooth unloading at delivery points,' says Rowe.

The loading system is known as the S-5, short for ship, schedule, storage and sortation system. Down on the shipping floor, it includes three telescoping booms that provide 51-feet of cantilevered extension beyond the fixed section of the unit. A 36-inch wide rough-top belt conveyor that runs 250 feet in length is part of the system as are pendant controls that allow the operator to ensure the mattresses enter trailers at the right height to avoid lifting.

As the mattresses reach the trucks, should an item need to be flipped for better load stability, the employee can simply guide the bedding over as it falls onto the stack in the trailer. The end result is that, following wrapping, the mattresses make their way onto the trucks with little to no human intervention.

'We've eliminated all ergonomic injuries,' Rowe says. 'In addition, we don't have to worry about OSHA fining us for mistakes in handling.'

But the story doesn't stop there. 'Our focus now is on complete materials flow. And that is especially important when the finished product could weigh as much as 200 pounds,' Rowe adds.

Something else also happened. - Rowe found that his employees are happier as well as healthier. Turnover rates, once an issue at the company, have been slashed. 'This is key,' Rowe says, 'because it lets us meet our customers' needs better.'

Click this icon to read about Lucent Technologies' material handling system in Dublin, Ireland.

Click this icon to read more about conveyors.