Slane Hosiery Mills
Athletic Socks Manufacturer

New Powered Conveyor System Helps Increase Plant Production by Over 20%

For sock manufacturer Slane Hosiery Mills, a packaging area that depended on manual conveyors provided to be the weak link in the manufacturing chain.

The company recently replaced all of the manual conveyor with a powered conveyor system, and plant production jumped over 20%. Employee morale climbed upward as well.

Slane Hosiery Mills manufacturers athletic socks for major sportswear companies at its plant in High Point, N.C. The High Point plant performs all of the operations involved in the manufacturing process: knitting, dyeing, finishing, and packaging. Until recently, the wrong materials handling system in one area of the plant was limiting employee productivity and plant output.

In the plant's packaging operation, employees receive socks from the finishing area, package them, and then send them on to shipping. For a number of years, the packaging operation was an entirely manual one. Employees loaded cartons onto sections of manually powered roller or skatewheel conveyor, then pushed the cartons along to the next work area. Due to poor system layout, the conveyors consumed more than their share of floor space, limiting the amount of space available for workstations.

Recognizing that their packaging operation needed a boost, company managers approached their local Hytrol Conveyor distributor, Advanced Equipment Co., and asked for possible solutions. The distributor's suggestion was a straightforward one: tear out all of manual conveyor and replace it with a powered conveyor system that has been specifically designed to meet the needs of both the application and the building layout.

Company managers considered a number of possible solutions, but decided that the idea of converting from an entirely manual operation to one based on the use of powered conveyor systems held the most promise. Plant Engineer Steve Ferguson recalls the logic behind their decision: "The High Point plant is our only facility that makes athletic socks. We were therefore not in a position to risk plant production by experimenting with different design approaches. We needed a system that would go in as promised, start up as promised, and perform as promised.

"Those requirements translated into a need to use a distributor that could correctly apply the conveyor manufacturer's products to our application. Regardless of the quality of the materials handling equipment, if it isn't correctly applied for the specific application, the odds that it is going to provide the solution that the user is looking for are pretty slim."

After reviewing several proposals, the company chose the design that featured conveyors and other components supplied by Hytrol Conveyor.

A Solution That Delivers the Goods

The new system consists of four parallel lines of powered roller conveyors. Workstations are positioned on each side of each of the four lines.

Three of the four lines are equipped with hinged gate sections that can be easily lifted to allow employees to move between areas.

As an employee completes filling a carton with finished product, the carton is placed onto one of the four main conveyors. The carton then flows along the length of the line to a transfer point. Accumulation sections keep the cartons properly spaced as they move along and prevent pile-ups.

At the end of the four main lines, cartons are powered onto a right-angle, zero-pressure take-away conveyor by O-ring transfers. Carton spacing and destination are controlled on this takeaway conveyor by a series of photo cells and the zero-pressure accumulation zones.

Two types of cartons are handled on this conveyor. The cartons are identified by the presence or absence of a metal tag or metal framework. Cartons with a metal identifier are recognized by a combination metal detector and photo cell; a pusher-type diverter will steer these cartons from the takeaway conveyor onto the appropriate conveyors for transport to the warehouse. Cartons that do not have a metal identifier will be pushed onto another line by a second pusher diverter.

More Production, Less Maintenance

The installation and start-up of the new system went without a hitch, according to Wesley Hutchins, Assistant Plant Manager at the High Point facility. "Once it was installed, it took about twelve minutes to get the whole system up and running. And it's been running with very little unscheduled downtime ever since," says Hutchins.

The new system has provided other benefits as well. Hutchins explains: "By tearing out all of the old conveyor and starting the layout design from scratch, we were able to really optimize our use of existing floor space. As a result, we have been able to add over a dozen new workstations in this area. As you can imagine, it would have been easy to cost-justify this conversion to a powered conveyor system based just on the production increase of the new workstations."

The combination of the new conveyor system and the additional workstations has produced an impressive 20 to 25% increase in plant output. And by eliminating the manual pushing of cartons on the old conveyors and reducing the amount of lifting required, the new system has improved employee morale at the same time.

According to Maintenance Technician Kenneth Conrad, the plant's new conveyor system not only delivers the goods - it does so while requiring very little maintenance. "We do have a good preventative maintenance program set up here at our High Point plant, but, frankly, this new system requires very little attention.

"We inspect each of the conveyor sections on a regular basis as a part of our PM program, but they rarely require anything. The only time we need to focus on the conveyors is when a piece of debris accidentally finds its way onto the rollers. But we have one member of our maintenance staff who keeps an eye on the conveyors and removes any pieces of debris that get into the system. To say that that's our only maintenance concern says a lot about the conveyor equipment.