The Challenge

An architectural millwork company realized a need to improve workflow through their paint and finishing area and contacted Pacline for assistance.  Their process at that time included the use of carts to manually move wooden parts through the stages of finishing, including sanding, spraying, curing and finish coating.  The carts were being moved many times causing workflow obstructions and wasted labor. 

The Solution

A Pacline engineer worked with the customer to confirm the system requirements as well as to share the conceptual layouts. The layout of the conveyor path was coordinated with the customer’s spray booth, oven and other processing areas. The final layout design was approved by the customer and met the project objectives. 

The wooden parts are carried on carts that are attached to an in-floor towline conveyor. The carts are pulled through a sanding area, then through a paint booth. After painting, the carts move through a serpentine area for flash off, prior to moving through a curing oven.  To reduce the length of the curing oven, the conveyor doubles back through the oven then moves the carts to an unloading area.

The Result

The installed conveyor system helped control the overall process flow while reducing labor, improving throughput, and reducing handling damage. The Pacline customer was able to install the conveyor using a local qualified contractor.  

Pacline offers flexibility in the scope of supply, providing only equipment, as in this case, or complete turn-key conveyor solutions.

An overhead conveyor offers many advantages over other methods of moving parts between various manufacturing operations. It can transport items through areas not accessible to workers, such as automatic spray booths and drying ovens, or where hazardous conditions exist. The weight carrying capacity is greater than any employee, and it does it without tiring or taking breaks.

Often an enclosed overhead conveyor can be installed where a floor conveyor would be impractical. When there is a need to temporarily hold work-in-progress, carriers can be switched to recirculating loops or storage spurs until needed. Safety devices can be installed on inclined sections to control runaway carriers in the event of chain breakage.

Specializing in overhead conveyors for woodworking applications, PACLINE’s pre-engineered standard conveyor components feature an enclosed-track design and bolt-together construction. The conveyor chain travels within an enclosed track, where it is protected from the plant environment. The extremely low-friction design of the chain makes it possible to power long
systems from a single drive.

Because the drive system is one of the most important components, PACLINE conveyors incorporate a unique caterpillar drive unit, which can be placed in most the convenient location. It is not restricted to corner placement, as is typical in many systems. Another feature of PACLINE systems is the elimination of sprocket turns that, in addition to being dangerous, are also costly and difficult to install and maintain.

Published in Canadian Woodworking, November 1989

The process of building wooden furniture has numerous steps, many of which have little to do with the actual construction.  A large aspect of the assembling chairs, tables, kitchen cabinets and several similar items is the finishing stage, which is a multi-phase procedure that includes multiple spraying and sanding steps.  Next to overall style, the finish – stain or paint – is the most highly visible criteria of a potential consumer.

The Challenge

For one furniture manufacturer, the finishing stage of their process was causing a bottleneck in their process.  Having only one spray booth, workers were continually moving chairs, tables, desks and dresser units in and out of the single booth on manual push carts.  With their high quality, four-coat stain finish, furniture pieces had to be stored around the plant for curing between coats and intermediate sanding steps.  With all the shuffling of carts, valuable time and floor space were not used efficiently and it was difficult to keep track of all the partially stained furniture staged around the building.

Furniture pieces could be cut, milled, assembled and sanded at a higher rate than they could be stained, resulting in lowered production rates.  Because the furniture varied greatly in size and weight (from 5 lbs. – 200 lbs.), many items were cumbersome to move manually through the various finishing processes.

A system was needed that would eliminate the bottleneck, increase production rates, minimize handling and reduce “work in progress” storage space.

The PAC-TRAK™ Towline Conveyor Solution

To create a viable solution, the furniture manufacturer would require additional spray booths in the plant; no system could run effectively with just a single booth present. PACLINE worked with a spray booth company, who would supply the additional booths and flash off (curing) tunnels.

PACLINE provided a customized PAC-TRAK™ Towline conveyor system which would allow floor workers to be freed up from shuffling carts and tracking storage locations of partially finished pieces of furniture.  A 430 ft on-floor cart line with 75 carts was conceived and created to transport furniture through the multiple spray booths with close-packed accumulation in between, allowing every item to flow through each step of the finishing process in a consistent, timely manner.

New carts were created, with the bottom portion mated to the on-floor conveyor and rotating rectangular top platen, allowing the top platen to be automatically rotated in close-pack accumulation areas or manually in the spray booths.  The system also allowed for variable speed operation to accommodate both simple and complex items.  At the maximum 9 FPM set point, raw pieces could be completely finished in only 83 minutes.

Results

PACLINE performed a complete mechanical and electrical installation of their PAC-TRAK™ Towline Conveyor – complete with in-floor drive pit and carts – and seamlessly integrated it with the booth supplier’s equipment.  The very next day the customer was able to train their staff and run afternoon production – seeing positive results and a sound return on their investment.  The finishing bottleneck was completely eliminated and throughput through this process increased by 400%, without an increase in the number of staff.  This, combined with the reduction in finishing costs, meant PACLINE’s solution helped the customer save time and money while increasing the overall plant production rate. 

Contract Supply produces an
extensive line of chairs and stools.

Small shop owners don’t realize the tremendous payback they can enjoy by adding a paint line conveyor to their operation.

I recently attended the AWFS show in Las Vegas, where I met over 200 wood industry professionals, many of whom were the owners of small shops. Many visitors seemed to approach me with caution, saying, “I’m only a small shop, I don’t have the type of cash needed for automating.”

This intrigued me. Many small shop owners were clearly unaware of the cost of our monorail conveyor systems and were quick to jump to the conclusion that any conveyor equipment was prohibitively expensive.

I changed my approach on the second day of the show, immediately discussing with visitors the cost of a 100 foot and 200 foot system. That changed everything. They stayed longer and they came back later in the show for a second look.

PACLINE has worked with several small wood shops. To show you how automation might benefit your operation I would like to share with you the recent experience of one of our customers – Contract Supply Inc.

Conveyor loops at ceiling elevation
and takes advantage of the warmer
air space to speed up drying time.

Contract Supply (CS) manufactures chairs and tables primarily for the restaurant and hotel industry. They also handle large volume refurbishing and refinishing of chairs and tables.

This company was at a stage where they needed to take on larger orders with inherently lower margins. Because of the low margins, CS needed to be highly efficient with production costs, and with the larger size orders they could not afford any rework. One problem, and he would be ‘in the red’.

CS normally processed chairs in batches, and they needed to maintain this ability. The paint room floor was already filled to capacity with carts so, potentially, CS would need to expand their space to accommodate the higher volume. They considered a floor towline with ovens for shorter cure times, but the cost was in the $400,000 range. In addition, there would be the added expense of natural gas to fire the oven, and various permits would have to be secured to carry out the work.

PACLINE came forward with a very different approach. Our goal was to use the existing space and equipment at CS but connect the processes into an “assembly line”. This was all made possible by developing a wood finishing conveyor system that utilized the unused ceiling area of the existing facility. Using this overhead space where it was naturally warmer also aided in the drying process.

Steep inclines convey product
up off the floor.

An overhead chain conveyor is absolutely the most flexible conveyor available. With only one drive, it can snake around obstacles and incline and decline in very short distances. Our conveyor was able to move items at Contract Supply through the paint spray booth, incline to the ceiling where it wound back and forth to allow the precise drying time required, and then moved down to the floor for approximately 20 feet of sanding. The conveyor was set approximately 7 feet from the floor to allow workers and batch carts to pass beneath, and the hooks were made to a length that would allow for good operator ergonomics.

The conveyor was designed to route through the three existing booths: stain, lacquer and sealer. Within each booth, the conveyor made an elevation change to allow the operator to reach both the top and bottom of the chair parts. PACLINE supplied a rotator for each hook and the operator turned the parts as he desired without physically touching the parts.

A convenient clip is attached to the
wood part to allow handling on conveyor.

The PACLINE system was able to satisfy all of the Contract Supply’s criteria:

1. Increase production within the exiting space
2. Clear the floor of all parts while they are drying
3. Allow the customer to continue to process their low volume special items in batches using push carts
4. Produce a predictable quality product by creating an ‘assembly line’

But that was not all. CS management was pleasantly surprised to discover that the new assembly line helped ensure that their people worked at a much more consistent and sustained speed. Workers no longer had to walk to get carts. The product now came to the workers at a rate of production set by the manager. When product entered the spray booth, the worker had to be there and ready.

Overall productivity increased substantially. Despite some initial reluctance to operate on an ‘assembly line’, workers at CS soon realized how the automated finishing line made their job easier.

When it was time for expansion this wood finisher thought ‘over the top’.

Small and mid-sized furniture manufacturers are often threatened with high volume, low margin orders, meanwhile, small facilities and manual handling methods can lead to disastrous quality and financial results. Canadian furniture supplier Contract Supply based in Mississauga, ON needed to automate its finishing operation in an already tight space.

Contract Supply (CS) has manufactured chairs and tables for the restaurant and hotel industry for over 20 years. Within their 65,000 square foot facility, CS handles all design, upholstery, assembly and finishing operations. As with most small and mid-sized furniture manufacturers, these processes were generally done manually. The company supplies high quality wood and metal products primarily to the commercial food service market including: hotels and resorts, restaurants, food courts, shopping malls, libraries, schools and healthcare facilities. They will even tackle large volume refurbishing and refinishing of customer’s existing chairs and tables.
As business grew for CS so did the size of their jobs and eventually, CS was faced with the following production issues:

• There was a need to increase volume to accommodate the larger customers;
• Current space was limited;
• Their (wood) finishing process in particular (from sanding, staining, sealing and lacquering) was ‘back breaking’ and time consuming;
• Smaller ‘special’ batch jobs were still an important part of the business.

Shopping for ideas

Eugene Honcharuk, president of Contract Supply knew something had to be done to meet production demands and maintain efficiency so he went to a trade show to shop for ideas. One option Honcharuk was presented with was a cart-type floor conveyor system to move wood parts through the finishing process. Although this system would help improve production capacity, there were several drawbacks for CS. The cart system would require drying ovens that would add to energy costs and would make the work environment hotter. In addition, the cart system would require an increased use of the already limited floor space.

Finally, Honcharuk was introduced to Pacline Conveyors of Mississauga, ON and Buffalo, NY and was presented with a system designed to free up floor space by making use of the currently unused ceiling space for the finishing process.

“I was upfront in revealing that I did not have the capital to spend on a towline and ovens, particularly if it was going to increase my overhead and reduce floor space,” says Honcharuk. “Our paint shop was already full of drying parts.”

PACLINE engineers assessed the situation at Contract Supply Corp. carefully reviewing all aspects of their finishing process including: space, production needs, variable parts sizing, drying times between the three finishing operations, etc. and the need to be able to continue to “batch process” the way they always did.

Freeing the floor

Pacline recommended an overhead chain conveyor to create an automated finishing line that would allow increased production while freeing up valuable floor space. Pacline designed a system using their enclosed track conveyor. On a single conveyor line, wooden parts are taken through the entire finishing process (staining, sealing, drying, sanding and final lacquer, drying). Pacline’s system was designed to convey product from each spray booth up to the ceiling area and off the floor entirely. The ceiling area proved particularly useful as the warmer air helped accelerate the drying time between stain, sealer and lacquer applications.

“Many of the small shop owners we meet have small environmental rooms and don’t want to disrupt or renovate in part because of the lost production time, as well as permit requirements,” Pacline’s General Manager Karl Scholz, explains. We were able to add the overhead conveyor to CS’s shop without moving a single thing.”

The new Pacline system allowed Contract Supply to take on high volume, low margin jobs effectively without interfering with their previous operation. They could continue to store small batches of low volume, specialty items on the floor beneath the overhead conveyor without interference.

“We mounted the conveyor track at seven feet off the floor to allow batch carts and personnel to travel beneath without any restrictions,” says Scholz.

Special considerations

Custom hooks and rotators allowed the parts to move easily through all steps. Operators can spin the parts through 360 degrees so that all sides of the product could be finished. The conveyor was designed to travel through two elevations in the staining booth to accommodate staining of longer items. This ensures the correct ergonomics for the operator.