Liquid-to-Powder Conversion

Link 51 designs and manufactures a full range of storage and shelving solutions which help users improve their work environment. From pallet racks for warehouses, to mobile shelving, to lockers and multi-tier storage systems for hospitals, warehouses, schools, gyms and a broad range of other facilities.

In 1951, Joe Kinnear and his son Peter combined ingeniously designed slotted steel angles with matching clamping plates to form an extremely stable and versatile configurable shelving system. They founded “The Handy Angle Company” which, since 1966 operates under the “Link 51” brand name.

Today Link 51 is a part of Whittan Storage Systems Ltd. – one of the largest manufacturers of steel storage products in the United Kingdom, operating with several market-leading companies and processing 1,000 tons of steel each week. To stay in the premier league of surface technology, Link 51 Shelving plant has recently installed a specially-designed Nordson powder coating booth equipped with advanced dense-phase spray systems.

“The nature of our product is such that it allows us to load the line quite densely, with minimum gaps between the products. Because of this, the old liquid system delivered a rather high application efficiency and material utilization”, said Christopher Walker, “however, each day we came to work smelling solvent in the air. Although all cleaning and disposal procedures were closely followed, we have a high level of environmental awareness and it was time to do the right thing – convert to a more environmentally friendly finishing method.” 

“In 2015, our sister-plant, Link Lockers, installed a new Nordson spray system with dense-phase pumps and significantly improved their powder usage”, explains Tom Clayton, the Powder Coating Line Manager and a member of the project team. “It was clear that we had to get away from liquid and convert”. “First we defined our goals,” recalls Christopher Walker, “and agreed that if we were to improve the paint system, it would need to deliver not only environmental benefits but also improve our operating efficiency and finish quality”.

After Link 51 joined the Whittan Group in 2017, the move from liquid to powder became a priority project. In early 2018, Link 51 began a search for a powder coating system tailored to their production needs. “We were used to our liquid system applying 25 micron of coating. One of the concerns with powder was the ability to match that thickness consistently, without daily fine-tuning, and to reduce the overall applied coating and operating costs”, recalls Peter Charles, Engineering and Maintenance Manager at Link 51, who also led the upgrade of the Link Lockers’ line to Nordson technology back in 2015.

The targets for the new system were set quite high

• 4 m tall products with a line speed of up to 3,5 m/min
• Highly efficient powder application
• Consistent and uniform 25 microns of coating thickness
• Full automatic coverage of the shelving corners
• Fast color change for flexible production
• Clean, environmentally-friendly work place

Once the specifications were defined, the team started the supplier selection. “We knew our requirements were challenging, so we were looking for a supplier with demonstrated abilities to design a system to match our needs and reliably support our production.” Says Lyndon Woodfield, Sr. Team Leader, Manufacturing, who has extensive powder coating experience with Link 51’s old line.

High line density and application efficiency combine to deliver unmatched powder utilization and operating efficiency.

Link 51 team knew about the positive experience at their two sister-plants, Lockers and Pallet Racking, which were using the new dense-phase powder delivery technology from Nordson. So, the team headed to the suburbs of Dusseldorf, to experience the new spray systems first-hand at the Nordson demonstration center.

“It’s nice to test the equipment with our products and powder.” Says Tom Clayton. “Since I was to operate the new system, having a chance to work with it without the pressure of running production was important.” “A few days of testing at Nordson helped us gain confidence in the attainability of our goals.

Their solution was easy to work with and was proven to apply highly controlled coating thickness with no operator intervention. Process control was important for our production efficiency.” Recalls Christopher Walker. “Additionally, Nordson offered a special booth allowing Tom to clean it from the top down using convenient, high-level openings with platforms. That made good sense to us.” Because of the close team work, demonstrated abilities, and the special booth solution, Nordson was awarded the order for Link 51’s new powder coating system with the target to install in late December 2018 and start of production on January 6th – just 3 weeks later. 

The new system features a custom-engineered, 6,5 m tall ColorMax® booth with a Spectrum® HD powder feed center and advanced controls. The booth is designed to provide reliable powder containment while also ensuring soft airflow in the spray area. Special high-level openings with platforms enable operators to clean the booth walls from the top down. This way, no powder is blown in the direction of the conveyor opening against the booth airflow. The automatic floor cleaning system keeps the powder in the booth to an absolute minimum.

The high line density combines with the efficient powder application resulting in minimum overspray. Any airborne powder is efficiently recycled through a twin-cyclone system and screened through an ultrasonic sieve prior to being returned to the fully enclosed feed center. The new system also delivers on the fast, contamination-free color change. “The step-by-step color change instruction on the main controller and many of the color change tasks being fully automated, makes my work much easier” – confirms Tom Clayton.