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Optimized Manufacturing Process uses Long Fibre polyurethane

  • Sunday, 14th September 2008
  • Reading time: about 3 minutes

Sunbelt Spas recently switched from traditional extruded polystyrene parts for its spa cabinets to Long Fibre Technology (LFT) using the Baydur 675 polyurethane system from Bayer MaterialScience.

The structural nature of LFT allowed Sunbelt to eliminate the need for a traditional spa frame, and the resulting impact was two-fold: Sunbelt Spas was able to design an innovative spa cabinet with superior Class A surfaces and major aesthetic appeal, and it dramatically reduced the amount of time and labor required to assemble the finished product.

Sunbelt’s seven- and eight-foot LFT spa cabinets, designed and manufactured by Romeo RIM, Inc. of Romeo, Mich., feature durable, rigid panels that can withstand a major impact without damage. While traditional extruded polystyrene cabinets are manufactured in sections that have to be assembled in a labour-intensive process, LFT allows Romeo RIM to produce the Sunbelt Spa cabinets in a few large, one-piece panels that are fully molded and easy to assemble. The spas are now assembled in 16 parts – four corners, four sides, four top rails and four bottom rails – which has resulted in a dramatic boost to Sunbelt’s manufacturing throughput.

“The extruded polystyrene material we had previously used for our spa cabinets required a lot of labor to put the individual parts together, but by switching to LFT-moulded parts, we went from teams of assemblers putting together roughly 12 cabinets per day to smaller teams of assemblers each being able to finish a spa cabinet every 25 minutes,” said Matt Markiton, vice president, Sunbelt Spas. “The move to LFT-moulded spa cabinets has been a win-win situation for us, because they’re not only more aesthetically pleasing, but also stronger, more durable and less labour-intensive for us to put together.”

In the LFT process, a robot is programmed to move over the open mould cavity while simultaneously dispensing both long glass fibres and Bayer 675 polyurethane system in an open-pour method. After the robot is finished pouring the material into the cavity, the mould is closed and the material is then put through the traditional closed-mould RIM cycle. To achieve a durable surface for the finished LFT part, an in-mould coating is applied on the cavity tool prior to the material being poured into the cavity. This creates a polyurethane coating that chemically bonds itself to the LFT substrate, resulting in a surface that is extremely durable and scratch resistant.

“The LFT process allows Romeo RIM to mold large, intricate parts with thick or thin walls and very smooth, hard finished surfaces,” said Harry George, head-new applications, Diversified Industries Group, BaySystems™. “In the case of Sunbelt Spas, LFT provided them the freedom to design an innovative spa cabinet that would not have been possible to achieve with other manufacturing methods.”

“These spa cabinets were an extremely collaborative effort among Bayer, Romeo RIM and Sunbelt Spas,” said Patrick Foster, customer development manager, Romeo RIM. “The combination of Sunbelt’s vision, Bayer’s materials expertise and our design resources has allowed us to develop something that’s completely custom and extremely unique to the spa industry.”

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