To engineer its new line of upholstered ready-to-assemble furniture line, Hooker Furniture turned to 3D printing.

Art Raymond, who served as Hooker Furniture Senior VP casegoods from 2010-2013, says 3D printing let Hooker chair develop and bring to market its ready-to-assemble upholstered furniture lines on a compressed schedule. Sold online through Wayfair and other online vendors, the upholstered accent chairs are shipped directly two consumers in two cardboard boxes, that weigh in at just under 70 lbs. together. A video below shows the assembly process by a consumer.

Raymond described the development of the chairs in his “3D Printing: The Future of U.S. Manufacturing,” which included the Hooker Chair manufacturing case study. That presentation  was one of several surprise gems at the wood industry Executive Briefing Conference 2014. The annual EBC, a TED-like conclave for woodworking execs, which examines trends and key issues in technology and business practices, was held in Denver April 6-8, 2014.

Raymond, a manufacturing consultant to the furniture, cabinet and millwork industries, delivered his description of the Hooker Furniture 3D printing project in a deadpan Carolina delivery that understated the significance of the technology he revealed.

Beginning with the basics of 3D Printing – or additive manufacturing, as it is sometimes called – Raymond peeled the onion back with the analytical mind of an engineer, one who, in this case, was in a process of discovery as he examined the new technology. That alone was fascinating to witness.

Raymond explained two types of 3D printing technology. One, called fused filament fabrication, uses a melted plastic material that bears a resemblance to hot-melt glue. These are heated into viscous fluid which is then “printed” in a fashion not dissimilar to standard inkjet printing. The melted plastic is deposited by a series of print heads in layers to build up the desired product.  

The other approach is called granular materials binding. Metal or plastic in powder form is solidified in layers as required to build up the product. That binding process is typically through sintering (heating the powder to just below its melting point) or through melting. Raymond showed a video which illustrated production of a metal injection molding tool using sintering technology. 

In 3D, print heads deposit layer upon layer of material to build three-dimensional objects. This additive build-up of material is the exact opposite of 5-axis CNC, which carves away, shaping or carving an original block or board into the intended component.

Once cured and cooled, the 3D printed object solidifies as it cools, and may then be polished or sanded. It may also form the basis of a casting mold for prototype parts - the approach used in the Hooker project.

The printing and curing can take hours. This was brought home as Raymond showed a video of the printer building a project through its additive process, but sped-up dramatically for the sake of the presentation.

“If you look at this in real time, you see something that is only slightly faster than grass growing,” Raymond noted, eliciting a laugh from the audience. “You could have a battery of these machines in production,” Raymond suggested. But so far, while this is not a production technology, it does form a basis for rapid prototyping.

In the case of the Hooker chair development project, 3D printing was used in creating parts to allow the parts of a ready-to-assemble upholstered chair to be bolted together by the average woman shopper, without tools, in the comfort of her living room - as shown in the video below.

"The prototype parts were the proprietary plastic parts for the connector," Raymond says. "The metal parts - bolts, thumb bolts, washers - were off-the-shelf. We only ‘printed’ prototypes until the design was finalized and tested. We then had the final tool and die made for injection molding."

Hooker had been looking for ways to manufacture new furniture lines that could be sold through online shopping networks, then drop-shipped to end consumers.

“We find more and more furniture is sold online,” Raymond said. To ready a chair for market to meet the key buying season, Hooker Chair wanted to compress the development cycle. The 3D inkjet printing was key. The chairs were designed in Solid Works software, with plywood parts and corner braces cut on CNCs.

To make it feasible for the consumer to readily assemble the flat-packed chair parts, large thumb bolts were used that can be easily hand tightened without tools. Legs screw into metal parts in a conventional fashion. Once assembled, the Rizzo chair looks for all the world like a conventional upholstered wingback chair.

“We’ve got this online and it is selling very well,” says Raymond. “We would not have been able to do this without 3D printing.”

Raymond advised his audience to think creatively in looking at applications for 3D printing – such as decorative embellishments, or replacements for carvings. But, he advised, “We’re not going to print a wooden chair.”

Raymond joined Hooker Furniture in 2010 as VP Casegoods Operations on a three year contract. He continues to consult with the company as it expands its product line and distribution channels. Reach Art Raymond at www.raymondnet.com