Recline Transom Prototyping and Development for "Be" Chair


The Recline Transom is one of the key parts of this innovative chair design which offers a new standard of comfort and unrestrained movement, supporting the range of postures and work styles typical of today’s workplace. Designed by Formway Design, the "Be" chair transom design utilizes material technologies and design to maximum effect.


The single co-moulded part when compared to Formway’s existing high end task chair (‘LIFE’) replaces 5 die cast aluminium parts plus various pivot pins, bushes, retaining clips etc, a total of 21 separate parts. This reduces assembly time / cost and requires much less stock holding.


Hytrel over-mould allows flexing movement through controlled deformation to provide enhanced user comfort. The chair can move to support the user through a broad range of postures.


Fewer moving parts means less assembly tolerance issues, less opportunity for squeaks or other noise during use and lower potential warrantee costs. Simple, clean aesthetics possible with exposed mechanism. No covers or shrouds required.


Tool design and manufacture was all undertaken by AXIAM. This in itself was an interesting challenge. A very thick section, odd shaped part which would naturally be inclined to shrink/warp badly required very good tool temperature control, even through the multiple moving parts of the tool. Adding to the  complications, the substrate needed to then fit accurately into a second tool for co-moulding.


Tooling went through no less than 5 design iterations before the desired functional results were achieved. Several things needed to be achieved through research and many trials over a 10 month period since the tool and part design was agreed on and tools commissioned.


Material trials consisted of several grades of Crastin PBT for the substrate, the unusual thick section part design and material combination needed to withstand extreme structural tests as well as a degree of chemical and mechanical bonding to Hytrel.


Aluminium inserts were heated to specific temperature before being loaded in the tool to prevent stress on the PBT moulding during cooling.


The same exercise was done to find the right combination of design and material for the Hytrel co-mould to fit the function expected from the part. Results proved that this radical new idea will give the performance and function that the customer was looking for.


Once proven, the prototype tool was sent to the US for further trials and from there a new production tool was built and commissioned for manufacture in the US.


The "Generation by Knoll" is now an integral part of Knoll’s office seating range and is sold throughout North America and Europe. Sales so far have been above expectations with the general reception overwhelmingly positive.


The "Be” chair as it’s known in NZ and Australia is now due for release here.





Recline Transom Prototyping and Development for "Be" Chair

A single co-moulded part in the place of multiple parts reduces assembly time & cost