Cutting & Packing Workshop Spring 2008

Furniture Manufacturing

Upholstery Industry Manufacturing process Design Wood frame cutting Assembly Foam Textile cover Production technology – cutting machines

Wooden Frame

Wood Cutting

Fabric Cutting

Foam Cutting Movie:

Assembly Assemble wood frame & springs Cochins and Textile cover

2D Cutting Wood Metal Textile Foam

CNC Router Heads Hold-down system Tables Tool changer Controller

Accu-Router Movie

Fabric Cutting

What does it have to do with computational geometry Given a set of 2D shapes (polygons): place the shapes on a material such that they will not intersect. Variant #1: Use infinite roll with a given width. Variant #2: Use sheets of material with a given width and length. Optimize your solution to use as little material as possible.

Business Value - Example Bassett Furniture ( $300M in revenue per year 13 routers Cuts ~650K sheets for ~650K frames. $13M cost of wood $26M cost of foam (outsourced) $26M cost of fabric Total $65M material Saving 5% wood material = $650K per year

Different approaches to the nesting problem Manual nests (or semi automatic): Human made Automatic nests Software made Static nests Nest few kits and use the same nest again and again Dynamic nests

Dynamic approach Advantages: Nest according to demand. Nest the exact amount of needed parts. Support custom styles. Mix different jobs of the same material. Disadvantages A lot of nesting work – requires software. Each nest is different – sometimes cause difficulties in production process.

Example – build you own furniture tom-upholstery/custom- upholstery.asp?type=loft

Additional Options Keep grain direction: part cannot be rotated. Stripes and plaids

Additional Options (cont.) Hold-down systems & cut order (wood) Vacuum Rollers Flexible Fires (cut path) Movie: Foam (cannot leave material during cut) Stacking (foam) – Cut time/ efficiency trade-off Leather – quality areas

Metal cutting – Laser Machines

Laser cutting Movie Restrictions: Heating Tabs – holding small parts Small parts first

Metal Cutting – Waterjet machines