I often look at non-wood products and think what is the barrier of entry preventing a wood alternative to plastic/vinyl or metal. Extrusions are often one of the reasons. A constraint to processing wood is that it is difficult to extrude. Even with all the techniques we can use to manufacture wood there are some profiles and shapes that are simply not achievable with current manufacturing methods. Coming from the window and door industry I can think of many times where we would have to settle for a PVC or aluminum component, which would be a stark and unwelcome contrast to the aesthetic of our otherwise solid wood products. I think there is potential to create composite wood 3D printed alternatives to many of these components.
I agree that extrusions are very difficult. A big part of the problem is that wood is not conducive to “flow”. Further, when used at a scale that is does flow, flour, then we loose the directional strength properties of wood.
I believe Laminated Object Manufacturing is a better approach for objects that are usually relatively planer, like doors and windows. This process would be similar to building up a thickness of Laminated Veneer Lumber, only each veneer would be cut to the objects profile before being glued up. Other materials can be added into the process, like insulation, to create a smarter wood frame. One may also change the grain direction to build a dimensionally stable product (like a plywood).
Some amazing printers have been doing this process with sheets of paper, rather then 1/8″ veneer.
This image, attached, shows using a laser on paper, I suggest using a router on veneer.
At the very outset, let me say that the idea is not to promote our own project / process / website by commenting.
A window frame is made of extruded lengths of profiles, and assembled manually (or semi-automated with newer machines) into rectangular shapes. Since lengths of raw material are standard, so are the extruded sticks which yield waste with every mitre cut (for corners) and end pieces as dimensional waste. A profile stick of 10′ for example yields, a 1′ waste piece (10% of finished and processed wood) while making a window frame of 3′ x 3′. There is no way around that.
We have showcased a window frame at http://4axyz.com/wood-iot/ which is 3D-Built using the SAM process, where there is no need to: a) take standard lengths and run them through routers, then, b) cut, c) assemble manually and d) look on the shop floor at all that waste. Furthermore additive processes can blend materials (cork with wood in the example shown) for special properties of the finished product.
“Direct-from-CAD-files” has to become the future of wood products manufacturing because manufacturing needs to flex on the fly, and material consumption needs to be “just-as-needed”. If doing all this also keeps the production cost-effective, vinyl and metal will have no opportunity to replace wood for millwork.
Modern high-tech glass [as seen at] http://www.viewglass.com suffer when encased in vinyl or metal frames. For best performance, the glass needs electrical insulation which the metal frames cannot provide. And of course the aesthetics are matchless if we can get additive manufacturing of wood to work.