Technology Fabrication Machinery Technology
The Next Big Thing

3D printers are changing how fenestration profiles are designed, and may one day change how they are manufactured.

If one thread runs through the conversations that we’ve recently had with window and door manufacturers about their 3D printers, it’s that they could not do without them.

These high-tech tools are simply indispensable, speeding up the manufacturing process, providing flexibility in design and allowing companies to more easily produce exactly what customers want. Window and door manufacturers are clearly very pleased to have this technology – and are looking forward to expanded applications and material selection in the future.

There are many present uses for a 3D printer in the glass industry, including much quicker production of tooling compared to traditional methods, says John O’Hara, sales manager at Chicago-based 3D printer maker Sciaky. “These tools can be used,” he says, “to form vinyl, aluminum and stainless steels into parts of windows or doors.” Reuben Menezes, a 3D printing solution specialist at Proto3000, lists other industry applications to include design testing, marketing of new concepts, production of jigs and fixtures for inspection or assembly, and extrusion test moulding. Multi-material printing, he adds, can allow for testing of seals without a two-step process.

3D printers also allow window and door manufacturers to meet demands for increasing efficiency and durability/structural integrity, explains Matt Havekost. “The ability to prototype quickly before cutting expensive extrusion die tools allows [manufacturers] to stay flexible with designs until they have been proven,” adds the director of additive manufacturing sales at Advanced Technology Systems of St. Paul Minn., a U.S. distributor for Stratasys 3D printers. He says most manufacturers use the technology for some functional lab testing, such as evaluating how the adhesives flow inside the channels between the extrusion profiles and the corner keys.

Company perspectives
Andersen Windows has several large Stratasys 3D printers which run non-stop. The company does a significant amount of business in re-modelling old homes, where new windows need to match the size of those being replaced, as well as match the hardware finishes, grill patterns and so on. Their large printers were purchased over the last few years for use at their larger facilities, and a few small desk-top printers are also in place at some of their smaller facilities. “We use the printers primarily to prototype parts to verify fit and function, figure out how things will be fabricated, and to build small window units for testing,” says manager of Window Product Development, Dale Fitterer. “We have a tough time if the machines are down. They also help with attachment methods, making quick physical displays and doing test fits for presentations and for marketing. Customers can get a quick feel for what we have in mind, give us their feedback and we can look at ideas or make changes. It all helps in making customers happy.” The printers are also used at Andersen to build parts that are used by production, like temporary fixtures or brackets.

Over the time they’ve had the printers, Fitterer and his colleagues have seen industry applications expand significantly. “The newer large printers offer more materials and more colours than before, and the materials are stronger than the ones we previously used,” he explains. “The desktops can use a few different types of material as well. It allows us more flexibility to get better strength properties in parts, and the different colours mean it’s easier to see how things go together.”

In the future, Fitterer expects 3D printing applications to keep growing. For example, he foresees that they’ll be used for making more detailed pieces to do even smaller fit and function. They will also help in building more units for testing and for better prototyping. “We have a Stratasys fused-deposition model that provides relatively good definition,” he explains. “We outsource now to access different materials to get smoother, more aesthetic finishes than what we can achieve, but we’ll be able to do that in-house someday. As material selection increases, we’ll be able to do some structural tests on prototypes as well. If you can skip the machining, it’s much more efficient.”

All Weather Windows in Edmonton first purchased a 3D printer (a Stratasys Dimension 1200es) in early 2011 in order to build prototypes. “It was a significant investment at the time but it’s proven to be very capable and reliable,” says Jesse Tufts, product development engineer. “It prints in ABS, which is reasonably strong so the finished pieces can also be functional (for testing). The material comes in cartridges which are easy to load and handle, but quite expensive at  around $5 per cubic inch of printed material. Despite the operating cost, it’s usually used several times per week.”

3D printing means the All Weather Windows team can produce a window profile prototype in hours instead of the months it can take for a PVC extrusion die. Tufts notes that getting a die cut is obviously very costly if there has been a mistake, and 3D printing means the details of how things fit together are all sorted out before that point. “It also requires no special skill versus hand-building a prototype,” he notes. “The biggest advantage for me is it allows me to go through multiple design iterations in a single day. For parts that need to fit and function with other parts, this is invaluable and allows me to make better design decisions before sending something off for production.” He adds, “Things like doorsills can be visualized on the screen, but until you actually hold it in your hands, you can’t be completely sure about fit.” Tufts believes the speed and the cost savings that 3D printers offer provide a competitive advantage to window and door companies which own one or more of them.

Aside from prototyping, another common use for the All Weather Windows 3D printers is creating machining jigs and router templates which are often used for low-volume production on the floor. “For low-volume small plastic parts, it can actually make sense to 3D print the parts themselves instead of paying for an injection mould,” says Tufts. “Small caps, plugs and clips can function just fine as 3D printed parts and can usually be printed reasonably quickly and economically.”

To Tuft, another big advantage to having in-house 3D printing is the ability to create full-sized functional parts and use them to build windows or doors for lab testing. “I’ve 3D printed entire door sills from several pieces and tested them full scale,” he says. Their newest printer, a Makerbot Z18 purchased in August 2014, has been “very useful” for printing large prototypes and can print pieces that are 50 per cent longer than those that can be made with their older printer. The firm also wanted a second printer because delays in getting projects finished were occurring when the 1200es was tied up. “We were looking at other more expensive options to expand our capability when MakerBot announced the Z18,” Tufts remembers. “It has a larger print volume, higher resolution and uses much less expensive (about $1 per cubic inch) PLA filament which comes in simple rolls. Its purchase cost was also about one-sixth of our original printer, so it was relatively low-risk.” He says subsequent software and firmware updates gave the brand new Z18 better functionality and print quality in the months after purchase. Tufts notes the PLA material isn’t as quite durable as the ABS, but prints are still functional.

In terms of the future, Tufts turns to materials, noting that some new Stratasys printers can print in nylon, and therefore provide increased possibilities for doing small production runs of custom parts. “We have a lot of aluminum extrusion profiles as well as PVC extrusions,” he adds, “and a 3D metal printer could speed up the prototyping process for these designs. As this technology develops, I can see 3D metal printing becoming a lot more common and preferable in some ways to CNC machining or wire EDM due to the material efficiency.” He points to multi-material 3D printing as another area of advancement. “We can’t do it here but we often send out weatherstrip designs to be 3D printed in rubber-like materials before getting dies cut,” Tufts explains. “They can print combinations of flexible and rigid materials on the same piece, for example a weatherstrip with a stiff base and a more flexible top, or a prototype of a rigid plastic extrusion with a co-extruded gasket.”

Combinations of materials is why Rehau is currently exploring 3D printer purchase options. The company is quite interested in a CubePro Duo made by 3DSystems, which can print multiple materials (e.g. PLA and ABS) in the same part. “The reason we are just now looking into this relates to a new development we are currently working on,” says Rehau’s Window and Door Division designer, Justin Taylor. “This development has several mechanical parts, both plastic injection-moulded and zinc die-cast. As we have inquired about outsourcing prototypes, the price to have these parts produced triggered us to look more heavily into bringing prototyping in house.”  

Although Rehau only extrudes the lineal for windows and doors, the company often works closely with hardware and moulding companies in order to provide all the required components for a window or door system, and 3D printing will also come in handy with this work. “The use for [the technology] is not only for prototyping these components, but will allow us to ensure accuracy in various fabrication or processing steps,” says Taylor. “For instance, a window unit that requires a T-mullion will need a certain end mill procedure to fit into the contours of a frame. Being able to replicate our design of the end mill on a 3D printer allows us to test fit and function before sending the design out for tooling a cutter stack on an end-mill machine.” Tooling can be very expensive so it’s imperative to have a prototyping phase in the design to reduce the chances of tooling changes.”

Echoing others, Taylor notes that 3D printing will assist Rehau in not only increasing the precision and accuracy of parts, but in getting products to market much faster. “In our current situation, a part can be designed in a matter of days, then quotes need to be obtained for outsourcing prototypes,” he explains. “Once the administrative side is complete, it can be a week or more before we see the actual part. Having our own printer dramatically decreases that time, especially if the part requires revisions and a second or third prototype is required.”

Tufts at All Weather Windows says having a 3D printer “makes so much sense” and believes that as things advance, the advantages become greater. “It’s the next step,” he notes. “We went from hand-drafting to Autocad to 3D drafting to 3D modeling. It’s a breakthrough change. It’s not completely essential to buy one, as there are companies that can do it for us and we can have the part in two to three days, but the printers are becoming so inexpensive that they pay for themselves quite quickly. If you do a lot of design work and you need to visualize and hold things in your hand, it’s a no-brainer.” Tufts notes that with each new generation of printers coming onto the market, purchase price, speed, accuracy, print quality, and material selection are all improving. “I can’t imagine how we got along without it for so long,” he says.

How does 3D printing work?
3D printing is actually a blanket term for several different additive manufacturing processes. The core concept is that instead of taking material away from a block, as in machining, material is added in precise layers and gradually built up to create the finished shape. CAD/CAM software is used to model the desired shape and output machine control instructions to CNC actuators that position the manufacturing heads. What those heads actually do is where the various 3D printing methods diverge.

xtrusion deposition
Extrusion deposition printers use a nozzle head to heat and extrude tiny quantities of thermoplastic filament or metal wire that hardens quickly once it is laid down. It is the least expensive 3D printing technology on the market now, but has some restrictions on the shapes it can produce.

Selective fusing
Another approach is aim a laser at a bed of granular material, hardening the material only where the laser is focused. Once a layer is printed, another layer of material is spread over top and the laser prints the next layer, fusing it to the shape beneath. The material can be sintered, or completely melted. For extra-strong metal parts, a high-energy electron beam can be used. An inkjet-like process also exists where the nozzle head spreads a binder on a powder causing it to harden in the correct pattern.

Photopolymerization
In a process similar to the old idea of stereolithography, liquid polymers are exposed to controlled lighting, causing them to cure at the focal point. The vat of liquid is then moved down incrementally, building up layers. A version of this method using lasers can make extremely small parts, and parts with complex internal workings.