Written by Aaron Minard
A 3-D printing revolution has seamlessly altered manufacturing, prototyping, and design processes for countless industries from space exploration to the operating room. Part of this transformation has resulted in the potential for improved surgical outcomes.
This potential was realized by a Houston mother whose daughter was diagnosed with transposition of the great vessels that required an emergency operation. With a business background in the 3-D printing industry and the support and enthusiasm of pediatric cardiothoracic surgeons, Anne Garcia founded the non-profit “OpHeart”. The mission of OpHeart is to place 3-D printed technology in the hands of pediatric cardiac surgeons to improve surgical outcomes in the lives of children.
Dr. Redmond Burke, Director of Cardiovascular Surgery at Nicklaus Children’s Hospital, aptly suggested that “You can’t give someone a piece of paper with a picture of a rubrics cube on it and say “How do you solve this?” You have to hold that three dimensional object in your hands and then come up with a solution.” Burke goes on to explain that 3D printing technology “..helped take someone from being inoperable to operable. And we saved their life.” 3-D printing technology affords surgeons the ability to hold, examine, plan, and practice their procedure on a patient specific model prior to entering the OR.
3-D printed models are also being utilized by Memorial Hermann Oral and Maxillofacial Surgeons in the Texas Medical Center for facial reconstructive surgery. Raw CT data is sent to Materialise, a company that created software known as “Mimics” which converts the CT data to a format understood by the 3-D printer. A patient specific model is then printed and an accurate model of the facial deformity, tumor, or injury is provided to the surgeon.
After the surgeons receive the 3-D printed models, they are used as a guide to contour titanium implants to reconstruct the framework of a face. This allows surgeons to perform and perfect their intended surgery outside of the OR on a model prior to engaging in complex facial reconstruction. Dr. Jonathon Jundt, an Assistant Professor and Oral and Maxillofacial Surgeon at Memorial Hermann in the Texas Medical Center stated that, “The ability to pre-bend plates prior to surgery can save hours of time in the OR. Before 3-D models were available, complex three-dimensional bending of titanium implants were done by hand in the OR while the patient remained under general anesthesia. Now, most titanium implant contouring is done before the patient sets foot in the OR.” Both hospitals and patients benefit from shorter and more accurate procedures in the OR. In some cases, additional corrective surgeries may be avoided by precisely realigning facial bones during the initial reconstruction.
While the current process of outsourcing the conversion of CT data to a 3-D printable format and the creation of a 3-D printed model is a useful resource, the timeframe for submitting the data and receiving the models can be lengthy. In order to reduce time and streamline model generation, some surgeons have elected to incorporate 3-D printing technology within their hospitals. One such hospital, the Salisbury District Hospital, acquired a Stratasys Objet 3-D printer and has utilized this technology extensively in their Oral and Maxillofacial Surgery division.
See a video highlighting their story here:
Given the positive affirmation by surgeons in multiple specialties on the advantages of utilizing 3-D printing for patient care, it seems likely we’ll continue to hear even more stories about 3-D printing for medical applications in 2016.
As promised during last week’s blog posting, we are talking some more about thermoforming tools produced by 3D printing.
A 3D printed thermoforming tool can take advantage of Stratasys build style to build in the vacuum channel and eliminate the need to drill out pin holes and vacuum feed areas for tooling. So you have the option of building in several ways to make the tool. Each way has some advantages but each is going to be different.
If the part needs to be fairly smooth on both the outside and inside of the shape, using a solid surface with a more traditional hole pattern where the material is drawn down by the vacuum until the tool may be the best bet. The part build style can be modified to have a spare build interior to maximize the draw (vacuum sucking the plastic sheet against the mold) while keeping the traditional solid surface. The holes can be built in by the use of the CAD program to the surface so that the need for post build finishing and drilling is minimized.
For addition, modification of the surface and fine tuning the vacuum, (as an example for areas where the sheet is difficult to be drawn into a crevice feature) the area can feature more holes in the solid surface walls. In some cases, the tool can be built with no skin so that the sheet draws down onto the open lattice surface where the part is open. This technique Is particularly useful when using a vacuum table for a quick prototype of the shape or for thin gauge applications for food packaging. The ability to pull the vacuum can be modified by using different sparse build styles and in some cases having an internal channel for vacuum channeling. There are many academic papers regarding the design of 3D printed vacuum forming tools, numerous white papers and technical bulletins that speak to design and “how to” tips when developing these tools.
Whether the choices are to create the tool with a solid surface and designed in holes, use sparse build on the interior, have a built vacuum manifold in the bottom of the tool, or to do a simple shell with holes, the possibilities of using 3D printing is endless in this application area. A couple of notes of caution, food packaging including clamshell disposable containers that are thin guage thermoforming may be subject to FDA registration rules. When In doubt on whether your application should be registered with FDA such as blister packs, thin gauge thermoforming, disposable food containers, or cosmetic packaging, always consults with experts on packaging regulations.
In general, thermoplastics sheet used for thermoforming can be used with any of the tools printed from the filaments that come from the Stratasys standard stock. For even more detail and glass smooth surfaces, PolyJet tools can be used with build in vacuum channels and pin holes.
For more information about thermoforming and how 3D printing can improve your bottom line, contact Engatech at email@example.com or call our offices at 866-499-7500.
Often the terms of vacuum forming and thermoforming are used interchangeably but the processes may actually be different for different professionals. In general terms, thermoforming refers to any process where the plastic is in a sheet form,is heated to soften and then placed into a mold. Thermoforming is a generic term nowadays and usually includes vacuum forming, pressure forming and twin sheet forming to form a coverall type of generic molding.
Within each process there is an incredible amount of tribal knowledge and tips and tricks; too much to cover in a blog posting. As an example, the “art” in developing a good thermoforming process may involve knowledge of snap back boxes, pre heats, female versus male molds as well a large scale sheets, draw down ratios, custom heats and more. Because of the complexity, we will stick to the basics in this blog posting today – vacuum forming and pressure forming 101. We will leave twin sheet thermoforming for a different time.
Vacuum forming is taking a sheet of thermoplastic and heating it up to soften it in preparation for molding. The softened sheet is positioned over the mold in preparation to be sucked down onto the surface of a mold. Afterwords, the formed sheet is removed from the mold, allowed to cool and then readied for further finishing. The product is trimmed and any secondary operations are completed prior to shipment.
In pressure forming, the sheet is heated and positioned the same as in vacuum forming, but a second piece of tooling (or box as some call it) with positive pressure is used in addition to the vacuum to push the sheet into the shape. Secondary trimming and additional operations are the same as in vacuum forming. The softened sheet prior to shaping may be stretched prior to the operation in order to get a better wall thickness distribution particularly in areas where the sheet will be stretched over the mold.
Each process has advantages. In vacuum forming, the pressures are lower and the overall costs of molds and set ups are usually lower. The process is ideal for larger parts and runs of less than 10,000 pieces.
Pressure forming on the other hand allows for more detail and surface texture to be added to the resulting part. Some claim that the walls are more uniform with less thinning in corners. Differences in cost are highly dependent on the processor and equipment.As far as which process is better for each part that is mostly a factor of design.
One option to consider in either process is using 3D printing to quickly produce a mold. FDM 3D printers allow you to choose your part density and by selecting a sparse style you can 3D print a prototype mold/short run mold quickly & cost effectively. This “quick to completion mold” opens up opportunities for low volume production, quick turn runs, verification of design and custom vacuum patterns for hard to draw areas in the tool.
Another aspect of using 3D printing is building a pattern for a traditional aluminum sand cast thermoforming tool. The pattern can be scaled up easily in the printer software to compensate for the shrinkage ratios as well as eliminate much of the hand work and polishing needs. With fewer skilled pattern makers working today molders need to find alternatives to patterns made from wood or resin board.
3D printing is the next stage of mold building evolution. Design moves from concept to CAD to mold directly using a 3D printer. This month we will be exploring thermoforming using 3D printing as well as blow molding tooling, but if you need to hear more NOW, we have a couple of options for you. Tune in for our webinar on June 9th at 9:00 where we will do an overview of vacuum forming and blow molding tooling done with 3D printing. You can register here: https://attendee.gotowebinar.com/register/8238370521790898948
You can also contact our offices for links to white papers, technical papers and case studies. Call 866-499-7500 or email firstname.lastname@example.org and we will be happy to share information about this technology with you.
Rapid Prototyping Remains the Largest Use of 3D Printing Since the 90s.
Engatech Application Engineer Barbara Arnold-Feret summarized the use of 3D printing in the 2010s as going “back to the future” but also sounded out new paths for the technology at the DFW “3D Printers and Pastries” breakfast held this morning in Grapevine TX.
She presented to a small group of industrial users of 3D printing, where she detailed that 3D printing remains the technology of choice in developing rapid prototypes of new design.
“Over 80% of all uses of 3D printing remain in rapid prototyping, where the technology is used to prove out design, fit, form and function. While we are seeing growth in tooling and end use parts, the first parts usually printed on new machines are to prove out a design or new idea.” – Barbara Arnold-Feret – Engatech
Citing new machines and materials in the market for 3D printing, she noted that the industry continues to look for faster production, stronger and more durable materials while lowering the cost of making parts via additive manufacturing. She said the recent introduction of Carbon’s and HP’s new equipment has caused speculation within the industry watchers on what the next move will be for leaders such as Stratasys.
Applications for 3D printing have added up over the years, but none are more important than the first application that inspired 3D printing machines– rapid prototyping. Rapid prototyping is loosely defined as using a manufacturing method to develop a model of a part quickly prior to deploying the full production parts. In most cases, rapid prototyping uses additive manufacturing but rapid prototyping has never been exclusive to 3D printing. In fact, in the 90s, rapid prototyping commonly included the high speed machining processes and CNC work.
However, in the present day, rapid prototyping is most used in references to additive manufacturing and 3D printing. Both terms refer to using layers of material to build up into a part from 3D data. This additive technique is compared against subtractive methods of making a part where material are taken away from a block or raw shape until the part is all that is left. Because extractive techniques have inherent manufacturing limitations such as what types of shapes, hidden features and geometries, plus hard to reach spots where cutting tools may not easily reach, often the time frame and expenses of doing prototypes was skipped in favor of a “fingers crossed” 1st article of production as a proof prior to full scale up.
Unfortunately, “fingers crossed” often became “pointing fingers” when problems were discovered after a physical part was produced. In contrast, if rapid prototyping was used prior to production, the errors and guessing was eliminated. 3D printing offers a cost effective and fast method of getting a physical part produced plus the ability to do different versions prior to full production. Not only can designs be verified, the best possible design option can be selected. The pre-production parts also offered teams members such as tooling and machine shop engineers, production engineers, supervisors and design professionals a part that they could see and hold that allowed them to come together and collaborate earlier in the design process. All the aspects of planning could be accessed more easily ranging from design to how to gear up for production. With each team member holding and looking at the exact same part, this coloration tool resulted in time and cost savings plus generally less stress on all the members of the team.
One customer in aerospace for example noted rapid prototyping saved their facility over 6 months in retooling the very first time there was a change order, since the prototype could be used to plan assembly line tooling and fixtures prior to receiving a modified part. One specific instance he used was drill guides for putting in brackets – by being able to have a prototype in hand with a modified screw pattern, he could quickly put the brackets from his suppliers into the line without the trial and error and headaches from retooling that he used to suffer through.
Nowadays, time savings and collaborations are even more widespread and accepted as part of the competitive nature of business. Over 80% of all 3D printed parts are used as rapid prototypes. Some figures estimate that as much as 90% of all parts are still “prototyping” parts used to approve and collaborate on design, fit and function prior to production.
With a history of over 30 years of rapid prototyping giving great results to users, now is the time to “go back to the future” and make your mark with 3D printing! Click Here to request more information.
Last week’s AMUG conference was a great meeting to see lots of the current technology on metal 3D printing. With machines ranging from the methods where parts are made directly by melting the metal particles with a laser, ballistic particle methods where metal particles are blown into the path of a laser or melted then thrown onto a build platform, metal powders with binders that are formed by use of a laser then the bonder burned off and any voids replaced with other materials, and more. The types of machines, the metal suppliers and the technology was new and yet the same as in years past.
Back in 1996, Barbara Arnold-Feret worked with a firm called Plynetics Express exploring the PHAST (Prototype Hard and Soft Tooling) concept where metal particles coated with a plastics binder were sintered with a laser to form green parts. The green parts where carefully removed from the powder bed, cleaned and then the binder burned out by placing the green part into a hydrogen furnace, cycling, then adding a second metal to the graphite crucible to be sucked up into the void created by the burnout of the binder. The development was eventually passed to P & G, who then donated for further research to the Milwaukee School of Engineering. The end goal of the project to develop and commercialize a metal matrix production tool with conformal cooling built into the inserts. The inserts were then used in a MUD base for injection molding. About the same time, development of the 3D Systems KelTool was being evaluated.
KelTool was first brought to market by 3M, and after the purchase by 3D systems, KelTool was an early prototype tooling method. KelTool relied on making a master pattern from which a RTV rubber mold was cast around for both halves of the inserts. After the pattern was removed, the resulting RTV cavities were filled with thoroughly mixed “slurry” of 70% A6 tool steel powder, tungsten carbide powder, and 30% epoxy binder which is used to bring the two powders together.
Once this slurry was cured in the mold, the resulting “green part” was removed and lightly finished to ready the green part for sintering. The green parts are placed into a graphite furnace boat, which is then loaded into a hydrogen-reduction furnace. During sintering the binder material burned off yielding a “brown part” that was including a 30% air space from the burned off binder. The final step filled the open spaces in the brown (sintered) part with copper by the brown part absorbing molten copper which had been placed as copper blanks into the graphite boat adjacent to the brown part. The result was a part comprised of 70% A6 tool steel and tungsten carbide, and 30% copper.
Challenges with both methods included “mass compensations errors.” Simply put, thick walls drew up more copper into the voids than thinner walls, which made predicting tolerance difficult from area to area of the tool. Adjacent features, such as ribs and bosses would also cause nearby walls to sink in towards the boss or rib due to material being shifted away from the thin section to the thicker and more “demanding” area that required more infiltration.
However, with the newer and more straightforward methods of producing metal parts, many of the problems with older methods of building metal tools or parts seem to be lessening. New equipment for building metal pieces is meant to produce prototype metal parts without the expensive and time consuming hydrogen oven. However they all require a gas generator to eliminate the safety hazard of putting a laser into a powder vat. But all in all, the processes are still evolving and “not yet” on the timeline for mass adoption as production technology.
So what were users looking for last week? They were evaluating the ROI, the cost of ownership, the potentials and finally the comparisons of dollars spent on proven existing tech versus unproven and still evolving processes.
I just got back from the annual Additive Manufacturers Users Group in St. Louis where I met fabulous people, saw wonderful machines and technology and saw so many of my old friends. I can’t begin to cover everything but I do want to share some highlights.
On Monday, I was privileged to be at the unveiling of the J750 Connex 3 printer. This printer is an enhanced Connex printer with WYSK color capability, increased speed and better resolution of features/layers, an enhanced software suite for dealing with files plus the ability to build with 6 materials and 1 support on one tray at one time. It runs in 3 modes including high quality, high mix and high speed and dispenses droplets that are ½ of the size of what the Connex machines did in previous generations. In high speed and high mix, the resolution is 27 microns and in high quality the resolution is an incredible 14 microns. The ability to mix the 6 colors at once allows the user to mix colors to achieve a full spectrum of color and with the PolyJet Suite (formerly called Objet Studio) you can compare what you are specifying to what the machine output would be on the color to fine tune to get just the right brightness and density as well as color saturation.
The J750 represents the product line between the Connex 3 and the Objet 1000 for better speed, resolution, color use and part size. Using the Connex 500 size build platform, the machine also features the “file cabinet” hot swappable material bays we first saw introduced in the Connex 3 color machines and a new print head design.
The print head allows the material to flow thru the nozzles by having two build materials come thru the nozzle dedicated to that build or support. It is explained as follows:
This makes the print head very reliable and robust. This also makes the print very detailed with the color with well-defined borders.
All in all, this new printer could indeed be the bigger, faster, better offering that customers have been looking for in color 3D printing equipment.
In the new Objet Studio software, the new user interface gives you a better experience since it has buttons and more interactions on print speed, color selection and mixing as well as more options on digital material selection. Objet Studio also gives users a better interface that is easier to use with more feedback on materials and file set up as well as repeatability and customization.
Compared to traditional color application, the new machine plus the new software give the user time savings and more options than ever possible.
The three printing modes of the J750 means that the users get 3 build options and 26 base materials with over 360,000 color combinations that give them both resolution and speed with different material selections. Additionally the digital material selection for different material mixes gives them color thru rigid and soft durometer parts.
If you would like more information on the J750 or the PolyJet Studio software, give us a call.
I was fortunate to be part of an event that focused on pharmaceutical packaging and how 3d printing fits into this expanding area of medical markets. Great stuff was shared by the presenters including how changes in the medical markets are coming about.
One of the presenters was Nicolas Webb – a world re-owned “innovation evangelist” with special expertise in healthcare and consumer products. He had insights about how the customer perception of the digital information from our firms impacts how we are perceived in terms of quality, reputation, willingness to listen and then finally the buying experience. One of the concepts that he outlined this morning was the innovation mindset. Or rather how we say innovation and then start to try and bend innovation to our comfort level.
3D printing and automotive manufacturing seems like a perfect marriage between the need for new product and concept development and the means to get those parts into user’s hands quickly at lower than expected cost. 3D printing technology has been doing exactly that for major car manufacturers out of Detroit, but it seems like start-ups and disruptors may have a leg up on how, when and why to use additive manufacturing.
In 2014, the Local Motors (www.localmotors.com) 3D printed car ate up the road with a car produced in under 44 hours at the IMTS show in Chicago. I received more inquiries on that car and requests for pictures than most products that had broken new ground in previous years. I saw that same excitement when the car was exhibited at the NPE show in Orlando, with standing room only around the black coupe and countless camera phones taking pictures. Local Motors, the producer of the car has been taking orders for the production model, and their goal is to make the car even faster to build with more customizing features than the initial offerings displayed. Their website highlights the build process and underscores how they changed the way we look at car manufacturing today.
Based on printing using polymers, their idea is that the car can be reprinted if you have a fender bender and they are getting highway crash testing in place. For the latest look at their production series cars, check out this You Tube videos on their offerings. (I personally like the red LM3, but a 3D printed car seems like it would make me the envy of the neighborhood no matter what the color.) Now a 3D printed car may seem over the top on the uses of 3D printing in auto manufacturing, but probably where I see 3D printing being the most impactful is a bit more down to earth and used in production settings right now.
Joe Gibbs Racing (JGR) has used 3D printing for years to do prototyping for very simple reason;, it saves money and time. “When milling these prototypes, we could have as many as seven machine setups. This was an inefficient use of our machines and manpower,” says JGR technical director Mark Bringle. “A prototyping system can make these complex parts in one operation, and it doesn’t require CAM programming,” he says. “So we looked into our options.” “…we wanted to model with the strong thermoplastics available for FDM – Polycarbonate and Polyphenylsulfone.
We can build prototypes tough enough to bolt onto the car, even the engine block, for evaluation, and they can take the heat. With our FDM machine, we can start building new concepts 15 minutes after the CAD design is complete,” says Bringle. “And prototypes are ready within a day. Previously, prototyping took a minimum of a week, and the delays became longer when the inevitable design changes occurred. Now, with the FDM machine, we make the changes and build another prototype immediately after a design flaw is corrected.”
This is just one example of where automotive uses for 3D printing are making an impact. For more information about 3D printing and automotive applications, give me a call at 866-499-7500 or email me at Barbara@engatech.com.
One of the most pleasing aspects of 3D printing is changing a fundament rule of manufacturing. Using 3D printing to make soluble cores and tooling makes the process easier, faster and more cost effective. Soluble cores for composites does exactly that by using a 3D print of soluble support material to form a core/mandrel/layup form that can be dissolved in water; the complex becomes now simple and fast. Here’s is how it is done.
First create a CAD file of your tooling or form. It is natural to want to do the part rather than the tooling but remember that you are 3D printing the tool, not the part. Be sure and build in any features or details for the tool that you need to be incorporated into the finished part such as fasteners, gaps or hooks or fittings.
Next, if building the tool on the Stratasys 3D printer, go to the preferences on the modeler configuration. Select invert build materials, select yes and then clink on the green checkbox.
That will build the part in support materials, which will in turn dissolve in the support removal bath that is standard on our clean stations.
For core builds where you are using the soluble support as the build, a general guideline from the Stratasys technical guidelines includes the following notations:
SR-30 (used with most of the ABS materials) is recommended for soluble core applications. SR-30 For lower temperature curing below 93 °C (200 °F), SR-30 is capable of producing nearly any geometry and should be used unless higher temperatures are necessary. SR-100 (used with PC as an example as support for builds, ) can be used for soluble core used at higher curing temperatures above 121 °C (250 °F), SR-100 may be an option. However, part geometry is limited and guidelines for acceptable part designs are currently not available. High temperature applications are not suitable for soluble core use, and alternatives in FDM materials can be utilized. (Call me at 866-499-7500 for how to use Ultem as a sacrificial core material in high temp situations as an example.)
When using the SR-10, building the layers so that material usage is decreased and the core dissolves faster is a good method of increasing output of demolded parts. Decreasing the amount of material in the core build so that it dissolves faster is most efficient, and can be assisted by selecting a layer resolution that is coarser and using sparse build. At the same time, the core must maintain structural integrity while exposed to lay up/winding and curing. To achieve this sparse but sound structure, use a modified Sparse – double dense Part interior style (Modeler > Setup… > Part interior style > Sparse – double dense) so that liquid flow thru the completed part with core areas will assist with quick dissolving of the core materials. Additional steps such as removing the “endcaps” on the core biuild will also assist in liquid flow thru the core and decrease the time needed to dissolve the core.
For more details on how to configer for best build, do the solid outer skin removal and to get expert help with your application, contact us at email@example.com or call 866-499-7500 and ask for Barbara. Additionally we host several webinars on soluble core applications throughout the year – make sure you register for the next one coming up.