Cost Impact of Post-Processing
$30-$100 per hour burdened labor rate
$100K-$500K per year staffing expense
$25K-$50K per year, per 3D printer
Capability limitations due to staffing
Peak demand: added cost to outsource
Facilities (1/2-1 sq. ft. per sq. ft. of 3D printer space), plus equipment and utilities
At Reebok, a typical build time is eight hours for its material extrusion process. The 3D-print jobs are then followed by post-processing, which may include a four-hour soak to dissolve support structures. This semi-automated step adds 50% to the total process time, but the total elapsed time to deliver the part can increase by 350% to turn one-day delivery into two.
According to Gary Rabinovitz, Reebok's RP lab manager, “Post-processing can add another day to the schedule, which means that the design review and release of the next design iteration are also delayed.”
For example, if a file is received the morning of day one, the build could be launched at 9:00 AM. With an eight-hour build, 3D printing finishes after hours at 5:00 PM. Support removal starts first thing on day two and finishes at noon. This eight-hour print has a 36hour turnaround even if the schedule is wide open and staff is available. Of course, a second shift could accelerate the process, but as discussed earlier, that second shift would add an expense that budgets may not support.
Time Impact of Post-Processing
17%-100% increase over 3D printing time
Delays exceed added time
Bottlenecks and backlogs
Without post-processing, delivery and design iteration could occur one day sooner. The cumulative effect over multiple iterations may extend a week or more, as one consumer products company noted. Its engineering manager said, “If a build ends in the afternoon and if there was no post-processing, we could have the next iteration building by the end of the day. With post-processing, it is pushed out a full day.” This company typically does five to ten iterations for each product, which translates into a total delay of one to two weeks, if weekends are included.
For these companies, eliminating post-processing would dramatically accelerate the product development process, which in turn can reduce the time to market. At the day-to-day level, post-processing may be the difference between delivering in time for an important meeting or walking in empty-handed.
Another factor that adds to the potential for delays is that post-processing can be a bottleneck that is subject to backlogs. The automated 3D printing process typically outputs many parts per build, which all enter post-processing at the same time. Considering the need for direct labor and access to supporting equipment, parts wait in queue until the resources become available. The AM technology leader at the medical device company said, “It kills me to see trays of parts late on a Friday, knowing that they won't be delivered until late in the day Monday.”
The automotive company noted that the bottleneck becomes very evident following a long holiday weekend. Leveraging the unattended operations, as many parts as possible are nested to print in one long run over the three days; however, post-processing resources are overloaded when work resumes. A casting engineer at the company said, “There are backlogs even if post-processing is automated. Sometimes the post-processing equipment simply doesn't have the throughput or capacity to match that of 3D printers running over multiple days.”
Without post-processing, the value of 3D printing could increase substantially. For some, it would allow them to perform more value-added tasks to improve part quality and expand the application base. For others, it would dramatically accelerate the total process, which increases responsiveness and total throughput. For those adding new 3D printers, eliminating post-processing would reduce labor expense by $25,000 to $50,000 for each machine; however, post-processing's burdens don't stop with labor cost and total process time.
Impact: Secondary Issues
Post-processing's impact is far more widespread than the cost of labor and the delays to schedules. While considered to be secondary issues by the six companies, the impact on quality, staffing, facilities, and safety cannot be ignored.
Quality. Ultimately, the quality of 3D-printed parts is in the hands of the part finishers that wield X-Acto knives, sandpaper, and spray nozzles for media blasting or waterjetting. The medical device company noted that maintaining consistency and accuracy across many copies of the same part is difficult when manual labor is involved.
For intricate parts with delicate features, a consumer products company said that it often opts to build a duplicate just in case the original is damaged or broken. Making duplicates increases cost and consumes valuable 3D printer capacity.
Staffing. For those who have the budget to hire post-processing personnel, the issue becomes one of finding the right talent. According to a consumer product company's engineering manager, “Post-processing is kind of an art form.” Part finishing requires a unique skill set and a unique personality.
To maintain the quality of a 3D-printed part, the post-processing personnel must have model-making skills: manual dexterity and experience with the tools at their disposal. Yet, they must demonstrate those skills while under intense pressure to delivery rapidly. Of the entire labor pool, only a small percentage possess this combination of skill and temperament, which complicates the hiring process.
Facilities. Floor space is required to house the staff, workbenches, and post-processing equipment. As stated earlier, a ratio of one-half to one square foot per square foot of 3D printer space will be needed in many cases. This space can be an impediment for those who don't have an option to expand into existing areas, an expense for those who have to take on construction, or an ongoing cost for those who have internal cross-charges for floor space used by the department.
Another cost consideration is the purchase of the workbenches and equipment, which will run into the thousands of dollars for the typical, yet small 3D printer lab. There is also the additional cost to run utilities such as electrical, water, and air lines to the equipment.
Safety. Safe operations, handling, and disposal are sources of hidden costs that many do not account for until after the implementation of a 3D printer. According to the medical device company, the organization has a rigorous safety program, which means that more safety resources are required for each employee added to the post-processing staff. Additionally, the 3D printing operation is the largest generator of hazardous waste in its entire R&D facility. Proper disposal of hazardous waste generated during post-processing is quite costly.
In a lab environment, the issues and limitations created by post-processing are impediments to throughput and part quality, as well as a drain on budgets and resources. In a design or engineering area, these issues are significant barriers to adoption.
Three of the six companies expressed an immediate desire to deploy 3D printing in office areas while maintaining the existing 3D printing lab. The advantage of distributed 3D printing is that a designer or engineer would have quicker turnaround both for office-built and lab-built parts.
Placing 3D printers in the office, the self-serve model is more responsive because it sidesteps the work queue of the lab. Meanwhile, the lab is more responsive because it offloads the work for basic models and prototypes. All agree that office deployment is not reasonable when primary post-processing is required. The architecture firm cited a messy and unsightly work area, the automotive company cited chemicals and equipment, and a consumer products company cited the high burdened labor rate for engineers to execute part finishing.
For 3D printing in the office to become realistic, it must mimic the workflow of a full-featured 2D printer or a digital camera. It becomes realistic when a single device outputs ready-to-use items with no requirement for additional labor, equipment, and floor space. It becomes a viable option when skill, temperament, and safety are no longer considerations.
Eliminate post-processing and it becomes feasible to place 3D printers within the workgroups who need the models and prototypes. Eliminate post-processing and 3D printer labs become more efficient, more responsive, and less costly.
Post-processing is a non-value-added function that is both a burden and a bottleneck. Without it, the promise of a simple, fast, and automated digital workflow becomes a reality for all parts, whether simple or complex in design. In that new reality, 3D printing adoption will accelerate, and the breadth of applications will expand for organizations of all types and sizes, and for every industry and market.
This article was written by Todd Grimm on behalf of RIZE Inc., Woburn, MA. For more information, visit here.