Direct Rapid Manufacturing - Is it Possible?
A look at the many barriers to rapid manufacturing.
The strength of manufacturing depends on the ability to quickly respond to the needs of industry and develop solid processes from which to build better parts - having the desire to set the competitive standard rather than follow it. Now more than ever industry is faced with enormous pressures to enhance itself from top to bottom. Among the enhancements is direct rapid manufacturing and the return on this investment is promising, but why haven't more companies jumped aboard? Following is some industry insight into what is hindering direct rapid manufacturing.
Beth Israelnaim, RP Specialist, BD (RTP, NC):
I believe that speed of the RP systems and materials are the two main
issues that we have to overcome to get to direct rapid manufacturing.
When the properties of the RP materials can rival the thermoplastics
that we currently use in injection molding, then the last hurdle will
be the speed of the systems using these new materials and the
speed/capacity of the throughput for the entire process.
Terry Wohlers, Wohlers Associates, Inc. (Fort Collins, CO):
The idea of rapid manufacturing has tremendous potential, but several
obstacles stand in the way. Among them are material properties, surface
finish, build speed, removal of support structures (for those systems
that require them) and cost. The biggest obstacle is our flawed
thinking. Most people do not believe that it is possible and dismiss it
as a viable option. While this is true for many manufacturing
applications, it is not true across the board. RM will succeed where
unit price is high, production volume is low, and parts are small and
hidden from view. Thousands of parts across many industries fall into
this category. As companies find success in this unusual approach to
manufacturing, others will wake up and take notice.
Ron Jones, president, Shared Replicators, Inc. (Tulsa, OK):
1. Insufficient material properties.
2. High cost of equipment and raw materials.
3. Slow throughput speed in comparison to conventional manufacturing.
Todd Grimm, Accelerated Technologies, Inc. (Hebron, KY):
The barriers are speed of the equipment, surface finish and necessary
post processing labor, accuracy, material properties, limitations in
the size of parts, and cost of the equipment, materials and
maintenance. The biggest barrier is skepticism and doubt. People don't
want to believe that it can work and they don't want to change. If
people would view the opportunities rather than the barriers, amazing
applications could result. Just look at Align Technology. This company
applies RP in a rapid manufacturing environment to achieve a previously
unheard of result - custom, invisible orthodontics! Rather than looking
at the inability to match a current used production material or the
inability to achieve low RMS values for surface finish, look for
applications that can benefit from today's material or that can
accommodate the available surface finishes.
In the past, plastics had a rough go of it. Why? Because people tried to use a cheap way to replace metal parts. Not too long ago, anything made of plastic was a bad thing. Today, we apply plastics to applications that metals could never accommodate. It is true that metal properties of plastics have come a long way, but do they give the same material properties as metal? No. They are not meant to. Different solutions for different applications.
Many are unaware that photopolymers are already used in 'production' applications. Dentistry uses photopolymers for repair work. Some disposable contact lenses are made from photopolymers. In these applications, they are taking advantage of the properties of the photopolymer. What is to stop us from finding many new applications for this class of material and be able to make them in very low volumes from RP equipment? Nothing except our own self-imposed limitations.
Joel Segal, University of Nottingham (England):
The main obstacles to complete direct manufacturing - assuming that
current RP based technologies are adapted/changed - are the materials,
cost of materials and machines, speed of build and manufacture,
accuracy and surface quality which is linked to machine and material
limitations.
Preston Smith, New Product Dynamics (Portland, OR):
The main
hurdle in the way of on-off manufacturing (or mass customization) is
mostly financial. The question is whether the extra cost of a very
small lot size is justified by faster response, extra product features
or improved performance. Due to various advances in computer
technologies, it is becoming easier, faster and cheaper to make single
copies. As this propagation continues, we will continue to see the
balance shift toward more items made just for us. Custom bicycles and
wheelchairs are good examples. Automobiles - and especially heavy
trucks - are headed in this direction. But coffee makers are likely to
never justify customized manufacture. The economics are so different in
each situation, which is why we see mass customization much more in
some areas than in others.
