524
M. Matsumoto et al.
36.3.3 Trends and Challenges
AM has been widely used in remanufacturing, among which cladding by welding and
re-coating are the most popular. The trends and challenges in these techniques are
as follows. Firstly, the cost is critical in remanufacturing. Thus, cost reduction of the
AM techniques is important. As restoration processes generally rely on manual work,
as described in the automobile parts remanufacturing cases, automation or semiautomation of the inspection and these restoration processes should be advanced.
Cost reduction is also important because a survey in the United States revealed
that AM techniques are used mostly by large companies, not much by small-andmedium sized enterprises (GIS RIT 2017). To further activate circular manufacturing,
development and commercialization of affordable AM techniques is necessary.
One approach to reduce the cost of re-coating is to develop local re-coating
processes. In re-coating, generally the coated layer is removed from the entire surface
and then a new layer is coated on the substrate. However, when only the damaged
part of the layer is removed and re-coated, the total cost be reduced.
Another challenge is increasing the value and the quality of restoration. Conditions
of damages in products vary depending on the customers’ usage of the products. As
such, remanufacturers can customize the restoration depending on the usage pattern
of the customers, which can lead to an increase in the value of remanufacturing and
the effects of prolonging the product lifetimes.
Technological development of material restorations for new types of materials is
also needed. As with the case of aircraft turbine blade repair, new types of materials
can make remanufacturing more challenging. In this case, re-coating techniques
that do not harm the substrate by re-coating should be developed. Product design for
remanufacturing (DfReman), or material design for restoration, is equally important.
36.3.4 Application in Surface Embedded Sensors
Another potential application of AM in circular manufacturing is the development
of intelligent tooling based on surface-embedded sensors. Feasibly, AM can be
employed to realize surface-embedded sensors; machine tools can become smarter
by perceiving their own states and the state of the surrounding environment. The
key enablers for this capability include smart sensors embedded into machine tools,
a system that is useful in evaluating the tool’s health conditions and predicting its
remaining lifetime, as well as a possible breakdown or malfunction before that (Yang
et al. 2018). The system is also useful for monitoring of the manufacturing process
within the tools. Martinsen et al. conducted R&D of surface-embedded sensors
used in injection molding dies (Martinsen et al. 2017). In principle, pressures and
temperature distributions within the mold cavities are critical parameters for injection
molding of thermoplastics components, whereas in-mold sensors are highly useful
for improving the manufacturing process controls. In the research, the sensors were
M. Matsumoto et al.
36.3.3 Trends and Challenges
AM has been widely used in remanufacturing, among which cladding by welding and
re-coating are the most popular. The trends and challenges in these techniques are
as follows. Firstly, the cost is critical in remanufacturing. Thus, cost reduction of the
AM techniques is important. As restoration processes generally rely on manual work,
as described in the automobile parts remanufacturing cases, automation or semiautomation of the inspection and these restoration processes should be advanced.
Cost reduction is also important because a survey in the United States revealed
that AM techniques are used mostly by large companies, not much by small-andmedium sized enterprises (GIS RIT 2017). To further activate circular manufacturing,
development and commercialization of affordable AM techniques is necessary.
One approach to reduce the cost of re-coating is to develop local re-coating
processes. In re-coating, generally the coated layer is removed from the entire surface
and then a new layer is coated on the substrate. However, when only the damaged
part of the layer is removed and re-coated, the total cost be reduced.
Another challenge is increasing the value and the quality of restoration. Conditions
of damages in products vary depending on the customers’ usage of the products. As
such, remanufacturers can customize the restoration depending on the usage pattern
of the customers, which can lead to an increase in the value of remanufacturing and
the effects of prolonging the product lifetimes.
Technological development of material restorations for new types of materials is
also needed. As with the case of aircraft turbine blade repair, new types of materials
can make remanufacturing more challenging. In this case, re-coating techniques
that do not harm the substrate by re-coating should be developed. Product design for
remanufacturing (DfReman), or material design for restoration, is equally important.
36.3.4 Application in Surface Embedded Sensors
Another potential application of AM in circular manufacturing is the development
of intelligent tooling based on surface-embedded sensors. Feasibly, AM can be
employed to realize surface-embedded sensors; machine tools can become smarter
by perceiving their own states and the state of the surrounding environment. The
key enablers for this capability include smart sensors embedded into machine tools,
a system that is useful in evaluating the tool’s health conditions and predicting its
remaining lifetime, as well as a possible breakdown or malfunction before that (Yang
et al. 2018). The system is also useful for monitoring of the manufacturing process
within the tools. Martinsen et al. conducted R&D of surface-embedded sensors
used in injection molding dies (Martinsen et al. 2017). In principle, pressures and
temperature distributions within the mold cavities are critical parameters for injection
molding of thermoplastics components, whereas in-mold sensors are highly useful
for improving the manufacturing process controls. In the research, the sensors were