Registration Number: 160142183
1.
Introduction
In a growing economy, additive manufacturing process exponentially starting to become a great business interest in manufacturing industry as it is highly versatile and convenient as compared to other processes. In conjunction with the new ZetaSports Tech business plan, the aim of this report is to introduce the company regarding main types of additive manufacturing,
AM processes which can be implemented upon developing new products for personal and sporting goods which could help improve productivity, quality and business reputation.
Additive manufacturing is commonly defined as a process of joining materials to produce objects from a 3D model data which usually occurs by layer upon layer. This process can also be known as additive fabrication, additive process, additive layer manufacturing or freeform fabrication. AM processes which such as stereolithography (SLA), laser sintering, and ColorJet
(a commercial name for inkjet 3D printing) could be used for many different types of purposes such as prototyping, mould tooling and product manufacturing.
2.
Application of AM in ZetaSports Tech
With the involvement of AM technology, ZetaSports Tech is targeting to satisfy future demands for the upcoming Tokyo 2020 Summer Paralympic games. Using AM, the company will initially be focusing on manufacturing development for sporting goods such as shoe, and medical instruments for Paralympians such as wheelchair and prosthetic legs.
2.1.
Sporting goods
For the production of athletic shoes, types of AM processes which have been currently implied in the industry includes stereolithography (SLA), selective laser sintering (SLS) and
ColorJet 3D printing (Manoharan, 2013). SLA in this case is a process whereby laser is used to scan a tank of liquid photopolymer and cures it layer-by-layer. However, this process creates thermoset polymer parts which is somehow too brittle to be used in ‘real life’ therefore, SLA will be better off for the use of rapid prototyping instead of product manufacturing as it has the ability to provide a high feature resolution and accuracy apart from its fast operation. On the other hand, SLS in targeted sporting goods production operates by scanning its laser onto the

Registration Number: 160142183
Polyamide (Nylon) powders whereas they will be sintered together. In contrast to SLA, the powders in this process are ‘fused’ together and not melted layer-by-layer. In terms of quality,
SLS finished product has better mechanical properties as compared to SLA and this would be the best option upon creating small numbers of single-piece production as it can be quite slow with very complex geometries thus become inefficient for large supply.
Another process which is called ColorJet 3D printing would be another option for
ZetaSports Tech sports shoes production. From a 3D model generated on the computer using
CAD (Computer Aided Design), product is created as the polymer deposited layer by layer until it is finished. ColorJet printed models can exist in many different colours causing the finished product to appear more appealing and vibrant. This process serves many advantages whereby it is reasonably quick, cheap and does not require additional work painting. Despite the advantages, there are still some drawbacks arise that needs to be considered whereby the end product will tend to have poor mechanical properties causing it to be less functional. To overcome this problem, post process such as curing is required in order to avoid the product from being too brittle.
Through critical analysis regarding the AM processes described above, it can be decided that ColorJet 3D printing will be the selected process for sports shoes rapid prototyping and product manufacturing. With this process, the actual production of ZetaSports Tech athletic shoes aspired to be developed using a combination of ColorJet printing for upper shoe section and digital light synthesis (DLS) for sole. DLS is a process that uses light from a custom highperformance LED to project sequence of ultraviolet (UV) images exposing a cross-section of the part causing the UV curable resin to partially cure in a precisely controlled way. Resin is then further cured and heated creating a finalized product with high elastic properties (Howarth,
2017). With the existence of DLS, excellent surface finish and accuracy of sole shape can be produced despite its high cost and slow build process (A.M. Tofail, 2017). ColorJet on the other hand is relatively faster and produces 0% material waste as the printer will only inject required quantity of material to create a certain product (Gaget, 2017). With a combination of ColorJet printing and DLS for the future shoe manufacturing plan, professional sports athletes will have the opportunity to create their own custom-made shoe which accurately fits their feet curves by having their feet scanned before getting their shoes printed. This will not only allow multiple adjustments in a short period of time but also provide better stability and control on any types

Registration Number: 160142183 of terrain. Renowned sports brands such as Adidas, Nike, New Balance and Under Armor had been implementing the ColorJet printing technology in sports shoe manufacturing and therefore this will be a good opportunity for ZetaSports Tech to be more competitive in the market.
2.2.
Medical Instruments
Additive manufacturing can be applied in the company’s production of the athletes’ wheelchair. With AM, every wheelchair seat will be individually moulded according their body shape to provide the best possible support and comfort (Page, 2016). AM customised wheelchair will additionally aid the professional athlete to enhance their acceleration, speed and maneuverability if they were to play in courts (EPSRC: Best seats in the house for
Paralympics GB hopefuls, 2012). Therefore, this will overall improve their performance during tournaments and also give a higher chance to win the game. One of the processes which can be considered for the production of these athletic wheelchairs include SLA, ColorJet 3D printing and also direct metal laser sintering (DMLS). SLA and ColorJet process techniques for athletic wheelchair manufacturing will be similar as mentioned previously in the sporting goods section. As for DMLS, the process itself is closely similar with selective laser sintering (SLS) except for that it uses very fine, granule size metal alloy powders such as Titanium alloys,
Stainless steel alloys, and Aluminium alloys. In order to even out, these powders must be in perfect shape as each of the printing layers will be ultra-thin and must be exactly at the same height at a micron level (Fabian, 2017). Therefore, this explains the level of accuracy involved in this process which will support the main purpose of the athletic wheelchair production.
Apart from that, DMLS also possesses other great advantages whereas its finished parts have no thermal residual stress and this may prevent the metal part to break into two or more pieces or causing visible distortion. However, DMLS causes the built part to be denser than investment cast parts thus adding weight to the wheelchair seat causing it to be heavy instead of wanting it to be as light as possible. Therefore, by looking at all AM processes discussed above, it can be proposed that ColorJet 3D printing would be the best option for rapid prototyping and SLS for product manufacturing. This is because, ColorJet process is reasonably quick especially when there are no complex geometries involved in the wheelchair seat design apart from poor mechanical properties of its end product making it non-functional and more suitable for rapid prototyping. On the other hand, SLS is chosen instead of DMLS because light

Registration Number: 160142183 weighted carbon fiber reinforced polymer (CFRP) will be used as the seat material instead of metal alloys. Unlike ColorJet, SLS does not require post processing as the end product has good mechanical properties leading to high durability despite its slow process.
For ZetaSports Tech, additive manufacturing technology would be best adapted in the manufacturing of prosthetic legs for athletes. Initially, an athlete’s leg will be 3D scanned in order to create a perfectly fitted equipment based on each’s handicap. With customised prosthetic legs, high level of comfort will be provided thus helps improving their performance during training and competition (Bragaru, 2012). This can be proven by an achievement recorded by Denise Schindler who had lost her leg since she was 2 years old but managed to win a bronze and silver medal at Rio 2016 (3D natives: 3D Printing in Sport (Feature Story),
2017). A perfect athletic prosthetic leg must possess strength to endure high levels of stress especially for long jump events and has to be ultra-light for better speed performance when it comes to running. Therefore, it is recommended for ZetaSports Tech to use ColorJet 3D printing for the rapid prototyping of prosthetic legs whereas SLS process with CFRP as chosen material for the real production of prostheses. ColorJet 3D printing is the best option for prostheses rapid prototyping because it is highly economical as it is cost effective since there will be a high number of prototypes to be tested before the perfect prosthesis is created.
However, as previously mentioned, ColorJet printed products tend to be brittle if not post processed thus requires skilled workers for this operation therefore increasing the capital cost of production. Selective laser melting on the other hand is also reasonably cheap, has the ability to create end products with high mechanical strength and does not require post processing therefore making it a suitable choice for the manufacturing of targeted product.
3.
Conclusion
The application of AM processes upon developing ZetaSports Tech sports shoes, prosthetic legs and wheelchair seat for Paralympians will definitely help boost the company’s production efficiency and quality. With this new initiative, ZetaSports Tech will bound to be more competitive with other mega sports manufacturing companies such as Adidas, Rebook, Nike and many more. Further research and developments will be made in the future with different uses of environmental friendlier materials and fibers which can be obtained from recycled materials that could help turning waste into profit and taking industrial revolution to a whole new level.

Registration Number: 160142183
4.
References
3D natives: 3D Printing in Sport (Feature Story) . (2017, December 28).
A.M. Tofail, S. (2017). Additive manufacturing: scientific and technological challenges, market uptake and opportunities. 1369-7021.
Bragaru, M. (2012). Sport prostheses and prosthetic adaptations for the upper and lower limb amputees: an overview of peer reviewed literature. Prosthetics and Orthotics International , 290-296.
EPSRC: Best seats in the house for Paralympics GB hopefuls . (2012, August 30).
Fabian. (2017, April 19). How Direct Metal Laser Sintering (DMLS) Really Works .
Gaget, L. (2017, October 31). 3D printed shoes: How 3D printing revolutionizes the footwear industry .
Howarth, D. (2017, April 10). Dezeen: Adidas shapes Futurecraft 4D shoe soles using light and heat .
Manoharan, V. (2013). Application of additive manufacturing techniques in sports footwear. Virtual and
Physical Prototyping , 249-252.
Page, T. (2016). Performance benefits of sports equipment produced using rapid prototyping techniques.
Journal on Future Engineering and Technology , 1-13.