Bulletproof vest or body armour is defensive gear to withstand or avoid them for physical attacks. This is traditionally used in the protection of military personnel and is generally often used in various forms of police (in particular the riot police); private security guards or bodyguards; and, at times, ordinary civilians.  Currently , there are two primary styles: standard body armor for moderate to substantial defense and hard-plate reinforced body armor for maximum protection, as used by military combatants.

1. Bulletproof Vest with Ceramic Insert
DEPARTMENT OF MECHANICAL & MANUFACTURING ENGINEERING
FACULTY OF ENGINEERING & BUILT ENVIRONMENT
UNIVERSITI KEBANGSAAN MALAYSIA
FAISAL HUSAINI BIN BADRI
MOHAMAD FAIZ BIN MOHAMAD ZAIS
MUHAMAD NAJIB BIN ROSLAN

2. Acknowledgement
 Special thanks to our lecturers PROF. DR. ANDANASTUTI MUCHTAR and
DR. NABILAH AFIQAH MOHD RADZUAN for teaching and guiding us in
KKKM4672 Processing of Ceramics course.

3. What is Bulletproof Vest?
 Bulletproof vest or body armour is defensive gear to withstand or avoid
them for physical attacks. This is traditionally used in the protection of
military personnel and is generally often used in various forms of police (in
particular the riot police); private security guards or bodyguards; and, at
times, ordinary civilians.
 Currently , there are two primary styles: standard body armor for moderate
to substantial defense and hard-plate reinforced body armor for maximum
protection, as used by military combatants.

4. Material
 Ceramic armours are designed to absorb blast debris and to avoid the
penetration of bullets.
 Alumina, Boron Carbide, Silicon Carbide,and Titanium Diboride are ceramic
that commonly being used in armor.
 Ceramic armor never used as naked ceramic tiles, but must be wrapped in
fiber-reinforced polymer (FRP) cladding.
 It is important that the ceramic is fragile enough for the projectile to
pulverize.
 Ideally the ceramic density should be as low as possible for minimum Areal
Density and maximum Equivalent Mass performance.

5. Alumina
 Alumina (aluminum oxide, Al2O3) is the budget ceramic armor choice.
 Usually used in the civilian sector of the ceramic armor industry.
 Alumina mosaics is cheaper than others. For example, alumina cost $200 per square meter
and carbides cost more than $1000 per square meter.
 Does not required any specialized furnace technology for sintering as it is sintered in ambient
air.
 Slow crack propagation velocity (3 km/s) than the shock wave propagation velocity (10 km/s)
which means that brittle fracture is unable to keep pace with the shock wave..
 Mechanical Properties of Alumina:
i. High hardness of alumina 1800 HV
ii. Density of 3.9 g/cm3
iii. Young Modulus of 380 Gpa
iv. Flexural Strength > 300 Mpa
v. Sintering temperature in range of 1500-1700 °C

6. Manufacturing Process
 Manufactured using a process called Viscous Plastic Processing (VPP) and Extrusion
 VPP is a shaping process which alumina powder is mixed with polyvinyl alcohol (PVA) as a
binder for aqueous system and polyvinyl butyral (PVB) as a binder for organic solvent
system.
 They are mixed using a double blade mixer in order to obtain a high shear mix condition
to form a dough.
 The high shear mixing breaks down the agglomeration of powder while mixing.
 As the dough is obtained, it is processed into more complex shapes through extrusion
process which act as the secondary forming method.
 Extrusion is a process involving compaction and shaping of a highly viscous by forcing it
through a nozzle.
 Extruded compacts will undergo drying process and sintering process.
 The liquid solvent is removed by evaporation during drying process and the binder will
be eliminated during sintering process at temperature range of 300°C–700°C.

7. Strength comparison Suitability of forming technic

8. Local Manufacturer
 Most local company import the bullet proof vest from the international
market player.
 However, Stec Advance Equip emerged as one of small growing company
which manufactured bullet proof vest and body armor in Malaysia.
 Stec Advance Equip are an OEM manufacturer and had a manufacturing
plant composed of 100 staff entirely concentrated on making world-class
security vest for the arm forces and private protection service.
 Their main target market is USA and local military.

9. Technology And Improvisation
 Over the years, researchers are more interested towards the study of ceramics insert
rather than the backing material.
 This is because armour which made mainly from metal reduced the impact by plastic
deformation while armour which mainly consists of ceramics tend to reduce the impact
by efficient energy absorption and excellent load-spreading mechanism.
 Ceramics remain as the most important material which influenced the military world due
to their effectiveness against heavy ammunition.
 Injection molding has emerged as one of the most important in polymer processing
nowadays. However, this process is not well known and preferable in the manufacturing
of ceramics insert.
 This is because of their success criteria mainly depend on the selection of binder system.
 The addition of binder in large quantity also will affecting the strength of the product
formed as the binder will leave the body.
 Thus, we need to study more on this processing method as this method is very suitable
for producing complex part in a huge scale.

10. References
 Appleby-Thomas, G. J., Jaansalu, K., Hameed, A., Painter, J., Shackel, J. & Rowley, J. 2020. A comparison of
the ballistic behaviour of conventionally sintered and additively manufactured alumina. Defence
Technology 16(2): 275–282.
 Crouch, I. G. 2019. Body armour – New materials, new systems. Defence Technology 15(3): 241–253.
 Piconi, C. 2011. Alumina. Comprehensive Biomaterials 1: 73–94.
 Ruys, A. 2019. Alumina in lightweight body armor. Alumina Ceramics.
 Yang, M. & Qiao, P. 2010. 4 - High energy absorbing materials for blast resistant design. Dlm. Uddin (pnyt.).
Woodhead Publishing Series in Civil and Structural Engineering, hlm. 88–119. Woodhead Publishing.
 Quéfélec, B. & Dartois, M. 2016. 13 - Ceramic-faced molded armor. Dlm. Bhatnagar (pnyt.). Woodhead Publishing
Series in Composites Science and Engineering, hlm. 369–391. Woodhead Publishing.
 Bracamonte, L., Loutfy, R., Yilmazcoban, I. K. & Rajan, S. D. 2016. Design, manufacture, and analysis of ceramic-
composite armor. Lightweight Ballistic Composites: Military and Law-Enforcement Applications: Second Edition
349–367.
 Leo, S., Tallon, C., Stone, N. & Franks, G. V. 2014. Near-Net-Shaping Methods for Ceramic Elements of (Body) Armor
Systems. Journal of the American Ceramic Society 97(10): 3013–3033.
 Cegła, M., Habaj, W. & Podgórzak, P. 2014. Cegła+i+inni.pdf 3(17): 23–34.