Body Armour Thesis:Texts for: Introduction, Rationale, Conclusion
Body Armour Thesis
Body armour has traditionally been designed with the principal purpose ofto provide providing protection for the wearer against sharp objects and ballistic threats. A ballistic ballistic-resistant fabric stops projectile penetration by reducing energy transfer to the body upon impact, i.e. the fabric flattens the bullet and diffuses its energy [1]. On the other hand, stab stab-resistant fabric should resist pointed/sharp object penetration and slash. However, the point surface of a knife tip, ice pick or syringe needle is much smaller than that of a bullet and remains the same size as it passes through a fabric. In fact, currently available ballistic ballistic-resistant fabrics do not properly fully protect against stab or slash attacks [2]. Protection from stabbing is important - especially for personnel such as police and prison officers who might be exposed to sudden stabbing attacks of stabbing.
Traditional protective body armour panels are heavy, bulky, inflexible, and uncomfortable to wear. Modern, soft body armour usually consists of multiple layers of fabrics made from expensive high high-performance fibres such as Kevlar, Zylon, Twaron, Spectra or high–performance polyethylene (HPPE) [3,4]. Advanced body armour technologies aim to reduce the body armour vest weight in order to enhance the comfort level [5-7]. It was reported that users were reluctant to wear an uncomfortable protective vest [8]. Therefore, the interaction between the protective vest and the body is an important factor that needs to be considered while when designing body armour. There is a great potential for some traditional textile methods to be properly utilized in modern soft body armour through new designing and engineering methods. The most recent method has been developed for female body armour panel by angle–interlock [12,13]. This method developed 3D seamless woven Kevlar fabrics that have a female bust shape. This fabric shapes can be created readily without forming any wrinkles which would improve the fit comfort for female officers and other females needing to wear body armour.
One of the critical factors is the selecting selection of the ballistic fabrics, especially when both protection and comfort are considered [3]. Sinnappoo et al. [9] developed a ballistic Kevlar–wool fabric, which was engineered based on an existing commercial Kevlar fabric, by integrating the wool and Kevlar yarns together as equivalent yarns into the warp and weft of a simple square–sett plain weave. For comparable ballistic performance, tThe Kevlar–wool fabric reduced the number of layers used in a ballistic panel, thereby reducing its bulk as compared to the 100% Kevlar panel for comparable ballistic performance. The reduced ballistic panel weight may result in comfort enhancement [7,10]. Also, wool enhanced the frictional interaction at yarn intersections, as well as increases increasing the forces needed to pull yarns out of the woven fabric [9]. However, the reaction of wool in terms of moisture behaviour and thermal comfort on this fabric was not evaluated. Incorporating wool in the aramid fabric might have the additional benefit of transferring moisture through the fabric and thereby improve improving wearer thermal comfort [9,11].
A composite knitted fabric structure has been used in knitting body armour fabric to enhance the strength and damage tolerance of composite structures [14]. Knitted fabrics were used widely for making body armour fabric, including wrap wrap-knitted fabric, interlock and bi–axial warp–knitted fabrics [15]. A new re-evaluation of knitting machinery developed a whole garment knitting process which were was used to laminate eliminate the cut cut-and and-sew method in clothing. This method of knitting technology can produce 3D seamless female body armour vests, which would improve fit comfort. Furthermore, laminating eliminating seams in the bust area would improve the protection of the vest, since seams causing cause weakness points in the fabric. It is essential to study and evaluate aramid fabric and vests in order to enhanced the performance of the female body armour with better stab protection and improved thermal comfort and fit.
Rationale Text: (Rana – note that rationale has an “e” on the end)
Why?? More info – answer why your thesis work must be done (please rewrite the flowing points in scientific ways to show the research gab)
- The principal rationale of the study undertaken is to fully understand the necessity of body armour for prison officers (especially female) to protect against low-energy threats. The aim is to assess the risks that prison officers face, in order to design and develop suitable body armour fabric and female vests that could improve the level of protection. Moreover, there is a need to understand the difficulties that face prison officers while wearing a body armour in terms of comfort. With that latter objective in mind, a survey will be conducted in a location with a hot and humid climate. This project aims to evaluate stab resistance, bursting strength and thermal comfort. (This is an existing investigation).
- This thesis focuses on studying the comfort properties of 100% woven Kevlar (commercial fabric) against woven Kevlar–wool fabrics, to determine how wool enhances the thermal comfort of the fabric. (This is an existing investigation).
- This study adopts a knitted structure for development of the aramid fabric and vests. The reasons for selecting knitted rather than woven are:
- 1) fFrom the literature it is found that the knitted structure provides better stab resistance than is provided by a woven construction.
- 2) However, all existing knitted structures investigated create flat panels that can only be used for male body armour, not for female, due to their flat shape.
- 3) The woven Kevlar fabric has been engineered as 3D seamless female body armour panels, not as complete vests, nor for ballistic protection.
- 4) The knitted 3D seamless female body armour has not been developed (not existing before this study) and there are no further studies in regard to producing a complete garment.
- The 3D seamless female vest can provide a complete garment that eliminates the traditional cut-and-sew method to create the bust contour, which improves the protection performance as well as providing a better fit for female wearers. Furthermore, the female vest can be multi–layered as required, according to the protection level required. The vest can also be upgraded for different sizes.
- This study focused on stab protection capabilities rather than ballistic protection. The reasons are:
- 1) From the survey results obtained (see chapter 4) it was found that prison officers do not wear body armour for protection, yet the risk assessment undertaken indicated the need for low-energy threat protection.
- 2) Most of the attacks faced by officers were in the form of stabbing using a blunt instrument. Also, it had been reported that in some other prisons kitchen knives and some workshop tools were stolen and used to attack officers.
- 3) Lastly, it is unlikely for officers to be experience attackeds by gunfirearms because gunsfirearms are not not been carried by officers who dealing with inmates, and it would be extremely difficult for inmates to obtain a firearm from other sources.
- In this initial study we have investigated the knitted Kevlar fabrics for knives and other objects tools for the evaluatingion of stab resistance. not slash of spike because this is an initial study.
- Also, tThis study investigateslooking for thermal comfort performance (for hot and humid climaxtes). The evaluation relayies on (dry) thermal resistance and (wet) evaporative resistance., as well as m Moisture management’s properties, fabric permeability, and porosity.
Text for Conclusion:
Write thesis conclusion here: show the importantce of each experiment chapter with and linking them together
Having evaluatedT the risks to prison officers from inmate attacks were evaluated as described in Chapter 4 and determined that the principal type of attack threat is of the low-energy type, caused by stabbing attacks with improvised tools and stolen kitchen knives, etc. However, there was a general consensus among prison officers surveyed that the vests with which they were supplied were heavy and uncomfortable to wear, hence they tended not to wear them. Female officers surveyed felt that contoured vests would be more comfortable and would provide better protection. However, it should be noted that the number of individuals surveyed was relatively small; greater numbers would in all probability increase confidence levels in our findings.
Our , tests were undertaken ofusing suitable composite knitted fabrics containing Kevlar. Development of an advanced 3D knitting technique, facilitating seamless construction of vests contoured for the female bust, has eliminated the cut-and-sew method of manufacture, and thereby also eliminated the weak points inherent in seams, and thus provides increased levels of protection. Furthermore, the contouring of the vest and the choice of composite fabrics provides increased thermal comfort for the body armour wearer. This is especially important in hot and humid climates.
As mentioned in Chapter 2, multi-layer fabric body armour can provide protection, even against ballistic threats, although our study focused on the lower-energy threats most likely to be faced by prison officers. Multi-layer fabrics reinforced with Kevlar provide a good compromise between protection, weight and comfort, although still lacking some degree of air permeability.
Our tests were in all cases implemented in accordance with the applicable standards. The stab resistance and bursting strength test procedures used were as described in Chapter 3. Our choices of fabrics were based on existing research which indicated that a Kevlar-wool combination would allow a reduced number of fabric layers for the equivalent level of protection, due to the increased friction provided by the Kevlar. As mentioned in Chapter 5, the wool was treated to be water-repellant, in order to compare with commercially available Kevlar fabric. Test results discussed in Chapter 5 suggest that the wool component in the tested fabrics is advantageous in several respects, including marginally greater bursting strength and better thermal comfort properties.
As described in Chapter 7, a comprehensive series of bursting strength and stab resistance tests carried out on our test fabrics, including fabric with an applied abrasive coating, showed that the coating was a useful addition. As might be expected, of all the test tools used in the testing, the double-blade knife produced the greatest degree of penetration. Results differed when the blade was aligned with the courses or the wales of the test fabrics. The blade aligned parallel to the wales produced the better results, suggesting that in a multi-layer fabric vest, it would be advantageous to alternate layers at 90 degrees to each other.
Chapter 8 dealt with the important comfort aspects of our knitted body armour vests. Tests included evaluation of thermal comfort and moisture management properties performance. The tests found that the wool element provided good moisture absorbance performance and good moisture transport capability.
Overall, our research and testing showed that 3D knitted seamless body armour vests can provide an effective solution for the body armour requirement for female prison officers, particularly where the primary threat is from low-energy attacks (stabbing) rather than ballistic threats (firearms). Body armour for female prison officers needs to be comfortable so that they will actually wear the armour and therefore be protected while carrying out their duties. Increasing the number of layers also increaseds the degree of protection, but carrieds the penalty of increased weight and a consequent reduced level of comfort.
- Future research:
- Based on our findings from the experiments undertaken, further research into female body armour the following areas could include the following, with the objective of expanding and enhancing the knowledge of fabrics and coatings that could increase the overall effectiveness of the woven fabric type of body armour against the various types of threats.
- ( you may found something for this section from your reading not been included in the thesis)
- More investigation on damage tolerance in order to improve cut resistance to knives and other sharp objects.
- Different coating methods that can be applied in the knitted fabric to improve stab protection for high -energy threats as well as improved thermal comfort and permeability for the wearer, particularly in hot and humid climates.
- Further protection investigation including studies of ballistic performance and the degree of protection from slash attacks.
- The research found that the fabric is less effective toagainst a double–blade knife (two sharp edges),; further investigation is required for this sort of weapon, in order to determine ways of minimizing penetration depths.
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