Development of a high-density nonwoven structure to improve the stab resistance of protective clothing material

Abstract

The purpose of this research was to enhance the stab resistance of protective clothing material by developing a new high-density nonwoven structure. Ice picks often injure Japanese police officers due to the strict regulation of swords in the country. Consequently, this study was designed to improve stab resistance against ice picks. Most existing anti-stab protective clothing research has focused on various fabrics impregnated with resin, an approach that brings with it problems of high cost and complicated processing. Seldom has research addressed the potential for improving stab resistance by using nonwoven structures, which exhibit better stab resistance than fabric. In this research, we prepared a series of nonwoven structures with densities ranging from about 0.14 g/cm3 to 0.46 g/cm3 by varying the number of stacked layers of Kevlar/polyester nonwoven under a hot press. We then proposed two methods for producing such hot-press nonwovens: the multilayer hot-press method and the monolayer hot-press method. Stab resistance was evaluated according to NIJ Standard-0115.00. We also investigated the relationship among nonwoven density, stab resistance, and flexural rigidity, and here we discuss the respective properties of the two proposed methods. Our results show that stab resistance and flexural rigidity increase with nonwoven density, but flexural rigidity of nonwovens prepared using the monolayer hot-press method only shows a slight change as nonwoven density increases. Though the two methods exhibit little difference in maximum load, the flexural rigidity of nonwovens prepared using the monolayer hot-press method is much lower, which contributes to superior wear comfort. Finally, we investigated the mechanism behind the stabbing process. Stabbing with an ice pick is a complicated process that involves many factors. Our findings indicate that nonwovens stop penetration primarily in two ways: nonwoven deformation and fiber fractures.

New development of research on personal protective equipment (PPE) for occupational safety and health

“…Thus, we believe that this special issue provides recent and significant information of international (Brazil 8 ) , China 10 ) , Finland 3 ) , Netherlands 2 ) , Norway 3 , 4 ) , Poland 11 ) , Switzerland 7 , 11 ) , Sweden 3 ) , the UK 8 ) , and the USA 2 , 8 , 12 ) ) and Japanese 1 , 5 , 9 ) research progress on PPE at work. Even so, this issue has a limitation in that we could not cover every PPE that is important for occupational safety and health, especially concerning head protection, foot protection, protection against falls, ballistic protection, eye and face protection, hearing protection, and respiratory protective devices.…”

“…From this viewpoint, this special issue was planned to represent state-of-the-art knowledge on the development and evaluation of PPE. It is presented by many internationally distinguished experts representing the fields of physical (stabbing 1 ) , radiant heat 2 ) , cold 3 , 4 ) , ionizing radiation 5 ) , vibration 6 ) ), chemical 7 , 8 ) , and biological 9 ) hazard protection and assessment of thermal properties 10 , 11 , 12 ) of PPE and the environmental impacts on occupational safety and health.…”

“…Of particular note is that this special issue includes the latest results 1 , 5 , 9 ) of an ongoing research project “Creation of new functions and structural materials for protective clothing/PPE and establishment of evaluation method suitable for on-site activities” (Project leader: Professor Hideaki Morikawa, Shinshu University) supported by JSPS KAKENHI Grant Number 15H01789, the Ministry of Education, Culture, Sports, Science and Technology.…”

Graphene Modified Multifunctional Personal Protective Clothing

“…Organic and metal electroconductive fibers are used in protective clothing to make it antistatic . Resins impregnated with fabrics can increase the mechanical strength of protective clothing . In recent years, due to thermal insulation properties, light weight aerogel/nonwoven composites have been used in fire protective clothing instead of conventional dense, weighty, and multilayer clothing 47c,52…”

Thermally Bonded PET–Basalt Sandwich Composites for Heat Pipeline Protection: Preparation, Stab Resisting, and Thermal-Insulating Properties

“…When composites were thermal-bonded at 160 • C, LPET lost their fiber shape, and conversely, a relatively bigger void was found, which can explain the decreased tendency of knife resistance and spike resistance as function of thermal-bonded temperature in Figures 6b and 8b. Thermal-bonding points can increase the fibers cohesion and decrease the inter-fiber slippage, which is beneficial to improve the stab resistances and their stability [26]. However, when surpassing the melting point, the composites' excessive shrinkage conversely produced a large number of voids after hot-baking, which in turn decreases the stab resistance.…”