Technical textiles for knife and slash resistance

Law enforcement and medical personnel require a high level of protection when dealing with physical, chemical, and biological threats under various environments. The demands they make from protective garments are ever increasing and are becoming more focused on ballistic protection, anti-stab protection, and antimicrobial protection. 

The perception of risk for a violent assault at work is also highest for the protective service occupations, followed by health and social welfare professionals. According to various crime surveys (BCS) over the years 2(X)7 and 2011, on average, there were 3225 assaults per 10000 workers per year in the security and protective services. Understandably, the risk of violence while at work is the highest for security and protective services, with a risk percentage of 11.4%, while the average risk of violence while at work is only 1.2%. The police are at most risk, followed by social workers, probation officers, publicans, bar staff, and security guards. 

A review of the real life wounding patterns that investigated 500 patients attending an accident and emergency unit in Glasgow revealed that the majority (63.3%) of the wounds caused by knives were slash-type, and these attacks could be disfiguring and also be life-threatening if they involved the blood vessels.  

A review conducted by Bleetman et al in 2003 also revealed that one third of the assault victims admitted to the hospital were injured by a knife. The majority of those knife injuries were slash-type injuries to the face, with fewer affecting the upper Umb and the trunk. Less than a quarter of fatal wounds caused by stabs are inflicted in the chest region and the distribution of the wounds suggests that, in real life attacks, most of knife assaults are slash attacks in the arm, neck, shoulder, and thigh regions. UK National Health Service (NHS) data suggests that, in 2010/11, there were 4643 people admitted to hospital as a result of assault by sharp objects. The number of admissions was more or less similar in the previous 10 years. Fig. 7.1 shows the percentage of assaults by injury location. 

Anti-stab protection, on the other hand, relies on tightly woven structures that offer protection from sharp pointed objects, with or without sharp cutting edges. Even though stab-resistant armour defeats slash attempts, it is impractical to provide stab protection to the arms, neck, shoulder, and thigh regions because of the thickness and stiffness required if armour materials are to withstand the force of a stab attack. Slash resistant armours, in contrast, need not be excessively bulky and/or stiff. They can be more flexible and lighter as the maximum load exerted by a slash is approximately 25% of the loads measured in stab attacks. 

---