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The objective of this work was to develop a pre-treatment (cleaning) procedure for a wide range of apparel fabrics and to determine whether differences observed in the properties of fabrics which had and had not been pre-treated were significant. Properties relevant to the manufacture and/or performance of apparel included mass per unit area, thickness, bending length, flex-ural rigidity, drape coefficient, air permeability, water vapor permeability, liquid absorptive capacity, drying time, ‘dry’ thermal resistance, ultra-violet transmission. Results for the same property on the same fabric measured when the fabrics had and had not been pre-treated generally differed significantly, confirming the importance of pre-treatment prior to measuring these properties, particularly when claiming in-use attributes of fabrics. A procedure for pre-treatment is recommended: six consecutive cleaning cycles following procedure 8A of British Standard EN ISO 6330: 2001 (i.e. not dried between cycles), and dried flat following procedure C of this standard.

Ballistic head injury remains a significant threat to military personnel. Studying such injuries requires a model that can be used with a military helmet. This paper describes further work on a skull-brain model using skulls made from three different polyurethane plastics and a series of skull ‘fills’ to simulate brain (3, 5, 7 and 10% gelatine by mass and PermaGel™). The models were subjected to ballistic impact from 7.62 × 39 mm mild steel core bullets. The first part of the work compares the different polyurethanes (mean bullet muzzle velocity of 708 m/s), and the second part compares the different fills (mean bullet muzzle velocity of 680 m/s). The impact events were filmed using high speed cameras. The resulting fracture patterns in the skulls were reviewed and scored by five clinicians experienced in assessing penetrating head injury. In over half of the models, one or more assessors felt aspects of the fracture pattern were close to real injury. Limitations of the model include the skull being manufactured in two parts and the lack of a realistic skin layer. Further work is ongoing to address these.

Tissue simulants are typically used in ballistic testing as substitutes for biological tissues. Many simulants have been used, with gelatine amongst the most common. While two concentrations of gelatine (10 and 20 %) have been used extensively, no agreed standard exists for the preparation of either. Comparison of ballistic damage produced in both concentrations is lacking. The damage produced in gelatine is also questioned, with regards to what it would mean for specific areas of living tissue. The aim of the work discussed in this paper was to consider how damage caused by selected pistol and rifle ammunition varied in different simulants. Damage to gelatine blocks 10 and 20 % in concentration were tested with 9 mm Luger (9 × 19 full metal jacket; FMJ) rounds, while damage produced by .223 Remington (5.56 × 45 Federal Premium® Tactical® Bonded®) rounds to porcine thorax sections (skin, underlying tissue, ribs, lungs, ribs, underlying tissue, skin; backed by a block of 10 % gelatine) were compared to 10 and 20 % gelatine blocks. Results from the .223 Remington rifle round, which is one that typically expands on impact, revealed depths of penetration in the thorax arrangement were significantly different to 20 % gelatine, but not 10 % gelatine. The level of damage produced in the simulated thoraxes was smaller in scale to that witnessed in both gelatine concentrations, though greater debris was produced in the thoraxes.Electronic supplementary materialThe online version of this article (doi:10.1007/s00414-015-1309-9) contains supplementary material, which is available to authorized users.

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Reports on penetrating ballistic head injuries in the literature are dominated by case studies of suicides; the penetrating ammunition usually being .22 rimfire or shotgun. The dominating cause of injuries in modern warfare is fragmentation and hence, this is the primary threat that military helmets protect the brain from. When helmets are perforated, this is usually by bullets. In combat, 20% of penetrating injuries occur to the head and its wounding accounts for 50% of combat deaths. A number of head simulants are described in the academic literature, in ballistic test methods for helmets (including measurement of behind helmet blunt trauma, BHBT) and in the 'open' and 'closed' government literature of several nations. The majority of these models are not anatomically correct and are not assessed with high-velocity rifle ammunition. In this article, an anatomically correct 'skull' (manufactured from polyurethane) and 'brain' (manufactured from 10%, by mass, gelatine) model for use in military wound ballistic studies is described. Filling the cranium completely with gelatine resulted in a similar 'skull' fracture pattern as an anatomically correct 'brain' combined with a representation of cerebrospinal fluid. In particular, posterior cranial fossa and occipital fractures and brain ejection were observed. This pattern of injury compared favourably to reported case studies of actual incidents in the literature.