TOUGH SKIN FROM HOLLAND
By Adam Baddeley, Deputy Editor, BATTLESPACE
The simplistic story behind a lot of the science in composite technology is the provision of the best ballistic protection for the lowest possible weight. In composite protection for land, sea and air platforms as well as personnel Dyneema® is the market leader.
Dyneema® is invented and manufactured by Dutch firm DSM as Marketing Manager Adri van der Waals explained, “Dyneema® is the product, the strongest fibre in the world on a weight for weight basis. The reason it’s the strongest lies in the structure of the material. Customers of ours have been using Dyneema® for ballistic applications for about 15 years now, applying it for both vehicles and personal armour.”
Dyneema® is an ultra high molecular weight polyethylene (UHMWPE) fibre. The material’s very long, linear, polymer molecules, as straight as you can get in chemistry, are the backbone of its high strength. The proprietary process orients the molecules in the direction of the fibre, which maximises the material’s strength. Dyneema® also floats on water and is extremely durable and resistant to moisture, UV light and chemicals.
There are two production variants for Dyneema®, used for ballistic applications; Dyneema® SB (Soft Ballistic) products for flexible armour solutions such as bullet resistant vests and Dyneema® HB (Hard Ballistic) armour materials that can be pressed into rigid panels. For personal armour inserts the most favourable material is the Dyneema® HB2. For vehicle applications where typically secondary aspects of the shaping of the part or the function of the panel are more demanding, a different product Dyneema® HB26 is used. This has different characteristics in terms of secondary properties.
One of the most recent UK uses of Dyneema® has been its use in the NP Aerospace primed delivery of Osprey inserts for the British armed forces using Dyneema®.
Dyneema® based inserts are formed by the compression of a number of Dyneema® HB2 or Dyneema® HB26 layers into a rigid panel. This provides density of approximately 19 Kg per square meter, the density that can stop multiple AK47x39 mild steel core rounds.
The typical insert is 25x30cm in size and has a weight of 1.3 to 1.4 Kg. The next nearest solution; ceramics like aluminium oxide, silicon carbide or boron carbide that could stop the same round would result in a 2.3-2.5 Kg insert, whilst still having lower multi-hit performance. Pound for pound, Dyneema® fibre is fifteen times stronger than steel and 40 percent stronger than Aramid fibres – such as Kevlar. Dyneema® based panels offer a decrease in back face deformation and an improved edge performance, the latter yielding a greater effective coverage.
Van der Waals said, “Personal armour has been a very important application for us in terms of being very successful. Many militaries across the world have adopted this solution with one of the key militaries being France who have bought over 1,000,000 inserts made from Dyneema® in the last decade. Internationally we are responding to requests for higher protection against armour piecing rounds. Hybrids are now applied using a strike face to break up an AP bullet and then using backing material to catch the shrapnel of the ceramic strike face and the energy from the round.”
Van der Waals describes that Dyneema® is, ‘by far the favourite backing material for the plates used by the US Army in their ESAPI and side plates, which typically use boron carbide for the strike face and Dyneema® as the backing material. DSM provides the Dyneema material to key suppliers including Ceradyne, Armor Holdings and ArmorWorks. In doing so they have substantially outsold their competitor, Honeywell’s proprietary Spectra, another brand of polyethylene fibre.’
Different protection options are sometimes required for vehicles. Van der Waals said, “Typically vehicles will also be protected although it’s not possible to stop all proje