Can You Make An Motorcycle Helmet Bulletproof and If So How Do You Do It?
First Question – Are Motorcycle Helmets Bulletproof?
Can a helmet stop a bullet? Let’s find out together! An avid Youtuber (by the name of Alex) put together this rather lovely video of you guessed it, him shooting a helmet to find out if it is bulletproof.
Some Helmet Bulletproof History
That a helmet can sustain a bullet was discovered 45 years ago by mistake. Just before World War II, the government wanted to produce a helmet made of steel and wanted to replace the heavy helmet with the light material but still keep the safety.
DuPont thought about the materials used to produce cars and motorbikes which are tougher and stronger. They even considered materials like the spider’s silk. In 1965, researcher Stephanie Kwolek discovered a super fiber during the process contemplating polymers. A new material was invented called liquid crystalline polymers. This material had tight connection structures, the molecules were vulnerable to break down. Thanks to addition of a special solvent, the molecules could be reinforced and made very strong. Eventually, she discovered a material which was much lighter by five time as strong
How to Make A Helmet Bulletproof?
Carbon fiber shell:
The original material for the shell was AS4/polyphenylene prepeg tape. This type of material was widely used because it was stiff, tough, rust free and durable in wide temperature range. It is proved that PPS has more than twice the modulus of other two substitute materials. Polypropylene and polyamide 6
Aramid/Thermoplastic Polyurethane Anti-Ballistic Layer, Its structural system includes a biaxial weave of aramid with a film of thermoplastic polyurethane laminated to one side. In order to have a perfect bullet resistance surface, 39 plies are needed in which the nominal thickness of each ply is 0.23mm (0.0091 in), so the whole ballistic layer has the thickness of 9.01 mm (0.355 in). Because of the folding materials, the thickness of ballistic material in the finished part is not the same.
This experiment has been researched extensively with woven fabrics (6). When a complex curve is formed by a tensioned cross-ply material, there is a change in the appearance of the angle between fibers such as the shear angle. Because the elongation of aramid is relatively low (2.4 percent (5)), this change in shear angle is the major mechanism that the fabric can conform to the mold geometry. At the top of the helmet, the shear angle stays 90°.
The shear angle, which progresses down from the top along the direction of the weft fibers and warp, keeps nearly 90°, whilst the shear angle varies accordingly along the diagonal. The density suitable for the ballistic material is 730–1220 g/m2 (approximately 0.15–0.25 psf). The available carbon/PPS tape has an areal weight of 386 g/m2 (around 0.079 psf/ply), of 3 plies of tape maximum.