Thai silk cocoon vests can 'catch bullets'

PHOTO: The Nation/ANN

A Khon Kaen University researcher and a weaver from the Northeast have successfully developed what has been labelled the world's first silk-cocoon bulletproof vest.

The men behind the innovation are Orapin Thongnonggoy, Phu Viang Silk Handicraft Centre's community enterprise president, and KKU chemical engineering lecturer Assoc Prof Panomkorn Khoahong.

Inspired by a desire to help soldiers and police perform their duties in the strife-torn deep South, the inventors tried to come up with a better quality bullet-resistant vest using silk cocoons as the main material.

The invention won a regional award at the Department of Intellectual Property's product innovation contest and the men will represent the upper Northeast in the national arena with this creation.

Panomkorn said silk was selected as the most effective material because despite its thin diameter, silk was unbelievably strong and stretchy.

He said the strength of silk threads measured 4.8 gigapascals and its flexibility allowed it to stretch 35 per cent. A two-year study that helped create the vest found its fibres could "catch" bullets or reduce their speed - from .22 calibre weapons to an M16 - without the bullets protruding into the body.

That meant the wearer is protected from internal injuries, unlike if a person wears a soft-body armour vest, as they do not cause a bullet to ricochet like a hard-body armour vest. Silk cocoons not yet drawn to their full extent is the key.

The cocoons are laid in a mould and specialised resin is poured into the moulds so the cocoons stick together.

After being suppressed with a hydraulic machine for eight hours, the vest is 20-millimeters thick and weighs four kilograms.

It is 2.5 times cheaper than general bulletproof vests, Panomkorn said.

The cost of producing a 2.4kg silk cocoon sheet is around Bt2,000 (S$78) and the specialised resin costs Bt1,500.

KKU Faculty of Engineering dean Prof Dr Apirat Siritaratiwat said projects to make innovative bulletproof vests could be beneficial to government sectors, especially the military. The university aimed to introduce the silk bulletproof vest project to the Ministry of Defence, he added.

SERVICES