METHOD FOR MANUFACTURING MOTORCYCLE HELMET FRAMES FROM IJUK FIBER COMPOSITE WITH SEGMENTED WOODEN HEAD MOLD

Abstract

This invention concerns a method for making a motorcycle helmet shell from a palm fiber composite material with a 5-segment wooden head mold measuring an adult's head with a horizontal diameter from left to right of 20 cm, a horizontal diameter from front to back of 25 cm, a height from the top of the head to the bottom of 22 cm, a curved length from the back of the head to the edge of the forehead of 50 cm, a helmet shell thickness of 4 mm, made from a 2-layer palm fiber composite in a resin matrix with an epoxy-liquid resin hardener ratio of 2:1 with a method of stacking palm fiber on the resin arranged in layers with pressure towards the base of the mold using a roller and pressure with a hand force of about 1 kg known as the hand lay up method until 2 layers of palm fiber are obtained in the resin.The size of the coir fibers is between 0.2 mm and 0.3 mm in diameter and between 50 mm and 100 mm in length, which is previously washed clean with water, then soaked in an Alkali solution (NaOH) with a concentration of 5%, then dried and arranged using the hand lay up method into a helmet shell in a mold in the form of a human head imitation that has been enlarged in size for placing 15 mm thick cork foam in the shell in the form of a half-face helmet.