Post-curing effect on flexural strength of glass epoxy composites

Abstract

The present investigation deals with an experimental evaluation of flexural performance of glass epoxy composite when they have been undergone for various temperatures like 40 °C, 100 °C, 120 °C, 140 °C, 160 °C, 180 °C, 200 °C, and 220 °C, for a time period about 6 h. In detail the total experimentation was carried out with two sets of specimens, the first set of specimens were tested for flexural strength below the glass transition temperature (Tg) after normal curing whereas the second set of specimens were tested for flexural strength above Tg after normal curing. A cross ply glass epoxy laminates were manufactured by match die mold technique (MDM) followed by hydraulic press loading with hand layup process. A 13mil E-Glass fabric, Lapox L-12 and K-6 were taken as raw materials for fabric, resin and hardener respectively. The main objective of this investigation is to study the flexural strength of said laminates as per ASTM D790 when laminate specimens are exposed to two kinds of post cure temperatures i.e. below and after of glass transition temperature. A brief explanation about manufacturing of a laminate with match die mold technique was presented in this investigation. The results showed that the flexural strength of laminate with the above said combination of reinforcement and matrix is exhibiting a gradual increase in the case of post cure temperature from 40 °C to 140 °C and a drastic decrease from 140 °C to 220 °C.