Experimental studies on changes in mechanical properties of polymer composites under impact of thermal load determined based on compression testing

Agata Walczak,Daniel Pieniak,Ireneusz Naworol,Kamil Pasierbiewicz,Grzegorz Dzień,W Rogula-Kozłowska,A Polańczyk,A Walczak

doi:10.1051/matecconf/201824700027

Abstract

The objective of the study was to carry out an analysis of changes in mechanical properties of polymer composites in conditions of thermal load. Such an analysis may allow an initial verification of possibilities of deploying new composites in production of fire helmet shells. The reference material chosen for testing was the Ultramid composite, which is currently used for the production of fire helmet shells. In addition three different materials were selected that contained reinforcement by glass fibres bearing the trade name of Tarnamid, which are not used in manufacturing of shells. Testing was conducted in conditions of quasi-static load, during which compressive tests were performed. Mechanical loads were applied at different levels of thermal exposure, which was to simulate presence in fire conditions. Results of tests indicated that the Tarnamid composites are characterised by better compressive strength and rigidity determined on the basis of the Young module value than Ultramid PA66 GF25 used in the production of head protective shells. It has also been proven that thermal loads contribute to significant degradation in strength and rigidity of tested materials, which affects adversely protective properties of the helmet.

Highlights

During rescue actions firefighters are exposed to elements that pose a hazard to health and life, including mechanical and thermal loads [1, 2]
Materials produced by Grupa Azoty S.A. offer a much higher compressive strength than the Ultramid PA 66 GF25 material
The mean value of the strength offered by Ultramid PA66 GF25, Tarnamid T-27 GF25 and A3 GF25 at the temperature of 100oC is from 43 to 54% lower than at the temperature of 20oC

Summary

Introduction

During rescue actions firefighters are exposed to elements that pose a hazard to health and life, including mechanical and thermal loads [1, 2]. Basic elements of personal protective equipment comprise: fire helmet, special clothing and gloves, balaclava, boots, respiratory apparatus including mask [3]. Depending on the nature of the incident such injury may be caused by dynamic and static loads. This leads to a cumulation of hazardous factors

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Conclusion