Fire behavior of flame retarded sandwich structures containing PET foam cores and epoxy face sheets

Christian Bethke,Manfred Döring,Lais Weber,Daniela Goedderz,Tobias Standau,Volker Altstädt

doi:10.1002/pc.25786

Abstract

AbstractWithin this work, the investigation on interactions of a phosphorus‐containing flame retardant (FR) DEPAl in epoxy face sheets and five different FRs in the PET‐foam core of a sandwich laminate on the fire behavior is focused. Fourteen different combinations of resin face sheets and PET foam cores are produced by vacuum assisted resin infusion (VARI). The combustion behavior of the sandwich laminates is tested by cone calorimetry. The time to ignition is lowered when a FR resin is used while the subsequent burning behavior is mainly influenced by the PET foam core. In order to evaluate the interactions of the flame retardants in the core and face sheet, a total improvement value (TIV) was set up which compares the performance related to the specific FR combinations. The highest TIV value (76%) indicating positive interactions with DEPAl was observed with a 2‐PSMP‐PET core, the lowest value (−2%) with a DEPZn‐PET core.

Highlights

Sandwich composite structures offer an excellent balance between lightweight and favorable mechanical properties
The results were evaluated with regards to time to ignition (TTI), peak heat release rate, total heat release (THR), the maximum average heat release rate (MARHE) and total smoke release (TSR)
It is shown that the burning behavior of the foam core in a sandwich composite is affected by interactions with the resin layer from the face sheet and its flame retardant

Summary

Introduction

Sandwich composite structures offer an excellent balance between lightweight and favorable mechanical properties. They exhibit an advanced performance with regard to specific strength and stiffness, thermal insulation, fatigue endurance, thermal expansion and corrosion resistance compared to comparable bulk and metal alloys. This makes them suitable for applications in transportation and construction sector with increasing demand.[1,2] The foam core provides weight reduction and shear rigidity, whereas the solid skin exhibit significant tensile load bearing and in-plane compressive properties.

Objectives

Results

Conclusion