Consumer safety summary profile of expert
Name and organisation
Further information

Consultants, expert witnesses and testing faciilties for all rubber, plastic & other polymer issues

Ms Helena Vivash (contact)

Smithers RAPRA Technology Ltd
View website

Request CV, rates or a discussion

World leading independent plastic & rubber specialist  provides a complete range of services for polymer processors, product manufacturers & end users. Smithers Rapra's UKAS accredited laboratories provide a comprehensive service supporting material selection, independent assessments, product development, quality assurance & product/material failure analysis.


Expert Witness
Smithers Rapra can provide experienced registered, expert witnesses via our consultancy team for rubber, plastic & other polymer cases. Failure investigations represent a large part of the work conducted by our team of consultants. This experience has generated extensive knowledge covering all industry sectors including; Pharmaceutical, Transport, Automotive, Industrial & Consumer.


Failure Analysis

The success or failure of a component is dependent on five factors:

Material Choice
Product Design
Length of time in Service
These five factors all need to be considered in order to identify the root cause of failure which might be due to one or any multiple of factors. As a methodology, we aim to answer the following questions.


What is the failure?

Smithers Rapra's consultants are able to apply their extensive knowledge & experience on the failure of polymeric materials to identify possible causes. The actual root cause of failure needs to be confirmed by supplementary testing to provide evidence to support the initial hypotheses. During detailed examination the general failure & fracture surfaces are photographed to document the condition of the product when returned by the client.


Is your failed item as specified?

The second consideration is to confirm that the product is as specified. This needs to include the material & design of all component parts. In terms of liability, it is relatively straight forward to confirm non-compliance. Smithers Rapra has comprehensive analysis equipment to determine the material type. This can range from simple polymer identification via infra-red or a complete breakdown & analysis of the polymer formulation. If necessary, dimensional confirmation can also be provided.


Are there design flaws?

There are a number of factors that need to be considered: Has the correct material been specified to meet the operating conditions? Temperature & exposure to fluids causes changes in mechanical properties & these need to be considered during material selection. Is the material adequately specified? Changes in the material composition cause huge variations in its properties. What analysis & testing has been carried out to predict service life? For plastic components Smithers Rapra is able to predict stress levels utilising Finite Element Analysis (FEA) & relate this to creep & fatigue data.


Has the product been manufactured correctly?

Any flaws in the product can result in a reduction of service life. Smithers Rapra has a range of techniques & analysis methods that can be used to quantify process issues. For example:

3D injection moulding flow simulation to determine residual stresses, pre-gelation, scorch & detect knit & weld lines.
GPC & Rheology to measure levels of degradation during processing
Swelling tests to determine the state of cure for rubber materials

Deterioration or misused?

Data needs to be generated on the properties &/or performance of the failed product compared with new samples & those of similar service history that are performing satisfactorily. Smithers Rapra has extensive testing facilities to quantify the degradation of products during service.