Failure Analysis - Material Composition/Product Failure

To determine the causes of a breakdown or failure of a product the first thing to consider is the overall composition of the materials that make up the product, i.e. the identification and percent composition of all of the components.

Often the causes of failure are that the wrong materials were used in the product's fabrication, or perhaps, the materials were not processed correctly, e.g. poor annealing, rapid drying, incomplete curing, etc.

Investigation of causes of product failure can be summarized for each type of material as follows:

The identification of all the major components of a molded of extruded plastic product and determination of percent composition and comparison with the composition of a known, well performing material.
Determination of the pertinent physical properties of the plastic material, e.g. impact strength, tensile strength, etc.

Determination of the effect of certain chemical agents such as oils, acids, soaps, etc. on the plastic's performance (e.g. Stress Crack testing).

For rubber and resin compounds the correct composition of all components is extremely important to the product's performance. The complete breakdown of the material's composition should be carried out and compared with the composition of a known good product.
The important physical properties of the product should be determined e.g. hardness, elasticity and compared with the required specifications.

Tests should be carried out to determine if the rubber/resin product is properly cured and if it is resistant to attack by oils, fuels, etc.

Paints and coatings are usually complex formulations consisting of unique organic resins, plasticizers, pigments, extenders, fillers, hardeners, etc.
These essential components are usually dissolved or suspended in an aqueous or solvent medium which is designed for best application characteristics.

Hence the starting point in understanding why a coating fails in a certain application is to determine its exact composition.

The causes of adhesive failure also comes down to their composition. If the right components are not used in its formulation it cannot be expected to perform well.