Services
GT Engineering provides forensic engineering, scientific analysis, and expert testimony in a range of technical disciplines.
Polymer Analysis
GT Engineering has established itself as a Pacific Northwest leader in forensic analysis of polymers and plastics. We have provided expert consultation in litigation in this field across the United States.
Our experienced staff includes specialists in materials science and chemistry. We have established in-house laboratory capabilities to support work in this field, including differential scanning calorimetry (DSC), high performance liquid chromatography (HPLC) and Fourier Transform infrared spectroscopy ( FTIR). We utilize a 'nature' scanning electron microscope (SEM) fitted with energy dispersive spectroscopy (EDS). The 'nature' SEM allows work under a soft vacuum, permitting imaging of non-conductive and organic materials. Additional instrumentation is available through strategic alliances at the University of Washington and other laboratory and research facilities, where we conduct gas chromatography - mass spectrometry (GC-MS), atomic absorption (AA), thermal gravimetric analysis (TGA) and differential thermal analysis (DTA). Our goal is to provide comprehensive accurate analysis through knowledgeable application of state of the art techniques and instrumentation.
Forensic analyses of plastic components can encompass recognizing numerous factors. These can include issues of stress, misapplication of the polymer for the intended environment, exposure to unintended environments, fabrication deficiencies in the polymer and polymer design/compounding issues. Stresses can arise either due to application or improper installation techniques. GT Engineering provides stress analysis including finite element stress analysis modeling. We can assess polymer design/compounding issues through deformulation to determine the additive package, through tests that assess homogeneity of the product, and testing of the polymer morphology. Environmental degradation is addressed through standard means of accelerated testing.
Examples of projects:
- Rubbers and Elastomers - Investigations of tire failures, failures in hoses, deterioration of expansion joints, thermal analysis of sealing compounds.
- Paints - Identification of source, thermal analysis related to fire investigations.
- Adhesives - Elastomeric contact adhesives, analysis of load-creep behavior, identification of adhesive components.
- Plastics:
- Polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) piping and fittings, fire protection systems, issues involving material defects, stress corrosion cracking, bonding.
- Polycarbonate (PC) and other safety glasses materials; ability to withstand impacts in support of accident investigations.
- Acetal resins, corrosion degradation in chlorinated waters, stress induced failures.
- Polyethylene (PE) analysis of chemical storage tank failures in a Chlor-Alkali manufacturing facility.
- Cross-linked polyethylene (PEX), environmental degradation of residential potable water and hydronic heating system tubing, issues of anti-oxidant stabilizer package, ultraviolet light (UV) degradation, and electrical cable insulation failures.
- Polypropylene (PP), manufacture, antioxidant/stabilizer package deformulation of water heater dip tubes, failure analysis of consumer products.
- Acrylonitrile Butadiene Styrene (ABS), environmental degradation of filter nozzles in a municipal water system.
- Nylon, cases involving failures of nylon safety lanyards, typically associated with environmental degradation and/or local deterioration from service conditions. Testing of rope strength and elongation.
- Composites - Analysis of fiberglass reinforced chemical storage tanks.
For specific questions regarding polymer analysis services, please contact Robert Clark, PhD.
