Plastics have proven to be the predominant material for developing durable, highly customizable, and cost-effective interior components. Corrosion resistant properties allow finished components to last longer with little to no maintenance. The versatility of plastic allows automotive designers to customize interiors while maintaining low costs. Modern manufacturing processes allow a vast array of colors and textures to create an aesthetically pleasing environment for the passengers. Additional benefits include reduced weight and high vibration dampening, increasing the ability to meet environmental regulations.
Variability of Results
Design engineers should find it important to understand the tensile properties of plastics to recognize the benefits and potential risks as they are developing solutions. Standards such as ASTM D638-14 and ISO 527 provide guidelines for test setup to help with comparability between test results. One of the greatest challenges is getting repeatable strain data and to meet the measurement accuracy required in the relevant standards.
An extensometer is required to accurately measure strain. The optimal solution is using an automatic extensometer, either a non-contacting type, such as the Advanced Video Extensometer (AVE2), or a contacting type, such as the AutoX 750. These two types of extensometers will decrease variability in results when compared with clip-on types. This is because, unlike clip-ons, they do not need to be attached by the operator and manually centered onto the specimen.
Many may not be following standards correctly, and our research has shown that much of the time it is a result of the customer simply not being aware of changes made to standards, or misinterpretation of the standard itself. Some of the implications that result from this can be failed audits, lost time investigating why results from different labs do not agree, and production delays.
The goal of any standard is to provide instructions and guidelines around a test so that different companies, labs, or operators are able to test in the same manner, thus allowing the ability to compare results. If all tests were conducted differently, then key information such as material datasheets and part specifications would offer virtually no value.
To help our customers to comply with the latest standards we have been offering free educational assistance to anyone that would like it. Our application experts have also produced a large number of default methods conforming to these key standards when using Bluehill® Universal software.