Chemicals can react very aggressively with plastic parts. Whether it’s fuel, oil, exhaust gas, water glycol, battery acid, sunscreen, cleaning agents or foodstuff, many chemicals can be absorbed by or attack the polymer, causing a change in material properties.
Chemical exposure needs to be considered in every application. Even things we may not consider as “chemical” – such as sebum or water – can have strong effects on the plastic materials, depending on the temperature, concentration, and length of exposure. Accounting for chemical exposure is challenging as the material properties needed for each application vary. A structural part under the hood of a vehicle needs to retain its mechanical properties, while a soft-touch part on a handheld device needs to retain its color and haptics.