Honda’s R&D department has revealed details of the development process for a new seat fabric, formulated to repel most everyday stains, particularly from food and drink, in an effort to improve longterm occupant comfort.
The development was spurred by a study it commissioned looking at the functionality end users wanted from car seat fabrics, based on feedback from owners in Japan, the USA, China and Thailand. Ease of cleaning, resistance to spilled food and drink and lack of odor were all highly rated as desirable traits.
Traditionally, water-repellant fabrics are used in interiors to aid cleaning, but these are still susceptible to staining by oily substances, such as those found on fast food items. These oils can seep through the fabric into the underlying seat padding, which leads to a buildup of odors over time.
Honda therefore set out to develop a fabric that better resisted staining while still maintaining the correct level of durability, along with a pleasing appearance and feel. The solution it selected was a fabric coated in a fluororesin compound, which was subjected to a barrage of tests to check its stain resistance and durability.
Three different types of fluororesin were selected for initial testing, each with different characteristics. Some were harder and more impervious to stains, others softer and less resistant. It was found that no single type could satisfy all requirements. This necessitated the formulation of compounds of these different resins to achieve the desired results.
After refining the combinations – for example, it was found that a particular resin greatly aided oil repellency, but if too much was used, steaming during the fabric manufacturing process left chalky residues – Honda settled on a final balanced formulation of three resins.
However, this was not the end of the process and Honda’s chemists and engineers also identified that variations in the dipping process of the fabrics, where the resin blend was applied, altered both the stain- and fire-resistant properties. Similarly, alterations in the drying process of the dipped fabric changed the color fastness.
All of these issues needed addressing before a production process could be signed off. Additionally, it was decided to apply a coating of a single resin type to the back of the fabric to prevent liquids penetrating the seat structure.
The culmination of this development process was a new fabric that outperformed traditional water-repellant materials, for example when daubed with salad oil, while still maintaining all of the aesthetic and tactile qualities demanded of an interior fabric.
To date, the material has been put to use in Honda’s 2020 model year Stepwgn MPV.