Find out why leather wrapping of plastics can cause bonding issues
Polyamide (nylon) and other engineering plastics are commonly used in the automotive industry to make components for the car interior. Engineering plastics have good resistance to heat and chemicals, and this means that parts made from these materials have the ability to withstand environmental conditions and are less susceptible to general wear and tear. This robustness does however pose a problem if the component needs to be joined to other materials with adhesive as part of the manufacturing process.
Components such as seats and dashboards may need to be wrapped with leather if this forms part of the trim specification, so good bonding is important for preventing unwanted delamination from the plastic. Whilst some adhesives are capable of giving the required bonding performance between leather and the plastic, they usually rely on chemicals to swell the nylon surface and cause polymer chain entanglement with the adhesive. This means that the manufacturer is limited in the choice of adhesive that they can use. There is a drive towards water-based adhesives in this industry which do not contain the solvents required to cause swelling of the plastic surface. This means that in order to ensure good bonding to nylon and other engineering plastics some kind of surface preparation will need to be carried out prior to bonding.
Surface preparation comes in many forms, including roughening methods like sanding, plasma techniques or chemical treatments. All have their pros and cons, so however you choose to carry out your manufacturing it is important to consider which is the most suitable for your process – it could save you time, effort and money as well as giving you better leather to plastic bonding performance.
To learn about simple and effective surface preparation, contact OAS.