Usually the goal of surface preparation is to accomplish several functions listed. A series of sequential cleaning techniques are suitable where a single step or process may not suffice. In fact, the strength of the surface treatment procedure used depends on various factors, all of which need to be considered during the product design process.
1. The type of plastic
Higher surface activity reduces the need for surface preparation. Some molded thermoplastic parts that require high melt temperatures and rapid cooling cycles are easier to coat. Many thermoset plastics, such as phenolic resins, are easy to coat.
2. Surface pollution
The type and level of contamination will determine the degree of cleaning required. Silicone release agents on molded parts require intensive cleaning procedures.
3. Initial and ultimate strength requirements
Adhesion of the film develops faster on prepared and cleaned surfaces In addition, a higher level of surface cleaning results in higher adhesion values.
4. Service environment
Better surface adhesion generally indicates a longer-lasting coating, better suited to end-use conditions.
5. time
Delays between surface preparation and coating application often require repetition of preparatory steps for re-cleaning, or initial higher levels of cleaning to overcome possible re-contamination.
6. Portion size
In general, large parts are more difficult to machine than small parts, and some processes are not suitable for large parts.
7. Cost
During the manufacturing/product cost cycle, certain constraints affect the degree of readiness used. Restrictions on surface preparation procedures can affect returns and warranty claims, costs that are often overlooked during the design phase.
