Martin,
You are right on the Harken blocks, I've read that in one of their data sheets, but I don't know what make of PA66 are they using. The material properties varies a lot from different manufacturers. For example Ensinger PA66 GF30% (Tecamid) has 160MPa tensile breaking strenght(dry) and 140MPa wet, while Zellamid ( Zell-Metall Austria) PA66 GF30% has 110 MPa dry.
Different length of fibers?
Different ways of measuring?
Regarding PEEK price : I'm puzzled on this. The prices I received are for industrial quantities, from Zell-Metall Austria, Ensinger Germany and a few other manufacturers. That price is for semi-finished products like rod,tube and plates. Maybe the price you heard of is for PEEK pellets for injection moulding.
I don't know why there is such a huge price difference. Do you think you can further inquire about the price ? I'm interested to know for sure.
However, I don't think the use of PEEK is necessary because it has almost the same tensile breaking strenght as top glass reinforced PA66, which is much cheaper. PEEK is justified only for industrial aplications, for hight temps, and corroding environments.
I would be interested if you can confirm that price from a local company, but for semifinished products like rod, tube and plate.
The prices I alluded to in earlier posts are for finished parts: Injection molded PEEK part from supplier A sent to suppler B who molds high-grade silicone rubber to it (+ post curing to minimize creep). Both suppliers manufacture in Sweden.
One thing PEEK is pretty good at for being an organic material is low creep at elevated temperature. PA66 is not bad but it does not hold up well to the silicone rubber molding process.
/Martin
