Plastic Memory

Reinforce the PP with fibers. PP manufacturers know the standard percents and changes in appearance if fiber is added. Fibers can be different length, different cross-sectional shape etc. Fiber can be different types of carbon, different types of glass, and different orientations.

PP can be cross linked.

Bobguz

I would also suspect that adjustment of the type and amounts of plasticizers would be necessary.

ah, I remember my first plastic show in Chicago - 1979; walking the aisles, collecting the STUFF, man I was in junk heaven. When I got to the airport, the stewardess told me that anything that didn't fit under my seat had to be thrown into checked luggage (I hadn't any so the resin furniture pieces were, sadly the first to go), and I dutifully folded up a beautiful pink and white co-extruded polyolefin "hula-type-hoop" and stuffed it in under the cushion. Confession - It never remembered anything CLOSE to being a hoop - fibers or not.

Now, instead of FOLDING up a hoop, why not disconnect the hoop at some point and tighten the coiling down into a smaller package, then REOPEN the hoop and rejoin? Might be easier -

Jim

Mostly because disconnecting and rejoining would involve special injection molded fasteners. The hoop is not made from round extrusions but from flat extrusions.

Don'tcha just love trade shows? I prefer them to any other form of entertainment.