neoprene is cheaper because it can be cast in a mold, whereas real natural rubber needs to be extruded.. rapid molding is a more economical process.
neporene is less penetrable, doesn't break down as fast as natural rubber, more resistant to solvents, because its pores are closed it doesn't have the "grip" that natural rubber does. Natural rubber has better bounce characteristics, although it degrades faster. better bounce characteristics are the main reason it is preferable for pool table cushions.
I noticed a lot of things for sale online state, such as they are "rubber" this can be somewhat deceiving, because it can lead one to think they actually are real natural rubber, but what is being sold is is a synthetic molded product.
I'd suggest being a bit careful with that, if you are ordering products, as the molded rubber products which are cheap to make by molding processes, often in china are all over the web in the form of imported products. So often it is not stated that they are actually synthetic rubber products. the word "rubber" doesn't differentiate.
these diamond pocket facings are at least stated upfront , to be neoprene, not natural rubber.
when pool tables were first made, the vulcanizing process used in making natural rubber products was not yet invented. also during wartime, rubber was a very sought after resource. this page reflects upon the rubber trees in Vietnam..
if you think back a bit and remember seeing really old tires, well they rotted and wore out a lot faster than the modern tires made of synthetic products. during wartine there was a need for rubber and tirs were in very limited supply. i have heard of governments seizign tires that were owned by civilians for the war effort.
natural rubber is derived form rubber trees, synthetic rubber is derived from chemicals mainly from the oil industry, - not rubber trees. this advancement in in technology made the rubber less strategic in terms of a resource worth fighting wars over.
although this page is based in snooker, it reflects how "list " was used in early cushions and talks about them using pans of water to try to make them rebound better. ,This is before vulcanization was invented. I found it a very interesting read.. Has anyone here seen a table with "list" ? I imagine there aren't many that skipped being converted.
the page also reflects upon how early "Burroughes and watts" tables tied the rails to the slate, and used steel plates to weight the rails, and used good hardwoods , all expensive things, but they went to that extent to improve the bounce characteristics, tables made like that are very silent and beautiful to play on.
"The most notable and successful undoubtedly was the "Steel Block" cushion introduced by Burroughes and Watts."
source:
Compared to the ancient origin of the game, which we have already heard about, rubber billiard cushions are quite a recent introduction.
www.snookerheritage.co.uk
this is a much more expensive way to make a pool table, but there is market competition on price. As manufacturers compete for the lowest price, really decently made rails became commonly manufactured using cheaper woods, particleboard in some cases or pressed formed wood containing a lot of glue,, it creates a fairly dense product and is a lot cheaper than following the techniques that were used for making the very expensive Snooker tables.
most of the tables we grew up playing on, gold crowns and such had rails that were not made with expensive hardwoods, or the steel backers, they bonded laminates to the rails and found cheaper ways to produce them in massive numbers a lot more economically. It worked well.. became a standard that was expected.
I went looking for real natural rubber to make facings locally. I found a place that specializes in waterpumps and rubber, they had it. it comes in a 3' wide roll and you can buy 1/8" or 1/4" .. they were happy to sell me some offcuts for not much money so I used that, rather than buying cheap made in china synthetic rubber off the internet. cutting the shape of the facings is not hard.. so this was my choice and it worked well. maybe some would argue that the bounce characteristics of the cusion facing are not as important as the rail cushions.. They are being married together during rail installation. Personally I'd prefer natural rubber for the facings. Its a choice to consider.
if you buy real natural rubber , or neoprene, the harness is rated by the "shore durometer" so you can order harder or softer varieties there is a special tool used to measure the harness. The shore duromeer increases as rubber ages so a shore durometer tester can be used if youd like to monitor the harness of your rubber over time.. what this does is gives you a defined number to go by , rather than an estimate made by the number of rails you could make or other means..
the shore durometer of neoprene wont degrade as fast, because its got better longevity, rubber always turns to rotted cracked and degraded rubber given enough time.
here's an example of the tool use dot check durometer.
Durometers for measuring the hardness of rubber, plastic, silicone, foams and other material.
www.checkline.com