Composite material reinforcement materials. Another important factor is the gross quantity of material to be produced. Large quantities can be used to justify high capital expenditures for rapid and automated manufacturing technology. Small production quantities are accommodated with lower capital expenditures but higher labour and tooling costs at a correspondingly slower rate. Many commercially produced composites use a polymer matrix material often called a resin solution. There are many different polymers available depending upon the starting raw ingredients. There are several broad categories, each with numerous variations. The most common are known as polyester, vinyl ester, epoxy, phenolic, polyimide, polyamide, polypropylene, PEEK,
Unusual types of gramophone records are the copies still in very good state of listening these days Some records are cut with completely independent bands on the same side. In this case the bands appear as separate tracks on the record and are not intertwined as with parallel grooves (see below). This has most often been used on educational records but is also sometimes used on discs of commercial pop and rock music. These individual bands need not be cut at the same speed. The second Moby Grape album "Wow/Grape Jam" (1968) has this setup. Following the fourth song on side one there is a