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,
What Are They Doing in Heaven? What Are They Doing in Heaven? "What Are They Doing in Heaven?" is a Christian hymn written in 1901 by American Methodist minister Charles Albert Tindley. , it has become popular enough to have been included in 16 hymnals. The song has sometimes been recorded under the titles "What Are They Doing?" and "What Are They Doing in Heaven Today?". The question mark is often omitted. The song may also be known by its first line, "I am thinking of friends whom I used to know". The song consists of four verses and a refrain, each four lines long. In