Linoleum Floor Covering
Linoleum is a sheet material used for covering floors and walls. It is made from a mixture consisting of unseed oil, finely ground cork or wood, resins, gums, and pigments. The mixture, commonly called linoleum compound, is applied to a fabric backing, which is usually burlap, cotton canvas, or felt.
The first step in linoleum manufacture is the purification of the linseed oil. It is placed in large tanks to allow foreign matter to settle to the bottom. The purified oil is exposed to warm air, and the oxygen in the air causes the oil to thicken. To increase its thickness still further, resins and gums are added. The resulting mixture, known as linoleum cement, is aged until it becomes a tough, rubber-like substance.
Powdered cork, or wood, and pigments are added to the linoleum cement under heat to form linoleum compound. The compound is then "scratched" into small particles. The particles of linoleum compound are pressed together and rolled out into sheets by a machine called a calender. These sheets are pressed into the backing material. The linoleum sheets that come out of the calender are soft because of the heat and pressure applied to them and must be seasoned until properly hard. The seasoning process is done in special ovens and may last from a few days to a few weeks. Linoleum made in this way may be solid colored or marbleized, or may have a printed design. In inlaid linoleum a pattern is formed from unbacked linoleum of various colors that is cut into pieces and then pressed into backing material.