Baler twine is a general term used to describe any one of several types of tough string-like cord used to secure bales of material, such as hay, paper products, and recyclables. While some baling is done by hand, most baling is performed by machines called balers that are specifically designed for such work. Baler twine is generally sold in spools or rolls that are designed to be used by these machines. It was originally made from natural materials like sisal fibers, and though natural fiber baler twine is still used, many man-made materials are now used for this purpose as well.
The history of the use of baler twine began in the second half of the 19th century. With the development of automatic reaper machines, a need for some mechanism to bind the piles of grain and hay became evident. Originally, this was done by hand with wire by workers following behind or riding on the reaper. In the late 1800s the first automatic binder machine, which bound bundles of grain as they were harvested, was invented. The use of binder wire for this machine created numerous problems and an alternative was sought, leading to the invention of a knotter that used twine, which at the time was called binder twine.
Automatic baler machines, which were designed for binding bales of hay and straw were invented in the 1930s. These machines relied on binder twine for their automatic knotters, and as these machines became more and more common, the twine was marketed as, and became known as, baler twine. Early types of baler twine were manufactured from natural fibers, such as manila, cotton, and sisal. Hemp, another natural fiber that was used extensively in making rope and other products proved unsuitable for twine as it was too stiff and clogged machines. By the late 1930s sisal was the most common fiber used in making baler twine, although other natural fibers were and continue to be used.
In the 1960s, companies began to experiment with manmade materials for baler twine. Polypropylene, a plastic, was the first such material and had great advantages over sisal. It was stronger, resisted the elements and wear much better, and was suitable for baling much larger bales of hay and other materials. Technology for baler twine advanced rapidly, and today, many manmade plastics are used in baler twine. Most of these twines are made from several smaller strands of fiber that are twisted or braided together, although monofilament, or single-strand, baler twine is sometimes used as well.
Today, many types of baler machines that use baler twine besides hay balers are used in agriculture and industry. A few examples of the things balers are used for are waste materials, newspapers, and recyclable materials like cardboard and rags. Baling twine is available in a wide range of colors, strengths, and materials for all of these and other applications.