Baler twine
Baler twine is the name for twine that is used to bind straw , hay or silage bales and keeps them in their shape. Other names are twine , harvest twine or cord .
Press twine mostly consists of polypropylene (PP), but sisal is (still) also used. The twine is tied around the bale using a straw press . For so-called high-pressure bales (small bales of straw with a weight of around 10 to 20 kg) these are two cords, for large square bales 4 to 6 cords, for round bales up to 20 cords; For round bales, a so-called round bale net is often used instead of baler twine.
In practice, cords in the middle of the bale are sometimes left out for reasons of cost. The outer cords are particularly important for the durability of the bales during transport. The latest trend is to create a kind of bar code with different thread colors. In this way, the bales can be assigned to an owner more easily and unintentional loading by strangers is counteracted.
The required thickness of the baler twine depends on the type of straw press used (e.g. whether a square or round baler, etc.). The strength is determined indirectly by specifying the length of the run (unit: meter per kilogram )., D. H. the smaller the value for the run length (per kg of press yarn), the stronger the yarn. Typical specifications for the run length are approximately: 130 m / kg, 150 m / kg, 320 m / kg. For high pressure bales , a "strength" (running length) of 200 m / kg for sisal cord or 400 m / kg for PP cord is sufficient. Smaller square bales are bound with twine with a "strength" (length) of 150 m / kg, for large square bales twine with a "strength" (length) of up to 110 m / kg is required.
A special case are baler yarns with a running length of 750 m / kg. These extremely thin yarns are used in round balers instead of net. Due to the approximately 20-fold wrapping around the bale, a secure hold is achieved here, despite the low thickness of the twine.
In the trade, baler twine is usually offered on spools with a weight of 5 to 9 kg each, in packs of 2. The bobbins are placed on the side of the baler and connected to the machine with the correspondingly marked bobbin beginning. For this purpose, the coils are wound in such a way that they can be unwound without having to turn the entire coil. The beginning of the twine is pulled out of the center of the bobbin, the bobbin itself stops.
In the early days of straw presses, iron wire was sometimes used for binding. In addition to the high costs, it was above all the high risk that animals would swallow iron parts that put an end to this material.
Expectations
Baler twine should be easy to cut by the knotter. The yarn should be flexible enough to handle the high speed of the knotter. The many deflection points of a baling press load the twine on one side, but should not lead to fraying. In addition, it must also be able to cope with the increased tensile stresses of grass silage bales. Even after a period of storage, the baler twine must remain UV-stable.
Tear resistance
Typical values for the tensile strength of press yarn are around 400 daN for a yarn with 110 m / kg, around 200 daN for a yarn with 150 m / kg or 140 daN for a yarn with 320 m / kg, although there are of course fluctuations depending on Material composition and manufacturer there.
Individual evidence
- ↑ ballensilage.com ( Memento of the original from April 5, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ behrens-scheessel.eu
