Check the condition of twine guide rings for wear and damage, that could cause abrasion to the twine when passing through
Remedy – rotate ring so twine is in contact with smooth area or replace the worn ring
Inspect the wheels on the end of the needles for wear and damage
Ensure no sharp surfaces
Ensure wheels are free turning
Ensure that twine is located correctly inside the recess in the wheel
If the tension on the wheels is too tight, the twine surface can be damaged
check correct spring tension force in accordance with OEM recommendations
If the twine has come out of the needle wheel, it can become damaged, creating a weakness
check twine is correctly located in needle wheel
Twine coming from spool in a ‘bird-nest’
Remedy – ensure twine spool is not crushed or damaged
Remedy – check condition of spool packaging, to ensure it has not damaged
Remedy – check that the spool is correct way up in the baler and twine is pulling correctly from the spool
Twine restricted from pulling from spool and not running freely, due to spool centre shape
Remedy – check size and shape of spool centre
Check twine cross-section shape is not causing problem at tension plates
Check size and type of spool joining knot
Ensure that any raffia-joining knot is not too big
During production, it is possible the twine inside the spool centre can be damaged by excess compression on the winding shaft. This can cause some of the fibres to be broken.
Heat damaged twine
Twine too thick or thin
If the twine is too heavy or thick, the bill hook may be unable to open wide enough to collect all of the twine, to form the knot correctly.
This can create serious problems, the knotter is unable to make a correct knot and could be damaged by trapped twine on the bill-hook.
It is essential that the twine guide plates and twine tension wheels are correctly adjusted to provide the correct twine tension at the knotter.
Remedy – check twine tension with spring-tension gauge and adjust according to OEM recommendations.
The twine clamp or retainer must be correctly adjusted to ensure the twine is held correctly during the knot formation.
Too tight = twine will be crushed and damaged
Too loose = twine not held correctly, affecting quality of the knot
Incorrect twine tension
Remedy – check for correct twine tension at tension plates and tension wheels.
Remedy – check knotter system mechanism timing, in accordance with OEM recommendations.
Inspect twine – carefully check that twine is not flat or un-twisted. Twine with uniform cross-section and compactness will assist with correct knotting process.
Slippery property of twine
The raw material mixture and manufacturing process could have produced a twine that it too slippery, causing the knot to open after tying.
Crop type/condition vs Baler set-up
Crop too dry/short?
Un-even bale density?
Abrasion by crop
On single-knot system balers, the twine end is held in place in the retainer on top of the bale, and is pulled from the spool below the bale. As the bale length increases, during bale formation, this action causes the twine to be pulled across the bale surface, creating high friction against the twine.
Abrasion by baler guide rings
Anywhere that the twine is in contact with metal in the baler, as it is feeding to the knotter, can create friction on the twine. If any metal surfaces or twine guide rings are worn or damaged, this can break fibres on the twine surface, creating a weakness.
Damage from needle wheel
The twine is delivered to the knotter by the needle, running on a free-turning wheel at the tip of the needle.
Ensure the needle wheel is free turning
Ensure the needle wheel is not worn or damaged that could damage the twine
Ensure the twine is located correctly within the recess on the wheel surface
Damage from tension wheels
Too high tension between the wheels or damaged wheel surface, can cause damage to the twine
Ensure that tension wheels are adjusted to correct tension, in accordance with OEM recommendations
Inspect tension wheel surface for any sharp edges or damage
Damage from sharp surface on baler canal floor
Inspect the surfaces of the baler canal for damage or sharp edges that can damage the twine as the bale is moving down the canal.
Damage from lower tensioner arms scraper / cleaner
On some balers, a small hook is fitted to the lower slacker-arm, which can become bent, or mis-shaped that can cause damage to the twine.
Lower twines under extreme tension as bale leaves chamber.
In certain circumstances, if the bale is able to flex too much when exiting the baler, it could create excess tension on the twine at the moment the bale touches the ground.
This may happen if bale length is too long when bale density is too low.