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8. Weaving and unraveling ropes and wicks:
Biblically: One who weaves ropes of any type of material is liable for [the] tying [prohibition]. The amount [needed to be tied] to be Biblically liable is to the point that the rope can last with its weaving without needing to be tied at its end, in which case the work done to it is lasting.
Rabbinically: However, Rabbinically it is forbidden to [weave it] any amount.
Unraveling: Similarly, one who separates a wick is liable for untying and its measurement is like that of one who weaves it, although [this liability is only applicable] as long as he did not intend to destroy [the wick], as all those that destroy are Biblically exempt although it is Rabbinically forbidden to be done.
Summary–Weaving and unraveling ropes and wicks:
Biblically: It is Biblically forbidden to ravel threads together to the point that they can last without needing to be tied at their ends.
Rabbinically: It is Rabbinically forbidden to ravel threads in any situation.
Unraveling: It is forbidden to unravel all ropes and wicks and the like. However, one who does so is only Biblically liable if a) The rope would have been Biblically forbidden to make and b) One made it with intent to rewind the rope.
May one wind or unwind twist-ties on Shabbos?
Some Poskim rule it is forbidden to do so. However, there are authorities which defend the widespread custom to allow doing so on the basis that here one has no true intent to make the twist tie into a rope.
 Admur 317:11; M”A 317:20; M”B 317:34
 Meaning that if the wick could have lasted without needing a knot at its end then one who undoes it is liable.
 Admur 317:11
 Piskeiy Teshuvos 317:6
 SSH”K 9:13 writes that tying or untying twist-ties is forbidden on Shabbos if done strongly due to that this is similar to raveling threads together into a rope, which is forbidden due to the tying prohibition. It is therefore likewise forbidden to undo.
 Sheivet Halevy brought in Piskeiy Teshuvos ibid