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Gentle spinning: A game changer

Mar 01, 2021
Gentle spinning: A game changer

All spinners would agree that they could produce a better yarn if they can ensure good fibre opening and cleaning while avoiding fibre rupture. Yet, most preparatory lines meet this objective only partially. The objective of this paper is to present a case for how to achieve gentle opening and good cleaning of fibres without rupture and in doing so, what are the phenomenal benefits in the process, cost and quality that can truly prove to be a game changer for the spinning business.

The aim for any preparatory process should be to retain the original properties of the fibres and yet achieve good opening and cleaning. Reaching this target gets more challenging as the speeds and production rates of beaters and cards increase. However, no one will dispute that if this target is met, there are a lot of fallout benefits that result in the downstream process. We will discuss here both how to achieve gentle opening and what benefits it provides downstream.

Most spinners know that a majority of the process problems encountered take birth at the preparatory stage of blowroom and carding. Another way of stating this is that the majority of the process problems can be resolved if they are prevented at their inception when the blowroom and carding operations are optimised.

While most users readily accept without debate that pins provide gentle opening and prevent rupture whereas saw tooth wire has a harsh opening action, many among them prefer using saw tooth for multiple reasons. While some believe pins are good for cotton and not synthetic fibres, others believe vice versa.

Then there are those who claim pins are good for trashy and recycled cotton fibres, while others believe the opposite is true. Some believe wire is better for blends or mélange, while others disagree. Further, some believe pins are not effective for long staple fibres while some think pins are more suitable for longer staple than shorter! People also have the opinion that Pinned Lickerins are suitable only for 3-Lickerin Cards and not for Single Lickerin ones.

Many prefer using wire over pins purely from operating convenience point of view. They believe that wire costs less to replace, replacement in case of an accident is easy and fast, it is easier to achieve process parameters using wire than pins and their team is comfortable maintaining wire clothed rollers rather than pin rollers. Still others may choose to play safe and follow the OEM recommendation or prefer to continue using what came with the machine.

Lack of sufficient experience or awareness of how pins work may be a reason for creating such contradicting opinions regarding what pins can do and what they cannot. Based on our experience at Basant Fibertek and the numerous studies we have conducted in various mills in India and abroad, we shall attempt to address most of these issues in this article.

Before we go into the details of results of using pins versus saw-tooth, let us first study how pins act on fibres differently than saw tooth wire.

The above graph illustrates that pins, having a smooth spherical tip provides a very gentle action on the fibres as opposed to wire which has a knife-edge as the acting portion. The pins help to disentangle the fibres without rupture whereas the wire tends to rip open the neps. This creates rupture as well as micro dust. Further, wire tends to pulverise the trash, making it more difficult to remove it from the fibres as opposed to the pins that have a dedusting action on the fibres, resulting in the trash being separated from the fibres without getting broken into smaller particles.

Another major benefit of pins is that the rounded tip wears out very slowly and a new tip keeps getting formed as the original one wears out. The resultant effect is that pins last 5-10 times that of wire, thus ensuring more consistency in quality, besides dramatically increasing life multifold.

At the outset, we can state that any fibre or any fibre mix can be suitably acted on using pins provided the pin pattern, angle, pin projection and pin density are suitably designed according to the application and the machine settings are optimised for best performance. Just as one type of wire cannot give the optimum result of all types of fibres, the same is true for pins also.

Having interacted with many competent technical people in the industry over the past years, we can emphatically state that only a few, after a scientifically conducted trial on their particular fibre mix, have come to a conclusion regarding whether wire or pins are better suited for their requirement.Even in such cases, it is debatable whether the correct pin pattern and optimum settings were used for the trials or not. The rest have come to this conclusion either based on assumptions and presumptions or influenced by another’s opinion.

Most of the leading spinning machinery manufacturers are increasingly adopting gentle spinning. They have redesigned their blowroom to reduce the number of beating points for cotton as well as synthetic fibres. They have also adopted, wholly or partially, pinned beaters and pinned lickerins in place of saw-tooth wire rollers. One can see many more preparatory lines now using pinned rollers than 10 years ago and this trend is going to only increase as we move into the future.

Gentle opening and cleaning of fibres ensures a high quality, clean card sliver with lower content of short fibres. This in turn significantly reduces the level of comber noil, seed-coats sticking inside combers, the level of ends down on the ring frame and winder cuts This can have a huge overall impact on productivity, quality, efficiency and cost reduction, all leading to a dramatic boost in profitability. This is why we believe that gentle opening is a game changer for the spinning business.

Over the years, we have been successful in replacing saw-tooth beaters with pin type in all types and makes of beaters for all types of fibres, in India and abroad. Similarly, many successful retrofits of Pinned Lickerins are running in Single Lickerin Cards of all makes and models for counts from 2s to 80s. We have successful installations for virgin as well as recycled fibres, cotton as well as synthetic fibres, grey as well as dyed fibres, short as well as long staple.

If we do not have an existing installation for a certain type of fibre mix or machine, we offer the client a risk free trial with money back guarantee in case the trial doesn’t meet the pre-agreed objectives. All we need is a client willing to try something new with an open mind and full commitment, which is a prerequisite for any successful attempt at innovation and progress.

While wire is much cheaper than pins and pin rollers take more time to repair than wire ones, the lifecycle cost of pin rollers is far less than wire. We have detailed study reports and calculations to demonstrate that pins are much cheaper to use than wire in terms of cost per tonne of production. If the savings resulting from long life, consistent quality and the gentle opening action are taken into consideration, the payback on the investment on pin rollers comes to less than a year.

The risk of damage to pins is lower than for wire because pins are optimally heat-treated to ensure that they are resistant to bending or breaking easily. Pin rollers can be repinned at less than half the cost of new. Moreover, pin rollers do not require frequent cleaning.

We at Basant Fibertek are committed to serve and guide our clients in spinning to create a new benchmark for the global industry for quality, productivity and profitability and claim their true place in the world. The expertise we have acquired is largely through client experience sharing and cooperation in studies. For us, customer success is our success. We are ready to serve as soon as our client is ready to explore growth through continuous process improvement. As one customer once rightly commented, “Competitiveness is like a treadmill. You have to keep running to stay in the same place!”