SpringUnit® – The P3-1 toparm modernization opportunities

Dr. Laszlo Olah (R&D Engineer, CDO)
Resul Istrefi (Managing Director)

Published by:
Simon Wilhelm (Co-Author, Marketing Manager)

Introduction: The need for sustainability and modernization of old parts in the textile industry

The world – now more than ever – needs to think about ways of optimizing its outdated parts and co2-emissions, acting with care when it comes to the preservation of natural resources and energy consumption. It is not just the presence of the crysis, but the greater demand of the population which unavoidably leads to a restructuring process of political views and economic perspectives in the upcoming years. Like in every other segment, stagnation leads to extrusion in any market. How you position your company now, adapting to the opportunities in this recession, will determine how strongly your company can grow when the economy works in your favor again.

Even in the time of the recession, valuable opportunities are present to make the right decisions now and adopt to energy saving processes, cut back on power consumption and turn to long lasting, mechanical products. Swinsol develops these innovations specifically targeting the ring spinning industry. With the introduction of the SpringUnit for the P3-1 toparm, spinning mills will be able to switch from their old pneumatic P3-1 tube system to a mechanical solution, fullfilling the need of a more sustainable process driven machine park. It is now possible to modernize your P3-1 toparms and be ready and set for the future.
In the patent database we can also find information that go back to the beginning of 2000. There were several attempts to develop possible mechanical solutions. Today, with rising energy prices, it is more important to check this possibility more closely. 


History & Function of the outdated P3-1 tube system

Many decades ago, spinners used to turn off the pneumatic spinning machines over the weekends. After the machines were stopped for a longer period of time without lifting the top arms, the cots took damage at the pressure spot. To prevent the deformation of the cots, the spinners had to lift the spring loaded top arms after turning off the machines. The requirement was to keep the top arm on low pressure over the weekends to ensure a pressure for drafting is given, to keep the machine in operation until the speed is increased again during the working week. The P3-1 top arm was born. During the week, the tube in the hexagon chamber was constantly filled with air, to apply the pressure to the top arms. On the weekends, spinners could centrally reduce the pressure volume. No more cot deformation or yarn breakage after the weekends. However this concept is now outdated. The spinning world has changed and the machines are running 24/7. The constant draw of air and energy is no longer required. Instead we have invented a once set & forget mechanical insert for the hexagon chamber, that makes the air tube no longer necessary. We achieve more equal pressure results with our mechanical SpringUnit® without the use of any energy or air.

This is the conventional tube used in P3-1 toparm. The tube is located in the hexagonal rod:


The Beginning: The P3-1 toparm has some serious issues

A toparm is an indispensible part of the ringspinning frame, which has a measurable influence on the yarn quality in the spinning process. With a main compacting unit, like the Recompact system, it is important to adjust the toparm and its pressure perfectly in order to guarantee a constant and high yarn quality output. The main purpose of the toparm is to equally apply the same pressure to each and every spindle at all time. If it fails to do this, the worst thing that can happen is a great deviation of the desired yarn quality. As we integrate our compact systems in the ring spinning frame, the equal toparm pressure is essential for the proper installation.

We have been asking the question for some time now, wether especially the P3-1 toparm is still suitable today for modern and sustainable spinning mills.

The main problem is, that this toparm still works with a pneumatic tube system, which uses a lot of energy and air pressure and over some time, the tube – which controls the pressure load on the roller – can not be guaranteed to maintain the same pressure on every toparm. The truth is, that despite the amount of energy and air pressure which is wasted with the tube system, there are often air leaks after some time and the pressure load will be unequally distributed between the rollers on the toparm which leads to a deviation in the yarn quality and quite some unnecessary maintenance work. On top of it, there are many expenses related to this issue and the constant draw of unnecessary energy. We came to the conclusion, that the P3-1 toparm has several issues but we also found out that there can be solutions and the opportunities to modernize the P3-1 model. We are going to go into great detail and bring some light to those opportunities in this article.


Specific problems of the P3-1 pneumatic tube system

Our extended research in the laboratory results in these inherent problems in the P3-1 model toparm:

1. The requirement of energy and air pressure

Besides causing unnecessary expenses, the pneumatic tube system works with air pressure which inflates a tube in the hexagon rod. The fact, that for example a spinning machine with 1200 spindles has 50 sections, and 2 connectors for the air pressure for each section, means, that there are exactly 100 connectors for only one machine. Over time, the tube and the connectors get worn out and start to leak air. More constant pressure needs to be used and if there is great leakage, the machine needs to be stopped and the leaking spot has to be searched and fixed. It is out of question, that this can get very expensive for spinning mills – it certainly does. Finding the faulty spot in the tube system is not an easy task and can take a long time. This is also a reason why some companies like Texpart removed the PK3025 toparm – another pneumatic tube based model – from its sortiment entirely.

2. The abscence of individual pressure adjustment

The conventional tube system does not offer any way to adjust the pressure of a toparm individually. But in practice, over time a toparm and its parts can be slightly bend and some parts lose its original shape. This causes the demand of adjusting the pressure individually as specific toparms in a section might deviate from their initially adjusted pressure over time. The spinners came up with an optional metal insert on the toparm to tackle this problem and achieve additional pressure if some of it got lost on any toparm. However, this is only a temporary solution of necessity and does not solve the problem over time.



3. Differences in pressure on each side / roller

Like one can witness in the pictures below, pressure should be centrally applied so that we have an equally distributed pressure load on both rollers. Only then we can achieve great yarn quality. When time passes however, the pressure load is not centered anymore and deviates more to one side of the toparm. In our laboratory we have measured differences in pressure values up to 3-4kg. Theoretical the pressure difference to one side can be more than 30%. Differences and unequal pressure needs to be avoided at all time.

New: P3-1 toparm with perfect pressure distribution (a=b)

Old: P3-1 top arm with imperfect pressure distribution (a≠b)

The result is, that the roller touches the sides of the holder (red circles) and is not centered, which should not happen:

If we can find a solution for bringing constant pressure to both sides and adjusting toparms individually without needing the outdated tube system, then there is potential for innovation and hope for the P3-1 toparm.

Providing solutions with the mechanical “ SpringUnit®”


Researching mechanical solutions

So we went on a journey with the goal to extend the potential of the P3-1 toparm and modernize it in order to unlock potential for the future. We wanted to make the P3-1 toparm future-proof. Constantly on the lookout for improvements, we have researched a mechanical and durable solution to replace the old and out-dated tube system which still runs in many spinning mills with air pressure even today. As a result of the prior research, an entirely new product has been developed, allowing to replace its predecessor with mechanical and durable parts.


The Swinsol modernization kit solution

The development of the modernization kit was made in order to solve the problems discussed above. The new product goes by the name “SpringUnit”. The SpringUnit® itself consists of a main part, several pressure settings discs and a connector. It replaces the old tube system in the hexagonal rod on P3-1 toparms. The invention is purely mechanical and focuses on durability and pressure adjustment. There is no more waste of energy or air. The pressure on the top roller is individually adjustable with the SpringUnit®. The pressure can be adjusted in discrete increments with the spring and the setting discs from 16kg up to 21Kg. Increases can be made by 1kg at a time. The Swinsol SpringUnit® is therefore the perfect replacement for the tube system to save ressources and increase profits. No Co2-emissions, no additional energy, carbon neutral and highly durable.

SpringUnit is a patent pending solution from Swinsol


1. Pressure load is generated with the spring

The SpringUnit® uses a mechanical spring to adjust the pressure load of the toparm individually instead of using a tube or air pressure. It is more durable, flexible in adjustments and saves expenses for power consumption.

2. Force is adjustable individually adjustable with the setting discs

The exact pressure load can be individually adjusted at any time, if the load on the toparm needs an adaption in the future. This is possible due to the settings discs, which allow to target any pressure load between 16-21kg depending on your needs. Adding a settings disk of the size of 0.5mm equals 1kg added pressure to the toparm.(Include table)

3. Obsolete parts are replaced by new parts which center the pressure

With an additional element that we offer, we also create a distance between roller and holder, so there is no point of contact which could lead to friction. This is often the case with the P3-1 toparm.


SpringUnit Balancing Spacer Insert for perfect centering:                          Old P3-1 top arm with new Balancing Spacer Insert to achieve a perfect pressure distribution (a=b):


With the additional Balancing Spacer Insert, the spinning unit and the pressure on the rollers are automatically centered. The Balancing Spacer creates a space between roller and holder, which eliminates the prior problem. The first picture has no distance between roller and holder. The second picture however, has the Balancing Spacer installed and creates a distance between roller and holder.


Placement of the SpringUnit® after the installation

The SpringUnit® is located inside the hexagonal rod after the installation:


After the upgrade, the old parts of the tube system are replaced by the new ones of the SpringUnit®. The new parts make the outdated ones obsolete. Also, the SpringUnit® together with the additional element for the toparms will keep your pressure equally distributed on rollers at all times. The SpringUnit replaces the pneumatic system with a innovative mechanical system. It offers high durability, great economic advantages, individually adjustable pressure loads and modernizes the P3-1 toparm. It ensures constantly high yarn quality while not requiring any kind of power consumption.

  • One-time-installation
  • No air / energy
  • High durability
  • Zero emmissions
  • No worn out rubber

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Nik Istrefi











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