From the Sector

ITMA 2023 was a successful platform for the flat knitting machine manufacturer STOLL to present its latest new developments. The business unit of the KARL MAYER GROUP will be following up this fair on 3 July with the launch of a further innovation package. With the solutions contained in this package, STOLL will be offering its customers additional added value when using their flat knitting machines - in line with the concept of bundling innovations.

The new features include an optimised central lubrication system that reduces both maintenance effort and oil consumption, this as standard from July 2023 for all models of the CMS and ADF series produced in Reutlingen.
Compared to the previous optional variant, it ensures more efficient and comprehensive lubrication. All needle bed elements, from the holding-down jack to the coupling part and intermediate slider to the selection jack, are now supplied with oil. The machine itself recognises whether lubrication is required. Independently of this, the lubrication intensity and oil distribution can be adapted to the individual machine conditions by setting various parameters, if required. To ensure that the required amount of lubricant is reliably supplied, a message is sent if the level is too low.

In addition, a new oil drain container as standard equipment for all CMS and ADF models catches used oil from the needle bed under the machine. This prevents soiling of floors or knitted fabrics. The emptying of the container can be efficiently managed by an adjustable reminder function. The neat and at the same time sustainable solution does not require cleaning agents or hoovers and offers the possibility to reuse the oil after cleaning through special filters, if necessary.

Users of CMS and ADF belt take-down machines can benefit from optimisations around the belt take-down. Thanks to the new STOLL innovation package, this can be turned forwards and backwards by means of a switch as standard in order to easily eliminate fabric wraps and thus reduce maintenance times. In addition, a mirror, which is also fitted as standard, ensures a simple visual check of the belt take-down.

Another solution of the STOLL innovation package from July 2023 includes new cams that enable split-stitch implementation without cam box modification. This reduces manual effort and thus conversion times and costs. The feature is standard on all fine gauges ADF and CMS machines.

For the W machines from STOLL, there is now a further inlay yarn carrier, the Qt, in addition to the previous Qw yarn carrier. The extension means that the number of inlay yarn carriers used in a system can be increased from the previous one to three. No additional system is required for the weft yarn, and the process steps weft yarn insertion and knitting take place in the same system.

According to the World Health Organization (WHO), cardiovascular disease is one of the most common natural causes of death. Every year, it is the cause of death of around 17 million people worldwide. The Peter Dornier Foundation Prize 2022 has now awarded a research work that is to improve the medical care of people with insufficient heart valve function in the future and prolong the patients' lives.

The human heart is a high-performance machine: over the course of a person's life, it beats almost three billion times, pumping around 200 million litres of blood through the body. Enormous stresses that can sometimes lead to life-threatening signs of wear and tear. If a heart valve gets out of step, patients usually get artificial-mechanical or biological valves as a replacement. However, mechanical solutions imply patients to take blood-thinning medication for the rest of their lives. In addition, there may be audible closing noises. For example, almost a quarter of patients with mechanical heart valves complain of sleep disturbances. Biological heart valves, on the other hand, such as those made from animal tissue, require a great deal of manual work and have a shorter lifetime.

Potential of weaving for medical products demonstrated
For this reason, Graduate Engineer Mathis Bruns at the Institute for Textile Machinery and High-Performance Textile Materials Technology (ITM) at the TU Dresden is researching an implant alternative made of fabric. As part of a research project that also involved heart surgeons from the Dresden Heart Centre and the University Hospital in Würzburg, Mr. Bruns provided important findings for weaving an artificial heart valve in his diploma thesis. For his work entitled "Development of tubular structures with integrated valve function", Mathis Bruns has now received the Peter Dornier Foundation Prize 2022, endowed with 5,000 euros. In his laudation, Dr. Adnan Wahhoud, former head of the development department of air-jet weaving machines at DORNIER in Lindau, said: "With his work, the winner of the award demonstrates very clearly the potential of weaving technology to produce fabrics of complex form, geometry and structure with the aim of prolonging and improving people's lives." The award-winning thesis enriches research into three-dimensional tissues for use in medicine.

Weaving replacement heart valves without seams
"A particular advantage of our approach is the integral production method", says foundation prize winner Mathis Bruns. “The geometry and function of a heart valve is that complex that woven heart valves could not be produced in this form previously. Through the combined use of a rigid rapier weaving machine with bobbin shield and a Jacquard machine, it is possible to weave the replacement heart valve in such a way that it no longer has be sewn together. Even the tubular structures for the blood vessels and the integrated valve function are ‘all of one piece’. Seams are always a weak point in textile medical products," Mr. Bruns adds. “Another advantage of the woven heart valve is the possibility to insert it by the help of minimally invasive surgery. Hence, the folded valve which is about the size of a tea light is to be pushed with a catheter via the bloodstream to the target position in the heart and unfolded there. The patient's chest and heart would then no longer have to be cut open”, explains prize winner Mr. Bruns.

Textile structure is similar to human tissue
A wide variety of medical products have always been produced on DORNIER weaving machines. Customers use them to produce fabrics for bandages, prostheses, blood filters and orthoses among other things. For Mathis Bruns, it is only evident that implants such as heart valves will more and more be woven on the machines from Lindau in the future. "Textile tissue is very similar to human tissue," he says. The human body consists largely of thread-like materials, just as a textile fabric is made up of thousands of individual threads. "Muscle fibres convey force impulses, nerve tracts send stimuli such as pain and brain cells convey information via thread-like dendrites and axons." Because of their ‘thread-like properties’, woven implants are therefore particularly suitable for medical applications.