Nearly 10% of the total emission of greenhouse gases is released by the textile & footwear industry. The onus lies on mill workers and management to identify the different types of material wastes and minimise them. Read this blog to find out how spinning mills should manage operational wastes.
2. Introduction
● With growing concerns over pollution and environmental integrity, the material wastes
generated in textile and apparel sectors have come sharply into focus.
● Annually, 0.5 million tonnes of microfibres are dumped into water bodies, contributing a
significant chunk of the total microplastics-related water pollution.
● Owners of spinning mills as well as OEM manufacturers, suppliers of spinning cans and
other stakeholders need to take up the responsibility of efficiently managing the waste
levels, so that the ecosystem is not harmed in any way.
3. 1. Understanding the Different Types of Waste
in Spinning Mills
● The waste material generated as by-products of the day-to-day activities at mills can
broadly be classified as ‘useful’ and ‘non-useful’.
● The ‘useful’ wastes can be applied in open-end spinning processes, count yarn
coursers, and related operations. The ‘non-useful’ wastes cannot be reused – but
there is the possibility of using them as fertilisers.
● For efficient waste management, it is also important to distinguish between ‘hard
waste’ and ‘soft waste’.
● Once the different types of wastes are identified, managing them optimally becomes a
lot more simple.
4. 2. Good Fiber Ratio in Clean Waste & Dirty
Waste
● Strippings, broken sliver, webs and lap ends are obtained as waste products during
different stages of spinning – are known as the ‘clean waste material’ and typically
have >95% of ‘good fibre ratio’.
● On the other hand, the good fibre ratio of the waste material generated during carding
and blowroom processes is significantly lower – ranging from a minimum of 35% to a
maximum of 55%. Filter strippings can have good fibre content of upto 80%.
● In order to effectively manage the different types of wastes, mills have to adopt a
customised set of procedures.
● The material that has relatively high waste fibre should ideally be used in
coarse/medium coarse rotor yarns.
5. 3. Maintaining Steady Yarn Retention Levels
● For waste control and reuse in mills, the importance of establishing a steady yarn
realisation percentage (YR%) cannot be overemphasised.
● Three key factors – the expected quality of yarn, cotton & cotton trash levels, and the
machinery used – determine this YR% figure. The YR% is different for combed counts
and carded counts.
● Comber noil, usable waste, card waste, yarn waste and mixing trash are some of the
parameters that are used to calculate the YR%. It also has to be kept under
consideration that the YR% calculation has to be done separately for mills that reuse
waste material in the mixing, and for those that do not.
6. 5. The Need for Waste Processing Machinary
● Irrespective of whether spinning wastes are reused or have to be sold/disposed of,
they have to be systematically pre-processed.
● This is where the need for waste processing machinery comes into the picture.
Premier machines, willow machines, thread extractors and pickering waste openers
are some commonly used machine tools used for soft waste processing.
● Hard waste processors work differently, by converting the waste material into a
fibrous and loose matter.
● Over the last half a decade or so, the trend of installing advanced waste spinning units
at mills has become more & more prominent.
7. 6. Waste Management at the Carding Stage
● Various types of wastes are generated during the carding phase in spinning mills, like
sliver cut/breaks, flat strips, droppings, filter waste material and others.
● ‘Tandem carding’ is a technique that can be adopted to increase cleaning efficiency
levels by upto 7%.
● In addition, mill workers can also make use of perforated undercasings – as well as
increase the licker-in speed – to minimise wastes and optimise waste management
processes.
● For reducing neps and eliminating seed coats, maintaining high cylinder speeds (with
high flats) is also effective. Generally though, focusing on the licker-in area is
imperative for card cleaning.
8. 7. Waste Recording & Controlling Hard Waste
● Accurate calculation of waste stock is extremely important to minimise ‘invisible
losses’ and inefficient waste handling.
● The waste percentage has to be calculated by considering all the shifts and the
machine production volumes.
● Dedicated waste investigation lies at the heart of the waste management strategies
devised by any spinning mill.
● Apart from bringing down the cop rejection figures and ensuring smooth material
handling, adoption of systematic winding and ring frame practices are also proven
methods of hard waste control in mills.
9. 8. Waste Management at the Combing Stage
● With comber wastes contributing more than 15% of the total cotton waste material in
mills, proper waste-management is hugely important at this stage.
● Between the comber and the cards, the number of reversals should be fixed at an
even number – while the amount of pre-combing draft can also be increased, in order
to bring about a significant reduction in wastes.
● Due care, however, has to be taken to ensure that the quality of the final yarn is not
adversely affected.
● Mechanical problems and/or process-related problems also lead to too much waste
generation during ring spinning.
10. Jumac smart can technology is presented in a comprehensive and
user-friendly way to facilitate the operations. Utilization of this
smart can technology will be a core competence of the mills in the
near future, adding a competitive edge.
- From an expert