Is your converting environment contamination free?
By Jenni Westwood, Commercial Manager, Rainbow Technology Systems
Converters today are under increasing pressure to maintain productivity and high quality with increasingly tight profit margins and demanding customers.
The ultimate goal is to have the production line running continuously with as little interruption as possible. The quicker the current job can be completed the faster a new job can be started.
One of the main barriers to efficiency in the industry is contamination. Surface contamination on the web means that production is stopped until print plates, impression rollers and other parts can be cleaned manually. Moreover if the contamination remains on the product it can lead to waste and scrap and therefore lower profits. If quality issues go unnoticed it can lead to returns and dissatisfied customers.
There are many sources of contamination in the production environment. Dust, dirt, fibres, insect debris and even skin particles and hair from operators will affect the efficient running of converting equipment. Materials used in processes such as slitting, bag making, coating and lamination are also prime sources of contamination as they produce dust, fibres, chaff and other by-products which can attach themselve to the web.
The contamination problem is compounded by the fact that a moving web creates a electrostatic charge. This makes particles stick to the surface like glue making it very difficult to remove them.
Over the years a number of methods to remove contamination have been tried but are they fit for purpose in the modern converting environment?
At the basic level clean rags are attached to a traverse bar placed across the web surface to pick up debris but this is very ineffective. Other methods have been introduced using blowers, vacuums, brushes and ultrasonic waves. Whilst these methods may remove moderate levels of contamination (over 150 microns) manufacturers striving for the highest quality product and lowest waste need to look at removing smaller particles.
Apart from the moving web creating a static charge, which attracts debris to the substrate, there is also the problem of the rapid movement creating a boundary layer of air (known as the Bernoulli effect). For effective cleaning to take place this layer has to be penetrated as the air pressure effectively traps the particles making it very difficult to remove them. Even high-powered blower systems simply displace particles from one area to another.
Given these factors, contact cleaning has become the preferred method of contamination removal in the converting industry as it makes direct contact with the web overcoming the static and boundary air issues. A specially formulated elastomer roller runs in direct contact with the moving web. The roller picks up all particles down to the microscopic level . The debris is then transferred on to sheets of adhesive film wound on another roller. When this film becomes saturated the sheet is simply removed leaving a fresh one underneath.
To be truly effective the contact cleaning technology needs to be used in conjunction with anti-static equipment. The faster the web moves the greater the electrostatic charge. Therefore once the substrate has been through the contact cleaning process anti-static bars need to be installed immediately after so that the web does not become re-contaminated.
In summary, converters looking to maximise yields, minimise downtime, increase profits and reduce waste need to consider the benefits of contact cleaning technology to effectively remove contamination.
For further information about KSM Superclean please visit https://www.rainbow-technology.com/solutions/ksm-superclean/
About the author: Jenni Westwood is Commercial Manager of Rainbow Technology Systems and has over 20 years experience in the contact cleaning sector. KSM Superclean is one of the world’s leading providers of surface contamination removal equipment, services and consumables to a wide variety of industries including the converting sector.
In 2017 KSM became part of the Rainbow Technology Systems group of companies. Rainbow is an innovative design, manufacturing and consumables supply company based in Glasgow. Its projects range from bespoke process automation installation to the supply of consumables to a wide range of industries.
For further information about Rainbow Technology Systems please visit: www.rainbow-technology.com