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in Vol. 19 - March Issue - Year 2018
Green Alternative To Ceramic Chips



Ceramic Media


Porcelain media


A modern vibratory finishing system, for the deburring of steel components with QF media


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"Ceramic media" or "ceramic chips" are available today in many shapes, sizes and abrasive rates. A real date for their origin is quite difficult to state, but for sure, their diffusion started to substitute for natural stones in the early sixties, where most precise geometry was needed.

In other words, ceramic media have made a big step forward since the last half of a century and in fact today, ceramic media are the largest and most popular finishing media for vibratory finishing and tumbling.

The ceramic media are substantially divided in two main families, respectively:

Ceramic Media

Their composition is based on ceramic bonding material mixed with abrasive of extra fine, fine or rough sizes, like corundum, in variable percentage. For a low percentage of abrasive, it is associated with low-cutting ceramic media, as well as to a high percentage of abrasive associated with a high cutting ceramic media. Concerning the size of the abrasives contained, it is associated with a coarse or a fine finishing action. The average wearing rate of a ceramic media with high cut degree, manufactured in Europe, could be placed around 6~10% in 24 hours.

Porcelain media

The composition of porcelain media is based on Alumina or Aluminium Oxide (Al2O3) that, in its various levels of purity, is used to achieve the needed media formulations, distinguished mainly by:
• Density level;
• Polishing capacity;
• Other finishing performances;

This kind of media is generally employed for polishing, but the applications (or process technologies) can be much more. The most popular quality is of a white colour, although some kinds of high density are brown and light-brown. The average wearing rate of a porcelain media manufactured in Europe, could be placed around 0,05~0,1% in 24 hours.

This media, to release the required polishing effect, is generally conditioned before use.

Conditioning has the target to remove the rugosity left on the skin of the brand new media after cooking – their original skin is in fact not yet slippery and smooth as it should be for the polishing performances. The conditioning process is generally done in a tumbling unit for five to ten days and nights, in wet mode.

Coming Back To Ceramic Media

After the above preface, it is important that, for the good understanding of this article, the term "ceramic media" is referring only to the first family, the one of ceramic media having an ABRASIVE function and, accordingly, a certain wearing rate.

This is in fact the point: the wearing rate of the abrasive ceramic media.

The volumes of waste (wet muds) produced every day by the world consumption of ceramic media employed for metal removal in vibratory finishing or tumbling processes is huge.

To understand how positive can be the impact of reducing this volume of waste (wet muds), it is enough to relate this value to the "cost per kg." of the waste disposal that, in some European Countries like IT – FR – DE – CH, have an average cost between 0,25 to 0,35 Euro/Kg.

A finishing area using 10 tons per year of ceramic media can generate about 14 to 16 tons of wet mud; therefore a cost of about 4.500,00 Euro per year is added to the cost of the ceramic media.

"QF Media" Represent The Beginning Of A Green Alternative

QF media (Acronym for: Quattrofinish media – Patent pending - I) is a new generation of polymeric ABRASIVE media offered in several possible formulations.
  
To avoid confusion, the object of this article is to describe the family of QF identified with the final letters C (Like Ceramic), for use in WET MODE.

In fact, the manufacturing program of QF media provides:
• QF – P_   To substitute Plastic Media in wet mode finishing processes
• QF – C_   To substitute Ceramic Abrasive Media in wet mode finishing processes
• QF – L_    New family of media for dry mode finishing processes (Vibrodry – Patent pending – I)
• QF – PV    New family of media for Microfluid  finishing processes (very low water consumption finishing processes based on multitasking finishing, including final drying option with hot air – Patent pending – I)

Where the final "_" is left, a number informs the abrasive degree, whilst the final letter "V" means "Vectorial technology" with non-abrasive composition (for a certain way similar to the porcelain media, but for different finishing targets).

In the pictures 1, 2 and 3, the typical phases of final separation and discharge of steel workpieces from a vibratory finishing machine (1) into a rinsing/passivation tank are represented, with a transport belt conveying the workpieces over a drying tunnel with hot air (2) that, after the translation inside a hot air recycled section, is released for the final transfer into a metal box (3).

The deburring action offered by the QF media, in this example the type QF20NC3, is excellent both for efficient separation over the grid and to avoid the media becoming stuck into the complex section of the steel component.

QF20NC3 means: "QF" like Quattrofinish Media, "20" mm. size, "N" like Pirakon (half pyramid and half cone), "C" like Abrasive Ceramic Performance, "3" like "Abrasive degree 3".
A comparison trial has been made with ceramic chips CB15TH on one hand and QF20NC3 on the other hand.

In the same finishing time, with similar finishing results (slightly different colour, clearer for the QF media) the perspective simulated with an average wearing rate of:
• 8% for CB15TH
• 1% for QF20NC3

Has produced a difference of consumption of new media of about:
• 16.000 Kg/year for CB15TH
• 2.000 Kg./year for QF20NC3

With a corresponding production of wet mud of about:
• 25.000 Kg/year for CB15TH
• 3.200 Kg./year for QF20NC3

Considering the difference ONLY OF THE MUD PRODUCED, the relative disposal at an average cost of 0,3 Euro/Kg. means, per year:
• 25.000 Kg/year x 0,3 = 7.500,00 Euro for CB15TH
• 3.200 Kg./year x 0,3 = 960,00 Euro for QF20NC3

Of course, although the price of QF media per Kg is sometimes higher than the one of the Ceramic media, the cost per year of 2 tons against 16 tons offers wide margins of cost saving.
In consideration of the additional advantage offered by the WASTE DISPOSAL savings, and by the reduction of transport costs and storage volumes, the QF MEDIA represent the beginning of a green alternative run across a better way of finishing.

The R&D activity to develop more types, formulations, shapes and sizes of QF media has continued with incessant rhythm since 2007, offering to the market of 2018 a mature product with great growth perspectives.

Finally, it is important to know that QF media are manufactured with renewable energy, with low impact on the environment, and with the option to recycle the used media in almost all the standard applications.



For Information:
Rollwasch® Italiana S.p.a.
Via San Carlo, 21
20847 Albiate (MB), Italia
Tel. +39.0362.930334
Fax +39.0362.931440
E-mail: info@rollwasch.it
www.rollwasch.it
 
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