2. TThhee DDaayy iitt SSttaarrtteedd…………
It all began suddenly. A supplier of auto
guides contact me, and offered to use his
products. But I did not need these. He
further asked, “You might have to replace
ppaallmm ooff aauuttoo gguuiiddee,, iitt iiss mmoorree tthhaann 22 yyeeaarrss
old”. Before proceeding to discussions, I
asked my maintenance (Instrumentation)
man, and he told me that the palm is
perfectly OK, and there is no need to
change it in near future.
Rethinking Drainage Element Materials,
October 2014 2
3. PPaallmm ooff AAuuttoo GGuuiiddee
The palm of auto guide is always pressing
wire, the contact area is very less, thus
meaning relatively higher localized
pprreessssuurree aaccttiinngg oonn iitt.. SSttiillll,, nnoo ssiiggnnss ooff wweeaarr
for two and a half years.
On the contrary, every 8-10 months, we
need to regrind/replace suction box tops.
We have tried ceramix (ceramic mixed)
tops, but in that case wire life was poor.
Rethinking Drainage Element Materials,
October 2014 3
4. MMaatteerriiaall SSeelleeccttiioonn
Since long, we are doing our material
selection on the basis of a test called
“Sand Slurry Method”.
IInn tthhiiss mmeetthhoodd aa ddiisscc ooff tteesstt mmaatteerriiaall iiss
rotated in a slurry of sand for 24 hours at
rated speed, and the loss of material is
reported. The less the loss, the better is
the material.
But, did we forget something?
Rethinking Drainage Element Materials,
October 2014 4
5. Testing tthhee TTeesstt IIttsseellff
Looking into the possible reasons, I
started searching internet for more
information, and ended up at the
ffoolllloowwiinngg lliinnkk--
http://webcache.googleusercontent.com/s
earch?q=cache:http://www.ewing1.com/_v
endors/ads/AbrasionResistance.pdf
Rethinking Drainage Element Materials,
October 2014 5
7. SSaanndd ((CCooaarrssee oorr FFiinnee))
As one can see, there is a significant
difference in results with coarse and fine
sand.
For 15 fps, for coarse sand, polythene seems
4 times stronger than steel; while, for fine
sand, it is just one third. Similarly, aluminum
wears more than acrylic with coarse sand,
but the pattern is reversed with fine sand.
Further we can see that there seems no
correlation between the sets of data.
We neither use steel nor polythene; but this
gives a reason to rethink.
Rethinking Drainage Element Materials,
October 2014 7
8. TTeessttiinngg OOuurr PPrroodduuccttss
Considering the observations, it seems
necessary to conduct different tests and
develop suitable standards for our
aapppplliiccaattiioonnss..
Why sand only? Why should we not
evaluate wear performance with OUR
materials, with OUR clothings?
A typical test bench schematic could be
as under-
Rethinking Drainage Element Materials,
October 2014 8
10. TTeesstt BBeenncchh
The proposed test bench uses
conventional synthetic forming fabric and
felts being rub against sample materials.
TToo ccrreeaattee ssiimmiillaarriittyy wwiitthh aaccttuuaall
environments, addition of water can also
be done by means of a shower.
Rethinking Drainage Element Materials,
October 2014 10
11. Drainage EElleemmeennttss ttoo TTeesstt
Typical drainage elements could be what
we are using already-
◦ UHMWPE
◦ MMooddiiffiieedd pprroodduuccttss ffrroomm rreeppuutteedd ssuupppplliieerrss
◦ Ceramic
Later on, we may try alternate materials
like steel, different alloys etc.
Rethinking Drainage Element Materials,
October 2014 11
12. CCllootthhiinngg MMaatteerriiaallss
As abrasive, we may use our clothing
(wire, felt etc.) itself.
This will also help us evaluate the
ppeerrffoorrmmaannccee ooff tthheessee aaggaaiinnsstt kknnoowwnn
materials for drainage elements.
A step further, we may evaluate effect of
weave patterns of forming fabrics etc.
Rethinking Drainage Element Materials,
October 2014 12
13. EEffffeecctt ooff VVaaccuuuumm
We all know, wear is faster if we apply
more vacuum. With our test bench, we
can apply different levels of vacuum
aaggaaiinnsstt ccllootthhiinngg,, wwee mmaayy rreeddeessiiggnn tteesstt
specimen with provision for vacuum
application to determine the effect of
vacuum also.
Rethinking Drainage Element Materials,
October 2014 13
14. WWeeaarr PPeerrffoorrmmaannccee
This way, we’ll be able to evaluate wear
performance of different materials we use
against different types of clothings we use.
TThhee oovveerraallll ssttuuddyy wwiillll bbee hheellppffuull ttoo oobbttaaiinn
wear rates of different fabric/clothing
material and designs against known
materials as ceramic, UHMWPE etc., and
vice versa.
Rethinking Drainage Element Materials,
October 2014 14
16. About the Author:
Born in 1968, D K Singhal is B.E., M.E. (Pulp Paper, 1993) from Deptt. of Paper
Technology, University of Roorkee (now IIT, Roorkee). He is a Certified Energy
Auditor and Chartered Engineer also.
With nearly 7 dozen publications, he has emphasized on development of low cost
technologies and management practices for quality and profitability improvement.
With publications on slideshare.net, energymanagertraining.com and
paperonweb.com, he has been constantly contributing to IPPTA (Indian Pulp
Paper Technical Association). He is also serving IPPTA as a member of Editorial
BBooaarrdd..
An initiative by D K Singhal, a cyber campaign initiated against unjustified targeting
of paper industry by “Idea” mobile, in their “Sirjee” advertisement campaign, after
which this advertisement was taken off air.
He also moderated a Yahoo group, “PaperTechnology” (now at facebook) with
nearly 750 members from India and abroad to discuss problems related to pulp
paper making for five years.
He can be contacted at deveshksinghal@gmail.com
16
Rethinking Drainage Element Materials,
October 2014