paraffin wax deposition and fouling

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hiditional plssticc, tetrafiuoretiiylenc, polyethylene ans noiy—
propylene were also tested hut it was
found that these co:Jccteci
massive denosjts of extreme hardness and adhesion.
3ecause these
plastics are themselves oaraffinic in nature, they aPpear to possess
a high chemical attraction for paraffin either through hydrogen
bonding or a form of co—crystallization.
Jorda concluded that paraffin deposition on metallic and non
paraffinic plastic surfaces, at a given temrerature, is governed
oy surface rounaness. ee tag. 25.42. The experaments showes
that the amount, hardness, adhesion, per cent wax and
molecular weight of the deposits increase as the surface roughness
increases.
Patton and Casad
studied the effect 0f surface roughness
on paraffin aeposition. Wne apparatus and exerimental rnethon has
been discussec. in section 2.5. nree waxes in So1tro
70 so_vent
were investigated. Two of these, Cit—Con 550 and Sheliwax 200 with
me__ng pons o ann o • .C
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resrec1Vey, 2C OW oec_: wea
waxes composed primarily of normal paraffins and are higaly crystal
line. The third wax used was a Cit—Don recrystallized heavy
insermedsate (hTI) wata melting poant 72°C, a nign moLecular weagat
materaa contasnang sagnafcant amounts of non—norma para::ans,
thus exhibiting microcrystaline properties.
One
cold spot plates used by Patton and Casad were a highly
polished plate, a plate finished with 2D—gri; paper and a ma;e
finished with 50—grit rarer.
Plastic coatings were also used,
both smooth ann roughened. by 53—grit paper
It was found that the
deposition of Cit—Con 550 and SheJwax 203 differed from that cf
Cit—Don -:_.
.ae
neuosats of tae two crys;a_lane waxes, or, s::.oo:n
reta and las;c coatea surfaces, were :ouno. so se ocacue ann
tend so slough off, leaving a snan granular resanua nercsass
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o._a c
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