Hollow Corundum Microspheres in Industrial Rubber and Polyurethane Goods

The main objective of using hollow corundum microspheres (here in after, HCM) in industrial rubber goods and elastomers is to

increase durability of industrial rubber goods.

Areas of application of hollow corundum microspheres in industrial rubber goods:

screw pump stator to pump concrete, trowelling compounds, and abrasive fluids;
downhole motor stator to supply drill fluid when drilling wells for crude-oil and gas production;
dredge pipings for mining industry, fuel and energy industry, and iron and steel works;
rubber cushions for railroads;
conveyer bands to transport abrasive and highly-abrasive materials and fire-proof bulk solids (breakstone, ore);
rubber-coated roller conveyer rollers for conveyer bands tension and transfer of cargos;
inner lining for barrel and raw mills and rubber shakers.

The durability of industrial rubber goods increases two to five times due to the hollow corundum microsphere self-sharpening

effect accompanied by formation of open sharp edges of corundum which prevent rubber from disintegrating because of severe

exposure to abrasives.

The spherical shape of hollow corundum microspheres enables their easy intrusion in rubber mixture and even distribution

throughout it, and the extended surface of microspheres secures them in rubber.

The low conductivity and small thermal expansion coefficient of corundum microspheres enables us to enhance manufacturing

parameters of end products by increasing the time of pre-vulcanisation and improving moulding characteristics of rubber mixture,

and to improve its fire- and frost-resistance properties.


Conveyer bands with HCM	Rubber cushions for railroads with HCM	Inner lining for barrel and raw mills with HCM

For sliding bearings, OAO NIIRPI [Rubber Coatings and Goods Research Institute, Joint Stock Company] has developed elastomer compositions modified by hollow corundum

microspheres based on NBR and HNBR with enhanced physical and mechanical characteristics: enhanced heat resistance and high durability.

Elastomer compositions modified by HCM based on NBR and HNBR
Characteristics	No. 1 (initial)	No. 2 (modified)
Nominal tensile strength, GOST 270-75, MPa	28.9	28.2
Tensile strain at break, GOST 270-75, %	270	280
Relative breaking strain, GOST 270-75, %	6	7
Hardness, GOST 263-75, Shore A unit	72	71
Tear resistance, GOST 262-93, N/mm	35	36
Rate of set, GOST 9.029-74, A/B Method [in Cyrillic characters, ‘А/Б’], 130°C × 24hrs	16/54	19/57
Abrasive wear resistance, GOST 426-77, J/mm³	25.9	146.2
Change in weight after effects of aggressive environments, GOST 9.030-74, % Standard rubber testing liquid SZhR-3 [in Cyrillic characters, ‘СЖР-3’] (standard liquid IRM 903), 125°C × 24hrs	5.7	5.9
Aviation kerosine ТС-1, 23°C × 24hrs	3.5	4.5

The durability of the modified elastomer composition is five times higher than that of the initial composition and exceeds characteristics of durable thermoplastic

polyurethane by 36%.

The developed modified elastomer composition has the optimum level of physical and mechanical properties, high grease and heat resistance, and may be used in production of

industrial rubber items which must meet strict requirements to durability and heat resistance (gaskets, friction pairs, rubber-lined rollers, sliding bearings, etc.).

In Yaroslavl Rubber Plant was developed a rubber composition 60-446 (sole for shoes) with mix of NBR-40AM (60% wt.) and BR (40% wt.) modified by hollow corundum microspheres (HCM-L, 5% wt.), the results present in the table below:

Rubber composition 60-446 with mix of NBR-40AM (60% wt.) and BR (40% wt.) modified by HCM-L, 5% wt.
Characteristics	Norm	Initial	Modified
Nominal tensile strength, GOST 270-75, MPa	12	17.3	15.7
Tensile strain at break, GOST 270-75, %	300	430	400
Hardness, GOST 263-75, Shore A unit	62	60	62
Abrasion wear resistance, GOST 426-77, J/mm³		13	28
Change in weight after effects of aggressive environments, GOST 9.030-74, %, Oil I-40A	3	0.7	0.9

**Results of test HCM in different type of rubber**
Type of goods	Type of rubber (type of caoutchouc)	Abrasive wear resistance, GOST 426-77, J/mm³		Abrasion, GOST 426-77 m³/TJ
Type of goods	Type of rubber (type of caoutchouc)	without HCM	with HCM	without HCM	with HCM
sliding bearing, rubber for petrol and oil industry	NBR, HNBR	25,9	146,2	-	-
mud pump piston cup	NBR	-	-	44,3	9,4
rubber stator of downhole motor	NBR	-	-	27	4
sole shoes	mix of IR, SBR, BR NBR	-	-	80	59
sole shoes, inner lining for raw mills	NBR and BR	13	28	-	-
rubber coated roller		12,8	20,2	-	-
rubber coated roller	HNBRG-80	50,2	147,7	-	-
rubber cushions for railroads	mix of NR and SBR	-	-	88,2	38,5

Articles and reports about using of Hollow Corundum Microspheres in rubber goods.

HOLLOW CORUNDUM MICROSPHERES IN THE MANUFACTURE OF RUBBER COMPOUNDS. M.A. Salyaeva, E.M. Kashina, L.A. Noskova PJSC "Ural Zavod RTI", Yekaterinburg, Russia

TRIBOTECHNICAL PROPERTIES OF ELASTOMER COMPOSITIONS MODIFIED BY HOLLOW CORUNDUM MICROSPHERES OF ALUMINUM OXIDE. Tselykh E.P., Khodakov S.Y., Tretyakova N.A. FSUE "FRPC Progress", Omsk, Russia

EFFECT OF HOLLOW CORUNDUM MICROSPHERES ON PROPERTIES OF SOLE SHOE RUBBER. N.F. Ushmarin¹, D.V. Pelipenko¹, S.I. Sandalov¹, E.N. Egorov¹, N.I. Koltsov². ¹JSC "V.I. Chapaev Cheboksary Production Association”, Cheboksary, Russia. ²FSBEI HE "N.I. Ulyanov Chuvash State University”, Cheboksary, Russia.

Report "Mixing and testing of compounds with HCM" made in the German Institute of Rubber Technology (DIK) in the Materials Development and Testing Laboratory (WE).

Click the title of article to download it.

Hollow Corundum Microspheres in Industrial Rubber and Polyurethane Goods

Get a detailed consultation