RPA Nozzle
RPA studies and engineers with help of its clients the structural elements to build tunnel kilns as well as shuttle kilns and special parts suitable for each need.
By using the best of each building technology it has, RPA is prepared to manufacture extremely difficult parts, in cordierite, mullite-cordierite, high alumina content (97-98% Al2 O3), and with zirconium that allows reaching temperatures up to 1,600°C.

PAULISTA REFRACTORY PRODUCTS
We are exclusive suppliers for the ceramic industry in Spain of mullite refractory rollers which are widely used in national and international markets.
Mullite rollers for ceramic kilns are produced by diameter and in accordance to each client’s needs.
RPA-1083-TN Rollers
Technical features:
-Mineralogical Analysis: Mullite
-Chemical Analysis:
-SiO² 21-23
-Al²O³ 72-74
-ZrO² 1-3
-Fe²O³ 0,3-0,5
Bulk density g/cm³ 2.45-2.50
Bulk porosity % 23-25
Water absorption % 9-10
Bending strength at 25°C Kgf/cm² 470-500
Thermal expansion at 1,000°C Kx10 C 5.50-6.00
Thermal shock resistance Very good
Maximum Use Temperature °C 1,250
RPA-1083-AT Rollers
Technical features:
-Mineralogical Analysis: Mullite
-Chemical Analysis % SiO² 19-21
-Al²O³ 74-76
-ZrO² 3-5
-Fe²O³ 0,3-0,5
Bulk density g/cm³ 2.50-2.55
Bulk porosity % 25-27
Water absorption % 10-11
Bending strength at 25°C Kgf/cm² 500-530
Bending strength at 1,200°C Kgf/cm² 400-430
Thermal expansion at 1,000°C Kx10 C 6.00-6.50
Volume Resistivity D.C. .cm 3.2 x 10
Average pore diameter µm 1.21
Hardness (MOHS Scale) Quartz 7
Thermal Conductivity at 1,000°C W/mk 2.34
Thermal shock resistance Very good
Maximum Use Temperature °C 1,280
Instructions of use of ceramic rollers.
To extend the useful life of ceramic rollers special treatment is necessary:
1- Aplicar el engobe para revestirlos antes de ultilizarlos por primeira vez, evitando así que el engobe penetre en el interior de ellos;
2- Póngalos a funcionar cuando estén completamente secos, cubiertos con engobe o no;
3- Introducir fibra cerámica dentro de los rodillos, de acuerdo con las indicaciones del fabricante del horno;
4- Cuando necesite retirar los rodillos durante el proceso de producción:
-tome cuidado para evitar choques termicos violentos; evite el contacto con superfícies frías de metal; para transportar los rodillos calientes, es recomendable envolverlos en fibra cerámica; deben permanecer en movimiento de rotación mientras estén calientes;
Comments: The information and technical data provided are average values in our labs, they therefore do not constitute a guarantee.