SIO-2 - PRNI STONEWARE CLAY BLACK 0-0.2 MM CHAMOTTE

This black stoneware clay with 40% of impalpable chamotte ranging from 0 to 0.2 mm is designed for artistic ceramics and is ideal for turning and shaping pieces with fine details and smooth surfaces.

• The high chamotte content gives character to the ceramic piece and provides excellent behavior during drying and firing.
• The intense black color of the PRN range in oxidizing firing is very unique and appreciated, becoming an ideal means of artistic expression.
• In a reducing atmosphere, excellent metallization effects of beautiful blue tones are obtained.
• It is suitable for the production of tableware (food-safe), in compliance with ISO 6486.
• Available in extruded plastic clay.

Technical specifications:

• Firing temperature: 1200-1240ºC
• Biscuit temperature: 1000ºC
• Moisture: 21%
• Plasticity (Atterberg IP): 22
• Calcimetry (CaCO3): 0%
• Shrinkage during drying: 7.0%
• Shrinkage in firing (1240ºC): 7.1%
• Porosity (water absorption 1240ºC): 1.3%
• Dry mechanical strength: 4.6 N/mm2
• Mechanical strength in firing (1240ºC): 33.3 N/mm2
• Coefficient of expansion (a25-500ºC): 51.1x10^-7ºC^-1

Recommendations for the use of ceramic glazes

• Use glazes without zinc (Zn) to avoid unexpected reactions such as bubbles or color changes.
• Other elements that can react are zirconium (Zr) and tin (Sn).
• We recommend consulting your usual glaze supplier to ensure proper compatibility with this ceramic paste.
• Do not use glazes with a low coefficient of expansion (a25-300ºC <60x10-7ºC-1).
• The PRN clay baked at high temperature has a high coefficient of expansion in the range between 100 and 200ºC, which causes tensions between the glaze and the support, especially in the processing of pieces.