ISO 2747:1998

Overview

ISO 2747:1998 is an international standard developed by the International Organization for Standardization (ISO) that specifies a method for determining the resistance of vitreous and porcelain enamelled cooking utensils to thermal shock. Thermal shock resistance is a critical performance property for enamelled kitchenware, ensuring durability when subjected to sudden temperature changes during everyday use. This second edition, revised from the original 1973 edition, provides a standardized testing procedure that manufacturers and quality control laboratories can apply to assess enamel quality and longevity under thermal stress.

Key Topics

• Thermal Shock Test Definition: A series of operations starting with pouring cold water into a heated specimen and ending when the specimen reaches a targeted test temperature.
• Thermal Shock Temperature: The temperature to which the enamelled specimen is heated before being rapidly cooled with cold water.
• Thermal Shock Resistance: The difference between the thermal shock temperature and water temperature at which visible damage, such as chipping or tension cracks, first appears.
• Testing Procedure:
  • Heating the enamelled utensil incrementally from 200 °C with a 20 °C increase after each successful test.
  • Pouring cold water at 20 °C inside the hot utensil and observing for damage.
  • Repeating until damage is visibly detected.
• Equipment Requirements:
  • Electric hot-plate with specific diameters and power ratings to ensure consistent heating.
  • Temperature measuring devices accurate to ±2 °C.
  • Water receptacles, stop-watch, and drying materials.
• Sampling and Specimens: At least three representative utensils from a batch, tested without modification.
• Damage Assessment: Visual inspection at 250 mm distance or enhanced using colored penetrating fluids to detect fine cracks.

Applications

• Quality Control in Manufacturing: Ensures vitreous and porcelain enamelled cooking utensils meet durability expectations before release to market.
• Product Development: Helps manufacturers improve enamel formulations and processing methods for enhanced thermal shock resistance.
• Compliance Verification: Assists regulatory bodies and certification organizations in verifying that enamelled kitchenware complies with international safety and performance standards.
• Consumer Safety Enhancement: Reduces the risk of utensil failure due to cracking or chipping, preventing injuries and prolonging cookware life.
• Material Comparison: Enables standardized comparison of thermal shock performance across different enamel types and coatings.

Related Standards

• ISO/TC 107: Technical Committee responsible for metallic and other inorganic coatings, under which ISO 2747 falls.
• Other ISO standards related to vitreous and porcelain enamels, such as those covering coating thickness, adhesion, and chemical resistance.
• International standards involving kitchenware safety and performance, complementing thermal shock testing for comprehensive product evaluation.
• IEC standards when electrotechnical aspects of enamelled appliances are considered in broader household appliance standards.

ISO 2747:1998 provides a rigorous, well-defined testing methodology that ensures enamelled cooking utensils withstand the thermal stresses common in kitchen environments. Implementing this standard supports manufacturers and labs in delivering high-quality, reliable cookware that maintains its integrity even under rapid temperature shifts.