Under-glaze/in-glaze decoration porcelain
1 Scope
This document specifies the classification, technical requirements, testing methods, inspection rules, packaging, marking, transportation and storage of under-glaze/in-glaze decoration porcelain products.
This document is applicable to porcelains with under-glaze/in-glaze as the main decoration methods.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2828.1-2012 Sampling procedures for inspection by attributes — Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
GB/T 2829-2002 Sampling procedures and tables for periodic inspection by attributes (Apply to inspection of process stability)
GB/T 3295 Standard test method for 45° specular gloss of ceramic ware
GB/T 3298 Standard test method for crazing resistance of domestic ceramic ware by a thermal shock method
GB/T 3299 Test method for water absorption of domestic ceramicware
GB/T 3300 Test method for deformation of daily ceramics
GB/T 3301 Standard method for measurement of volume, rim diameter allowance, height allowance, weight allowance and size of defects of domestic ceramic ware
GB/T 3302 Rules of package, mark, transport and reserve for domestic ceramic ware
GB/T 3303 Terminology of defects for domestic ceramics
GB/T 5000 Terminology for domestic ceramics
GB/T 27587 Test method for the resistance to microwave heating of domestic ceramicware
GB/T 32680 Test method for mechanical dishwashing resistance of domestic ceramic ware
GB/T 34253 Test method for resistance to freezer to microwave/oven usage on domestic ceramic wares
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 3303 and GB/T 5000 apply.
4 Product classification
4.1 Products may be classified into dishes, bowls, cups, pots and other utensils according to their use.
4.2 Products may be classified into small, medium, large and special types according to their specifications. See Table 1 for the dimension range of various types.
4.3 Products may be classified into fine porcelain, common porcelain and stoneware according to their water absorption.
Table 1
Classification Type
Small Medium Large Special
Dish (caliber/mm) < 128 128~ < 228 228~350 > 350
Bowl (caliber/mm) < 110 110~ < 175 175~250 > 250
Cup (caliber/mm) < 60 60~ < 100 100~140 > 140
Pot (capacity/mL) < 250 250~ < 1,000 1,000~2,400 > 2,400
Other utensils Products may be classified into the above-mentioned types depending on the maximum size of their shape and shape similarities.
5 Technical requirements
5.1 Water absorption
The water absorption shall be no more than 0.5%, no more than 1.0% and no more than 5.0% for fine porcelain, ordinary porcelain and stoneware products respectively.
5.2 Thermal shock resistance
Small and medium-sized products shall not crack once after heat exchange from 180°C to 20°C, while large and special type products shall not crack once after heat exchange from 160°C to 20°C.
5.3 Glossiness
The requirements for glossiness shall comply with those specified in Table 2.
Table 2
In: gloss unit
Item Grade
Superior First-grade Qualified
Gloss of glaze surface ≥ 85.0 ≥ 80.0
5.4 Resistance to microwave heating
The heating energy is 72,000J, and no cracking, damage and arc shall occur after the test of 6.4.
5.5 Resistance to freezer to microwave usage
No cracking, damage and arc shall occur after the test of 6.5.
5.6 Resistance to freezer to oven usage
No cracking and damage shall occur after the test of 6.6.
5.7 Resistance to mechanical dishwashing
The average obtained by all observers shall not be greater than 1.
5.8 Product specification error
5.8.1 Caliber error
The error of caliber larger than 200 mm shall be within ±1.0%, the error between 60 mm and 200 mm within ±1.5%, and the error less than 60 mm within ±2.0%.
5.8.2 Height error
The error of height greater than 100 mm shall be within ±2.0%, the error of height between 30 mm and 100 mm within ±2.5%, and the error of height less than 30 mm within ±3.0%.
5.8.3 Quality error
The error of small and medium-sized products shall be within ±6.0%, and the error of large and special ones shall be within ±4.0%.
5.9 Appearance quality
5.9.1 The products shall be free from the defects of glaze explosion, bumping, cracking and leakage.
5.9.2 The glaze color and pattern glossiness of complete sets of products shall be basically the same, except for specially-designed products; the bottom edge of each product shall be smooth and stably-placed on the plane; the covers and spouts of the covered products are basically consistent; if one pot product is inclined to the bottom surface to form an included angle of 70 with the horizontal position, its cover shall not fall off; if the cover moves to one side, the gap between the cover and the spout shall not exceed 3.0 mm, with the mouth of the spout no lower than 3.0 mm of the spout.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Product classification
5 Technical requirements
6 Testing methods
7 Inspection rules
8 Packaging, marking, transportation and storage
