Leather - Raw cattle hides and calf skins - Part 2: Guidelines for grading on the basis of mass
1Key Takeaways
This document provides guidelines for the grading of cowhide and calfskin leather based on quality. It lists the practices followed by countries producing cowhide and calfskin leather.
2Expert Interpretation
This article provides an in-depth interpretation of the ISO/TR 2822-2:2017 technical report, detailing the quality-based international grading standards for bovine hides and calfskins. It includes a comparison of the classification systems for 10 major producing regions, an analysis of specialized terminology, and implementation recommendations, providing an authoritative reference framework for quality assessment within the leather industry.
Analysis of International Leather Raw Material Quality Grading Standards
The ISO/TR 2822-2:2017 technical report provides the global leather industry with a unified quality grading framework for bovine hides and calfskins. This standard establishes a classification system based on raw material quality, covering various processing states, from raw hides and wet salted hides to dry salted hides.
Core term definition system
| Term | Definition | Typical quality range |
|---|---|---|
| baby calf | Lightweight hides of young lactating cattle | ≤4.0kg(fresh weight) |
| bull hide | Hide of uncastrated bull | ≥27kg |
| cow hide | Hide of multiparous cows | 14-16kg (depending on country) |
Comparison of Regional Grading Systems
Typical Application Case: German Grading Standard
Germany uses a fresh weight grading system, subdividing calfskin into eight grades (≤4.5kg to 14.5kg), with each kilogram of raw material corresponding to an area of 0.09m². adult cowhide, on the other hand, is graded in 5kg increments, reaching a maximum of over 60kg.
Special Classifications in North America
North America has a separate classification for branded hides, with quality ranges significantly different from those for regular steer hides, reflecting the characteristics of the regional animal husbandry industry.
Key technical points of implementation
- Pretreatment specifications: Standardized treatments such as knee joint trimming and hoof square cutting must be completed
- Weighing method:
- Fresh hides: cattle hides accurate to 0.5kg, calf hides 0.1kg
- Salted hides: require mechanical desalination
- Moisture control: reasonable deduction standards need to be established for fecal residues, etc.
Analysis of standard evolution
This technical report replaces the traditional size grading method to solve the problem of large differences in quality ranges among countries. Of particular note:
- South Africa uses the air-dried weight standard (3.0-3.2ft²/kg)
- Regional differences exist between Hankou and Guangdong leathers in China
- India uses a dual standard for wet salted leather and dry salted leather