GB/T 15035-2023 in English

Core changes in the standard revision

Analysis of key technical terms

3.1 Drying method

High temperature heat treatment (3.1.32): Treating wood in a low oxygen environment of 160-230℃ can improve dimensional stability. For example, the tangential shrinkage of oak wood can be reduced by 40% after heat treatment.

Conventional drying (3.1.7): Specify that the medium temperature is ≤100℃, and distinguish between steam/hot water/electric heating and other heat media forms.

3.2 Drying facilities

Wood drying room (3.2.1): Emphasis on thermal insulation and corrosion resistance performance requirements. The metal shell drying room must be equipped with a 0.5mm thick stainless steel inner plate.

3.3 Drying process

Drying benchmark (3.3.4): Recommended applicable scenarios for moisture content benchmark (divided into 6-8 stages) and time benchmark (divided into 4 stages):

• Hardwood: semi-fluctuation benchmark is recommended
• Fast-growing wood: continuous temperature rise benchmark is applicable

Implementation suggestions

Drying quality control

Based on the Drying uniformity (3.5.70) indicator:
• The moisture content deviation of room-dried wood should be ≤±2%
• The deviation of air-dried wood is allowed to be ±4%

Equipment selection guide

High-frequency vacuum dryer (3.2.22) is applicable to:
• Hardwood with thickness > 50mm
• Special orders requiring drying cycle <72h

Analysis of Standard Evolution

The 1994 edition first established the terminology system → The 2009 edition added a chapter on drying theory → The 2023 edition supplemented combined drying technology and quality control indicators, reflecting the industry's development towards precise control.