Tomographic Log Inspection for Bluestain-Free Zone Identification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for identifying bluestain in wood logs are ineffective, leading to potential bluestain zones being missed in high-quality wood products, resulting in quality control issues and production rejects, as they rely on visual inspection and are not objective.
Innovation Solution
A non-destructive inspection method using tomographic scans to measure local moisture content within wood logs, correlating attenuation of X-ray beams with radio-density to differentiate between healthy and affected sapwood zones, allowing for the identification of bluestain-free areas suitable for high-quality products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If visual inspection is used to identify bluestain in logs, then the inspection process is simple and quick, but the detection precision is low and bluestain zones may be missed
Solution Approach 1:
The patent replaces the manual visual inspection system with an automated tomographic scanning system using X-ray or gamma radiation. This substitution enables objective, precise measurement of moisture content distribution within the log, allowing accurate identification of bluestain zones based on characteristic moisture patterns rather than subjective visual assessment.
Solution Approach 2:
The patent changes the detection parameter from visual appearance to moisture content distribution. By measuring local moisture content through tomographic scanning and comparing it against reference values for healthy wood, the system can objectively identify bluestain-affected zones which exhibit characteristic moisture depletion patterns, thereby improving detection accuracy.
2Reliability
If logs are kept wet or treated with antiseptics to prevent bluestain, then fungal attack is reduced, but the processing complexity and costs increase
Solution Approach 1:
The patent performs preliminary detection of bluestain zones in logs before they enter the processing line. By using tomographic scanning to identify affected areas in advance, the system enables selective processing where only healthy portions of logs are used for high-quality products, eliminating the need for blanket prevention treatments like keeping logs wet or applying antiseptics to all logs.
Solution Approach 2:
The patent applies the principle of local quality by treating different zones of the log differently based on their bluestain status. Healthy zones are directed to high-quality product production, while bluestain-affected zones are segregated for lower-grade applications, optimizing both product quality and material utilization without requiring complex prevention treatments for the entire log.
3Reliability
If logs are sawn immediately after cutting to prevent bluestain, then fungal growth is reduced, but the productivity of the logging operation decreases
Solution Approach 1:
The patent performs preliminary identification of bluestain-free zones in logs that have been standing for some time. This allows the logging operation to proceed at normal pace without requiring immediate sawing, while still ensuring that only healthy wood is selected for high-quality products, thereby maintaining both productivity and bluestain resistance.
4Reliability
If high-quality wood production is suspended during hot months, then bluestain risk is reduced, but the productivity and commercial output decrease
Solution Approach 1:
The patent implements preliminary screening of all logs during hot months using tomographic scanning. This allows the production line to continue operating at full capacity, with logs being processed normally, while the scanning system identifies and segregates bluestain-affected zones before they become problems in the final product, thereby maintaining both reliability and productivity.
Solution Approach 2:
The patent enables continuous production during hot months by applying local quality control through tomographic scanning. Each log is scanned and processed individually, with only the bluestain-free zones being directed to high-quality product lines, while affected zones are routed to alternative uses. This maintains overall production output while ensuring quality products are free from bluestain.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables objective assessment and optimization of log cutting patterns, improving quality control by accurately identifying and segregating bluestain-free zones, thus enhancing the commercial value and aesthetic quality of wood products.
Implementation Method 1
carrying out a tomographic scan of the log to be inspected and obtaining a three-dimensional representation of the log which is representative of the local moisture content of the log. This step comprises carrying out a tomographic scan of the log to be inspected using X-ray beams passing through the log
Implementation Method 2
carrying out a tomographic scan of the log to be inspected using X-ray beams passing through the log and obtaining a three-dimensional representation of the log which is representative of the local moisture content of the log
Data Source
AI summary
This invention relates to a method for non-destructive inspection of a log (1) to identify inner zones of sapwood (14) of the log (1) that have not been attacked by fungi that cause bluestain in the wood. The method comprises a first step of carrying out a tomographic scan of the log (1) to be inspected using X-ray beams that pass through the log (1) and a second step of obtaining a three-dimensional representation of the log (1) that is representative of the local moisture content of the log, the local moisture content being correlated with attenuation of the X-ray beams through the log. The method comprises the step of processing the three-dimensional representation of the log (1) to identify inner regions (145) of the log (1), in which the local moisture content is greater than or equal to a moisture threshold value for a spatial extent greater than an extent threshold. The moisture threshold value corresponds, for trees of the same species as the log (1), to a sapwood (14) with local moisture content such that it excludes the growth of fungi that cause bluestain in the wood. Each inner region (145) identified in this way is classed as a sapwood (14) zone free of bluestain. This invention also relates to a procedure for obtaining one or more wooden products from a log (1), as well as an apparatus for carrying out a non-destructive inspection of a log (1).