Artificial intelligence in visual veneer analysis improves on-grade accuracy

A visual veneer analyzer detects sound knots, splits, and other defects in a veneer mat or sheet to determine its grade. The more accurately each defect and its size are recognized, the more accurately the material can be graded for optimal processing and end-use.

Conventional visual defect recognition relies on contrast to detect defects: the greater the contrast, the easier it is to spot the defect. Some defects are surrounded by wood grain patterns that reduce contrast, making them difficult to spot with conventional cameras. Some defects, such as harvester marks and small sound knots, are so challenging to spot that conventional cameras cannot detect them at all.

To tackle this challenge, Raute has developed visual analyzers that use artificial intelligence to spot challenging defects with greater accuracy, improving quality yield.

Modernize your veneer production line with AI-powered analyzers  

In principle, any defect that can be detected by humans can also be taught to artificial intelligence. When all defects, including rub marks, harvester marks, or bark and decay, are accurately detected, the veneer sheets can be graded with utmost accuracy, which ultimately results in better end-product quality, raw material recovery, and profit. 

Read more about why and how you should grade veneer sheets in the first place: https://www.raute.com/blog/solutions/why-and-how-should-you-grade-veneer-sheets/ 

For example, typically, conventional systems cannot accurately determine the quantity and size of sound knots. This can result in either: 

• a high number of smaller knots remaining undetected, which means that the veneer sheets will be categorized inaccurately as higher grades. 
• overestimating the size of sound knots, which means that the sheets are inaccurately downgraded. 

“When you modernize your line with an artificial intelligence-powered analyzer, you can detect critical defects such as harvester marks as well as sound knots and their sizes with high accuracy. This improves your on-grade accuracy, helps avoid over-processing of veneer sheets, and minimizes financial losses that you have not been able to control before”, explains Tuukka Sorvari, Sales Manager of Analyzers at Raute. 

Accurate grading information enables existing systems and operators to make better decisions from peeling to panel repairing. 

“AI visual analysis pays back its investment cost through improved end-product quality and better raw material profitability: when you understand the true potential of your raw material at each process phase, you will increase value throughout the mill and boost efficiency in all phases by sending material to the correct destination at the first chance you get”, says Sorvari. 

Example of AI in use

The earlier you use AI in grading veneer sheets, the more your mill's profitability improves 

AI visual analyzers can be used in multiple parts of your process to improve profitability - read more about the benefits of AI-powered defect detection in different phases. 

Better grading accuracy in the peeling line improves efficiency in your whole production  

Conventionally, low recovery and poor quality veneer sheets are removed from the mill’s raw material flow at the core sheet composer. What if you start picking them out already before the peeling line stacker? 

Decisions made at the peeling line affect the efficiency of all the following process phases. That is why quality recovery optimization starts at the peeling line by understanding the raw material and its features with utmost accuracy.  

Read more about the benefits accurate grading brings at the peeling line: https://www.raute.com/blog/solutions/grading-at-peeling-line-frees-drying-capacity-and-saves-energy/

In veneer peeling, AI helps accurately detect round-up defects, such as bark, and defects that can be patched. An AI analyzer delivers value through extremely accurate clipping and efficient use of raw materials. Optimizing clipping and grading at the peeling line already improves your quality recovery.  

At the peeling line, you can also use built-in patching, composing, and drying simulations from Raute Analyzers to assess raw material usability in the following process phases. These simulations provide you with the perfect tools to ensure that the material that is sent from the peeling line onwards is suitable for your developing production needs. 

For example, by using the core composing simulation feature at the peeling line, you can control the veneer recovery level at the core composing process in the future. This allows you to control veneer inventory levels to improve overall process efficiency. 

Example of AI in use 

AI analyzer at the drying line optimizes sheet flow and end-product quality 

If you use veneer sheets as core veneer when they have the potential for face veneer quality, you miss out financially. Poor defect detection can also cause significant losses in profit through unnecessary panel downgrading. 

With conventional machine vision solutions in veneer visual grading, a very common challenge is to separate sound knots, dark knots, loose knots and certain bark defects from each other. If dark heart wood or grain pattern is added into the mixture, the mission is next to impossible.  

With AI, major improvement has been achieved in these previously challenging situations.  
At the drying line, AI can accurately detect defects that need to be patched or composed before further processing, and defects that can be later removed for example at the panel repairing line. Combining AI defect detection with process simulation features, the following processing phases can be accurately selected individually for each veneer sheet. 

For example, you can accurately grade face veneer sheets that don’t need patching already at the dryer, and send them directly to the lay-up line instead of the patching line. This optimizes your sheet flow and improves end-product quality. 

Raute AI analyzers can be retrofitted to any dry grading line. The accurate visual analysis can be combined in the analyzer platform with other features of the veneer - moisture grade, strength properties, waviness and roughness - to make better decisions on how to maximize the potential of your raw material. 

Read more about the benefits of accurate grading in the drying line: https://www.raute.com/blog/solutions/grading-at-the-drying-line-maximizes-profit/ 

Artificial intelligence in composing improves yield 

Composing lines without AI requires operators to rip corners from the sheets or mark the defects with fluorescent chalk to ensure they are noticed and cut. This manual work is time-consuming and inaccurate, slowing the process and impacting your output volume.  

Without an accurate analyzer, you end up clipping out more defects than needed, losing valuable raw material in the process. AI analyzers recognize these low-contrast defects without operator manual work, which has a significant positive impact on your yield and capacity in both face and core veneer composing lines. 

Read about our customer Koskisen’s experiences on using AI analyzers on birch veneer at their composing line: https://www.raute.com/references/koskisen-oyj/elevating-plywood-precision-and-productivity-with-ai-driven-veneer-composing/

Patching with AI visual analyzers minimizes veneer downgrading 

Conventional analyzers cannot detect all the defects that should be patched, resulting in a lower value for the patched veneer. Typically, patching line analyzers need to be fine-tuned to compensate for overall inaccuracies in defect detection, leading to excessive patching. This, in turn, causes veneer downgrading, financial losses, and poor patching efficiency. 

With AI, defect detection is superior, eliminating these challenges. This optimizes line efficiency by reducing unnecessary patching and increasing end-product value.  

AI in panel repairing improves panel value 

In panel repair, even a single undetected defect can cause the entire panel to be downgraded, resulting in an easily over 50% loss in panel value. 

Improved defect-detection accuracy realizes the full potential of the panels: only critical defects are identified and repaired accurately to their true size. By recognizing the potential panel value already at the repairing line, you can maximize your end-product value. 

AI-enhanced grading brings various benefits for different processes

Modernize your lines with AI-powered Raute analyzers 

Artificial intelligence is part of the new Raute analyzers. Each mill is unique, and it might not be feasible to modernize all analyzers at once. Raute experts are available to help you prioritize these opportunities to maximize the benefits for your mill. 

If your current Raute visual analyzers are less than 10 years old, you can send us digital samples. Our AI experts will demonstrate the effect and value of the AI in your production! 

Read more about the mill-level utilization of AI-based visual grading to understand how high-end defect detection transforms production and profits: https://www.raute.com/blog/solutions/what-mills-risk-without-high-end-defect-detection/