How an Integrated Metal Detector & Checkweigher Reduced Product Giveaway and Improved Food Safety for a Vacuum-Packed Atlantic Salmon Processing Plant

Industry Background

Atlantic salmon is one of the highest-value seafood products traded globally.

Major export markets—including the European Union, the United States, Japan, Australia, and the Middle East—enforce strict food safety and net weight regulations. Every retail pack must be free from metal contamination while meeting declared weight specifications.

For seafood processors handling thousands of vacuum-packed salmon fillets per shift, the final inspection stage has become a critical control point under HACCP plans and third-party audits such as BRCGS, IFS Food, SQF, and retailer-specific quality programs.

A processor in Northern Europe approached Shanghai Fanchi-tech Machinery Co., Ltd. with a clear objective: modernize the end-of-line inspection process without sacrificing throughput or accuracy.

Customer Profile

The processor specializes in premium Atlantic salmon fillets supplied to supermarket chains, foodservice distributors, and private-label brands.

Products

• Fresh Atlantic Salmon Fillets
• Skin-On Fillets
• Skinless Fillets
• Portion Cuts
• Marinated Salmon
• Chilled Vacuum-Packed Fillets

Packaging

• Vacuum thermoformed trays
• Vacuum bags
• MAP trays

Weight range:

500 g–2.5 kg

Daily production:

More than 32,000 retail packs

Original Production Line

Receiving

↓

Filleting

↓

Pin Bone Removal

↓

Skinning

↓

Portion Cutting

↓

Trimming

↓

Vacuum Packaging

↓

Labeling

↓

Metal Detector

↓

Checkweigher

↓

Cartoning

↓

Cold Storage

Although effective, this layout consumed excessive floor space and required two independent inspection systems.

Engineering Challenges

1. Limited Production Space

The existing metal detector and checkweigher occupied nearly five meters of conveyor length.

The customer planned to install an additional packaging lane but lacked sufficient space.

An integrated solution was required.

2. Moisture and Salt Increased Inspection Complexity

Unlike dry foods, salmon has high moisture content and natural salinity.

These product characteristics can influence the electromagnetic signal inside a conventional metal detector, making stable inspection more challenging than for bakery or snack products.

The customer required a system capable of maintaining consistent sensitivity while minimizing false rejects during continuous production.

3. Product Giveaway Reduced Profitability

To avoid underweight claims, operators intentionally filled each retail pack above its target weight.

Average overfill:

18–25 g per package.

With approximately 32,000 packs produced daily, the accumulated giveaway represented a substantial raw material cost over a full production year.

The processor wanted tighter weight control without slowing production.

4. Retail Audit Requirements

Major supermarket customers required:

• 100% finished-product inspection
• Automatic reject verification
• Inspection records
• Product traceability
• Statistical weight reports
• HACCP documentation

Fanchi-tech Engineering Solution

After evaluating the production line layout, package dimensions, conveyor speed, and hygiene requirements, Fanchi-tech proposed an integrated Metal Detector & Dynamic Checkweigher.

The system consolidated contamination inspection and weight verification into one synchronized platform, reducing equipment footprint while simplifying operation.

The integrated design also reduced conveyor transfer points, lowering the risk of product instability during inspection.

Inspection Workflow

Metal Detection

Each vacuum-packed salmon fillet first passes through the metal detector, where the system is configured to detect:

• Ferrous particles
• Non-ferrous contaminants
• Stainless-steel fragments

Typical contamination sources identified during the risk assessment included worn filleting blades, broken needles, loose fasteners, conveyor wear, and maintenance debris.

Any contaminated product is automatically rejected before entering the weighing stage.

Dynamic Checkweighing

Products passing metal detection continue directly to the dynamic checkweigher.

The system compares the measured weight with predefined tolerance limits for each product recipe.

Typical inspection parameters:

• 500 g fillets
• 1 kg family packs
• 2 kg foodservice packs

Packages outside the acceptable tolerance are automatically rejected, ensuring compliance with retailer specifications while reducing unnecessary product giveaway.

Engineering Results

Following commissioning, the customer reported several measurable improvements over six months of operation:

• Approximately 35% reduction in inspection line footprint
• One integrated inspection station replacing two standalone machines
• Fewer product transfers and smoother conveyor flow
• More consistent weight control across multiple product formats
• Reduced operator intervention during product changeovers
• Simplified maintenance through centralized controls
• Improved audit readiness with consolidated inspection records
• Enhanced confidence in food safety compliance

Although exact financial savings varied according to production volume and product mix, the processor confirmed that the integrated inspection solution contributed to lower operating costs and a more streamlined end-of-line quality control process.

Why Choose Shanghai Fanchi-tech Machinery Co., Ltd.

Shanghai Fanchi-tech Machinery Co., Ltd. provides integrated inspection solutions for the global food industry, including metal detectors, dynamic checkweighers, X-ray inspection systems and customized production line integration.

Our systems are engineered to help manufacturers improve food safety, optimize production efficiency and meet international quality standards across meat, poultry, seafood, dairy, bakery, convenience food and pet food applications.

Contact Us

Shanghai Fanchi-tech Machinery Co., Ltd.

Contact:Kerry

Email: kerry@fanchitech.net

Mobile / WhatsApp: +86 13917555254

Website: www.fanchitech.net

YouTube: https://youtube.com/@fanchitech3323?si=gyh-f9JCbjkJ3tEu