Multihead Weigher Buyer’s Guide: Choose the Right Model for Your Line

Multihead Weigher Buyer’s Guide: Choose the Right Model for Your Line

Choosing the right multihead weigher is a critical decision for any packaging line that needs speed, accuracy, and consistent yields. This guide explains how to match a multihead weigher model to your line’s throughput, product properties, hygiene needs, and automation goals. It also highlights the key technical specifications, integration considerations, and commercial factors to evaluate when selecting a supplier like Kenwei—an experienced manufacturer of multi-head weighers, metal detectors, linear weighers, and check weighers.

Understand Your Line Requirements

Throughput and Target Output

Start by defining your required output in packs per minute (PPM) and the typical pack weight range. Multihead weighers are chosen primarily by throughput needs. Common head counts (10–36 heads) are selected to meet different speeds and accuracy targets: fewer heads can be sufficient for slower lines or heavier packs; more heads are used for high-speed snack, confectionery, and frozen food lines. Always plan for peak production requirements rather than average expected output.

Product Characteristics and Handling

Assess product shape, size, fragility, and flow characteristics. Free-flowing products (nuts, chips, cereals) behave differently than fragile items (biscuits), sticky products (candies), or mixed SKU packs. Choose a model with the appropriate feed system (vibratory feeders, gentle infeed belts, or distribution bowls) and adjustable vibration settings. For delicate products, look for models with soft-drop systems to minimize breakage.

Pack Weight and Target Accuracy

Smaller pack weights (e.g., 10–50 g) usually demand higher accuracy and more heads to achieve consistent fill with acceptable giveaway. Larger pack weights (200 g and above) can tolerate wider tolerances. Accuracy also relates to legal metrology in your market—ensure chosen models can meet local regulations for net weight compliance.

Key Technical Factors to Compare

Head Count and Combination Strategy

Head count affects both speed and accuracy. Typical configurations include 10, 14, 16, 20, 24, and 32 heads. More heads generally equal higher throughput and finer combination options for better accuracy at small pack weights. Evaluate whether you need single-head or twin-head discharge setups for your packaging machine interface.

Weighing Accuracy and Repeatability

Look at guaranteed accuracy and tapping/settling strategies. Manufacturers often quote standard deviations or mean error ranges, but what matters is real-world repeatability across production runs and product changes. Check references or factory acceptance tests showing performance data for similar products.

Speed and Cycle Time

Cycle time per weighing event determines maximum PPM for a given head count. High-speed models support shorter cycle times, advanced algorithms, and faster CPUs to calculate combinations quickly. Confirm that the model can sustain the speed under continuous operation and with your product characteristics.

Hopper and Dosing System

Hopper size and design determine feeding stability. For powders and very light products, a controlled dosing funnel or special disperser may be required. For sticky products, choose hoppers with non-stick surfaces or optional heating and anti-clogging designs.

Materials and Sanitation

Food-grade stainless steel (SUS304 or SUS316 where needed) is standard. If washdown or CIP (clean-in-place) is required, confirm the machine’s IP rating and whether electrical components are protected. Hygienic designs with tool-less access to contact parts, rounded welds, and sloped surfaces speed cleaning and reduce contamination risk.

Controls, Software and Connectivity

Choose a multihead weigher with an intuitive HMI, recipe management, and data logging. Modern weighers support Ethernet, USB data export, and industrial protocols (e.g., Profinet, EtherNet/IP, OPC-UA) to integrate with PLCs, MES, or Industry 4.0 platforms. Remote access for diagnostics can reduce downtime.

Integration with Upstream and Downstream Equipment

Check mechanical interfaces and timing for your filler, bagger, or tray packer. Many suppliers, including system integrators like Kenwei, provide one-stop automated weighing and packaging solutions—making it easier to match discharge chutes, synchronization, and control logic with metal detectors, checkweighers, and vertical form-fill-seal machines.

Hygiene, Safety and Compliance

Food Safety and Regulatory Requirements

Ensure the weigher complies with local food safety laws and industry standards. For export markets this may include CE marking (Europe), FDA-related material compliance for the US, or other regional approvals. Verify that contact materials are food-grade and that documentation such as material certificates and inspection reports are provided.

Safety Features

Emergency stops, safety interlocks, guarded moving parts, and clear operator signage are basic necessities. If your factory has strict safety certification requirements, check for third-party safety validation or risk assessment documentation from the supplier.

Operational Considerations: Reliability, Maintenance and Spare Parts

Mean Time Between Failures (MTBF) and Reliability

Ask suppliers for real-world MTBF figures and reference customers in your segment. Reliability reduces unplanned downtime, especially at high-speeds. Look for robust motors, reliable load cells, and industrial-grade controls.

Ease of Maintenance and Changeovers

Tool-free changeovers, quick-release hoppers, and modular components cut downtime when switching SKUs. Request a walkthrough of a changeover procedure during factory acceptance or demo to confirm practical turnaround times for your team.

Spare Parts and Local Service

Assess the supplier’s spare parts availability and local service footprint. Fast access to replacement load cells, drive parts, or control modules can be the difference between a short fix and extended downtime. Kenwei emphasizes comprehensive installation, commissioning, technical training, and after-sales service—important criteria when comparing vendors.

Cost, ROI and Commercial Evaluation

Initial Investment vs. Total Cost of Ownership

Compare upfront purchase price but focus on total cost of ownership: energy consumption, maintenance hours, spare parts, accuracy-driven giveaway reduction, and labor savings. A more accurate multihead weigher may pay back quickly through lower giveaway and higher throughput.

Calculate Payback and Yield Improvements

Estimate savings from reduced giveaway: for high-volume lines, even a small reduction in average fill per pack can yield significant annual savings. Include expected increase in throughput (PPM) and any labor reallocation when calculating ROI.

Financing and Service Contracts

Explore options for extended warranties, preventative maintenance contracts, and training packages. Some suppliers offer service level agreements (SLA) that include regular calibration, software updates, and remote monitoring.

Selecting the Right Model: A Practical Checklist

Essential Buyer Checklist

• Define required PPM and pack weight range.
• List product types and special handling needs (fragile, sticky, mixed, powder).
• Decide on head count range based on throughput and accuracy goals.
• Confirm sanitary design, materials, and washdown requirements.
• Validate control and connectivity needs (PLC/ MES integration, data logging).
• Check interface compatibility with existing packaging machines and infeed systems.
• Ask for performance data and references for similar product lines.
• Evaluate spare parts availability, local service, and training options.
• Calculate total cost of ownership and payback timelines.

Industry Use Cases: How Requirements Differ by Sector

Snack Foods and Confectionery

High speeds and accuracy for small pack weights are paramount. Popular solutions include 10–24 head weighers with fast cycle times and gentle-feed systems for fragile snacks. Integration with metal detectors and checkweighers is common to ensure product safety and regulatory compliance.

Frozen Foods

Frozen lines require cold-environment designs, anti-condensation measures, and sometimes heated hoppers for sticky products. Hygienic washdown capabilities and stainless-steel construction are critical.

Fresh Produce and Vegetables

Products vary in size and moisture; adjustable feed and distribution systems plus soft-drop chutes reduce bruising. A multihead weigher must balance gentle handling with consistent accuracy.

Hardware and Non-Food Items

Heavier or irregular items (bolts, small components) need robust load cells and possibly a higher-capacity feeder system. Dust and metal contamination concerns will affect IP rating and design choices.

Why Choose a Manufacturer with End-to-End Capabilities

Working with a manufacturer that provides integrated solutions—from multi-head weighers to metal detectors and check weighers—reduces integration risk and simplifies support. Kenwei, located in Guangdong, China, offers automated weighing and packaging systems, design and development, manufacturing, installation and commissioning, technical training, and after-sales service. Their focus on high speed and high precision machines makes them a viable option for companies seeking a one-stop supplier for weighing and packaging automation.

Conclusion: Match Performance to Business Goals

Selecting the right multihead weigher requires balancing technical specifications with commercial realities. Prioritize throughput, product handling, accuracy, hygiene, and integration capabilities. Evaluate suppliers on real-world performance, spare parts and service, and total cost of ownership. For scalable, high-speed packaging lines, partnering with an experienced manufacturer that offers end-to-end solutions—such as Kenwei—can reduce integration complexity and improve long-term uptime and yield.

Frequently Asked Questions

Q: How do I know what head count I need?

A: Base head count on your required packs per minute and pack weight range. Higher head counts generally increase throughput and improve accuracy for small-weight packs. Ask suppliers for performance curves showing PPM vs. pack weight for each configuration.

Q: Can one machine handle multiple products and weights?

A: Yes. Most modern multihead weighers support recipes and quick changeovers for different products and weights. Tool-less parts, adjustable vibration, and recipe storage on the HMI help minimize downtime between SKUs.

Q: How important is sanitation design for a multihead weigher?

A: Very important for food lines. Hygienic design reduces contamination risk and cleaning time. Look for stainless-steel contact parts, tool-free disassembly, washdown-capable electronics, and smooth welds.

Q: What integrations should I plan for when buying a multihead weigher?

A: Plan integration with your upstream feeders, fillers, baggers or tray packers, metal detectors, and checkweighers. Confirm electrical interfaces, communication protocols (Ethernet, OPC-UA), and mechanical discharge alignment for smooth synchronization.

Q: How quickly can I expect a payback from a new multihead weigher?

A: Payback depends on throughput increases, reduced giveaway, labor savings, and uptime improvements. For high-volume lines, accurate weighers can pay back in months to a few years; run a simple ROI model using expected annual production, current giveaway, and projected accuracy gains.

Q: What after-sales services are critical?

A: Fast spare parts supply, field service or remote diagnostics, calibration support, training, and preventive maintenance programs are critical to maintain uptime and accuracy. Validate the supplier’s local service network and response times.

Q: How can I validate a supplier’s performance claims?

A: Request factory acceptance tests (FAT) with your products, customer references in your industry, and performance reports. Where possible, visit a live production reference site to observe long-term operation.

Q: Does Kenwei provide full-line solutions?

A: Kenwei develops and manufactures multi-head weighers, linear weighers, check weighers, and metal detectors and offers one-stop automated weighing and packaging solutions. They provide system design, manufacturing, installation, commissioning, technical training, and after-sales service from their facility in Guangdong, China.