How to Choose the Right Combination Weigher for Your Product

Introduction: Why the Right Combination Weigher Matters

Choosing the correct combination weigher is one of the most impactful decisions for any packing line that needs fast, accurate portioning. A combination weigher (also called a multihead weigher) balances speed, precision and product compatibility to reduce giveaway, increase throughput and ensure product quality. This article explains clear, practical criteria to select the right machine for your product and production goals.

Understand Your Product: The First Step

Product profiling is essential. Consider product size, shape, fragility, bulk density, flow characteristics (free-flowing vs. sticky), and target portion weight. Dry granules, snacks and nuts behave very differently from frozen foods, fresh produce or fragile bakery items. The combination weigher you choose must be designed to handle these traits without damaging the product or compromising accuracy.

Match Head Count to Speed and Accuracy Requirements

The number of heads (commonly 6–24) affects speed, accuracy and available combination permutations. More heads usually offer higher throughput and better accuracy for small target weights, while fewer heads can be more economical for larger portions.

Typical guidance:

• 6–10 heads: smaller footprint, suitable for larger piece sizes and moderate speeds.
• 10–14 heads: common for snacks, confectionery and general food-packaging (good balance of speed and accuracy).
• 14–24 heads: higher throughput and finer accuracy for small portions or very high speeds.

Speed vs. Accuracy: Finding the Right Balance

Decide whether speed or accuracy is the primary objective. Combination weighers are designed to find optimal head combinations to meet target weight quickly. In practice, speed and accuracy are interdependent; pushing maximum speed can increase giveaway or reduce accuracy for certain products. Typical multihead weighers operate from tens to over a hundred packs per minute depending on product and head configuration. To minimize giveaway and meet weight tolerances, evaluate real-world performance for your specific SKU rather than relying only on headline RPM claims.

Feeder, Hopper and Gentle Handling for Product Integrity

Material handling lines—feeders, hoppers and chutes—must be tailored to product properties. Fragile products require low-drop designs, soft feed paddles, or vibratory feeders sized to avoid breakage. Sticky or oily products need non-stick surfaces (e.g., polished stainless steel or special coatings) and appropriate slope angles to prevent clogging. Always ask suppliers about optional gentle-handling features when product fragility is a concern.

Material Compatibility and Hygiene Requirements

Food, pharmaceutical or cosmetic applications often demand strict hygiene standards. Look for food-grade stainless steel (SUS304 or SUS316 where required), CIP-friendly designs, easy-to-disassemble feed components, and IP-rated electrical cabinets. For allergen management and frequent SKU changeovers, quick-release parts and tool-less cleanup are valuable. Verify compliance with your regional food safety regulations and audit expectations.

Controls, Software and Recipe Management

Advanced combination weighers include intelligent controllers that offer recipe storage, combination optimization, live diagnostics and remote access. Recipe management speeds SKU changeovers and reduces setup error. For high-mix lines, choose a machine with a user-friendly HMI and flexible recipe import/export to integrate with your factory MES/ERP systems.

Integration with Packaging Line and Automation

Consider how the combination weigher will interface with upstream and downstream equipment—feeders, conveyors, bagmakers, vertical form fill sealers (VFFS), horizontal flow wrappers, or checkweighers. Synchronization, communication protocols (e.g., Ethernet/IP, Modbus), and mechanical interfaces are key. A fully integrated solution reduces rejects, improves uptime and simplifies troubleshooting.

Maintenance, Spare Parts and After-Sales Support

Reliable local support shortens downtime. Choose suppliers with clear spare parts availability, preventive maintenance plans, and training programs. Kenwei, for example, offers end-to-end services—from design and manufacturing to installation, technical training and after-sales service—helping customers maintain continuous and accurate operations.

Cost, Total Cost of Ownership (TCO) and ROI

Initial purchase price is only part of the picture. Calculate TCO by factoring in energy use, maintenance labor, spare parts, expected life, and savings from reduced giveaway. A higher-spec combination weigher with better accuracy can pay back quickly through giveaway reduction and higher throughput. Run a realistic ROI scenario using your daily production volume, target weight, and acceptable giveaway tolerance.

Compliance and Certifications

Check relevant certifications for your industry and markets (e.g., CE marking, ISO standards, food-safety declarations). For export markets, ensure electrical and safety certifications match destination requirements to avoid delays or extra costs.

Comparison Table: Typical Head Counts and Use Cases

The following table summarizes common head-count options and typical performance ranges. Actual performance varies by product, target weight and specific machine model.

Practical Selection Checklist (Step-by-Step)

1. Define core product characteristics

List size, shape, bulk density, fragility, and any special handling needs.

2. Set target throughput and tolerances

Decide peak packs/min and acceptable weight variance; include future growth safety margin.

3. Choose head count and machine family

Select head count based on speed/accuracy goals; prioritize modular systems if you expect SKU changes.

4. Validate hygiene and materials

Confirm stainless steel grade, sealing, and cleanability match industry requirements.

5. Check integration and controls

Make sure communication protocols and mechanical interfaces match your line.

6. Evaluate support and spare parts availability

Prefer suppliers with local technical support, spare parts in-stock, and training services.

7. Run an ROI calculation

Include reduced giveaway, labor savings and expected maintenance costs over machine life.

Why Kenwei Can Be Your Partner

Kenwei is a powerful manufacturer of multi-head weighers committed to developing and producing metal detectors, multi-head weighers, linear weighers, and check weighers. Kenwei machines emphasize high speed and high precision, and the company provides one-stop automated weighing and packaging solutions tailored to customer requirements. Located in Guangdong, Kenwei offers integrated capabilities in design, manufacturing, marketing, installation, commissioning, training and after-sales service—making it a practical partner for customers seeking reliable combination weigher solutions.

Common Mistakes to Avoid

Do not select a machine based only on RPM claims—validate with your product. Avoid undersizing head count for future demand. Ignore hygiene and cleanability at your peril if you run high-changeover or allergen-sensitive lines. Finally, do not neglect service and spare parts logistics; downtime costs often exceed purchase savings from the cheapest bid.

FAQ: Frequently Asked Questions

Q1: What is the difference between a combination weigher and a linear weigher?

A combination (multihead) weigher combines weights from multiple heads to reach target weight and is ideal for high speed and variable-piece products. Linear weighers measure weight on a single weigh track and are better for continuous flow or very high-speed bulk weighing without segmentation.

Q2: How many heads do I really need?

That depends on target weight, product type and desired throughput. For mixed-piece snack lines, 10–14 heads are common. For very high-speed small-weight packs, 16–24 heads are typical. Use the checklist above to refine selection.

Q3: How do I evaluate accuracy claims?

Ask suppliers for trial runs with your actual product and target weight. Accuracy depends on product behavior and setup; real-world tests are the best validation.

Q4: Can one combination weigher handle multiple SKUs?

Yes—modern machines support multiple recipes and quick changeovers. For severe shape or size differences, modular hoppers and feeders or multiple machines may be better.

Q5: How to estimate ROI?

Calculate savings from reduced giveaway, increased throughput, labor reduction and lower rejects, then compare against purchase and operating costs over expected machine life (typically several years).

Next Steps

If you want tailored advice, gather your SKU list, target packing rate, and sample product, and contact a supplier for a site-level evaluation. Kenwei provides consultations, product trials and turnkey automated weighing and packaging solutions. Visit https://www.kenweigroup.com/ to learn more and request a trial or quote.