Reviewed and updated: August 20, 2026.

Choosing a spot-on filling and sealing machine is not just about picking a model from a catalog. The right machine depends on your product viscosity, pipette dimensions, fill volume, accuracy requirements, sealing method, and production volume. Get any one of these wrong, and you end up with a machine that fills too slowly, seals poorly, or cannot handle your next product format.

Most procurement mistakes happen because buyers skip the evaluation steps and jump straight to price comparison. They compare two machines without understanding whether the filling technology suits their product, whether the sealing method works on their container material, or whether the supplier can support their long-term production needs.

This guide provides a structured, step-by-step approach to choosing a spot-on filling and sealing machine — from analyzing your product and container to evaluating suppliers and calculating total cost of ownership.

Why This Issue Matters

Choosing a spot-on filling and sealing machine is a decision that affects your production capability, product quality, and operational profitability for years. Unlike standard tube filling equipment, spot-on machines must handle micro-volume dosing, lightweight containers, and precision sealing — all simultaneously and consistently across thousands of cycles.

The cost of a wrong decision extends well beyond the purchase price. A machine that cannot achieve the required fill accuracy with your specific product will generate product waste, rejected batches, and potential regulatory non-compliance. A sealing system that is not properly matched to your container material will produce leaks, customer complaints, and possible product recalls. And a supplier that cannot provide adequate technical support, spare parts, or documentation will leave you stranded when issues arise during production.

Most procurement mistakes in this area share a common root cause: buyers skip the systematic evaluation process and jump straight to price comparison. They compare two machines without verifying whether the filling technology suits their product viscosity, whether the sealing method works on their container material, or whether the supplier can support their regulatory documentation needs. The result is a machine that looks good on paper but underperforms in production.

This step-by-step guide is designed to prevent that outcome. By following a structured evaluation process — from product analysis through filling trials to total cost of ownership — you can make a decision based on engineering evidence rather than catalog specifications.

Common Mistakes in Spot-On Machine Selection

Mistake 1: Comparing Machines Without a Filling Trial

The single most common mistake is comparing machine specifications on paper without testing them with your actual product and container. Catalog specifications are measured under ideal conditions; real-world performance depends on your specific viscosity, container geometry, and sealing requirements. Conduct a filling trial with representative materials before making a purchase decision.

Mistake 2: Focusing on Maximum Speed Instead of Stable Speed

A machine advertised at 8,000 pcs/hr may only sustain 4,000–5,000 pcs/hr with your product and container. Evaluate production speed based on filling trial results, not advertised maximums. Ask for sustained-run data over at least 30 minutes.

Mistake 3: Selecting a Sealing Method Without Material Testing

Heat sealing parameters vary significantly between LDPE, HDPE, PP, and multi-layer materials. A sealing method that works on one material may produce weak seals or deformation on another. Test the sealing method on your actual pipette material during the filling trial.

Mistake 4: Ignoring Changeover Time in the Selection Process

If you plan to run multiple formats, changeover time directly affects effective production capacity. A machine that requires 60 minutes to change between formats loses significant production time over a year. Prioritize machines with modular tooling and recipe-based changeover.

Mistake 5: Not Ordering Spare Parts with the Machine

Sealing jaws, pump tubes, gaskets, and nozzles are wear items that will need replacement. Ordering these with the machine ensures you have them on hand and avoids production stoppages while waiting for parts to ship from overseas.

Step 1: Define Your Product and Container Requirements

Before looking at any machine, document your product and container specifications in detail.

Product Information

Parameter	Why It Matters
Product name and type	Determines regulatory requirements and material compatibility
Viscosity (cP or mPa·s)	Determines filling technology (piston, peristaltic, time-pressure, auger)
Density	Affects volumetric-to-gravimetric conversion
Temperature sensitivity	Determines whether heating or cooling is needed during filling
Foaming tendency	Affects fill method (bottom-up vs top-fill) and nozzle design
Particle content	Determines nozzle diameter and pump type
Chemical compatibility	Determines wetted material requirements (316L stainless, PTFE, etc.)

Document the following product characteristics before evaluating any machine. These parameters determine which filling technology, sealing method, and machine configuration are appropriate for your application.

Container Information

Parameter	Why It Matters
Pipette drawing (dimensions)	Determines feeding, transport, and filling tooling
Material (LDPE, HDPE, PP, multi-layer)	Determines sealing method and parameters
Wall thickness	Affects sealing temperature and pressure
Volume capacity	Determines fill system range
Target fill volume	Determines accuracy requirements
Opening design (snap-off, twist-off, cap)	Determines sealing station configuration
Weight	Affects feeding system design (lightweight = precision feeding)
Surface finish	Affects gripping and transport

The pipette specifications determine the feeding system, sealing parameters, and handling requirements. Provide the supplier with detailed container drawings and physical samples for accurate machine configuration.

Production Requirements

Parameter	Why It Matters
Target output (pcs/hour)	Determines machine size and automation level
Number of formats to run	Determines changeover requirements
Annual production volume	Determines machine duty cycle
Cleanroom classification	Determines machine design and materials
Available floor space	Determines machine footprint
Available utilities	Determines machine compatibility (air, power, exhaust)

• Define your production targets and facility constraints. These parameters determine the machine size, automation level, and configuration that will meet your operational needs.

Step 2: Select the Right Filling Technology

Based on your product viscosity and fill volume, select the appropriate filling technology.

Filling Technology Selection Guide

Product Viscosity	Fill Volume	Recommended Technology
Water-like (1–50 cP)	0.1–1 mL	Time-pressure or servo peristaltic
Water-like (1–50 cP)	1–5 mL	Peristaltic pump or servo piston
Thin liquid (50–500 cP)	0.5–5 mL	Servo piston or peristaltic
Medium gel (500–5,000 cP)	0.5–5 mL	Servo piston
Thick paste (5,000–50,000 cP)	1–10 mL	Piston filler with wide-bore valve
Very thick (>50,000 cP)	Any	Auger filler or heated piston

Use the following guide to match your product viscosity and fill volume to the appropriate filling technology. When in doubt, request a filling trial with your actual product to verify performance.

Key Considerations

Servo piston fillers:

• High accuracy (±0.5–1%)
• Good for medium viscosity products
• Product contacts the piston cylinder (cleaning between batches required)
• Can handle some particle content

Peristaltic pumps:

• High repeatability when correctly specified and validated
• Product only contacts the pump tube (easy changeover, minimal cleaning)
• Best for low to medium viscosity
• Pump tube is a consumable (replace periodically)

Time-pressure fillers:

• Good for very low viscosity, micro-volume
• Accuracy depends on product consistency and temperature
• No mechanical contact with product
• Best for simple, non-foaming liquids

Auger fillers:

• For high-viscosity pastes and products with particulates
• Lower accuracy than servo systems
• Good for products that do not flow easily

Step 3: Choose the Sealing Method

The sealing method depends on your pipette material and design.

Sealing Method Selection Guide

Container Material	Recommended Sealing Method
LDPE (single layer)	Heat sealing
HDPE	Heat sealing (higher temperature)
PP	Heat sealing
Multi-layer laminate	Ultrasonic sealing or specialized heat sealing
Aluminum	Not typically used for spot-on pipettes (metal folding for tubes)
Rigid pipette with separate cap	Capping (not heat sealing)

The sealing method must be compatible with your pipette material and design. Use the following reference to select the appropriate method, and always validate sealing parameters during the filling trial.

Heat Sealing Parameters

For heat-sealed pipettes, the machine must provide precise control of:

Parameter	Typical Range
Sealing temperature	120–220°C (depends on material)
Sealing pressure	1–5 bar (depends on wall thickness)
Dwell time	0.3–3 seconds
Seal width	2–6 mm
Seal jaw profile	Flat, serrated, or patterned

Ultrasonic Sealing Advantages

• No external heat source (safer for heat-sensitive products)
• Faster cycle times (no heat-up or cool-down)
• Works on multi-layer materials that are difficult to heat-seal
• Clean seal with no burnt residue

Ultrasonic Sealing Limitations

• Higher equipment cost
• Limited seal area (horn size restricts maximum seal width)
• Requires specific material compatibility (not all plastics respond equally)
• More complex maintenance

Step 4: Evaluate Machine Configuration Options

Standalone vs. Integrated Line

Option	Best For	Typical Speed
Standalone filling + sealing machine	Single product, low to medium volume	2,000–8,000 pcs/hr
Semi-automatic machine	R&D, clinical trials, small batches	500–2,000 pcs/hr
Integrated filling + sealing + inspection line	Multiple products, medium to high volume	3,000–10,000 pcs/hr
Complete line (filling + sealing + cartoning + case packing)	High-volume, fully automated production	3,000–12,000 pcs/hr

The choice between a standalone machine and an integrated line depends on production volume, product range, and automation goals. Standalone machines are suitable for single products at low to medium volumes; integrated lines are justified for multiple products, higher volumes, and full traceability requirements.

Rotary vs. Linear Configuration

Configuration	Advantages	Limitations
Rotary	Higher speed, compact footprint	More complex changeover, higher cost
Linear	Easier changeover, simpler maintenance	Lower speed, longer footprint
Hybrid (linear feed + rotary fill)	Balance of speed and flexibility	Moderate complexity

For most veterinary spot-on applications (2,000–8,000 pcs/hr), a linear or hybrid configuration offers the best balance of speed, flexibility, and cost.

Automation Level

Level	Description	Best For
Manual loading, automatic fill/seal	Operator places pipettes; machine fills and seals	Small batches, R&D
Automatic loading, fill, seal	Fully automated from feeding to discharge	Dedicated production
Full line with PLC control	Integrated with inspection, cartoning, data logging	High-volume, regulated production

Automation level determines labor requirements, production consistency, and capital investment. Match the automation level to your current and projected production volume, not to aspirational targets.

Step 5: Evaluate Suppliers

Technical Evaluation

Question	What to Look For
Has the supplier built machines for your pipette format?	Request photos, videos, or references
Can they perform a filling trial with your product?	A trial is essential — do not skip it
What fill accuracy do they achieve with your product?	Ask for test data, not just specifications
What sealing method do they recommend?	Should match your material and design
How long is the changeover between formats?	Ask for a demonstration or video

Assess the supplier’s technical capability by evaluating their experience with your specific pipette format, their filling technology recommendations, and their ability to provide filling trials with your actual product and container.

Quality Evaluation

Question	What to Look For
What brands of electrical components are used?	Siemens, Schneider, Omron, Mitsubishi, or equivalent
What brands of pneumatic components?	Festo, SMC, AirTAC, or equivalent
What is the machine frame material?	Stainless steel or painted carbon steel (stainless preferred for pharma)
How is the machine assembled and tested?	Documented procedures and traceable quality records

• Evaluate component quality, manufacturing standards, and assembly procedures. Internationally recognized component brands ensure spare parts availability and reliable performance.

Documentation Evaluation

Document	Required?
Operation manual (English)	Yes
Electrical schematics	Yes
Pneumatic diagrams	Yes
Spare parts list with part numbers	Yes
Maintenance schedule	Yes
Material certificates (product contact parts)	If required by your regulatory framework
IQ/OQ/PQ protocols	If required
Safety documentation (risk assessment, CE declaration)	If required for your market

Verify that the supplier provides complete technical documentation, including operation manuals, electrical schematics, pneumatic diagrams, spare parts lists, and IQ/OQ/PQ protocols if required by your regulatory framework.

After-Sales Evaluation

Question	What to Look For
What is the warranty period?	Compare the offered term, exclusions and response obligations
How quickly can spare parts be shipped?	Obtain written lead times for common and custom parts
Is remote support available?	Remote diagnostics via internet connection
Is on-site support available?	For installation, commissioning, or major issues
Is there a recommended spare parts list?	Should include 2-year consumables and critical spares

Assess warranty coverage, spare parts delivery time, remote support availability, and on-site service options. A supplier with local or regional service presence is significantly better than one offering only remote support from overseas.

Step 6: Request and Evaluate Filling Trials

A representative filling and sealing trial is one of the most important steps in machine selection; complete it before final technical acceptance.

What to Send for a Trial

• Empty pipettes (minimum 200–500 pieces, covering all formats)
• Product sample (minimum 2–5 liters, or enough for 200+ fills)
• Detailed specifications (drawings, viscosity data, fill volume, accuracy requirement)
• Sealing design details (seal width, seal location, tip design)

What to Expect from the Trial Report

A proper trial report should include:

Section	Content
Test conditions	Product batch, pipette batch, ambient conditions
Machine configuration	Filling technology, sealing method, settings used
Fill accuracy data	Individual weights, average, standard deviation, Cpk
Seal quality results	Visual inspection, peel test, leak test results
Production speed	Pieces per hour over a sustained run
Observations	Any issues, adjustments needed, recommendations
Photos / video	Machine running, filled pipettes, seal close-ups

How to Evaluate Trial Results

Check	Acceptance Criteria
Fill accuracy	Within the approved, pre-agreed tolerance
Fill consistency	The capability criterion agreed in the URS and validation plan
Seal integrity	No leaks, consistent appearance, peel force within range
Production speed	Meets or exceeds your minimum requirement
Drip control	No visible product on outside of pipettes
Container damage	No deformation, scratching, or marking

Compare the trial results against your acceptance criteria. If any metric fails, the supplier should identify the root cause and propose corrective actions before proceeding. Do not accept a machine based on a trial that does not meet your requirements.

Step 7: Calculate Total Cost of Ownership

TCO Components

Component	How to Estimate
Machine price	Quoted by supplier
Shipping	Based on machine dimensions, weight, and origin/destination
Import duties	Check current tariff rates for your country (varies significantly)
Installation	Supplier on-site support + your internal labor
Commissioning	Time to reach stable production
Training	Operator and maintenance training
Initial spare parts	Recommended spare parts list (2-year supply)
Annual maintenance	Preventive maintenance labor + parts
Annual consumables	Sealing jaws, pump tubes, gaskets, filters
Downtime cost	Estimated lost production per year
Energy cost	Machine power consumption × operating hours

Include all direct and indirect costs in your TCO analysis. The purchase price is only one component of the 5-year total cost; include shipping, installation, maintenance, spare parts, downtime, and product waste in the same comparison.

TCO Comparison Template

Cost Item	Machine A	Machine B	Machine C
Purchase price	$X	$X	$X
Shipping + duties	$X	$X	$X
Installation + commissioning	$X	$X	$X
Training	$X	$X	$X
Initial spare parts	$X	$X	$X
Year 1 maintenance	$X	$X	$X
Year 2 maintenance	$X	$X	$X
Estimated annual downtime cost	$X	$X	$X
5-Year TCO	$X	$X	$X

The machine with the lowest purchase price may not have the lowest 5-year TCO. Factor in maintenance, spare parts availability, and downtime risk.

Step 8: Make the Decision

Decision Checklist

Before placing an order, confirm:

• Filling trial completed successfully with your product and pipette
• Fill accuracy meets your requirement
• Seal integrity verified
• Production speed meets your minimum
• Changeover time acceptable for your production plan
• Spare parts list reviewed and ordered with the machine
• Documentation package confirmed (manuals, schematics, spare parts list)
• IQ/OQ/PQ support confirmed (if required)
• Warranty terms agreed
• Installation and commissioning plan agreed
• Training plan confirmed
• Payment terms agreed
• Delivery timeline confirmed
• Total cost of ownership calculated and compared

Different Production Scenarios

• The appropriate spot-on filling machine configuration depends on the production context. Three scenarios illustrate how the 8-step selection process applies in practice:

Scenario 1: First-Time Spot-On Product Manufacturer

A veterinary company is bringing its first spot-on product to market — a flea and tick treatment in 1 mL LDPE pipettes, targeting 30,000 units per month initially with plans to scale to 100,000 within two years.

Recommended approach: A standalone automatic filling and sealing machine with peristaltic or servo-piston filling, heat sealing, and manual tube loading. Target output: 3,000–5,000 pcs/hr. The most critical step in this scenario is Step 6 (filling trial) — the company has no prior production data, so the trial with the actual product and pipette is essential for verifying that the machine can demonstrate the approved fill acceptance criteria. Budget for a 2-year spare parts package and on-site installation support.

Scenario 2: Scaling from Manual to Automated Production

A manufacturer currently using semi-automatic equipment for 50,000 units/month is upgrading to meet growing demand of 300,000+ units/month. The product range includes 3 pipette sizes (0.5, 1, and 3 mL) with both LDPE and multi-layer materials.

Recommended approach: An integrated automatic line with servo-piston filling (for accuracy across viscosity range), dual sealing stations (heat for LDPE, ultrasonic for multi-layer), inline checkweigher, and automatic cartoning. The Step 4 (machine configuration) decision should favor a linear layout for easier changeover between the 3 formats. Step 7 (TCO) is critical — the higher capital cost of the integrated line should be justified by reduced labor, higher yield, and lower waste over 5 years.

Scenario 3: Regulated Market Entry with Multi-Client Production

A CMO is investing in spot-on filling capability to serve clients in FDA and EU markets. Each client has different pipette designs, and the CMO expects weekly format changes. Regulatory documentation (IQ/OQ/PQ, audit trail, electronic batch records) is mandatory.

Recommended approach: A modular system with recipe-based changeover, interchangeable sealing tooling, and CFR 21 Part 11 compliant control system. Steps 5 (supplier evaluation) and 6 (filling trial) are especially critical — the supplier must demonstrate experience with regulated veterinary applications and provide documentation support. The TCO analysis (Step 7) should factor in the cost of compliance documentation, validation services, and the flexibility premium of the modular system.

When Does Automation Make Sense?

Not every spot-on production operation requires full automation. The decision to invest in automated filling and sealing equipment should be based on clear production indicators rather than the assumption that more automation is always better.

• Automation typically makes sense when one or more of the following conditions apply:
• Sustained production volume makes manual filling labor-intensive or inconsistent
• The approved product specification calls for a tolerance that manual or semi-automatic filling cannot maintain consistently
• Labor costs are rising, or the available workforce lacks the precision and consistency needed for manual micro-volume dosing
• Regulatory requirements demand batch traceability, electronic records, or audit trail capabilities that manual processes cannot provide
• Product waste from manual filling (overfill, spillage, container damage) is eating into profit margins
• Multiple product formats require frequent changeover, and recipe-based automated systems can reduce changeover time compared to manual reconfiguration

Conversely, automation may not be justified when production volumes are low or intermittent, when the product is still in R&D or clinical trial phases, or when the operation is a temporary pilot line. In these cases, a semi-automatic machine provides filling precision and seal quality without the capital investment of a fully automated line.

The key is to match the automation level to your actual production needs — not to your aspirational volume. A machine that is too automated for your current needs adds unnecessary complexity and cost; a machine that is not automated enough creates a production bottleneck that limits growth. Plan for your expected volume in 2–3 years, not just today’s output.

How King Pack Supports Your Spot-On Machine Selection

King Pack Machinery (Wuxi King-Pack Machinery Co., Ltd.) has been developing filling and packaging solutions since 2009. For spot-on filling and sealing applications, King Pack provides:

Machine Solutions

• Standalone spot-on filling and sealing machines — configured for your specific pipette and product
• Customized tube filling machines — adapted for small pipette formats
• Semi-automatic machines — for R&D, clinical trials, and small-batch production
• Complete spot-on production lines — from filling to end-of-line packaging

Filling Trial Program

King Pack recommends that every customer send product and pipette samples for a filling trial before machine configuration is finalized. The trial verifies:

• Fill accuracy with your specific product
• Seal quality on your actual pipette material
• Production speed under real conditions
• Any special handling or configuration requirements

Configuration Process

King Pack does not sell machines from a catalog. Each project starts with:

1. Review of pipette drawings and product specifications
2. Filling trial with your materials
3. Machine configuration based on trial results
4. FAT with your product and pipette before shipment
5. Installation support and operator training

Quality Standards

• Internationally recognized electrical and pneumatic components
• Documented assembly and testing procedures
• Complete technical documentation package
• IQ/OQ/PQ support available

After-Sales

• Recommended spare parts for 2-year operation
• Remote technical support
• On-site installation and commissioning support
• Operator and maintenance training

FAQ

What is the most important factor when choosing a spot-on filling machine?

Fill accuracy and seal quality. A machine that cannot fill your product accurately or seal your pipette reliably will cause production problems regardless of its speed or price. Always start with a filling trial.

How long does it take to get a spot-on filling machine after ordering?

Standard configurations may be available in 8–12 weeks. Customized machines typically require 12–20 weeks. Complete integrated lines may take 20–30 weeks, depending on complexity.

Can I use one machine for both spot-on pipettes and larger tubes?

In some cases, yes — but performance may be compromised. Machines designed for small pipettes may not handle larger tubes efficiently, and vice versa. If you need both formats, evaluate whether a multi-format machine or two dedicated machines make more sense for your production plan.

What is the difference between heat sealing and ultrasonic sealing?

Heat sealing uses heated jaws to melt and fuse the plastic. Ultrasonic sealing uses high-frequency vibration to generate friction heat at the seal interface. Heat sealing is more common and less expensive; ultrasonic sealing is better for heat-sensitive materials and multi-layer structures.

How do I verify fill accuracy during production?

Inline checkweighers provide 100% weight verification. Statistical sampling (e.g., weighing 10 units every 30 minutes) is a minimum. For critical products, inline weight checking with automatic rejection is recommended.

What spare parts should I order with the machine?

At minimum, order: sealing jaw inserts, heating elements (if heat sealing), pump tubes (if peristaltic), gaskets and O-rings, nozzles, and any wear-prone mechanical parts. Ask the supplier for a recommended 2-year spare parts list.

Do I need to visit the supplier’s factory for FAT?

It is strongly recommended. FAT is your opportunity to verify machine performance with your actual product and pipette before shipment. If you cannot travel, ask for a live video FAT with detailed documentation and photos.

What happens if the machine does not pass FAT?

The supplier should identify the issue, make corrections, and repeat the failed tests until all acceptance criteria are met. Do not accept a machine that fails FAT — the issues will only become more expensive to fix after shipment.

Can King Pack help with pipette design if I haven’t finalized the container?

King Pack can provide input on pipette design for manufacturability — ensuring the container design is compatible with efficient filling and sealing. Early collaboration between packaging design and machine selection avoids costly redesigns later.

Related Equipment and Resources

• Choose a liquid filling machine by viscosity, container and output
• Read common filling-machine questions

Conclusion

Choosing a spot-on filling and sealing machine requires a structured approach: define your product and container, select the right filling technology, choose the appropriate sealing method, evaluate machine configurations, assess suppliers, conduct filling trials, and calculate total cost of ownership.

The most common mistake is skipping the filling trial and selecting based on price alone. A machine that is cheaper to buy but cannot fill your product accurately or seal your pipette reliably will cost far more in wasted product, rejected batches, and production downtime.

Invest time in the evaluation process. Request filling trials. Compare total cost of ownership, not just purchase price. And choose a supplier who demonstrates technical capability, quality standards, and long-term support commitment.

Talk to King Pack

Start Your Spot-On Filling Machine Evaluation

If you are planning to purchase a spot-on filling and sealing machine, King Pack can review your pipette specifications and product requirements, conduct filling trials, and provide a detailed technical proposal with machine configuration recommendations.

Discuss your project with King Pack or send your product and container specifications.