Executive Summary
Automating precision dispensing processes presents unique challenges in high-performance manufacturing environments, especially when tolerances are tight, volumes are high, and materials are difficult to control. Precision dispensing automation refers to the controlled, repeatable application of fluids or adhesives at micron- or nanoliter-scale accuracy within an automated production system.
DWFritz applies a first-principles engineering approach to complex dispensing applications, combining risk mitigation, design-for-manufacturing methodology, and tightly integrated systems to ensure production-ready performance. This article explores the technical considerations, real-world challenges, and automation strategies required to successfully deploy precision dispensing solutions in medical device and consumer product manufacturing.
Why Precision Dispensing Is Difficult to Automate
Automating dispensing processes is inherently complex. Small variations in material properties, temperature, part geometry, or cleanliness can significantly affect process outcomes. These challenges are amplified in high-volume or high-precision manufacturing environments.
Common challenges include:
- Maintaining consistent bead geometry and volume
- Managing adhesive viscosity and temperature sensitivity
- Preventing dispense tip contamination
- Aligning parts precisely during dispense
- Ensuring cure stability and dimensional integrity
Solving these challenges requires more than selecting a dispense valve. It requires a system-level approach.
Reducing Risk Through Early Technology Validation
DWFritz prioritizes risk mitigation early in the project lifecycle to ensure technical feasibility and performance confidence.
We conduct:
- Proof-of-Principle (PoP) testing
- Proof-of-Concept (PoC) validation
- Performance benchmarking with commercial and custom dispense technologies
This work is performed both internally and with third-party vendors using customer-specific materials and geometries. Early validation reduces downstream investment risk, compresses development timelines, and prevents late-stage redesigns.
Designing for Manufacturing from the Start
Design for Manufacturing (DFM) is the practice of designing products and processes in a way that simplifies automation, improves yield, and reduces total system cost.
Automation is often considered late in product development. When manufacturing strategy and automation design are addressed early, significant gains can be achieved.
Example: Energy Storage Assembly
In an energy storage application, thermal adhesive was being extruded from the bond joint between battery cell and cooling system during compression, resulting in insufficient bond thickness. Rather than adding costly fixturing, DWFritz recommended incorporating controlled-diameter glass media into the epoxy. This established a precise bond line thickness without additional alignment hardware, reducing cost and improving repeatability.
Ready to begin?
Taking a Holistic Systems Approach
Dispensing performance depends on the interaction of multiple subsystems, not just the dispense valve itself.
High-performing dispense automation requires:
- Proper dispense hardware selection
- Precision motion control
- Custom software for process enforcement
- Integrated sensing and vision
- Robust material handling
Treating dispensing as a standalone operation introduces risk. Treating it as a fully integrated system enables reliability and scalability.
Ensuring Needle Cleanliness and Process Availability
Dispense tip contamination is a major source of downtime and quality issues.
Risks include:
- Frequent operator intervention
- Clogs and inconsistent bead formation
- Excess adhesive on parts
- Loss of positional accuracy
Medical Device Use Case
For a high-OEE medical device assembly system, DWFritz integrated a commercial wiping mechanism and developed a machine vision tool to inspect the needle after every dispense. When excess adhesive was detected, the system automatically executed a cleaning and priming sequence that recovered up to 5 minutes of runtime per hour and improved ROI by up to 8%.
Controlling Dispense Tip Temperature
The viscosity of adhesives, lubricants, and pharmaceutical fluids is highly sensitive to temperature variation. Even small ambient changes can destabilize a process.
DWFritz integrates:
- Active heating or cooling
- Thermocouple feedback
- Software-controlled temperature setpoints
This approach stabilizes dispensing performance across seasonal and environmental conditions, particularly in medical device, and consumer electronics wearable and handheld manufacturing.
Achieving Mass Accuracy Through Closed-Loop Control
To ensure consistent shot weight, DWFritz integrates high-precision analytical balances directly into automated dispense systems.
This enables:
- Automated taring
- In-process weight verification
- Software-driven compensation for material density variation
The result is deterministic control without operator intervention.
Managing Part Motion and Active Alignment
In ultra-small dispense applications, part and tool variation can exceed the dispense volume itself.
Medical Device Example
Applying ~35 nL of adhesive around a 1.5 mm diameter part required compensating for tolerance stack-ups larger than the bead height. DWFritz used metrology-class machine vision, custom lighting, and a high-precision multi-axis servo system to actively align every part, maintaining runout below 25 µm and enabling consistent application.
Integrating Cure and Cure Fixturing
Dispensing success doesn’t end at application. Cure behavior and part constraint during cure are equally critical.
DWFritz designs:
- Inline cure buffers
- Automated cure ovens
- Precision cure fixturing
- Integrated material handling systems
Software enforcement ensures parts meet time- and temperature-based cure requirements before downstream handling.
Frequently Asked Questions
What makes precision dispensing difficult to automate?
Small variations in temperature, material behavior, and alignment can dramatically affect outcomes at micron- and nanoliter-scale dispensing.
Why is early PoC testing important?
It validates feasibility using real materials and geometries, reducing downstream risk and cost.
Can dispensing systems maintain high throughput and precision?
Yes—when dispensing is treated as a system-level challenge incorporating motion, vision, software, and fixturing.
Glossary of Key Terms
Precision dispensing: Automated application of fluids or adhesives with tightly controlled volume, placement, and repeatability.
Design for Manufacturing (DFM): Designing products and processes to simplify automation, reduce cost, and improve yield.
OEE (Overall Equipment Effectiveness): A metric measuring availability, performance, and quality in production systems.
2K adhesive: A two-part adhesive that cures through chemical reaction after mixing.
Machine vision: Image-based inspection and measurement systems used for alignment and quality verification.