Automated Coatings: Precision for Hydrophilic Medical Devices

Hydrophilic coatings have become a critical component in the development of advanced medical devices. These coatings allow devices to be inserted into and move smoothly throughout the body, enhance patient comfort and improving patient outcomes. In addition these coatings improve compatibility with the human body, providing a greater degree of safety between the medical device and tissues. With the increasing demand for higher-quality devices comes the need for coatings that can reliably meet performance demands. At the same time, reliable application of the coatings onto the devices is also critical. 

As a result, coating automation is currently emerging to help manufacture and apply advanced, hydrophilic medical coatings onto these devices.

Automated coatings systems do more than just minimize labor requirements for operators. They also enhance control of the coating process and its variability, increase reliability, and allow for larger-scale production. Automation in coatings is transforming what can be done with hydrophilic coatings. These systems implement accurate machines, programmed movement, controlled environments, and advanced monitoring.

This article explores how coating automation can enhance the precision and efficiency of hydrophilic coatings. We look at the science of automated equipment, and determine why these processes are important to obtain the best surfaces for medical devices. If you are an engineer involved in manufacturing coated medical devices you will not want to skip this article.  

Why Automated Coatings Matter for Hydrophilic Applications

The problem: 

In the past, it was common to either manually or semi-manually apply hydrophilic coatings to medical devices. However, manual coating processes can cause variations at almost every step of the process. These variations can be caused by factors, such as dip time, immersed removal rate, rotation of the device during cure, substrate handling, and cure/ dry times. These variations can result in uneven coating thickness, inconsistent coverage, adhesion failure, and other problems. 

It is extremely important to control variability in the medical device coating application process. This is important both from a quality as well as a safety standpoint.

Automated Coating Systems Solve Application Issues (Repeatability, Precision)  

Effective coating automation addresses these quality challenges by providing:

1. Repeatability
2. Precision control
3. Increased throughput 
4. Contamination reduction
5. Regulatory compliance

We dive into each of these in more detail below. 

1. Repeatability

Automated dipping cycles, motion paths, and curing sequences are stored and programmed exactly the same way. This ensures every device is coated according to the same parameters. This removes the errors that can occur due to manual involvement. It also provides batch-to-batch consistency.

2. Precision Control

Automation can also help ensure precision of the coating. The following are some of the critical parameters that can be tightly controlled during the process:

• Immersion depth
• Pull rate
• Rotation speed
• Dwell time
• Viscosity control
• Curing intensity

3. Increased Throughput

To ensure increased throughput, multi-station, programmed automated systems are installed. These systems have the capability of running many devices through the coating process at the same time. This allows for an increase in production efficiency along with increased accuracy.

4. Contamination Reduction

The use of automated coatings reduces the need to manually handle the medical devices. Less manual handling of the devices results in fewer opportunities for particulate contamination, surface damage, and more.

5. Regulatory Compliance

Automation in the coating process allows for better process validation. It provides traceable data logs and reproducible procedures. Automation allows documentation in accordance with regulatory guidelines such as International Organization of Standards (ISO 13485, ISO 10993)^1,2 and Food and Drug Administration quality system regulations (FDA QSR).³ 

Key Elements of Automated Coatings Systems for Medical Devices

Modern, automated equipment used to apply hydrophilic coatings consists of multiple engineering components. These coating systems can include motion control, surface science, and curing physics, as well as software integration to produce repeatable results.

The components of an automated coatings system will have the following characteristics: 

1. Precision Motion Control

These systems utilize automated actuators and motors to achieve:

• Consistent speed during immersion,
• Controlled withdrawal speed,
• Stable vertical and rotational movement

The above parameters can directly affect coating thickness and uniformity, helping to increase reliability and consistency by limiting variations. 

For example:

• Fast withdrawal will give thinner films.
• Slow withdrawal will yield thicker films.
• Stable rotation provides circumferential application on cylindrical devices, such as catheter shafts or guidewires.

2. Automated Dip and Dwell Cycles

Automated coatings systems specify and store accurate cycles for immersion depth, dip duration, and drying time. This functionality is critically important for hydrophilic coatings that are sensitive to viscosity and crosslinking. Automated systems have efficient control over water uptake behavior, swelling ratio, and lubricity.

3. Environmental and Humidity Control

Hydrophilic polymers are sensitive to:

• Humidity present in the atmosphere
• Evaporation rates of the solvent
• Any airflow present in the environment
• Changes in temperature

An automated coatings system allows for controlled humidity and temperature. This helps coating viscosity to remain within a desired range during the manufacturing process.

4. Integrated, Automated UV Curing Modules

UV curing is an essential part of crosslinking many hydrophilic polymer coatings. Automated systems integrate multiple UV curing features, including: 

• Calibrated UV emitters with variable angles
• Adjustable intensity levels
• In-line rotation while curing
• Temperature monitoring 
• Exposing validation in real-time 

Uniform curing ensures superior adhesion, durability, and wear resistance for the hydrophilic coated device.

5. Real-Time Monitoring and Quality Control

Automated coating systems have smart monitoring features. These enhance overall process robustness and quality control dramatically. These components include:

• UV curing intensity sensors
• Temperature and humidity probes
• Viscosity monitoring
• Digital process logging
• Fault detection features 

These smart controls help to encompass the transition to automated hydrophilic coating. They also help to ensure production runs go smoothly. 

How Coatings Automation Improves Hydrophilic Performance

Coatings automation enhances the performance of the hydrophilic coating. Coatings applied using advanced, automated system can actually perform better, last longer, adhere better, and resist abrasion better. They also hold water better. This improvement is based on uniformly and accurately applying the coating to the substrate.

How Coatings Automation Helps Improves Coating Performance

Here is how coating automation can improve different areas of hydrophilic coatings for medical devices. 

1. Improved Lubricity: Automatic controls help to create a smooth and uniform coating layer. The coating will consistently hold absorbed water and develop the expected low-friction profile.
2. Stronger Adhesion and Duration: Automation standardizes the coating application process. For instance, it can improve crosslinking, enhancing the bonding of substrate and coatings that will last longer than others. 
3. Reduced Defects: Automation helps to reduce defect levels more efficiently than visual inspection. Sensors and feedback mechanisms integrated into the system allow for better quality and monitoring.
4. Enhanced Biocompatibility: Automation yields better biocompatibility by increasing the quality of the hydrophilic coating. The result is less particle shedding, leaching, or inconsistent swell behavior. 

How Automated Coating Lines Improve Efficiency

In addition, automation offers opportunities for substantial manufacturing efficiencies, such as: 

• Increased throughput without loss of quality
• Reduced waste and lower operational costs
• Data-driven factual insights for ongoing production improvement

Hydromer® Coatings for Automated Hydrophilic Coating Systems

Automated hydrophilic coatings systems are more than just coating equipment. Designing an effective system requires several interconnected components, such as polymer chemistry, process engineering, and equipment design. Hydromer® Inc. has 40+ years of experience in creating advanced hydrophilic coating formulations along with coating equipment and manufacturing processes. Hydromer’s recent strategic partnership with jMedTech provides additional coating equipment and capabilities, allowing us to even better serve our clients. 

In addition to our custom machine building services, Hydromer®, Inc. now offers a line of hydrophilic coating equipment, friction testing systems, and automated high-throughput coating systems. 

Hydrophilic Coatings Formulated for Automated Coating Systems 

Effective hydrophilic coatings should not be viewed as separate from chemistry and automation. Rather, these components should be looked at as a complete, designed system. As a result, our team designs coating formulations to work with automated hydrophilic coating machinery (ours or other machinery). 

Our hydrophilic medical coatings are designed to be compatible with automated coating systems. For example, Hydromer hydrophilic coatings: 

• Designed for precise viscosity control, slow and stable evaporation of solvents, and predictable UV or thermal curing properties.⁴ 
• Offer exceptional wetting characteristics to support uniform immersion and withdrawal. This allows motion-controlled devices to produce the same coating profiles, even in high-volume situations. 
• Come with application methods validated for many types of medical device substrates, including nylon, polyurethane, PEBAX®, PVC, polyimide, and silicone. 
• Designed for rapid crosslinking, uniform curing with rotation or static exposure, improved adhesion, and reduced tack, so that standard automated UV curing modules can access and deliver stable crosslink density and a minimum variability in film formation. 
• Reproducibility when scaled up. Our coatings can be formulated to work in R&D environments with single devices to fully automated lines with numerous stations. Our chemists  identical friction profiles, adhesion properties, and biocompatibility properties. 

Discover Hydromer® Hydrophilic Medical Coatings Formulated for Automated Coating Systems.

Conclusion: The New Standard of Hydrophilic Coating Excellence

Automated coating systems have the capability to change hydrophilic coating technology indefinitely. Coating application once required skilled labor and substantial manual effort. Now it can be executed autonomously while providing a high level of precision and efficiency, consistency in coating coverage, and a reliable quality. Automated coating systems consist of:

• Precise movement mechanics
• Controlled curing
• Stable environments
• Real-time monitoring
• Scalable production
• Digital tracking
• And more

These innovations established benchmarks for accuracy and reliability in contemporary medical device manufacturing. Growing requirements for higher quality in coating application also create a market for more automated hydrophilic coating systems. Hydromer provides automated systems along with hydrophilic coatings designed to be used with them.  Together, these high-performance coating technologies are meeting the demands of modern medical device manufacturers.

References

Click here to see references for this article.

1. Abuhav I. ISO 13485: 2016: a complete guide to quality management in the medical device industry. CRC Press; 2018.

2. Thangaraju P, Varthya SB. ISO 10993: biological evaluation of medical devices. Medical device guidelines and regulations handbook. Springer; 2022:163-187.

3. MacDonald K. Quality System Regulation and Manufacturing. Innovation in Nephrology. Elsevier; 2025:267-278.

4. Hydromer. Hydrophilic coating equipment. 2025;