In this technical product overview, chemical engineer Shannon DeMasi introduces SLEEK, New England Wire Technologies’ proprietary silicone-based specialty coating designed to eliminate the inherent tackiness of silicone rubber cables.
Silicone rubber is widely valued in demanding industries for its flexibility, thermal resistance, biocompatibility, easy stripability, and tolerance to repeated autoclave sterilization. However, untreated silicone is naturally tacky. This high surface friction causes cables to drag uncomfortably across a patient’s skin in medical settings and aggressively attract dust, lint, and debris that are difficult to clean.
Traditional methods for mitigating silicone tackiness carry significant drawbacks:
- Release Agents: Often migrate off the jacket and are generally unsuitable for biocompatible medical environments.
- Parylene Coatings: While effective at eliminating friction, Parylene requires costly vapor deposition, is restricted to batch-processed cut lengths, and cannot be directly overmolded.
SLEEK provides an economical, robust alternative by forming a permanent chemical bond directly with the silicone rubber jacket. It creates an ultra-slick, matte finish that will not peel, flake, or delaminate. In coefficient of friction testing, SLEEK achieves approximately a 36% reduction in surface tackiness compared to untreated silicone (approaching Parylene’s 50% reduction).
Crucially, SLEEK is applied during continuous reel-to-reel extrusion, is fully compatible with direct overmolding, maintains medical-grade biocompatibility, and allows debris to be wiped away without specialized solvents or harsh cleaning chemicals.
Key Technical Takeaways
- Friction Reduction: Delivers a ~36% reduction in coefficient of friction/surface tackiness compared to uncoated silicone rubber.
- Permanent Chemical Bond: Covalently integrates with the silicone jacket to prevent delamination, cracking, or flaking under flexing.
- Continuous Manufacturing: Available on bulk, continuous-length spools, eliminating the short-batch length restrictions of vapor-deposited coatings like Parylene.
- Overmolding Compatibility: Chemically receptive to direct connector overmolding without additional surface preparation or mechanical masking.
- Cleanliness & Maintenance: Eliminates static debris attraction; minor contaminants wipe off cleanly with water or mild soap.
- Biocompatibility & Sterilization: Preserves the core advantages of medical-grade silicone, including skin contact safety and autoclave sterilization resilience.
SLEEK Specialty Coating Transcript
Introduction to SLEEK Coating
Hi, I’m Shannon DeMasi, a chemical engineer for New England Wire Technologies. I’m here to tell you about some information on our new SLEEK specialty coating for silicone rubber.
The Problem with Silicone Tackiness
Silicone rubber is a material that’s a great choice for cables by providing flexibility, heat resistance, sterilization, biocompatibility, and stripability. One drawback, however, is that silicone rubber can be prone to tackiness. This can cause a cable to easily pick up dirt and debris when rubbed against various surfaces, which can be difficult to clean. This, along with the unpleasant feel of the friction of the cable when dragged across the skin, can be a concern, especially when dealing with medical cables.
Limitations of Existing Alternatives
Some current alternatives can be the use of release agents that aren’t suitable for medical applications, or coatings that can be costly to implement and are not available in bulk lengths.
The SLEEK Solution: Permanent Bonding & Matte Finish
Here at New England Wire, we’ve developed SLEEK as a cost-effective alternative coating to help overcome this tackiness issue while maintaining all pre-established expectations of silicone rubber itself.
SLEEK is a silicone-based coating that forms a permanent bond to the silicone rubber jacket. Its matte finish will ensure that the extreme tackiness of the silicone rubber itself is no longer a hurdle.
Although Parylene is a great coating option to help eliminate tack, it can be costly, is only available in cut lengths, and cannot be overmolded to directly, which requires additional processing limitations. SLEEK is not only cost-effective, but is readily available in continuous lengths and has the ability to be overmolded.
Coefficient of Friction Testing (36% Reduction)
We’ve reviewed the reduction of tackiness SLEEK provides by investigating the coefficient of friction. What this tells us is how much resistance there is against the cable while being dragged along a surface. Compared to silicone rubber with no coating or release agent, there was a noticeable reduction of approximately 36% in the tackiness. This is not too far off from the more costly alternative Parylene coating, which provides a 50% reduction.
Cleanliness, Overmolding, and Biocompatibility Benefits
Without SLEEK, you can expect your cable to stick to any surface rubbed against while easily picking up debris from the contact. The cleaning of this debris can be difficult and near impossible to completely eliminate. With SLEEK, the cable will move easily on the same surfaces, and any minor debris picked up can easily be wiped off without extreme effort or the use of cleaning agents.
SLEEK will not only provide all of the expected benefits provided by silicone rubber, but is a robust coating which is permanently bonded to silicone without delamination and will additionally provide an ultra-slick surface which offers low friction and mitigates drag and will glide easily over surfaces while being highly resistant to debris. These characteristics, along with its biocompatibility and ability to be overmolded to, make SLEEK a great option.
For any questions or interest in what SLEEK has to offer for you, please reach out to your New England Wire representative for further information.