Why You Should Consider a More Sustainable Alternative to Potting

When encapsulating electronics, you likely want to increase sustainability in both your finished products and manufacturing processes. To do so, you want to be aware how you are contributing to environmental impact – however, this can be challenging when using potting methods. 

While potting is a common way to protect electronics, it poses key limitations to accomplishing sustainability goals due in large part to the solutions needed to conduct it. That’s why you should consider low pressure molding (LPM), a manufacturing process that uses more sustainable resins and entails injecting molten plastic material into a mold to gently encapsulate the devices. 

Find out the limitations potting technologies pose, how LPM resins overcome them and how Bostik’s Thermelt® low pressure molding polyamides can help you further address sustainability goals. 

Potting technologies are typically two-part polyurethanes and two-part epoxies. They inherently pose sustainability challenges due to: 

Mixing requirements 

Potting requires mixing to blend two components together, which increases error likelihood that may therefore require additional material replacements.  

Extensive processing time 

Curing for potting technologies can cause additional production downtime and energy usage: 

• Two-part polyurethanes can cure within 24 hours at room temperature and be accelerated with heat; however, this increases energy usage and requires additional equipment 
• Two-part epoxies can cure within 24 hours; however, temperature, humidity and the specific formulation itself can vary and therefore impact the processing time  

Hazardous materials 

Potting technologies can contain volatile organic compounds (VOCs) in their formulation such as isocyanates, which are a harmful substance that pose toxicity concerns and can contribute to carbon emissions.  During the application and curing process, these substances can evaporate into the air, increasing risk of potential respiratory issues or sensory irritation for workers handling these materials. 

Carbon emissions due to increased weight 

Two-part polyurethane potting technologies tend to have high density that leads to an increase in the overall weight of the product, especially for large or complex assemblies where weight may already be a factor. While two-part epoxies may have slightly less density than two-part polyurethanes, they may require extra properties to be added to their formulation to yield capabilities like electroconductivity, which can increase the overall weight of the end-use product. Due to these technologies’ densities, they can increase fuel usage and carbon emissions during shipping if the products are heavier to transport. 

Unlike potting, which uses two-part technologies, LPM resins can be one-part hot melt polyamides (HMPAs), offering:  

Enhanced formulation 

HMPAs are comprised of 100% solids, which eliminates solvents or other hazardous substances from their formulation. This increased sustainability in the formulation helps LPM processes improve worker safety over potting methods. 

Reduced carbon emissions 

Additionally, HMPAs typically have less density than two-part polyurethanes and two-part epoxies. By using a lighter weight resin and reducing the volume of material used to protect the electronic component, LPM decreases the overall weight of the end-use product. This also helps improve overall fuel usage during shipping to decrease carbon emissions. 

Simplified processing 

Unlike two-part polyurethanes and two-part epoxies, HMPAs are one-component and do not require mixing for LPM. The thermoplastic properties in HMPAs also enable LPM to set rapidly for fast cycle times, helping to reduce overall energy usage during production. 

The Thermelt® product range includes grades with: 

• Environmental resistance: Thermelt® helps resist temperatures (-40C to 130C), chemicals, water and UV to enable a long-lasting electronic component.  
• Sterilization resistance to meet ISO certification: Certain Thermelt products have completed ISO certifications, rendering them confidently suitable for use in medical devices, including wearables, continuous glucose monitors and smart health patches as well as surgical tools. In addition to offering the same performance capabilities they’re known for, these products have been tested to ensure they do not cause sensitization or irritation if in contact with skin. 
• Low Tg and high adhesion: The Thermelt® product range makes it easy to choose a solution that provides your desired performance strength and molding capabilities for demanding substrates or delicate applications.  
• UL 94 V-0 rating: This rating means the product self-extinguishes within 10 seconds when exposed to a flame and won’t drip flaming particles for increased end-user safety.