Applications are considered “high heat” if the environment exceeds 60⁰C (140⁰F). At this temperature, regular cables and connectors begin to melt and will either fail or create a serious hazard. High heat cables, on the other hand, are specially engineered from the inside out using heat- and flame-resistant materials that won’t deteriorate under such extreme conditions.
As the outermost layer of a cable assembly (and the first layer that will come into contact with extreme temperatures, overmolding plays an important part in protecting internal components. The materials we typically use for high heat overmolding are Glass-Filled PBT (Polybutylene Terephthalate) and Glass-Filled PA (Nylon or Polyamide). PBT and PA are thermoplastic compounds reinforced with glass fiber to provide high-temperature deflection, low shrinkage rate, high rigidity, and good mechanical strength. Beyond protecting the cable exterior and maintaining a safe internal temperature, high-heat overmolding offers numerous benefits:
Longer Shelf Life = Greater Value
The thermoplastics used in high-heat overmolding are designed to withstand temperatures or direct contact with flames for a specified time frame. When properly manufactured, this duration will hold true and enable you to get the full value out of your investment. When improperly manufactured, there’s no telling when or how your cable assembly might fail, or how many times you’ll need to replace or repair electrical parts. Worse still, residual damages caused by a failed cable can be severe, fatal and costly.
Resistance to Other Environmental Factors
In rugged environments like industrial or automotive facilities, high heat is frequently accompanied by other contaminants such as pollution, chemicals and debris. The materials used for high-heat overmolding are inherently resistant to many of these damaging environmental factors, and can be further customized for even greater protection against the elements. For example, PA offers good resistance to many chemicals, and PBT repels fuels, oils, fats and solvents.
Moisture and water ingress is a real problem for high-heat applications. To begin with, rapid fluctuations in temperature can cause pressure changes that can pull moisture inward. If your cable isn’t properly sealed, this ingress can result in corrosion and cable failure. Furthermore, if an unprotected cable is exposed to fire, water will likely be used to extinguish the flames. Without an IP-rated overmolding design, it’s unlikely your electrical equipment will survive; at least not without substantial damages.
Safety, Compliance & Certification
Without the protection of a heat-resistant shield, the inner and outer layers of a cable can melt and expose live conductors and wires. If someone comes into direct contact with or close proximity to live conductors and wires, they can get shocked, burned, electrocuted or even killed. Heat-damaged cables may also short out or spark and start a fire. For these reasons, governing bodies like UL and the International Electrotechnical Commission (EIC) have strict requirements products must meet before they can go to market.
Working with an experienced connector and cable assembly manufacturer is the safest way to ensure your product performs in even the most extreme heat. iCONN Systems can produce cables and connectors that will perform safely and reliably in environments as hot as 260⁰C (500⁰F). We also have in-house certification power to help get your product to market faster. Click here to learn how in-house certification capabilities will benefit your project team.