Delrin® Components Meet Strict Standards for Life-Saving Automotive Safety Restraint Systems

Case Study

Project

The DuPont™ Delrin® portfolio of polymers—proven for almost 40 years to work in demanding safety applications—provides the foundation for collaboration between DuPont and Autoliv, the world’s largest automotive safety supplier.

In an auto accident, safety restraint systems must work without exception because lives are at stake. Worldwide each year, 1.2 million people die in traffic accidents. The top lifesaving device? The seatbelt which reduces fatality by 45%. Reliable, robust materials are needed for safety restraints to ensure the safety of children and adults as they make their way to school, work, and home each day.

DuPont and Autoliv have joined forces to substantially reduce fatalities and injuries even as the distance driven increases. Together, they’re working toward this goal with improved safety restraint systems that use components made with Delrin®.

Challenges

Safety systems are subject to stringent standards including:

• Zero manufacturing defects
• Ability of components to withstand temperatures of -40°C to +95°C
• Ability of components to withstand impact specifications
• Reliability within tight dimensions
• Adherence to low FA emission requirements

Smart cars that anticipate crashes and protect people before a crash even happens, rely on electrified systems. Designers need materials that allow for thin parts that function within an electrical system without compromising strength, toughness and stiffness for the lifetime of the vehicle.

Failure to deliver safety components on time risks stopping an OEM production line. Parts manufacturers must have access to a reliable supply of high-quality homopolymer technologies for on-time delivery.

Solution

In response to OEM demand for improved safety restraint systems and lightweighting, DuPont’s development team works with Autoliv and their suppliers to finetune formulas for push buttons, pillar loops, retractor mechanisms, gears, and height adjusters. The result? New products formulated with low-emission Delrin® acetal polymer that reduce the noise and weight of safety restraint systems without compromising safety, quality, or reliability.

For over 60 years, suppliers have found that Delrin® results in better mold processing of parts that meet the highest performance standards. They have also counted on steady and timely supplies of consistently high-quality homopolymer because of DuPont’s global distribution network.

Delrin® components make it possible for Autoliv to produce safety restraint systems that are more resistant to fracture and capable of absorbing more energy in a crash. These components simply must work every time for the life of the vehicle in order to protect what matters most: people.

Result

Autoliv and DuPont have collaborated for almost 40 years to develop components for safety restraint systems that save lives. Most recently they have:

• Reduced part size to enable space efficiency and lower total system cost
• Reduced noise from seatbelt retractor parts to enhance driver experience
• Increased safety with a high-impact gear in the seatbelt pre-pretensioner that limits restraint in preparation for impact and reduces injuries.

Delrin® E-grades for Low Emissions Bridge the Gap Between Metals and Ordinary Plastics

Delrin® acetal resin, the world’s first acetal polymer, commercialized in 1959, is the stiffest unreinforced polymer available. It’s highly versatile and bridges the gap between metals and ordinary plastics.

The new low-emission grades of Delrin® acetal resins combine high-impact resistance with high stiffness, strength and elongation—even at low temperatures. They also provide high surface hardness, very low wear and friction, resiliency and high resistance to chemicals and solvents.

SGS Institut Fresenius GmbH in Germany confirms that all E-grades of Delrin® meet the demanding emission requirements of all major automotive manufacturers. Their testing revealed emissions below 2 mg/kg for all grades, while internal testing showed their strength, stiffness and impact resistance to be similar or better than the standard grades.

Delrin® is the acetal polymer of choice for:

• Fasteners
• Seatbelt components
• Headrest adjusters
• Levers
• Gears

Delrin® E-grades for low emissions are available in three basic melt flow series that vary in their melt viscosity: 100 (most viscous), 300, and 500 (the most fluid).