Leaf Springs in Automotive Manufacturing
A leaf spring is a type of spring, made up of sandwiched layers of composites or steel, commonly found in vehicle suspension systems. Many automotive manufacturers choose leaf springs as a part of their suspension systems due to their unique advantages. Leaf springs can handle large vertical loads due to their tight-knit and arc-shaped structure, allowing the loads to be distributed along their length. Compared to helical springs, traditionally used for automotive suspension systems, leaf springs provide faster and more effective damping, leading to smoother, quieter and safer vehicles.
Leaf springs, traditionally made from steel, can also be made from composite materials to provide significant weight and size reductions, more flexible designs, resistance to corrosion and greater durability.
The global leaf spring market is estimated at a value of £2.1 billion in 2020, projected to grow to $2.4 billion by 2023. This growth is accounted for by the developing commercial vehicles, bus and truck markets. Additionally, key players in these industries are increasingly utilising leaf spring adhesives and resin systems to improve strength and efficiency, reduce costs and enhance sustainability.
Leaf Spring Adhesives
Huntsman Araldite adhesives for leaf springs allow manufacturers to increase the efficacy of leaf springs. Generally, adhesives provide many advantages over mechanical fastening techniques, from weight-saving to improved structural integrity. Araldite composite solutions can enable:
- High thermo-mechanical performance
- Excellent fatigue resistance
- Great dynamic load properties
- Fast latency and cure speeds
- Dedicated preform binder solutions
- High-temperature resistance
- Moisture resistance
- Weight reductions
- Greater sustainability
We will now explore Araldite products used in leaf spring manufacture for both HP-RTM and preforming.
Leaf Spring Adhesives for HP-RTM
Araldite® LY 3585 / Aradur® 3475 is a composite system with a glass transition temperature (Tg) of 125°C and cure time of 5 min (at 105°C) that covers most leaf spring manufacturing requirements. It improves toughness and can withstand high fatigue conditions in wet and hot conditions.
Araldite® LY 3585 / Aradur® 3834 is a composite system with a glass transition temperature (Tg) of 140°C and cure time of 5 min (at 105°C) that can be used on leaf springs near to the vehicle engine. This is due to its ability to withstand very high and wet conditions, providing reliable fatigue resistance.
Leaf Spring Adhesives for Preforming
Araldite® LT 3366 is a non-reactive binder that is ideal for the mass-production of powdered fabrics and preforms. It has a softening point of 150°C and a preforming cycle of 20 seconds at 180°C. Its high softening point leads to the prevention of ply-to-ply adhesion during storage.
Araldite® XB 6078 is a reactive binder that is ideal for the manufacture of thick preforms, such as leaf springs. It offers high preform stability, good aesthetic and resilience even in temperatures exceeding 160°C. It has a softening point of 85°C and a preforming cycle of 120 seconds at 140°C or 60 seconds at 160°C.