The high-pressure resin transfer molding process (HP-RTM) can offer significant time savings compared to standard RTM. Automotive applications include structural parts of the body-in-white, leaf springs, wheels, pressure vessels and battery housings. Huntsman offers a range of resin systems optimized for HP-RTM production of specific components.
High-pressure Resin Transfer Molding (HP-RTM) is well-suited to automotive mass production, as its short cycle times translate to high productivity, and the performance level of the finished parts is high. HP-RTM is a clean process that delivers high-quality laminate with low porosity. Compared to standard RTM, it offers faster injection and fast in-mold cure times (as low as 2 minutes). Huntsman’s resin systems for HP-RTM offer the ability to adjust reactivity to part size and process window requirements.
UL 94 rating:
GFRP 2 mm: V0 / CFRP 2mm: V1
Glass transition temperature (Tg):
265 - 275°C
Suitable for:
First generation, halogen-free and filler free system, combining fire resistance and very high thermal resistance. It enables the production of large parts such as battery housing.
UL 94 rating:
GFRP 2 mm: V0 / CFRP 2mm: V0
Tensile strength:
85 - 90 MPa
Suitable for:
First generation, halogen-free and filler free system, offering high mechanical strength and fracture toughness in addition to improve fire resistant properties. Excellent candidate to produce battery housing with demanding structural requirements.
UL 94 rating:
GFRP 2 mm: V0 / CFRP 2mm: V0
Cure time:
3 - 5 min 115°C
Suitable for:
Second generation fire resistant system dedicated to the mass production of battery housing parts. It offers excellent processability and fast cure.
Glass transition temperature (Tg):
120 - 130°C
Cure time:
2 min at 115°C (HP-RTM)
1 min at 140°C (WCM)
Suitable for:
Fast cure solution offering enhanced processing (1 min injection window at 115°C), reduced curing cycle and improved toughness versus state-of-art technology (ARALDITE® LY 3585 / XB 3458). High clarity system for production of cosmetic parts.
Glass transition temperature (Tg):
110 - 120°C
Cure time:
30 s at 140°C
Suitable for:
Very fast cure solution developed to improve productivity and meet requirements of structural automotive parts made by Wet Compression Molding (WCM) and Dynamic Fluid Compression Molding (DFCM).
Glass transition temperature (Tg):
125°C
Cure time:
5 min at 105°C
Suitable for:
First generation system proven to withstand real-world fatigue loading under severe hot / wet conditions. A cured Tg of 125°C covers most customer leaf spring requirements.
Glass transition temperature (Tg):
140°C
Cure time:
5 min at 105°C
Suitable:
Second generation solution offering a Tg in excess of 140°C without compromising fatigue resistance. Responds to the need for parts that can endure the harshest hot / wet conditions, such as those encountered close to the vehicle engine.
Glass transition temperature (Tg):
110 - 115°C
Fracture Toughness:
1.4 - 1.6 MPa.m½
Suitable for:
Highly toughened system designed to withstand the extreme pressure-cycling requirements of hydrogen vessels manufactured via the HP-RTM injection process.
Glass transition temperature (Tg):
210 - 220°C
Tensile strength:
40 - 45 MPa
Suitable for:
First generation system with high thermal resistance designed for the production of hybrid and full-composite wheels by RTM and HP-RTM. The system is OEM qualified and has proven performance and reliability from several years of on-road service.
Glass transition temperature (Tg):
195 - 205°C
Tensile strength:
70 - 80 MPa
Suitable for:
Second generation system with increased strength and toughness, plus high aesthetic properties for the most demanding wheel designs. Adjustable accelerator technology allows optimum fast-curing to be tailored to a given wheel design.
In the standard RTM process, the system components (resin and hardener) are usually mixed through a static helicoidal mixer at a relatively low pressure (<15 bars). In high-pressure RTM, the mixing is managed by the high-speed counter-flow of the reactive components in a cylindrical mixing chamber at high pressure, typically over 50 bars. The laminar liquid is quickly transferred into the cavity through an injection nozzle that fits a hole drilled into the mold, without waste.
With standard RTM, part production in the mold can take from 15 minutes to over an hour. In most cases, a post cure is required to develop the ultimate performance. Using Huntsman’s HP-RTM-optimized resin systems, finished parts can be produced in less than 5 minutes.
For various reasons (e.g. part dimension or reinforcement permeability), not all parts will require the same latency during production. This is why Huntsman offers versatile resin systems. Using different available hardeners, the system composition can be adjusted to optimize cycle times and to meet a wide range of latency/injection windows, without affecting mechanical performance.
Our leading composite expertise, broad product range and unique simulation capabilities can reduce development cycles by up to 50 %.
Huntsman Advanced Materials offers innovative solutions that support manufacturers in the design and production of composite pressure vessels for hydrogen storage and transportation.
Resins for HP-RTM applications require: very low viscosity (<300 mPas), adjustable reactivity (pot life, curing), low shrinkage (<2%), low reaction exotherm and good wetting of reinforcement.
Huntsman offers a range of resin systems optimized for the production of specific components by HP-RTM.
For body-in-white parts, choose ARALDITE® LY 3585 resin / ARADUR® 3475 hardener, a fast-cure solution that offers enhanced processing, reduced curing cycle and improved toughness. It is a high-clarity system, suitable for production of cosmetic parts.
For leaf springs, we recommend ARALDITE® LY 3585 resin / ARADUR® 3831 hardener, a first-generation system that’s proven to withstand real-world fatigue loading under severe hot/wet conditions; or ARALDITE® LY 3585 resin / ARADUR® 3834 hardener, a second-generation solution for parts that must endure the harshest hot/wet conditions, such as those located near engines.
For wheels, choose ARALDITE® LY 8615 resin / ARADUR® 8615 hardener, a first-generation system that’s OEM-qualified, and has proven performance and reliability from several years of on-road service; or ARALDITE® LY 1560 resin / ARADUR® 917-1 hardener, a second-generation system with increased strength and toughness, plus high aesthetic properties. Adjustable accelerator technology allows cure time to be tailored to a given wheel design.
For pressure vessels, select ARALDITE® LY 3508 resin / ARADUR® 3478 hardener, a highly toughened system designed to withstand the extreme pressure-cycling requirements of hydrogen vessels.
ARALDITE® resin solutions for battery housings are based on a unique halogen-free thermosetting chemistry that meets the fire resistance requirements of electrified vehicles. High thermomechanical properties ensure battery cells are fully protected, and provide design freedom, light weight and corrosion resistance. ARALDITE® FST 40004 resin / ARALDITE® FST 40005 resin is a first-generation system that combines fire resistance and easy processing. ARALDITE® FST 40004 resin / ARALDITE® FST 40007 resin is a second-generation solution that features improved fire resistance and structural properties, without sacrificing the process and productivity attributes of the first-generation product.
