In the preforming process, a dry 3D shape is created from fibers and inserted in a mold prior to impregnation with a liquid resin system. All parts made via RTM, HP-RTM or compression molding benefit from the use of preforms. Huntsman’s range of ARALDITE® resin binders, which are used to hold together the fibers in the preform, covers all automotive preform types.
Preforming is necessary to allow robotic handling of the fibers and their fast and accurate placement in molds. Making a preform requires a polymeric material called a binder, which holds the fibers together and ensures that they do not move under the pressure of resin flow during injection. This improves the mechanical properties of the composite parts, and also allows production of cosmetic parts that require fibers to be perfectly straight.
Softening point:
150°C
Preforming cycle:
20 s at 180°C
Suitable for:
Non-reactive binder for highly efficient mass-production of powdered fabrics and preforms. High softening point prevents ply-to-ply adhesion during storage and fiber distortion at injection temperatures up to 120°C.
Softening point:
85°C
Preforming cycle:
120 s at 140°C or 60 s at 160°C
Suitable for:
Reactive binder offering very high preform stability, even for injection temperatures exceeding 160°C. Recommended for production of thick preforms, such as for leaf spring manufacture, as well as for parts requiring high aesthetic quality.
At Huntsman, binders and injection resins are developed in tandem to be optimally compatible, ensuring the highest possible performance of composite parts. Huntsman’s binders allow fast preforming, thanks to their ideal rheology behavior under temperature. Their adhesion properties make them efficient at low concentrations, which increases the permeability of the preforms and consequently reduces the injection time of the resins.
Huntsman’s binders can withstand significant pressure and temperature variations during storage or transport—this means that preforms can be easily extracted from stacks even after hot transport, increasing productivity and reducing scrap rates.
Our leading composite expertise, broad product range and unique simulation capabilities can reduce development cycles by up to 50 %.
ARALDITE® binders are designed to meet the requirements of high-pressure RTM and wet compression processes in automotive composite applications including body-in-white, leaf springs, composite wheels and battery housings.
ARALDITE® resins display very low viscosity at injection temperature and maintain their low viscosity level during a long open time. This allows injecting large parts with high quality. The reactivity that allows the long injection window also permits a fast polymerization reaction when the mold is filled. This combination of features leads to short cycle times and a high rate of defect-free parts.
ARALDITE® LT 3366 non-reactive binder will be fully dissolved into the injected resin. It enables highly efficient mass-production of powdered fabrics and preforms. ARALDITE® XB 6078 reactive binder can be pre-reacted prior to the resin injection. It offers very high preform stability, even for injection temperatures exceeding 160° C. It is recommended for production of thick preforms, such as for leaf spring manufacture, as well as for parts requiring high aesthetic quality.
