FormuLITE

FormuLITE

FormuLITE

FormuLITE™ Amine-cured Epoxy Systems

Strong, durable, and versatile materials for specialty composites

FormuLITE amine-cured epoxy systems are a ready-to-use, high performance, bio-based resin matrix, specifically designed for composite manufacturers. These epoxy systems use renewable resources including Cashew Nutshell Liquid (CNSL).

FormuLITE epoxy systems offer low viscosity, excellent wetting of the reinforcements (glass, carbon and natural fibers), fast reactivity, and extended pot-life. In addition, the use of CNSL as a key building block yields excellent properties such as high thermal resistance, well-balanced mechanical properties, and good protection against water uptake, acid and alkali solutions.

FormuLITE™ Amine-cured Epoxy Systems

Strong, durable, and versatile materials for specialty composites

Part A/Part B	FormuLITE 2500A FormuLITE 2401B	FormuLITE 2501A FormuLITE 2401B	FormuLITE 2502A FormuLITE 2401B	FormuLITE 2501A FormuLITE 2002B	FormuLITE 2501A FormuLITE 2405B
Key Advantages	Good Tg, potlife, bio-content and mechanical properties	Higher Tg and better mechanical properties	Very low viscosity, longer pot life	High bio-content, faster reactivity	Fastest reactivity, room temperature cure and mould release
Calculated bio-content	36.6	34	27	45.4	36.9
Mix ratio by weight	100:30	100:31	100:33	100:52	100:41
Mix ratio by volume	100:36	100:37	100:40	100:59	100:45
Mix viscosity 25°C (cPs)	700	905	480	1,100	1,635
Mix viscosity 40°C (cPs)	242	302	175	377	650
Pot life at 25°C (min)	105	95	125	58	28
Pot life at 40°C (min)	57	50	63	27	11
Suggested cure cycles	4-8 hrs at RT + 2-4 hrs at 50-70°C* + 2-3 hrs at 80-100°C	4-8 hrs at RT + 2-4 hrs at 50-70°C* + 2-3 hrs at 80-100°C	4-8 hrs at RT + 2-4 hrs at 50-70°C* + 2-3 hrs at 80-100°C	4-8 hrs at RT + 2-3 hrs at 70-80°C	24hrs at RT (+ 3-4hrs at 60°C for optimal curing)
Tg (°C)	92	100	88	73	79
Tensile strength (MPa)	62	69	66	52	67
Tensile modulus (MPa)	2,615	3,134	2,893	2,599	2,608
Elongation at Fmax (%) Elongation at break (%)	4.8 / 6.4	5.2 / 6.6	3.4 / 3.4	4.3 / 11.3	5.08 / 6.75
Flexural strength (MPa)	92	113	96	73	106
Flexural modulus (MPa)	2,262	2,788	2,484	2,104	2,942
Recommended processes	Infusion, RTM, VARTM, lamination, wet lay-up	Infusion, RTM, VARTM, lamination, wet lay-up	Infusion, RTM, VARTM, lamination, wet lay-up	Wet lay-up, RTM, VARTM, lamination, infusion of smaller parts	Wet lay-up, RTM, VARTM, lamination
Documents	2500A_2401B_TDS_EN 2500A_MSDS_USA 2401B_MSDS_USA 2500A_MSDS_Europe 2401B_MSDS_Europe	2501A_2401B_TDS_EN 2501A_MSDS_USA 2401B_MSDS_USA 2501A_MSDS_Europe 2401B_MSDS_Europe	2502A_2401B_TDS_EN2501A_MSDS_USA 2401B_MSDS_USA 2501A_MSDS_Europe 2401B_MSDS_Europe	2501A_2002B_TDS_EN 2501A_MSDS_USA 2002B_MSDS_USA 2501A_MSDS_Europe 2002B_MSDS_Europe	2501A_2405B_TDS_EN 2501A_MSDS_USA 2405B_MSDS_USA 2501A_MSDS_Europe 2405B_MSDS_Europe
– Pot life determined upon viscosity increase up to 10,000 cPs (100 g sample) – Curing and post-curing cycles should be optimized according to the temperature of the working space, the size of the composite part and the available curing equipment * Optional low temperature post curing step for demolding prior to final post-cure

How-to Guide

Cardolite FormuLITE products are user friendly and high performance. The guidelines below provide additional information on how to best use these products. Please contact your Cardolite sales representative if more information is required.

Epoxy resins

Epoxy resins are characterized by excellent mechanical and thermal properties, low cure shrinkage, very good chemical and water resistance, high thermal resistance and excellent adhesion to reinforcing fibers and substrates. These properties allow epoxy resins to be used in various applications.

Two components (2K) epoxy systems

2k epoxy systems offer the possibility to obtain different properties by combining different parts epoxy resin (A) and an amine hardener (B). FormuLITE 2K epoxy systems have been designed for use in fiber-reinforced composites, however, they can be a valuable choice in other applications such as adhesives.

How 2k epoxy systems react

The blend of an epoxy resin and an amine hardener is a reactive liquid that undergoes an exothermic cross-linking reaction. During this process, heat is released and viscosity slowly increases.

The pot-life is a measure of reactivity. It defines the period during which the epoxy system is workable. The pot-life decreases when either temperature increases or large amounts of mixture are prepared due to the exothermic reaction.

The tack-free time is the interval before the cured epoxy system surface can resist damage by touch or from settling dirt.

Before starting the manufacturing of a composite part or any other use of FormuLITE epoxy systems, we advise users to carry out preliminary trials to verify that the pot-life in the actual working conditions fit the requirements of the manufacturing process.

How to prepare an epoxy formulation

Always follow the health, safety and environmental guidelines recommended on the material safety data sheet (MSDS). Copies of the MSDS can be requested on the Cardolite website or via your local sales representative.

The mix ratio in 2K epoxy systems is calculated on the basis of the reactive groups of the epoxy and the hardener. In order to obtain the properties described in the Product Technical Data Sheet, the mix ratio (by weight or by volume) has to be carefully followed and the two components have to be mixed thoroughly in a clean container until a homogeneous blend is obtained. If a balance is available, it is advised to carefully weigh part A and part B in two separate containers, then pour part B into part A and mix thoroughly with a wooden or metallic thin spatula, limiting the entrapping of air. In case of excessive air entrapment, appropriate quantities of air release additives can be used.

Evaluation of the curing stage

The maximum performance of an epoxy system is reached only when the composite piece has been completely cured. In some industrial processes, like RTM (Resin Transfer Molding), the formulated system is usually warmed up before the injection into the heated mold, where the temperature is high enough to enable the rapid curing of the composite piece and its demolding in a few minutes. In many other applications, from vacuum infusion to DIY works, the composite parts is left at room temperature.

The evaluation of the curing stage of an epoxy resin or composite can be carried out with several methods, depending upon the available equipment. If a well-equipped quality control laboratory is available, the best way to evaluate the degree of curing is to use a DSC technique (Differential Scanning Calorimeter) to measure the Tg (glass transition temperature), which is a good proxy of the softening point of the cured epoxy. In many composites production facilities the degree of curing is inferred from the surface hardness of the piece, which can be measured by Barcol or Shore D testers. For DIY applications, when the mentioned equipment is not available, a simple method is the tactile assessment of the surface: when it is tack-free, the epoxy resin has reached an acceptable curing stage (although not optimum).

To evaluate if the mechanical, thermal and chemical properties of the composite piece are adequate for the specific application after room temperature curing only, the user can expose it to the real working conditions (mechanical loads, aggressive fluids, etc.) and verify its performances. In case of negative results, it is necessary to allow a longer curing time at room temperature or to consider a post-curing procedure.

Post-curing

A tack-free surface after ambient curing does not mean that the piece has reached its optimum properties. To develop the best mechanical and thermal properties, a post-curing is needed, i.e. adequate and uniform heating has to be provided to the composite part.

Industrial equipment for post-curing includes ventilated ovens and IR lamps. In case of small pieces in DIY applications, a common IR lamp is enough for the part to achieve the required curing level. In case hot ventilation is available, 6 to 16 hours at 50-60°C (depending upon the size and shape of the composite part) are usually enough to provide the needed energy for post-curing.

FormuLITE 2500A/2501A/2501A + FormuLITE 2401B systems are brittle after RT curing only. Before demolding the piece, it is strongly recommended to post-cure at 50-60°C for 2-4 hours.

Technical assistance can be provided upon request.