F50 resin for high-thickness mass-casting

Citation

(2001), "F50 resin for high-thickness mass-casting", Aircraft Engineering and Aerospace Technology, Vol. 73 No. 1. https://doi.org/10.1108/aeat.2001.12773aad.012

F50 resin for high-thickness mass-casting

F50 resin for high-thickness mass-casting

Keywords: Axson, Resins, Casting, Coating

Axson informs us that it has widened its range of rapid setting polyurethane resins by developing F50, said to enable the production of models, negatives or tools requiring very thick castings.

F50 comprises a resin and a hardener that are mixed in a 2:1 ratio, while gradually adding an appropriate filler, chosen for both the required application and the volume of the casting. F50 is said to allow very thick castings of up to 400mm. According to Axson it is remarkable for its very low linear shrinkage and exothermic reaction, its excellent bonding to itself in successive castings, and its low viscosity even with high proportions of filler.

No special equipment is required for its preparation and its mechanical properties are claimed to be excellent. F50 can be coloured or pigmented and is compatible with various fillers, such as alumina trihydrate, aluminium or chopped glass fibre, used to increase its mechanical properties for a range of applications.

Some applications require particularly strong working surfaces, especially for foundry tools. Axson has developed S69, a polyurethane-based gelcoat or surface coating, for such situations. This reportedly allows the mechanical properties of tools made with F50 to be strengthened, in particular their resistance to abrasion and impact. Axson markets also a wide variety of fillers, colourants and mould release agents, all compatible with F50.

Used with a mineral filler and applied with S69 gelcoat, F50 is used to make patterns and negative moulds by direct casting in foundries. Core boxes for sand cores can also be produced. Used with S69 gelcoat, F50 is also said to enable significant time and cost savings in making foundry tools for bulky parts. With significant mechanical properties, castings made with F50 using an aluminium-based filler can be used as die-stamps for prototype metal parts such as 1.5mm steel sheet. These models can also be used to produce matrices and clamp frames, with the die being made in machinable board.

Fabrication of die-stamping tools with F50 is thought to be an excellent alternative to polymer concrete composites, as tools can be more easily machined. F50 is also believed to provide a better solution than the superposition of machinable boards, which, although certainly easily machined, require gluing and assembly that can be tedious.

Thermoforming tools (dies) can be made using the F50 associated with an aluminium filter. The F50 is then considered to combine four major advantages: low cost, very rapid stripping of model moulds, low material shrinkage, and faster polymerisation times. Other applications include hammer-forming and positioning tools, conveyor parts, counterweights, jigs, checking fixtures, stretch forming tools, stabilisers, and machinable boards.

Details available from: Axson. Tel: +44 (0) 20 7235 5330; Fax: +44 (0) 20 7235 2773.