Hot press moulding

Yang et al used a low viscosity resin solution which was allowed to infiltrate the buckypapers to impregnate the SWNT rope networks. A hot-press moulding process was used for moulding and euring to produce the final composites. Nanocomposites with preformed tube networks and high SWNT... 

Compression moulding (hot press moulding) Moulding compounds (often complex mixtures, e.g. dough or bulk moulding compounds) prepared in Z-blade mixer and heated under pressure in closed mould Small to medium articles, especially electrical mouldings large capital outlay... 

Compression moulding or hot press moulding is one of the oldest processes, dating from the early history of the rubber industry, before plastics were developed. In recent years, much of the innovation has been stimulated by the use of new materials. 

Dough Moulding Compound (DMC)—A mixture of chopped fibres, fillers and thermosetting resin, used in hot press moulding and injection moulding. 

Hot Press Moulding—Heated matched dies are loaded with thermosetting compound and pressed together until cured. 

Autoclave/vacuum bag No Compression moulding Hot press moulding No... 

Hot press moulding is a mass production method for the manufacture of composite components. A hydraulic press is used capable of applying a pressure of about 100 tonnes/m of platen area. A matched metal tool is located between the platens, the cavity between the tool halves having been machined to produce the shape required. The tool is heated to about 130-170°C either from the heated platens or directly (by cartridge heaters, etc.). 

Hot press moulding can be carried out either using dry reinforcement to which a resin mix is added when in the tool or by the use of a previously produced compound of resin... 

In contrast to the hand lay-up process hot press moulding is ideally suited to long production runs of relatively small components. The moulding operation is as follows ... 

ERF Ltd of Sandbach, Cheshire produce lorry cabs clad with glass-reinforced plastics (GRP) panels. The panels are hot-press moulded from sheet moulding compound, (SMC) then fitted to the steel frame of the cab (the safety cage) using an ERF patented assembly technique. 

The final decision was to adopt hot-press moulded SMC components mounted on an all-steel frame. See Section 16.6.1 for costings. 

Cure promoters include metal compounds, for optimal cure hot press moulding acetylacetone, with ketone peroxides and cobalt accelerator for a short geltime, giving a fast cure at room temperature and at elevated temperature and tertiary dodecyl mercaptane, for a gradual cure and moderate peak exotherm, in filament winding. 

Distitron 330/25 An unaccelerated, orthophthalic resin offering good wettability, suitable for RTM manufacture. Also has application in cold-press moulding and in the manufacture of hot-press moulding compounds. ... 

An unaccelerated, high reactive, chemical resistant, isophthalic resin suitable for the manufacture of pultruded profiles exhibiting good mechanical properties. Can also be employed for the manufacture of hot-press moulding compounds and centrifugal casting. 

An unaccelerated, high reactive, orthophthalic resin for the manufacture of hot-press moulding compounds. 

Zein is not water-soluble because of its high nonpolar amino acid content. Zein solutions are thus obtained by solubilisation in a solvent (generally alcohol or a volatile oi anic solvent), or in an alkaline medium, sometimes with a soap supplement. Zein water dispersions (zein latex ) are now commercially available (e.g., OptaGlaze from Opta Food Ingredients Inc., Bedford, MA, USA). Another technique involves direct hot press moulding of zein, after decreasing the glass transition temperature (Tg) via the addition of plasticisers [33]. 

Another polymer used as a release agent in the glassfibre moulding industry is cellulose acetate, dissolved in acetone. PTFE and related fluorinated polymers can be sprayed on. Silicone release agents are effective with epoxy resins but not usually with unsaturated polyesters, except in hot press moulding. They are also ineffective with certain polyurethanes. 

The tools themselves heat up and quite rapid mould turn-round can be achieved on large mouldings. Finish is not as good as with hot press moulding and tool life is limited. 

---