Plastic moulding compounds

Polymeric Beads, Expandable Polystyrene Beads, Expandable Plastics Moulding Compound A moulding material in bead or granular form consisting predominantly of polystyrene, poly(methyl methacrylate) or other polymeric material and containing 5% to 8% of a volatile hydrocarbon which is predominantly pentane. During storage a small proportion of this pentane is released to the atmosphere this proportion increases at elevated temperatures. IMO 9036... 

The large-scale industrial synthesis of organic cellulose esters is practically restricted to the production of esters from a few aliphatic fatty acids with up to four carbon atoms, namely cellulose acetate (CA), cellulose acetate propionate (CAP), and cellulose acetate butyrate (CAB) [22], Typical degrees of substitution for plastic moulding compounds are presented in Table 3.1 with data calculated from ref. [22],... 

Therefore, in order to produce plastic moulding compounds with reasonable melt flow characteristics, as a rule, 15 to 35% plasticizer is added for CA and 3 to 25% for CAP and CAB [22]. In Figure 3.11 the melt flow index (MFI), as a measure of melt viscosity, is shown for typical cellulose ester moulding compounds as a function of plasticizer content. Obviously, as expected, the esters with longer side chains are more flexible and need considerably less plasticizer than the shorter chain esters to reach the same flowability at a given temperature. 

ISO 10352, Fibre reinforced plastics— Moulding compounds and prepregs, determination of mass per unit area, 1991. 

To obtain a strong busbar mounting system, suitable to withstand the electrodynamic forces arising out of a system fault, modern practice is to make use of thermosetting plastics, such as DMC (Dough Moulding Compounds)... 

At the present time aminoplasts comprise moulding compounds based on amine resins (thermosetting condensation products of formaldehyde with carbamide or melamine or a combination thereof) and organic or mineral fillers or a combination thereof doped with dyestuff and modifying substances (plasticizers, stabilizers, crosslinking agents, and the like). 

W. Blakey, The history of aminoplastics The sixth Chance Memorial Lecture of the Society of Chemical Industry, Chemistry and Industry, (25 July 1964), 1349-1357, on p. 1352. Blakey received a D.Phil. in organic chemistry from Kings College, Cambridge, in 1928, and shortly after joined British Cyanides to undertake research into aminoplastic moulding compounds. Blakey was appointed chairman of British Industrial Plastics in 1962, one year after the firm was merged with Turner Newall Ltd. This lecture is an extremely useful source of information on aminoplastic developments. See also C.P. Vale and W.G.K. iy oi Aminoplastics (London Iliffe Books, 1964), which includes a historical introduction, and a portrait of Hanns John who in 1918 patented the first industrial use of urea-formaldehyde resins. 

Reinforced plastics first became commercially available in the 1940s. Unsaturated polyester reinforced with fibrous glass is the most widely used reinforced plastic today. Chopped glass mats are used for sheet moulding compounds (SMC), bulk moulding compounds (BMC) and hand lay-up composites. 

The valid and mostly used standard series for the tensile test of plastics is the ISO 527 Plastics - Determination of tensile properties. The specimens used for this preferred standard are shown in Fig. 4.2 depending on the kind of plastics. The specimen type lA well known as multipurpose specimen is the basic specimen corresponding to ISO 3167 which can be used for the characterization of moulding compounds [ISO 527-2], against what specimens type 2 and 4 are typically for films and sheets [ISO 527-3]. Type 5 specimens, also called spoon-like specimens, are preferred for testing of ductile materials with high... 

Figure 3.11 Melt flow index of cellulose ester moulding compounds as a function of plasticizer content. (Data calculated from ref 122].)...

Phenolic plastics. Collective designation for phenolic resin-based plastics. Phenolic resins are produced by condensation of phenol and/or its homologues, such as cresol, with an aldehyde, such as formaldehyde or with an aldehyde-releasing material such as hexamethylenetetramine. Phenol/formaldehyde and/or cresol/formaldehyde resins are used as binding materials in fibre board, laminated paper and fabrics. In phenolic moulding compounds, the proportion of filler (such as wood flour, rock flour, asbestos, stone powder, mica, glass fibre) can be equal to that of the resin. These thermosets can be processed by compression or injection moulding into black or dark-coloured products mainly for the electric industry. 

Fig. 2.22 Temperature dependence of oxygen index for various plastics 1 rigid PVC, can not be measured above 105 due to softening 2 asbestos-filled phenol/form-aldehyde moulding compound 3 epoxy-modified melamine moulding compound 4 phenol/ formaldehyde moulding compound filled with wood flour 5 glass fibre-filled epoxy resin moulding...

Reinforcement fibres—Sampling plans applicable to received batches Plastics—Prepregs—Definitions of terms and symbols for designations Textile glass reinforced plastics—Sheet moulding compound (SMC)—Basis for a... 

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 following account of how the newly developed headlamps were evaluated is taken from The development of a dough moulding compound for headlamp reflectors , in the Lucas publication Plastics Headlamps . 

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