ISO 294-5-2017 pdf free download

ISO 294-5-2017 pdf free download.Plastics Injection moulding of test specimens of thermoplastic materials
Part 5:Preparation of standard specimens for investigating anisotropy
Plastiques — Moulage par injection des éprouvettes de inatériaux thermoplastiques — Partie 5: Preparation d’éprouvettes normalisées pour determiner l’anisotro pie.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 294-1 apply.
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4 Apparatus
4.1 Type F ISO mould
Plates shall be moulded in a two-cavity type F ISO mould (see Figures 1 and 2). The preferred mould dimensions shall be such that the plates produced measure 80 mm x 120 mm (minimum:
80 mm x 90 mm) (the actual length and width of the mould will vary slightly because of the different shrinkage of different materials).
The preferred thickness is 2 mm, but other thicknesses may be used. A thickness of 2 mm Is representative of the actual wall thickness of many mouldings and gives a skin-thickness to core- thickness ratio corresponding to the maximum anisotropic properties. Other thicknesses may be used to give different skin-thickness to core-thickness ratios.
d) and e), not applicable;
1) see ISO 294-1:2017, 4.1.1.4, item F);
g) not applicable (see Figurc 2)
h), i), j) and k) see ISO 294-1:2017, 4.1.1.4. items h), I), j) and k);
I) to n) see ISO 294-1:2017, 4.1.1.4. items I) to n).
4.2 Injection-moulding machine
As specified in ISO 294-1:2017, 4.2, with the following exception In ISO 294-1:2017, 4.2.5.
The projected area of the preferred mould cavity Ap is 80 mm x 120 mm = 9 600 mm2. The total projected for a two-cavity mould area is therefore 19 200 mm2 + projected area of runners = approx. 20 000 mm2.
For a maximum mould-locking force. Fmax, of 100 metric tons (981 kN) and a value of 4 of 20 000 mm2, the maximum injection pressure is given by Formula (1):
Pmaz = Fmax/Ap = 981 kN/20 000 mm2 = approx. 50 MPa (1)
5 Procedure
5.1 Conditioning of material As specified in ISO 294-1:2017, 5.1.
5.2 Injection moulding
As specified in ISO 294-1:2017, 5.2, but with the following new text in ISO 294-1:2017, 5.2.2.
It has been found that the skin-thickness to core-thickness ratio changes with injection velocity. The slower the rate of injection, the thicker the skin (i.e. the thinner the core) and the greater the anisotropic alignment of the fibres. Also, the skin-thickness to core-thickness ratio changes with plate thickness. The thinner the plate, the thicker the skin (i.e. the thinner the core) and the greater the anisotropic alignment of the fibres. In addition, thin plates are less sensitive to changes in the injection velocity. Generally, if the ratio of the tensile modulus in the cross direction to that in the flow direction approaches 0,5, this indicates maximum anisotropy.
For type F ISO mouldings, it may be desirable to use more than one injection velocity. ISO 294-5-2017 pdf free download.