DS/EN ISO 294-5:2017

Plast - Sprøjtestøbning af prøveemner af termoplastmaterialer - Del 5: Forberedelse af standardprøver til bestemmelse af anisotropi


Status:
Gældende
Type:
Standard
Sprog:
EN
Pris fra:
kr. 423,00

Beskrivelse

This part of ISO 294 specifies a mould (designated the type F ISO mould) for the injection moulding of
80 mm  ≥ 90 mm plates with a preferred thickness of 2 mmwith a preferred size of 80 mm x 120 mm for
single-point and multi-point data acquisition because 2 mm has been found to provide the maximum
anisotropic properties, with only a slight sensitivity to the rate of injection. When ever possible a two cavity
mould shall be used. For the design of plastic parts, this will provide upper and lower bounds for the tensile
properties. Matching the plate thickness to a given part thickness is not a suitable criterion because of the
effect of mould filling rate and part geometry on anisotropy. Suitable test specimens [ISO 20753 type A22
tensile test specimens or type 1 (80 mm  10 mm) bars] are then machined or die-cut from the plates (see
Annex A) and used to obtain information on the anisotropy of thermoplastic parts.
Investigation of the anisotropy of materials is a special procedure intended to provide guidance in the design
of mouldings for end-use applications and is not intended as a quality control tool.
In the injection moulding of thermoplastic materials, the flow of molten polymer may influence the orientation
of fillers such as fibreglass or the orientation of polymer chains. This can result in anisotropic behaviour. The
knowledge of anisotropic behaviour is valuable in designing plastic parts.
For the purposes of this part of ISO 294, the flow direction is defined as the direction from the gate to the far
end of the mould cavity, and the cross direction as the direction perpendicular to the flow direction.
The type F mould is not intended to replace the type D mould used to determine the moulding shrinkage of
thermoplastics.


Antal sider: 20

Udgivet: 2017-12-21

Godkendelsesdato: 2017-12-19

Internationale relationer : EN ISO 294-5:2017 IDT ISO 294-5:2017 IDT

ICS: 83.080.20 - Termoplastiske materialer

Varenummer: M298994


Udvalg og komiteer

Komite

  • CEN/TC 249
  • ISO/TC 61/SC 9
  • ISO/TC 61/SC 9
  • ISO/TC 61/SC 9/WG 18
  • ISO/TC 61/SC 9/WG 18

Dansk udvalg

DS/S-872