This document specifies a method for determining the drawing and break characteristics of molten plastics. The method involves the measurement of the force generated in deforming a molten filament under defined extrusion temperature and drawing conditions.<\/p>\n
Data is generated under non-isothermal and non-homogeneous deformation conditions. However, it is useful for the interpretation of polymer behaviour in extensional flow.<\/p>\n
The method is suitable for thermoplastics moulding and extrusion materials that can be extruded using a capillary extrusion rheometer, or an extruder with capillary rod die or other extrusion devices and have sufficient melt strength to be handled without difficulty.<\/p>\n
The method is applicable to chemically stable materials that produce a uniform extrudate free from heterogeneities, bubbles, unmelted impurities, etc.<\/p>\n
This method can provide information on<\/p>\n
processability for all extrusion techniques,<\/p>\n<\/li>\n
the effect of mechanical and thermal history, and<\/p>\n<\/li>\n
the effect of chemical structure, such as branching, entanglements and molecular mass.<\/p>\n<\/li>\n<\/ul>\n
This technique is one of a number of techniques that can be used to measure the extensional flow behaviour of a material. This method of measurement does not necessarily reproduce the drawing conditions to which thermoplastics are subjected to during their processing.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | National foreword <\/td>\n<\/tr>\n | ||||||
| 6<\/td>\n | Foreword <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | 4 Principle 5 Apparatus 5.1 Apparatus for heating the polymer and forming the extrudate 5.1.1 General 5.1.2 Capillary extrusion rheometer <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 5.1.3 Extruder <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 5.2 Apparatus for drawing the polymer extrudate 5.2.1 Drawing unit 5.2.2 Drawing unit design <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 5.3 Data-acquisition system 6 Calibration 6.1 General 6.2 Test temperature 6.3 Capillary or rod die 6.4 Drawing-force transducer 6.5 Drawing velocity and drawing acceleration 6.6 Drawing length <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 7 Sampling 8 Procedure 8.1 Cleaning the apparatus 8.2 Rheometer or extruder preparation <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 8.3 Loading the capillary rheometer barrel 8.4 Preheating <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 8.5 Running the extruder 8.6 Preliminary checks of the extrudates 8.6.1 Absence of defects 8.6.2 Check on drawing down under gravity <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 8.7 Determination of the extrudate behaviour 8.7.1 Determination of the mean velocity 8.7.2 Determination of the drawing force as a function of the drawing velocity <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 8.7.3 Measurement of melt strength <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 9 Calculation and expression of results 9.1 Initial cross-sectional area of the extrudate 9.2 Initial velocity 9.3 Drawing velocities <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 9.4 Drawing forces 9.5 Draw ratio 10 Precision 11 Test report 11.2 General: 11.3 Material and test conditions: <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 11.4 Test results: <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Plastics. Determination of drawing characteristics of thermoplastics in the molten state<\/b><\/p>\n |