What is ISO 16790 about?  
ISO 16790 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.
Data is generated under non-isothermal and non-homogeneous deformation conditions.
The method is suitable for thermoplastic moulding and extrusion materials that can be extruded using a capillary extrusion rheometer, an extruder with capillary rod dies or other extrusion devices and have sufficient melt strength to be handled without difficulty.
Note1: The method is applicable to chemically stable materials that produce a uniform extrudate free from heterogeneities, bubbles, unmelted impurities, etc. 
Note2: This method of measurement does not necessarily reproduce the drawing conditions to which thermoplastics are subjected during their processing.
Who is ISO 16790 for? 
ISO 16790 on drawing characteristics of thermoplastics is relevant to:
- Plastic and polymer manufacturers
- Polymer scientists
- Plastic/polymer testing laboratories
- Chemical engineers  
Why should you use ISO 16790?  
Drawing is the process of stretching a filament of polymer melt that is being continuously formed by a capillary extrusion rheometer or extruder or other extrusion device. In ISO 16790, you can evaluate the drawing and break characteristics through a standardized test method. This method can provide information on:
- Processability for all extrusion techniques
- The effect of mechanical and thermal history
- The effect of chemical structure, such as branching, entanglements and molecular mass
If you are a manufacturer of thermoplastics, this assessment, in compliance with ISO 16790 can be beneficial in determining the durability and fatigue-resistance of your products. It is useful for the interpretation of polymer behaviour in extensional flow. The evaluation can also be important from the point of view of your product development initiatives for newer applications and uses.
What’s changed since the last update?
BS ISO 16790:2021 supersedes BS ISO 16790:2005, which is withdrawn. BS ISO 16790:2021 includes some technical changes with respect to BS ISO 16790:2005. These include: 
- The normative references have been updated
- The figure keys have been completed
- The test procedure and parameters have been revised
