This article outlines the top 20 standards for testing the viscosity and cure of rubber, elastomers and polymers in general, using a Mooney Viscometer, Moving Die Rheometer and dynamic shear rheometer (Multi-Function Rheometer). For more information on any of the instruments featured in this article, follow this links at the bottom of the page.
The rubber industry spans from the smallest producers to the largest compounders, across all continents and regions. As a global industry, it is essential for all parties involved to reliably know both the material composition and performance characteristics of any given rubber. With such a variety of raw polymers, compounds and bespoke formulations within a global supply chain, it is necessary to standardise the material assessment of rubber product to ensure continuity and integrity throughout.
International and National Standards Abbreviations
Most countries have their own organisations which act to organise national standards. In the UK, the national standards body is the British Standards Institute (BSI). To promote the exchange of international goods and services, the BSI is one of the over 140+ national standards bodies that form the International Organization for Standardization (ISO). Many BSI standards have been adopted by ISO and vice-versa, meaning that there is an equivalence between two standards. This extends to standards between countries who both adhere to ISO, so that two national standards, for example BSI and DIN (for Germany), are linked by the ISO equivalent and therefore comparable.
All standards used in the rubber industry are international, but many are still referred to using the national standards nomenclature. After ISO, the second most-commonly used format is ASTM.
|ISO||International Organization for Standardization||International|
|BSI||The British Standards Institute||United Kingdom|
|ASTM||The American Society for Testing and Materials||United States|
|DIN||The German Institute for Standardisation||Germany|
|AFNOR||Association Française de Normalisation||France|
|GOST||The State Union Standard||Russia|
|JIS||Japanese Industrial Standards||Japan|
Rubber Viscosity Testing Standards
Within the rubber industry, the viscosity of uncured rubber is expressed using Mooney Units (MU), an arbitrary, unitless scale that is measured using a Mooney Viscometer. Although this viscometer is specific to the rubber industry, the instrument and technique are firmly established throughout the rubber industry, with a long history of use.
Rubber technologists use viscosity testing standards to measure uncured rubber viscosity, which can be used to gauge the quality of a raw polymer. The Mooney viscosity can also be used to determine processability characteristics.
ISO 289 / ASTM D1646
This standard outlines the methods and procedures for measuring the Mooney Viscosity of a an uncured sample of rubber, including rotor dimensions, test temperature and sample size. In addition, ISO 289 covers test methods for Stress Relaxation and Pre-Cure Characteristics (Scorch Time).
Most Mooney Viscometer instruments are pre-programmed for industry standard tests, including ISO 289. For full specification details, view more information on the Mooneyline Mooney Viscometer.
Follow the links below to view the complete standard scope:
· DIN 53523 Rubber, Unvulcanized – Determinations Using A Shearing-Disc Viscometer
· BS 903 Physical Testing of Rubber – Part A58 Methods Using The Mooney Viscometer
· AFNOR T43-00/005 Rubber, Unvulcanized – Determination of Mooney Viscosity
· BS 1673 Methods Of Test For Raw Rubber And Unvulcanized Compounded Rubber
· GOST 10722-76 Rubber And Rubber Compounds – Test Methods For The Determination Of Viscosity And Tendency To Scorching
· JIS K6300 Physical Testing Methods for Unvulcanized Rubber
Rubber Cure Testing Standards
During the cure process, rubber undergoes both physical and chemical changes that fundamentally alter its material properties. It is important to understand both how this process occurs, and how the material changes during and after vulcanisation. Another important consideration is that for many applications, the cure process is one part of a larger manufacturing process. Therefore, it may be necessary to accelerate or delay the curing process depending on the surrounding processes.
Rubber technologists use rubber testing standards to explore cure properties, optimise their formulations and to increase production efficiency.
ISO 6502 / ASTM D 5289
This standard puts forward the test method and procedure for evaluating the cure properties of vulcanisable rubber compounds using a rotorless curemeter, more commonly known as a Moving Die Rheometer. These test methods are used for quality control, research and development and material evaluation.
Most Moving Die Rheometers (MDRs) are pre-programmed to work alongside international standards, such as ISO 6502. To find out more about an MDR and view the full instrument specification, head to the Rheoline Moving Die Rheometer page.
Follow the links below to view the complete standard scope:
· DIN 53529 Testing Of Rubber And Elastomers; Measurement Of Vulcanization Characteristics (Curometry); General Working Principles
Further and Advanced Standards
While ISO 6502 / ASTM D 5289 covers the main testing procedures used with a rotorless curemeter such as a Moving Die Rheometer (MDR), there are many other additional standards. These either concern areas of concern, such as material handling, or more advanced areas of material characterisation.
Some of these test methods can be performed on a standard Moving Die Rheometer (MDR). However, other test procedures require a more powerful instrument, called a dynamic shear rheometer. For more information on advanced rheology, and the full details, visit the Rheoline Multi-Function Rheometer (MFR) page.
· ISO 13145 Rubber — Determination Of Viscosity And Stress Relaxation Using A Rotorless Sealed Shear Rheometer
· ASTM D 6204 Standard Test Method for Rubber—Measurement of Unvulcanized Rheological Properties Using Rotorless Shear Rheometers
· ASTM D 6601 Standard Test Method for Rubber Properties—Measurement of Cure and After-Cure Dynamic Properties Using a Rotorless Shear Rheometer
· ASTM D 6048 Standard Practice for Stress Relaxation Testing of Raw Rubber, Unvulcanized Rubber Compounds, and Thermoplastic Elastomers
· ASTM D 7050 Standard Practice for Rubber from Natural Sources—Sampling and Sorting Bales Based on Predicted Processing Properties
· ASTM D 7605 Standard Test Method for Thermoplastic Elastomers—Measurement of Polymer Melt Rheological Properties and Congealed Dynamic Properties Using Rotorless Shear Rheometers
· ASTM D 8059 Standard Test Method for Rubber Compounds—Measurement of Unvulcanized Dynamic Strain Softening (Payne Effect) Using Sealed Cavity Rotorless Shear Rheometers
The table below summarises all the major standards associated with viscometer and rheometers for use with rubber, elastomers and polymers in general. Included in the table are the standard number, national or international standards body, full name and the associated rubber testing instrument.
|ISO 289||Rubber, Unvulcanized – Determination of Mooney Viscosity||Mooney Viscometer|
|ASTM D1646||Standard Test Methods for Rubber—Viscosity, Stress Relaxation, and Pre-Vulcanization Characteristics||Mooney Viscometer|
|DIN 53523||Rubber, Unvulcanized - Determinations Using A Shearing-Disc Viscometer||Mooney Viscometer|
|BS 903||Physical Testing of Rubber – Part A58 Methods Using The Mooney Viscometer||Mooney Viscometer|
|AFNOR T43-00/005||Rubber, Unvulcanized – Determination of Mooney Viscosity||Mooney Viscometer|
|BS 1673||Methods Of Test For Raw Rubber And Unvulcanized Compounded Rubber||Mooney Viscometer|
|GOST 10722-76||Rubber And Rubber Compounds - Test Methods For The Determination Of Viscosity And Tendency To Scorching||Mooney Viscometer|
|JIS K6300||Physical Testing Methods for Unvulcanized Rubber||Mooney Viscometer|
|ISO 6502||Measurement Of Vulcanization Characteristics Using Curemeters||Moving Die Rheometer / Dynamic Shear Rheometer|
|ASTM D 5289||Standard Test Method for Rubber Property—Vulcanization Using Rotorless Cure Meters||Moving Die Rheometer / Dynamic Shear Rheometer|
|DIN 53529||Testing Of Rubber And Elastomers; Measurement Of Vulcanization Characteristics (Curometry); General Working Principles||Moving Die Rheometer / Dynamic Shear Rheometer|
|ISO 13145||Rubber — Determination Of Viscosity And Stress Relaxation Using A Rotorless Sealed Shear Rheometer||Dynamic Shear Rheometer|
|ASTM D 6204||Standard Test Method for Rubber—Measurement of Unvulcanized Rheological Properties Using Rotorless Shear Rheometers||Dynamic Shear Rheometer|
|ASTM D 6601||Standard Test Method for Rubber Properties—Measurement of Cure and After-Cure Dynamic Properties Using a Rotorless Shear Rheometer||Dynamic Shear Rheometer|
|ASTM D 6048||Standard Practice for Stress Relaxation Testing of Raw Rubber, Unvulcanized Rubber Compounds, and Thermoplastic Elastomers||Dynamic Shear Rheometer|
|ASTM D 7050||Standard Practice for Rubber from Natural Sources—Sampling and Sorting Bales Based on Predicted Processing Properties||Dynamic Shear Rheometer|
|ASTM D 7605||Standard Test Method for Thermoplastic Elastomers—Measurement of Polymer Melt Rheological Properties and Congealed Dynamic Properties Using Rotorless Shear Rheometers||Dynamic Shear Rheometer|
|ASTM D 8059||Standard Test Method for Rubber Compounds—Measurement of Unvulcanized Dynamic Strain Softening (Payne Effect) Using Sealed Cavity Rotorless Shear Rheometers||Dynamic Shear Rheometer|
Within the rubber industry, there are a collection of about 20 standards concerning the viscosity and cure of rubber that are used extensively throughout the industry. These test procedures are carried out on either a Mooney Viscometer, Moving Die Rheometer or dynamic shear rheometer (Multi-Function Rheometer). Long-established and used worldwide, these standards offer touchpoints of comparison across global supply chains, maintaining quality and efficiency throughout.
For further information on any of these instruments, follow the links below to view the full product specifications. Alongside these products, Prescott Instruments offer full training and bespoke rubber consultancy to help you get the most out of your laboratory. To get started, view all products and services, or get in touch.