Sub-Group
PTM - Physical Test Methods - 2005
Objectives
- To propose and maintain CORESTA Recommended Methods (CRMs) and related documents for the physical testing of tobacco, tobacco products and their components.
- To organise interlaboratory testing related to Objective 1.
The Physical Test Methods (PTM) Sub-Group is a Sub-Group of the Product Technology Study Group and was established in October 2005 under the name of Monitoring and Maintenance of Physical Test Methods (MMPTM) Sub-Group. It was renamed to its current name in April 2011. The PTM Sub-Group's revised objectives, as listed above, were approved by the Scientific Commission and the Board in June 2018.
Since its creation the PTM Sub-Group has made substantial progress towards these objectives. It has conducted numerous international collaborative studies, published CORESTA Recommended Methods, CORESTA Guides and Technical Reports.
The PTM Sub-Group usually meets twice per year and the meetings are attended by 15 to 20 participants representing cigarette manufacturers, suppliers of materials and instruments for the cigarette industry, analytical laboratories and research institutions.
Development and Maintenance of CRMs
The PTM Sub-Group developed a method (CRM 90) for the measurement of snus pouch sealing strength and carried out a collaborative study to assess the variability of the method. The CRM and technical report on the collaborative study were both published in March 2019.
In April 2014, CRM 77 on the determination of diffusion capacity was published. This publication finalised a development work of more than four years, which was originally triggered by the need to measure the diffusion capacity of bands on lower ignition propensity cigarette papers. Most of the work was carried out in a separate working group usually meeting in close connection to regular PTM Sub-Group meetings. Within the near future it is planned to revise this method and provide an updated version of the CRM.
In May 2019, the PTM Sub-Group launched work on the development of a CRM from measuring the crush strength of flavour capsules for filters. Flavour capsules have become a common component in the filter of many cigarettes, filter cigarillos and also heated tobacco products, and the force needed to break the flavour capsule is an important quality parameter to be determined. The work was completed in August 2020 and a CRM published, supported by a Technical Report.
The following CRMs are in the responsibility of the PTM Sub-Group.
- CRM 06: Determination of Ventilation - Definitions and Measurement Principles (revised Jan 2020)
- CRM 16: Lamina Strip Particle Size Determination
- CRM 17: Stem Content of Lamina Strips
- CRM 40: Determination of Air Permeability of Materials used as Cigarette Papers, Filter Plug Wrap and Filter Joining Paper including Materials having an Oriented Permeable Zone
- CRM 41: Determination of the Draw Resistance of Cigarettes and Filter Rods
- CRM 53: Determination of Paper Wrapper Burn Speed (revised Jan 2019)
- CRM 77: Determination of Diffusion Capacity by Measurement of CO2 Transfer Rate Through Material Used as Cigarette Papers and Cigarette Papers having an Oriented Zone of Reduced Diffusion Capacity (revised June 2019)
- CRM 90: Determination of Dry and Wet Sealing Strength of Pouches for Smokeless Tobacco and Derivative Products – Definitions and Measurement Principles (revised June 2019)
- CRM 94: Determination of Crush Strength of Flavour Capsules for Filters – Definitions and Measurement Principles
Development of CORESTA Guides
As a complement to CRMs, CORESTA Guides cover more practical aspects of the measurement of physical parameters of tobacco products and their components and help the users in applying CRMs. Guides are also developed to give an overview over measurement principles and to document best practices.
The last Guide published by the PTM Sub-Group is Guide No. 14 “A User Guideline for the Determination of the Diffusion Capacity (D*) of Cigarette Papers” which was developed and published in connection with CRM 77.
The PTM Sub-Group has published the following Guides:
- Guide No. 04 – A User Guideline for the Measurement of Pressure Drop of Cigarette and Cigarette Filter Rods (revised Jan 2019)
- Guide No. 06 – A User Guideline for the Use of Balances for Cigarettes and Cigarette Related Products (revised Jan 2020)
- Guide No. 10 – A User Guideline for the Measurement of Diameter of Tobacco Products and Filter Rods (revised March 2020)
- Guide No. 14 – A User Guide for the Determination of the Diffusion Capacity (D*) of Cigarette Papers (revised June 2019)
Inter-Laboratory Collaborative Studies
On the one hand inter-laboratory studies are usually carried out during the development of a CRM to determine repeatability and reproducibility of the newly developed method, but on the other hand they are also regularly carried out in the form of a proficiency test to allow laboratories to assess their performance with respect to other laboratories. Particularly for accredited laboratories, participation in such proficiency tests is required.
The PTM Sub-Group generally carries out an annual collaborative study on physical parameters, in which filter rods and cigarettes are measured for weight, diameter, pressure drop and ventilation. These studies are statistically evaluated and the results are made publicly available in form of a Technical Report. In 2020, the PTM Sub-Group is carrying out its 13th Collaborative Study on Physical Parameters. Usually about 15 to 25 laboratories participate in such a collaborative study.
An additional collaborative study was intiated in 2019 on air permeability. This project replaces and complements air permeability cross-checks, mentioned below, often done on a bilateral basis between paper suppliers and cigarette manufacturers.
Furthermore, a smaller number of PTM Sub-Group members maintain calibration laboratories. In order to assess the performance of their calibration laboratories, inter-laboratory studies are carried out regularly as round robin tests. In these studies calibration standards for pressure drop, air permeability and filter ventilation are circulated between the laboratories for measurement. The results are statistically evaluated and also made publicly available as a Technical Report. As the measurement of calibration standards is a high-precision method, which requires sophisticated equipment and a highly controlled laboratory environment, only a very few laboratories participate in these studies. Also, due the time required for the circulation of the calibration standards, the studies are often not carried out on an annual basis.
Reviewed January 2021
Technical Documents
Recommended Methods : No. 94 - Determination of Crush Strength of Flavour Capsules for Filters – Definitions and Measurement Principles 08/2020Recommended Methods : No. 77 - Determination of Diffusion Capacity by Measurement of CO2 Transfer Rate Through Materials Used as Cigarette Papers and Cigarette Papers having an Oriented Zone of Reduced Diffusion Capacity 06/2019Recommended Methods : No. 90 - Determination of Dry and Wet Sealing Strength of Pouches for Smokeless Tobacco and Derivative Products - Definitions and Measurement Principles 06/2019Recommended Methods : No. 53 - Determination of Paper Wrapper Burn Speed 01/2019Recommended Methods : No. 6 - Determination of Ventilation - Definitions and Measurement Principles 09/2016Recommended Methods : No. 41 - Determination of the Draw Resistance of Cigarettes and Filter Rods 06/2007Recommended Methods : No. 40 - Determination of Air Permeability of Materials used as Cigarette Papers, Filter Plug Wrap and Filter Joining Paper including Materials having an Oriented Permeable Zone 10/1994Reports : 13th Collaborative Study (2020) on Physical Parameters of Cigarettes and Filter Rods 01/2021Reports : 5th Round Robin Test for Air Permeability Calibration Standards 01/2021Reports : 4th Proficiency Test (2020) on Diffusion Capacity of Cigarette Papers 11/2020Reports : Collaborative Study on Crush Strength of Flavour Capsules for Filters 08/2020Reports : 7th Round Robin Test for Multi-Capillary Ventilation Calibration Standards (2018/2019) 01/2020Reports : 14th Round Robin Test for Multi-Capillary Pressure Drop Calibration Standards (2018/2019) 01/2020Reports : 12th Collaborative Study (2019) on Physical Parameters of Cigarettes and Filter Rods 01/2020Reports : 1st Collaborative Study on Air Permeability in Accordance with ISO 2965:2019 11/2019Reports : Collaborative Study on Sealing Strength of Pouch Materials 06/2019Reports : 6th Round Robin Test for Multi-Capillary Ventilation Calibration Standards (2017/2018) 03/2019Reports : 13th Round Robin Test for Multi-Capillary Pressure Drop Calibration Standards (2017/2018) 01/2019Reports : 11th Collaborative Study (2018) on Physical Parameters of Cigarettes and Filters 12/2018Reports : 4th Round Robin Test for Air Permeability Calibration Standards 10/2018Reports : 5th Round Robin Test for Multi-Capillary Ventilation Calibration Standards (2016/2017) 06/2018Reports : 10th Collaborative Study (2017) on Physical Parameters of Cigarettes and Filters 03/2018Reports : 12th Round Robin Test for Multi-Capillary Pressure Drop Calibration Standards (2016/2017) 11/2017Reports : 3rd Proficiency Test (2017) on Diffusion Capacity of Cigarette Papers 05/2017Reports : 4th Round Robin Test for Multi-Capillary Ventilation Calibration Standards (2015/2016) 04/2017Reports : 11th Round Robin Test for Multi-Capillary Pressure Drop Calibration Standards (2016) 04/2017Reports : 9th Proficiency Test (2016) for Physical Parameters of Cigarettes and Filters 04/2017Reports : 8th Proficiency Test (2015) for Physical Parameters of Cigarettes and Filters 02/2017Reports : 7th Proficiency Test (2014) for Physical Parameters of Cigarettes and Filters 02/2017Reports : 3rd Round Robin Test for Air Permeability Calibration Standards 12/2016Reports : 3rd Round Robin Test for Multi-Capillary Ventilation Calibration Standards (2014/2015) 11/2016Reports : Recommendation of Measurement Area for Air Permeability Determination of Super-Slim Cigarette Papers 09/2016Reports : 10th Round Robin Test for Multi-Capillary Pressure Drop Calibration Standards (2014) 08/2016Reports : 2nd Round Robin Test for Multi-Capillary Ventilation Calibration Standards (2013/2014) 08/2016Reports : 2015 Proficiency Test Report - The Measurement of Diffusion Capacity of Cigarette Papers 09/2015Reports : Collaborative Study to Evaluate a Paperboard Substitute for a Diffusion Capacity Standard 08/2015Reports : 2014 Proficiency Test Report - The Measurement of Diffusion Capacity of Cigarette Papers 07/2015Reports : 2014 Collaborative Study for the Determination of Repeatability and Reproducibility of CRM 77 06/2015Reports : Tobacco Moisture, Water and Oven Volatiles 07/2014Reports : Comparison of Ventilation Standard Calibration Methods 05/2012Reports : Recommendation of Measurement Area for Air Permeability of Super Slim Cigarette Papers 05/2012Reports : Hardness Measurement on Cigarettes and Cigarette Filter Rods 03/2011Reports : Physical Properties of Special Filters 11/2010Reports : MMPTM 2009 Interlaboratory Proficiency Test 08/2010Guides : No. 10 - A User Guideline for the Measurement of Diameter of Tobacco Products and Filter Rods 03/2020Guides : No. 6 - A User Guideline for the Use of Balances for Cigarettes and Cigarette Related Products 01/2020Guides : No. 14 - A User Guide for the Determination of the Diffusion Capacity (D*) of Cigarette Papers 06/2019Guides : No. 4 - A User Guideline for the Measurement of Pressure Drop of Cigarettes and Cigarette Filter Rods 01/2019