TAPPI T547

Introducing TAPPI T547 – Industrial Physics

TAPPI T547 is an industrial testing method to measure the air permeance of paper and paperboard using what’s known as the Sheffield method.   

TAPPI is the technical arm of the American Paper & Pulp Association (APPA) and it gathers and disseminates information concerning production matters. 

So, what does air permeance testing offer? Also known as porosity testing, it reveals the air flow rate through unit area under unit pressure difference in unit time, under specified conditions. There are other types of porosity measurement available – including ISO 5636-5 which adopts the Gurley air permeance testing method.  

How do you carry out a Sheffield air permanence test?  

To carry out a Sheffield porosity test you first clamp a sample piece of paperboard or corrugated board between two rubber orifice plates. The absolute air pressure on one side of the porosity test piece is equivalent to atmospheric pressure. Then the difference in pressure between the two sides of the piece is maintained at a small, substantially constant, value.  

The air flow rate through the test area is determined and, by timing how long it takes for a set amount of air to pass through the sample, you can calculate the air permeance. So you can understand how porous the material is. 

The TAPPI T457 air permeance testing approach

The TAPPI T547 test measures the air permeance of a circular area of paper using a pressure differential of approximately 10 kPa (1.5 psig). In order to accommodate a wide range of paper products, rubber clamping plates are available for five commonly used orifice diameters:  

• 9.5 mm (0.375 in.) 

• 19.1 mm (0.75 in.) 

• 38.1 mm (1.50 in.) 

• 57.2 mm (2.25 in.) 

• 76.2 mm (3.00 in.).  

The air flow range for this method is 0 to 3348 mL/min (0 to 400 Sheffield units). Instruments are available with either variable area flowmeters (glass tubes with internal tapers and floats) or electronic mass flowmeters. 

Industrial Physics’ TAPPI T547 paper testing equipment  

So, how can Industrial Physics improve your TAPPI T547 air permanence testing? 

Across the entire supply chain, having the right paper testing equipment in place is critical. We can help you to meet international paper testing standards such as TAPPI T547 with our industry-leading equipment and advice.  

With TAPPI T547 specifically in mind, check out the Messmer Büchel Sheffield Type Smoothness Gauge. And be sure to check out the full portfolio of Industrial Physics porosity testing devices and accessories.  

Need paper testing solutions? Get in touch

At Industrial Physics, we’ve specialized in the design and manufacture of test and measurement devices for the paper and pulp industries for almost 100 years and have a wealth of experience behind us. 

Across the knowledgebase section of our website, we publish lots of blogs on related subjects. Why not start with our quick guide to paper pulp evaluation? Then you could move onto this blog on sample preparation for paper testing. 

If you have any questions about TAPPI T547 testing, then just get in touch!  

Your global test and measurement partner for TAPPI T547