TAPPI T411

Introducing TAPPI T411 – Industrial Physics

TAPPI T 411 is a global TAPPI standard method that uses a digital micrometer to measure the thickness of single sheets of paper, paperboard or combined board. 

Thickness is a key property of paper, paperboard, or combined board. It’s important to understand variations in thickness when working with papers or paperboards used for mechanical purposes.  

A definition of thickness

Thickness or caliper of paper, paperboard, or combined board is defined as the perpendicular distance between the two principal surfaces of the paper or paperboard under prescribed conditions, as measured between hard metal platens.  

Why is paper thickness testing necessary?

Thickness testing is useful for research work, routine control, design of end-use products, and for acceptance testing for conformance to specifications. Thickness is also one of the important characteristics that affects flexural stiffness. 

Because of the relatively high pressure of 50 kPa (7.3 psi) used in the TAPPI T 411 test method, it’s not the best test for measuring tissue or other soft or low-density materials which could collapse under the pressure.  

TAPPI T 411 test specimens

For successful TAPPI T 411 testing prep, cut ten specimens from each unit of the sample. Each sample strip should be at least 40mm (preferably 80 mm for combined board) in its shortest dimension and at least 120mm in its longest dimension. 

The TAPPI T 411 testing process 

For best practice TAPPI T 411 testing, before using the digital micrometer, make sure that the pressure foot and anvil surfaces are clean. You’ll need to check that the digital micrometer has been calibrated and verified and make sure that the instrument is mounted on a solid level surface free from noticeable vibration.  

You’ll need to place the specimen on the anvil in such a way that all points on the peripheries of the contact surfaces are at least 6mm (12mm for combined board) from the edges of the specimen. Use your digital micrometer to measure the thickness of each specimen at five non-overlapping regular intervals in a line at right angles to the machine direction of the paper. 

TAPPI T 411 thickness testing devices

So, how can Industrial Physics improve your TAPPI T 411 thickness testing? 

Digital Micrometer 49-56
With the Digital Micrometer 49-56 from Messmer Büchel you’ll achieve accurate thickness measurements of a wide range of sheet-like substrates even at low pressures. A popular choice from our range of easy-to-use digital micrometers, it offers impressive accuracy within 0.001mm (0.00004in.) or 1% of paper thickness, whichever is better. And the instrument complies with the most demanding of international standards! 

Digital Micrometer 49-86

The Digital Micrometer 49-86 quickly and precisely measures the thickness and caliper of most sheet materials – from paper, fabric and films to plastic, metal and leather.   

Brought to you by TMI Büchel, our physical property materials testing brand, this reliable digital micrometer is designed for the thinnest of samples. It has a highly accurate measurement range of 0-0.050in. (0-1.27mm), making it the perfect automatically operated micrometer for paper. 

Need TAPPI T 411 testing solutions? Get in touch

We’ve learnt a thing or two about thickness testing over the decades. Now Industrial Physics is recognized as a brand that likes to bring new, innovative automatically operated micrometer technology to market. 

We like to share our knowledge and we’re here to help you to answer your questions about thickness testing. Across the knowledgebase section of our website we publish lots of blogs on related subjects.   

For example, you could try this blog on how to measure the thickness of paper. Then follow up with this piece that talks about micrometers – all you need to know or try this simple procedure to improve the precision of micrometers. 

If you have any questions about TAPPI T 411 and how we can help you with your thickness testing, then please just get in touch!  

Your global test and measurement partner for TAPPI T 411