Introducing TAPPI T550 - Industrial Physics  

TAPPI T550 is a TAPPI industry standard method that’s used to determine equilibrium moisture in pulp, paper and paperboard for chemical analysis. 

This TAPPI moisture content testing procedure applies to most pulp, paper, paperboard, and paper products. However, it’s not suitable for samples that contain significant quantities of materials other than water that are volatile at 105 ± 2°C, or less. Plus it’s not the right TAPPI test for materials that are oxidized or decomposed above 102°C. 

The TAPPI T 550 testing process 

The TAPPI T 550 standard guidance lays out the method to follow to calculate the results of a chemical analysis of pulp, paper and paperboard on a moisture-free basis. 

Apparatus for TAPPI T 550 

To perform a successful TAPPI T550 paper test you’ll need: 

• A weighing container, a wide-mouth, glass-stopper weighing bottle  
• A drying oven that will control the temperature at 105 ± 2°C 

The TAPPI T 550 method 

First the pulp, paper and paperboard samples - plus duplicates - are prepared in accordance with the TAPPI T 402 standard approach. They should be cut from unsealed and unprinted sections. 

Next up, you weigh the specimen in the weighing bottle to the nearest milligram. Then you place it in the drying oven, remove the stopper and heat for the time prescribed in the TAPPI T 550 standard.  

From here you put the restopper in the bottle, remove it from the oven and cool to room temperature in a desiccator. The TAPPI standard advises you loosen the stopper momentarily to allow air in - then you reweigh.  

A second drying period follows until two successive weighings don’t differ by more than 0.1% of the weight of the specimen.  

TAPPI T 550 reporting 

Now here’s the interesting bit - how to work out your TAPPI T 550 results!  

You do this by calculating the moisture for each specimen as the percentage loss of the original weight of the specimen, to the nearest 0.1%. Repeat the process as recommended using your duplicate sample(s) and report the average moisture content testing result.  

TAPPI T 550 testing devices  

So, how can Industrial Physics improve your TAPPI T550 testing? 

Coefficient Friction/Peel Tester 32-76e 

Our horizontal bed coefficient of friction tester is the definitive method for measuring the static and dynamic coefficient of friction for a wide range of paper, corrugated, flexible films, rigid plastics and other engineered surfaces.  

Made by Testing Machines Inc, the 32-76e offers unparalleled performance and flexibility for paper testing across a wide range of standards including TAPPI T 550. 

We also build additional options for our reliable coefficient of friction and peel tester including the 180-degree peel accessory. 

Your global test and inspection partner for TAPPI T 550