History of Paper Research Materials
We thank you for your interest in our web site. If youíre here, you are either interested in papermaking wetend chemistry or youíre curious as to whether a Britt Jar is a object díart or a special form of seismic aftershock. We are papermakers and the following is a short history of the development of the Britt Jar and the papermaking application it fulfills.
The Britt Jar was developed to study how chemicals added to the wetend system of a paper machine effect the retention of fines solids during the papermaking operation. Fines are the mineral and cellulose solids (less than 76m in diameter) that pass through the forming fabric during paper manufacture. In the late 1960ís new retention aids (water soluble polymers that carry charge) were being introduced to the paper industry at a phenomenal rate. At that time the effectiveness of these retention aids was being evaluated by either making handsheets or directly on the papermachine. Because the handsheet is formed in a low shear environment, all additives, including alum, deliver high levels of fines retention. It was difficult to differentiate between retention aids of different charge and molecular weight. In addition, the results did not correlate directly with those seen on papermachines. This was due to the fact that, in contrasts to a handsheet, a commercial sheet was formed on the papermachine in a dynamic, high shear environment. Testing directly on the papermachine, although being a true test of performance, proved to be risky (sheet breaks, unacceptable formation, contamination of the white water system) and expensive.
In the early 1970ís, research being carried out on retention and drainage by Ken Britt and John Unbehend at the Empire State Paper Research Institute at Syracuse, New York, led them to develop a device that would more closely mimic the retention and drainage responses they had observed in their work with water soluble polymers in the lab and on various papermachines. Kenís original interest, sparked by work he had done on papermachine water removal during his many years in the paper industry, was to learn about drainage under dynamic conditions. This new device, the Britt Jar, soon proved to be more useful in measuring fines contents of papermaking stock system as well as the retention of fines. Not only did this provide an excellent means of rating the effectiveness of retention aids, it also proved to correlate well with the retention responses seen with additives on papermachines.
Although the drainage work was de-emphasized at this time, one hold over of the original work was the name original coined to describe the equipment: The Britt Dynamic Drainage Jar. This has been a source of confusion through the years in that scientists seeking to measure drainage with this device would be told that the primary function of the device is the measurement of fines retention.
The Britt Jar has been used extensively through out the industry as a quick, accurate and uncomplicated way of studying fines retention. It has been used by those carrying out research on polymer additives and retention aids because of its ability to mimic performance on the papermachine. Those in the sales / service end of the industry have found it to be an excellent way of demonstrating the effectiveness of their chemical additives to the papermaker. The papermaker has used it to great effect to screen the wide variety of chemicals that are offered. It also insures that before these materials are trialed on the papermachine they will not interfere with the action of other additives in the system.
In the past 35 years over 2500 Britt Jars have been sold through out the world. It has become the standard in the industry (Tappi Standard-261) for the evaluation of chemical additive performance. It has given colloid chemists, papermakers, chemical sale technicians, and paper chemists a tool to study the dynamics of the wetend of a papermachine. This in turn has allowed a clearer understanding of the molecular interactions and the ultimate performance of polymer additives on the papermachine.