56 MARINE PRODUCTS OF COMMERCE 



The Manufacturing Process. Production procedures vary among Irish moss 

 processors in many minor details and in a few major respects. In general the pro- 

 cedure outlined in the following is that used by a factory at New Bedford, the 

 largest processor of Irish moss in the United States. 



Bales of raw material are first sampled by laboratory technicians to determine 

 the nature and amount of the carrageenin content, an important step in main- 



{Courtesy McGrazv-Hill Publishing Co.) 



Fig. 5-2. The first step in the manufacture of Irish moss 

 extractive is to blend various lots of the dried "moss" in ac- 

 cordance with laboratory analyses. Then it is fed through a 

 tube that empties into a cooker on the floor below. 



taining uniformity of the finished product. The moss is then added to the cooker 

 where it is briefly washed with cold fresh water to reduce the salt content and 

 remove other impurities. In cooking 2 to 4 parts of dry seaweed to 100 parts of 

 water are used, depending upon the results of the test on the raw material. 



When a batch has finished cooking, the carrageenin solution and seaweed 

 residue are separated by a centrifuge and the residue is saved and cooked again. 

 The partially clarified solution, containing 0.8 to 1.0 per cent carrageenin, is sent 

 to stainless steel filter-slurry tanks in which it is constantly agitated while diatoma- 

 ceous earth filter aid and activated carbon are added. It is next pumped through 

 a plate-and-frame filter press to another tank. Filter aid is again added as the 

 solution is agitated, and the liquid is sent through a polishing filter. In the vacuum 

 evaporators about half of the water is removed, increasing the carrageenin concen- 

 tration to about 2.0 per cent. The solution is then fed to chrome-plated, double- 

 drum driers from which it is scraped in the form of dry flakes as the drums revolve. 

 The moisture content at this stage is only about 5 per cent. The flakes are passed 

 through a rotary cutter and finally groimd in a micro-pulverizer. Since the proper- 



