Day 8 – Visit to SAICA Mill
Day 8 – by Jared Wolfe and Austin Emery
We stayed the night in Zaragoza in the Aragon region of Spain. We woke up this morning to go to the SAICA mill which was about 30 minutes outside of the city. Some ramble groups ate breakfast at the hotel while others traveled a little down the street to pastry shops and cafés. We arrived at the mill a little early, so we were able to marvel at the size of the location. 3 massive buildings housed the paper machines, and 3 more huge buildings contained the stock prep and repulping areas. Our contacts met us and quickly showed us a safety and mill location briefing. Here are some highlights from these presentations.
SAICA has 11,000 employees across multiple nations in including France, the UK, Italy, Holland, and several more in Europe. The location outside of Zaragoza has 3 paper machines that run fully on 100% recycled paper. The various sources of the recycled paper are from Spain, Southern France, Northern Africa, and Portugal. The recycled material comes from about trucks and trains around 85% and 15% respectively. The material is separated based on quality and the different fiber sources. The overall yield for repulping was about 85% and the rejects usually include large pieces of plastic. An interesting note, the reject plastic is sent to their cogeneration plant on site to be converted into steam and energy. Excess energy is produced and sold to power companies in the area. This facility produces around 3.3 million tonnes a year with 50% of the product supplied to internal box plants.
During our tour we were able to see the stock prep area and their PM10 which produces lightweight liner and medium. The fiber is repulped in continuous tanks, and then the fibers are fractionated based on their size. The recycled material usually contains more short fibers than long. The longer fibers are sent to a refiner to help increase the strength properties of the sheet. Before leaving stock prep, the fiber is mixed with steam to change the characterisitcs of impurities such as glue and ink to prevent sticking problems later on the machine.
The machine we viewed, PM10, was a gap former with 2 layers which is not a common configuration for liner grades. Another interesting note is that in the dryer section, only one side of the sheet is dryed throughout the process. Steam cylinders dry the paper above then the sheet is transferred with vacuum below. The reason behind this is to prevent fluttering of the sheet since it is such a lightweight grade. This allows the machine to run faster and not have many breaks. The machine had a size press, and the starch was cooked with a color additive to try and make the sheet look more like liner. The most interesting part about the tour was the off machine coater (OMC). SAICA installed the world’s first OMC which takes the parent roll from PM10 and coats the top layer to try and mimic white top liner. The off machine coater includes both curtain coating as well as blade coating. The grade we observed just used curtain coating and added around 30 gsm to the overall sheet. The coating comprised of 20 different ingredients and was created onsite.
After the mill tour, we had a group lunch at a local restaurant. We had a 3 course meal, and the food was incredible. Some options included short ribs, cooked green beans, veal burger, sorbet, ice cream, and a few other local cuisine options. After lunch, we travelled back to our hotel in Zaragoza. Many of us took afternoon siestas, and some groups finished exploring the city.
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