Monday, September 17, 2007

146 Small Papermaking Factories in China Shut Down


Based on the news released by chinacsr.com dated April 5, 2007, Hunan Province has shut down 146 small papermaking factories that failed to meet standards on pollutant emissions.
The factories all circle Dongting Lake. The region around Dongting Lake is rich in forests, which provide abundant productive materials for local papermakers. However, with a huge profit, these factories also brought unexpected side effects on the environment. According to Hunan Environmental Protection Bureau, the factories have emitted over 1.7 billion tons of wastewater into the lake.
In a circular released at the end of 2006, the provincial government regulated all papermakers and said they must install soda recovery units and ensure wastewater within allowed standards before a March 31 deadline. These 146 failed to meet the stated standard and have therefore been shut down.**

**taken from chinacsr.com

Friday, September 14, 2007

Monday, September 10, 2007

Pickouts Problem at Papermaking Process


There are many problems happened in the process of papermaking. One of the common problem appeared is the material pickouts in the paper machine. We can catagorized the material pickouts based on the location happened/source.

a. Pickouts from the wet-end press: This pickouts happened at the wet-end press.
There are several ideas to solve this problem, such as:
- Check the white water pH to ensure it is within spec
- Check the cleanliness of all presses, carrier rolls and fly rolls
- Add a surface tension-reducing agent to high pressure cleaning shower water
- (Too) high moisture content in the web entering the press section
- Check the presses and felts for pitch build up

b. Pickouts from the dryers: This pickouts happened at the dryer section.
There are several ideas to solve this problem, such as:
- Check the temperatures in the lead-in dryers to be sure the temperatures are properly graduated
- Check for worn or damaged dryer felts

c. Pickouts from the size press: This pickouts happens at the size press.
There are several ideas to solve this problem, such as:
- Check any damage on the size press filters or screens. Starch contamicated with fibers and dust contributes to pick-outs
- Clean the size-press showers to eliminate the build of starch

d. Pickouts from the stock additives
There are several ideas to solve this problem, such as:
- Improperly cooked or mixed aditives such as gum, starch, retention agents, defoamers, etc. will contribute to pickouts

Monday, September 3, 2007

Waste Re-use in Paper Industry-FOXFIRE

For many paper mills in the world, managing the waste/rejects is always become a high concern. As we all know that nowadays finding the area for allocating the waste from paper industry is becoming more and more difficult. Most practice, the solid waste is "dumped" in the landfill, but now some european countries like Germany and Dutch prohibit the allocation of solid waste as a landfill, although in other european countries like England solid waste for landfill is still permitted, but a high charge is applied to the paper mills.
Foxfire company in Foxhol, Groningen, Holland has the solution for paper mill's waste management, especially for the solid waste, by processing it to be the secondary fuel that commonly used in Cement Industries. In August 2006, Foxfire had started with its production (7 million Euro-investment) by sourcing the rejects from 6 paper mills; 5 in Holland and 1 in Germany, with the capacity of 150,000 MT secondary fuel/year. With its full capacity, Foxfire able to process the rejects from 10-15 paper mills.

Foxfire is processing 60% paper mill's rejects and 40% other wastes-like sludge, domestric trash and rejects from plastic industry. Foxfire is specializing in "wet" raw material as they considered that handling the "wet" raw material is more difficult due to its unpredictable characteristics. Foxfire claimed that the raw material they used is safe. For this matter, Foxfire pointed N+P Company; the leader in rejects and wastes business. N+P provides the transporter trucks, checks the materials and arranges the licences needed by Foxfire.

At the initial process stage in Foxfire, the rejects (raw material) is pre-mixed with other waste materials (since this step is already catagorized as waste-processing-step, thus license is needed). After pre-mixing, the rejects (raw material) is then transferred to preshedder, to separate unexpected material inside the raw material (such as golf ball, stone, iron, even a hand granate..). The rejects (raw material) then thransferred to the dewatering press (the rejects normally containes 50% water content), and then transferred to the hopper using the t"transportation screw". Hopper will act as a buffer tank prior the drying stage. Drying stage is processed by using the natural gas burner, and continued with "Allgaier Tumbling Dryer". Since the whole process is highly dust-generating, thus a belt conveyor is used to transport the dried material to the storage before sending to the customers. The whole process/mill was designed by Foxfire but built by Siemens.

The secondary fuel as Foxfire's end product mostly sold to the cement industry, that commonly it uses 85% of the fuel from secondary fuel, including bark trees. Most important requirement for Cement Industry is the "Flying Burning Time", that the fuel used must be completely burned out in 2 seconds, and the secondary fuel able to fill this requirement.

Currently Foxfire had signed a contract from the potential customers in US and Japan for building mills there, but now Foxfire is still concentrating in European market.