The invention relates to a method of recycling waste paper. More specifically, the claimed method relates to a method for extracting fiber from waste paper and even more specifically, extracting the fiber from Old Corrugated Container (OCC) using mechanical operations.
Existing processes of waste paper recycling most often involve mixing waste paper with water and chemicals to break the waste paper down. The waste paper is then chopped up and heated, which breaks it down further into strands of cellulose, a type of organic plant material. This resulting mixture is called pulp, or slurry. The pulp is strained through screens, which remove plastic and other materials that may still be in the mixture. The pulp is then cleaned, de-inked, bleached, and mixed with water. This process is very water and energy intensive.
What is needed is a more efficient process for recycling paper to pulp. It would be further beneficial to develop a process which does not require the addition of chemicals to the waste paper. Additionally, it would be beneficial to provide a recycling process that uses very little water. It would be further beneficial to create a process for recycling paper that reduces the waste involved in conventional waste paper recycling operations.
The foregoing background discussion is intended solely to aid the reader. It is not intended to limit the innovations described herein, nor to limit or expand the prior art discussed. Thus, the foregoing discussion should not be taken to indicate that any particular element of a prior system is unsuitable for use with the innovations described herein, nor is it intended to indicate that any element is essential in implementing the innovations described herein. The implementations and application of the innovations described herein are defined by the appended claims.
In accordance with one aspect of the disclosure, disclosed is a method for recycling waste paper that employs mechanical force to reduce the waste paper to its constituent fibers. The disclosed method does not require the addition of chemicals or heat to the pulping process, but instead uses impact and frictional forces to break the waste paper down into fiber. The disclosed method also requires very little water, thus reducing the need for complicated water purification systems. Moreover, the disclosed method is very energy and space efficient in comparison to existing technologies.
Now referring to the drawings in detail, wherein like reference numerals refer to like elements throughout,
Magnetic belt conveyor 4 moves material to pneumatic conveyor 5. Pneumatic conveyor 5 also serves to filter out heavy objects from the flow of waste paper. Pneumatic conveyor 5 is used to transfer the waste paper to hammermill 7. A sprinkler system (not shown) may be used to add moisture to the waste paper to keep down dust and reduce the risk of fire. The waste paper material is fed into the grinding chamber of the hammermill 7, where it is reduced in size by a combination of the repeated impacts of the ganged hammers in the milling chamber, collisions with the walls of the grinding chamber and the impact of waste paper repeatedly impacting other pieces of waste paper. One section of the grinding chamber of the hammermill comprises a screen of uniformly sized apertures. When the particles of waste paper have been reduced in size such that they are able to fit through the screen, the particles may drop through the screen by gravity feed or be evacuated by negative pressure or both. The apertures in the screen of the hammermill may be modified to control the size of the output waste paper fiber.
In the embodiment shown in
The teachings of the present disclosure can find applicability in many waste paper recycling settings, but may be most useful in recycling OCC. In summary, bales of waste paper, preferably bales of OCC, are fed into first shredding operation to be reduced in size and then to a secondary shredding operation to be further reduced in size. Once reduced in size, the shredded waste paper is conveyed through a magnetic separator designed to separate metal from the shredded waste paper. A pneumatic separator may also be used to eliminate heavier materials from the shredded waste paper. The shredded waste paper is then conveyed to the hammermill where it is broken down to its constituent fibers.
Beneficially, the claimed method uses no chemicals to break down the waste paper Additionally, the claimed process does not use any significant amount of water, nor does it create any potentially polluting exhaust gases. Additionally, power consumption of the claimed method on a per ton basis is substantially lower than that of existing methods for pulping waste paper. Additionally, the claimed method results in a high yield of recycled pulp fiber.
While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of the disclosure. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.
Number | Date | Country | |
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63110891 | Nov 2020 | US | |
63211350 | Jun 2021 | US |