In modern paper production, the most used raw material are waste paper and virgin pulp, but sometimes waste paper and virgin pulp are not available in some area, it’s hard to get or too costly to buy, in this case, the producer can consider to use wheat straw as raw material to produce paper, wheat straw is a common by-product of agriculture, which is easy to get, abundant in amount and cost less.
Compared with wood fiber, wheat straw fiber is more crispy and weak, it is not easy to bleach white, so in most case, wheat straw is more commonly used to produce fluting paper or corrugated paper, some paper mill also mixed wheat straw pulp with virgin pulp or waste paper to produce lower quality tissue paper or office paper, but fluting paper or corrugated paper is considered to be the most favorite product, cause the production process is considerable simple and production cost is less.
To produce paper, wheat straw need to be cut first, a 20-40mm length is preferred, more easy for straw to be transferred or mixed with cooking chemicals, a wheat straw cutting machine is request to do the job, but with the change of modern agriculture industry, wheat is commonly harvested by machines, in this case, the cutting machine is not considered necessary. After cutting, the wheat straw will be transferred to mix with cooking chemicals, caustic soda cooking procedure is commonly used in this process, to limit cooking cost, lime stone water can also be considered. After wheat straw is well mixed with cooking chemicals, it will be transferred to a spherical digester or underground cooking pool, for small amount raw material cooking, underground cooking pool is recommend, civil work construction, less cost, but lower efficiency. For higher production capacity, need to consider to use spherical digester or contiguous cooking device, the advantage is cooking efficiency, but of course, equipment cost would be high too. The underground cooking pool or spherical digester is connected with hot steam, with a increase of temperature in the vessel or tank and the combination of cooking agent, the lignin and fiber will be separated with each other. After cooking process, the wheat straw will be unload from cooking vessel or cooking tank to a blow bin or sediment tank ready to extract fiber, the commonly used machine is bleaching machine, high speed pulp washing machine or bivis extruder, till then the wheat straw fiber will be fully extracted, after a process of refining and screening, it will be used to make paper. Beside paper production, wheat straw fiber can also be used for wood tray molding or egg tray molding.
Post time: Sep-30-2022