A manufacturing process for environmentally friendly flame-retardant straw boards

Application Number: CN201710450729.2 Application Date: 2017-06-15

[Publication Number] CN107127841A [Publication Date] 2017-09-05

[Applicant] Shi Zhi [Address] Building 61, Songtaoyuan, Wuchang District, Wuhan City, Hubei Province, 430064, China

[Inventors] Shi Zhi; Xu Zhengming; Shi Zhuwu

[Patent Agency] Wuhan Yucheng Patent Agency 42001 [Agent] Wang Minfeng

[Country/Province Code] 42

[Abstract] This invention discloses a manufacturing process for environmentally friendly flame-retardant straw boards, including the following steps: (1) removing impurities and crushing crop straw; (2) metering and packaging; (3) laying and molding; (4) pre-pressing; (5) shaping and cold pressing; (6) locking the mold; (7) curing and demolding; (8) drying; (9) sawing the edges of the semi-finished product; (10) sanding; (11) packaging and warehousing. This manufacturing process adopts room temperature cold pressing technology, which is simple and does not require high temperature heating. The bonding can be completed at room temperature. Only microwave technology is used to dry the board blank in the drying stage. It does not consume solid fuel, and the factory has no chimney. The whole process is green and environmentally friendly. In addition, this invention uses straw as the main raw material, combined with high-performance inorganic flame retardants and inorganic binders. The straw boards obtained are flame-retardant and do not carbonize, deform, or produce harmful smoke and gases at high temperatures above 1200℃. Furthermore, they do not conduct heat at high temperatures and do not expand when exposed to water, resulting in excellent comprehensive performance.

[Claim 1] A manufacturing process for an environmentally friendly flame-retardant straw board, characterized by the following steps: (1) Removing and crushing crop straw: using special equipment to remove bricks, stones, soil and metal impurities from the straw, and then naturally drying the cleaned straw to control the moisture content of the straw to between 7% and 12%; then feeding the straw into the surface and core layer crushers for crushing, the surface crusher crushes to 3.5mm and the core layer crusher crushes to 5.10mm; (2) Metering and packaging: weighing the raw materials according to 50-100 parts of surface and core layer straw particles, 10-200 parts of flame retardant and 1-50 parts of binder, and then packaging the straw particles, flame retardant and binder according to the different types of surface and core layer straw. (3) Laying and molding: The surface and core layer mixtures are transported to the laying machine respectively. The surface layer mixture is laid and the core layer mixture is laid. The laying machine lays the surface and core layer mixtures evenly on the pad in 40#60 times to form 40#60 layers of laying mixture. Then each layer of laying mixture is sent to the mold along with the pad. (4) Pre-pressing: At room temperature and humidity of 60#95 degrees Celsius, the mixture on the pad is subjected to a pressure of 1.5×105#1.0×106 Newtons. After pre-pressing for a certain time, the straw fiber precast board blank is formed. (5) Shaping and cold pressing: At room temperature, the 40#60 The straw fiber preform and the pad are placed in the mold locking mechanism and a pressure of 1×10⁷ to 1.5×10⁷ Newtons is applied. The pressure is kept constant for a period of time to form a straw fiber preform of a certain height; (6) Mold locking: The straw fiber preform and the pad are locked in the mold and a pressure of 1.1×10⁷ to 1.4×10⁷ Newtons is applied to it to solidify for a period of time to form a straw fiber shaped preform; (7) Curing and demolding: The straw fiber shaped preform is released from the mold and removed from the pad; (8) Drying: The straw fiber shaped preform is placed in an infrared circulating drying oven and dried for 15 to 35 seconds to obtain an environmentally friendly flame retardant preform. (9) Trimming the edge of the semi-finished product: Trimming the edge of the above-mentioned homogeneous straw core board semi-finished product according to actual needs to obtain environmentally friendly flame-retardant straw board semi-finished products of corresponding length and width; (10) Sanding: Polishing the above-mentioned environmentally friendly flame-retardant straw board semi-finished product after trimming the edge with a sanding machine to obtain the environmentally friendly flame-retardant straw board finished product; (11) Packaging and warehousing: Conducting quality inspection on the above-mentioned environmentally friendly flame-retardant straw board finished product, and packaging and storing qualified products in the warehouse; wherein, the raw material composition of the flame retardant in step (2) includes magnesium oxide, magnesium chloride, magnesium sulfate, nano antimony oxide and ultrafine silica powder, and the binder is an inorganic binder, the raw material composition of which includes aluminum sol, water glass, polyvinyl alcohol and deionized water.