Noise-reduced wall fresh air ventilator

[0024] see Figure 1 to Figure 3 , an embodiment provided by the present invention: a noise reduction wall fresh air fan, including a main box 1, a fresh air fan body 7, a fan 10 and a door panel 14, by setting the main box 1, the present invention can be inlaid and installed in In the wall, the effect of reducing the occupied space is achieved. A filter screen 16 is installed on the bottom surface of the main box body 1. By setting the filter screen 16, the dust is retained when the air enters and exits, and the effect of reducing dust entering the home is achieved. Effect, the inside of filter screen 16 is provided with fan 10, and fan 10 is provided with two, and two fans 10 are symmetrically distributed, and by setting fan 10, make it flow when entering and exiting wind, reached auxiliary function, fan 10 The fresh air outlet 9 and the exhaust air inlet 11 are connected through the transmission pipe 5, and the fresh air outlet 9 and the exhaust air inlet 11 can be connected t

[0027] The three-layer porous sound-insulating composite material comprises vermiculite powder / butadiene rubber layers of the upper and lower layers and the pure hemp embryo cloth of the middle layer, and its production steps are as follows:

[0028] S1, preparation of vermiculite powder / NBR layer, the ratio of NBR to vermiculite powder is 1:0.15-0.35, put the raw materials into the mixing machine, before mixing, raise the temperature of the machine to 105±5°C, the distance between the rollers Between 0.05-0.1mm; After starting up, the material is stacked above the roller, and due to the rotation of the roller, the material is pulled into the nip by friction and adhesion, and the material is strongly squeezed in the nip It plays the role of distribution, dispersion and mixing. The material is heated and softened, and rolled into a sheet. Generally, it is covered on the front roller with a higher temperature. It is necessary to use a knife to continuously cut and roll the sheet