Soft polyurethane foam molding

日期:2022/6/24 8:38:32 / 阅读: / 来源:本站

Soft polyurethane foam molding
Flexible polyurethane foam is a kind of polyurethane foam with the largest consumption and output. It is mainly used in furniture, various cushion materials and thermal insulation materials. In industry, it is also used as sound absorption, sound insulation, filtering, thermal insulation and other materials.
1、 Block foaming hollow board production line www.handern com
The production of block foaming equipment is large and suitable for large-scale production. The output of large rectangular block products accounts for about 80% of the total output of flexible polyurethane foam. After the rectangular block product is formed, it can be further cut into various required sheet or block products with a slicer. It operates a production line composed of foaming machine, cutting device, conveying equipment and slicing device. The main production equipment is foaming machine, which is composed of mixing head, metering pump, electrical control system, raw material storage tank, drying channel and exhaust device, conveyor belt, lining paper supply and collection system, etc. There are four types of block foaming production lines as shown in Figure 5-4 to figure 5-7. The working diagram of ordinary block foaming machine is shown in Figure 5-8. Hollow plate production line www.handern com
The maximum production capacity of the block foam foaming machine is 600kg/min, which can produce foam blocks with width of 2 ~ l.4m, height of 1~1.2m and unlimited length. The vertical foaming machine is a relatively new block foam foaming device. The foaming principle of the device is to send the reaction mixture from the lower part to the fully enclosed foaming room. The wall of the foaming room is lined with kraft paper or polyethylene film of sufficient strength. The expanding foam and lining paper are pulled upward by the side longitudinal conveyor belt, and their rising speed depends on the indoor pressure, foam formula and foam rising speed. When the foam reaches a certain height with the conveyor belt, it is cut off by the horizontal cutter and sent to the roller heated to a certain temperature for curing. The fully matured foam block can be cut into foam sheets of various thicknesses.
1. production process hollow plate production line www.handern com
① The materials are respectively fed into the mechanical mixing head through the metering system from the material tank.
② After mixing evenly, it is injected into the belt conveyor lined with kraft paper.
③ After several seconds of the material in the mixing head of the tank, i.e. Fig. 5-7vertifoam vertical generator
Foaming on the belt conveyor. Hollow plate production line www.handern com
④ Foaming diagram of foam body equipped with infrared (or other hot foaming machine
1 - foaming mixture; 2- feed into the lining paper source) and the heating oven of the exhaust device for curing and forming. 3- rewind the backing paper; 4-cut-off device:
⑤ It is sent out continuously from the other end. The 5-cut foam block is installed at the outlet with a cutting tool. The block foam body can be cut into a certain length as required, which is a semi-finished product. Motor mixing head casting foaming slurry foaming frame casting foam body formwork bottom paper movement diagram 5-8 working diagram of ordinary block foaming machine
⑥ The semi-finished product can reach the maximum after being placed at room temperature for a period of time for ripening
Final strength. Hollow plate production line www.handern com
⑦ The foam body is cut to remove the epidermis and cut into the desired shape to become a product.
The metering part of the block foaming device generally has five parts, namely, polyether polyol - foam stabilizer; TDI; Water triethylenediamine; Organotin polyether polyol; Pigment polyether polyols. The above five parts can also be combined for measurement, which is mainly based on the principle that the components are not easy to deteriorate and easy to control after mixing. The mixing head of the rectangular block foaming device generally uses a low-pressure needle type mixing rod. When a low shear needle type mixer is used, the mixing speed is usually 3000~6000r/min. The residence time in the mixing head is about 1s. In addition, there are mixing heads with high shear agitators.
The pore size of the final foam body can be adjusted by the input energy of the mixing head, which is related to two aspects: the linear velocity of the material entering the mixing head; Speed and shear force of mixing. In the low pressure and high shear foaming machine, injecting a small amount of dry air into the mixing head has a certain effect on improving the pore size; However, the effect is not obvious in high pressure and low shear foaming machinery. The size of the material output hole of the mixing head and the back pressure of the mixing head also have a certain impact on the product aperture. Generally, the reduction of back pressure and the increase of output hole diameter are conducive to the hollow plate production line with fine foam pore diameter www.handern com

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