Foamed plastic sheet

DATE：2022/1/25 9:08:24 / READ： / SOURCE：This station

Foamed plastic sheet

     1. High foam plastic sheet
      Use expandable particles to undergo pre-foaming treatment, and then mold and foam to form various high-foaming products and sheets. Figure 846 shows the schematic diagram of the structure of the foaming machine using ES material. Its structure and working principle are the same as those shown in Figure 8- The horizontal hydraulic press shown in 25 is similar. After the EPS particles are added to the mold cavity, they are heated, foamed and expanded, and then cooled and shaped to obtain a polystyrene foam plastic sheet. The processing conditions are the heating steam pressure of 98kPa, the heating time of 35 to 40s, and the water cooling time of 420 to 480s. After the pre-expanded particles are softened by heating, they expand and bond to each other as a whole. Since the plate is generally thick, there is a temperature gradient between the center and the surface. In addition, the stress state of the plate surface and the center is also different. The foam particles near the mold wall are subjected to the outward expansion force of the particles in the center and the reaction force of the mold wall to the inside, and the metal mold wall can be regarded as a non-deformable body. Therefore, this kind of stress condition makes the bulk density of the foamed plastic skin on the surface of the board the highest. Then the bulk density decreases in turn. Such a bulk density gradient will also affect the quality of the foamed plastic sheet. Attention must be paid to the control of its temperature and the limitation of wall thickness. The cutting of this sheet can be done in a number of ways. Such as heating wire cutting, use 0.5 ~ 1.0mm heating wire, control voltage 6 ~ 12V. Mechanical cutting can be sawing, milling and so on. This board can also be processed like wood with woodworking tools.
      Since the expandable polystyrene foam sheet cannot be made too thick, it is often possible to use
      The method of multi-layer training obtains thick plates. In addition, in practical applications, it is often used as a partition material in building materials to bond with wood, decomposed materials, cement blocks, etc. The conditions of commonly used binders are:
      ①The physical strength of the plastic sheet itself can be found to be not very high, so the training strength of other pigs does not need to be too large:
      ②The pig mixture of Luo dosage form cannot be used to prevent the plate from being dissolved and destroyed;
      ②The scouring agent should be able to cure at room temperature;
      ④The bond strength is reached 24 hours after bonding.
       Commonly used pig threads are asphalt, polyurethane, phenolic glue and polyvinyl acetate emulsion. 5·, 6· Asphalt and 30% gasoline are usually added to the lion paste essence, and the adhesive can be evenly applied to the Yinli grid plate on the pig shadow surface. This adhesive water repellent is good, but nothing. It is used for foaming plastic sheets and wood, steel, cement walls and foamed plastics.

Author：admin

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