Sponge Slabstock Foaming Machine-Vertical Foaming Machine

The vertical foaming process and equipment were successfully developed by the I&J Hyman Group in the UK in the early 1980s. In the following years, industrial production was successively implemented in the UK, the Netherlands, and China.

The basic principle of the vertical foaming process involves fully mixed foaming materials being delivered via two feed pipes to the bottom of a rectangular feed tank. The materials then gradually foam upward into a shaping mold lined with polyethylene film. Several vertical conveyors transport the foam block upward at a synchronized speed with the foaming rise. At a suitable height, a saw blade cuts the foam block, which is then moved by a horizontal conveyor to the curing area. The diagram illustrates a vertical foaming production line.

Schematic diagram of vertical foaming principle

Using the vertical foaming method, large cross-sectional foam blocks (e.g., 1m x 2m) can be produced at relatively low flow rates (e.g., 70–80 kg/min). In contrast, horizontal foaming machines require 3–5 times higher flow rates to produce blocks of the same cross-section. Vertical foaming lines usually exceed 60 meters in length and require significant equipment and facility investment. However, vertical foaming machines have a compact footprint and need a building height of only 12–13 meters, significantly reducing construction investment.

Another major advantage of vertical foaming is the flexibility to produce cylindrical foam blocks up to 1.5 meters in diameter by simply replacing the shaping mold and vertical conveyors. This provides economical blanks for foam slicing and offers high adaptability in block production, with lower investment compared to Romax systems. Additionally, vertical foaming produces no foam skin at the top, uses thin film for side lining, and results in minimal side skin, thereby improving the foam block yield compared to horizontal foaming.

Typical Technical Specifications of a Vertical Foaming Machine:

Due to the characteristics of the vertical foaming process, the length of the foam blocks cannot be too long. Additionally, producing foam of very high or very low density presents certain challenges, which somewhat limits its application. However, the economic efficiency (low investment, high product yield) and production flexibility of vertical foaming have led to its rapid development after entering the market. It is especially suitable for factories with an annual production capacity of around 1,000 tons, making it a highly viable production machinery option.