What is Compression Packaging Equipment for Flexible PU Foam?

Due to the large volume of flexible PU foam, transportation becomes challenging. To improve transportation efficiency, compression packaging is an effective method. Common compression packaging machines are divided into two categories: one uses atmospheric pressure, extracting the air from the packaging bag to create a vacuum and compressing the flexible PU foam using atmospheric pressure; the other uses mechanical force to expel the air from the foam, reducing its volume. Both methods can compress flexible PU foam by approximately 75%, significantly enhancing transportation efficiency. As long as the pressure is released within a suitable timeframe, the foam will rebound to its original shape without permanent deformation.

Vacuum Packaging Machine

The vacuum packaging machine consists of several components: a vacuum generator, suction hood, flexible hoses, etc. The vacuum generator, which serves as the vacuum source, uses compressed air at 0.4-0.6 MPa to operate a jet vacuum pump. The suction hood is connected to the vacuum generator via a spring-loaded hose. During packaging, the outer packaging tube membrane is placed over the hose, and the flexible PU foam is preloaded into an inner packaging tube. The suction hood is placed at both ends of the foam roll, and the inner tube is secured to the suction pipe. The vacuum generator then evacuates the air from the bag, and the foam gradually compresses until the diameter is smaller than the inner tube. The inner tube is then placed over the foam roll, the vacuum is released, the suction hood is removed, and the bag is sealed. The entire packaging process is shown in Figure 1.

   Figure 1: Schematic Diagram of Vacuum Compression Packaging

Compression Packaging Machine

The flexible PU foam is placed on a metal chain plate conveyor with many small holes to facilitate the expulsion of air during compression. The metal plate moves in a circular motion, driving the foam roll to rotate. The pneumatic cylinder retracts the support frame and compresses the foam roll through the metal chain plate. As the foam rolls, it is gradually compressed, and the diameter reduces. Once compressed to the predetermined size, the foam roll is wrapped in kraft paper, tightly sealed with tape, and the packaging is complete. The mobile frame is then opened, and the compressed product is removed. The chain plate speed is typically 19 m/min, with a compression force of about 20,000 kN. It takes around 3 minutes to compress one roll, with a maximum diameter of 1.4 meters before compression. After compression, the roll’s diameter is typically half its original size, reducing its volume to one-quarter of its original, improving transportation space efficiency by 3 times.