Basic Components of a Flexible PU Foam Production Line: Cutting and Weighing Equipment

In a continuous foaming machine, foam blocks are cut into specific lengths as needed. The cutting machines mainly use two types of blades: circular band knives and reciprocating saw blades (or straight blades). The cutting methods include top cutting, bottom cutting, and side cutting.

In a circular band knife cutter, the top-cutting type (Figure 1) starts from a stationary position above the foam block. The blade moves downward to cut through the foam and returns to the starting position after completing the cut. Each cutting cycle takes about 7 seconds. The bottom-cutting type (Figure 2) works in the opposite manner, starting from below and cutting upwards.

The side-cutting machine (Figure 3) typically uses a reciprocating double-sided saw blade to cut from one side of the foam block to the other. It allows for bidirectional cutting from either side.

In foam block production, an in-line density measuring instrument is often used. It determines the foam block’s density by measuring its absorption of radiation. This device is usually installed above the foam block approximately 15 meters after the mixing head, allowing early density detection for production control and adjustments.

After cutting, the foam blocks are weighed using an electronic scale mounted on a conveyor belt. Relevant data such as weight, dimensions, and model information are printed on the foam block and can also be recorded in a log, printed, or sent to a connected computer system. The conveyor belt scale is typically used for foam blocks up to 30 meters in length.