What Is Batch Foaming Vs Continuous Foaming
1.Batch Foaming
Batch foaming primarily involves mixing the raw materials in a single pass, injecting them into a mold or chamber, and then removing the finished product after foaming and curing. This process is primarily batch production, with each batch operated independently. It is typically suitable for complex, customized products (such as automotive seats and special-shaped parts). The equipment consists of a mixing head and a mold/chamber, requiring frequent mold cleaning. Mixing is done at high or low pressure, and the material is injected in a single pass. The foaming process occurs within a closed mold, resulting in precise shapes. Curing times are long (dependent on mold temperature). Batch foaming is generally slow (due to mold loading and unloading for each batch, resulting in long cycle times). Labor requirements are high (due to mold handling and equipment cleaning). Raw material loss is high (due to residual material and cleaning losses). Density control is more precise (the mold limits expansion space). The closed-cell ratio is high (mold pressure inhibits bubble coalescence). The mold is limited by size (typically small). The surface is smooth (contacting the mold surface).
2.Continuous foaming
The principle of continuous foaming involves continuous mixing of raw materials, allowing them to foam and solidify indefinitely on a conveyor belt, and then cutting them into the desired length. Production operates on an assembly line, running 24 hours a day. This process is typically suitable for large-volume, standardized products (such as mattresses, rolls, and packaging sponges). The equipment consists of a mixing head, conveyor belt, and cutting system, eliminating the need for frequent downtime. High-pressure mixing is employed, with raw materials continuously injected. The foaming process occurs on an open conveyor belt, allowing for free expansion. Curing is rapid (via a heated tunnel or infrared light). Production speeds are high (several to tens of meters of sponge can be produced per minute). Labor requirements are low (automated control requires only monitoring). Raw material loss is low (continuous feeding reduces waste). However, uniformity may be slightly reduced (free expansion can result in uneven density at the edges). However, the porosity is high (free expansion can easily form interconnected pores). Extra-long/extra-large sponges (e.g., 2 meters x 2 meters x infinite length) can be produced. The top open surface can be rough (requiring later cutting and trimming).
In summary, intermittent foaming offers flexibility and is suitable for high-value-added products, but it also suffers from low efficiency and high costs. It is suitable for small-batch, high-variety production. Continuous foaming optimizes cell uniformity and reduces waste. It is therefore suitable for large-scale, standardized production (e.g., mattresses and furniture upholstery).
