In the brick and tile industry, how to choose between soft-plastic extruders and hard-plastic extruders?
In the brick and tile industry,how to choose between soft-plastic extruders and hard-plastic extruders?
In the brick and industry,Soft-plastic vacuum extruder and hard-plastic vacuum extruder.They are two common molding machines, with key differences in raw material properties, equipment structure, molding process, and product applications. Many business owners are unclear about these differences, so today we'll explain.
1. Raw material moisture content and plasticity
Soft plastic vacuum extruder.Applies toHigh raw material moisture content (typically 15%~20%), strong plasticity, and relatively soft texture.Generally used forProduction of hollow bricks, porous bricks, decorative bricks, and other products requiring high plasticity.Process characteristics: The formed green body requires a longer drying period (natural or artificial drying) to reduce moisture-induced shrinkage and deformation.
Hard plastic vacuum extruder, suitable for raw materials with low moisture content (typically 12%~15%), high hardness, and poor plasticity.
Generally used for producing high-density solid bricks, paving bricks, refractory bricks, and other products with high strength requirements. Its process feature: after forming, the green body can be directly fired in the kiln, with short or even no drying time.
2. Device structure and working pressure
Soft plastic extruder, with lower extrusion pressure (1.5~3 MPa) and slower screw speed. Structural design: deeper screw grooves and a smaller compression ratio (about 2:1~3:1) to reduce material extrusion force. Vacuum system: lower vacuum level (about -0.06~-0.08 MPa), mainly used to remove air bubbles and improve body uniformity.
Rigid plastic extruder, high extrusion pressure (3–6 MPa), fast screw speed, and greater power. Structural design: shallower screw channel, high compression ratio (up to 5:1–8:1), enhancing body density through strong squeezing. Vacuum system: higher vacuum level (approx. -0.08 to -0.095 MPa), ensuring thorough de-airing of raw materials to prevent cracking.
3. Finished product features
Soft-mud molded products, lighter body, higher porosity, good thermal insulation, but lower strength. Smooth surface, suitable for decorative tiles and bricks.
Hard-plastic molded products feature high body density, strong compressive strength, and excellent wear resistance and durability. Ideal for load-bearing structures or high-load outdoor applications (e.g., paving bricks, building facade tiles).
4. Energy Consumption and Maintenance
Soft-plastic extruder: low energy consumption, but sensitive to raw material moisture content, requiring strict control of the drying process.
Hard plastic extruder: High energy consumption (due to high-pressure extrusion), rapid equipment wear, requiring regular replacement of wear-resistant parts (e.g., screw blades, liners).
■ Recommendations for selecting between these two types of devices.
If producing lightweight bricks, decorative bricks, or when raw material moisture is high, prioritize a soft-plastic extruder.
If producing high-strength bricks, solid bricks, or when raw material moisture is low, choose a stiff-plastic extruder.
The core difference essentially lies in design optimization for different raw material characteristics and product requirements. In practice, selection should consider raw material properties, product positioning, and production costs comprehensively.