Extruder for Hollow Core Slab Production: Technical Specifications and Integration at Precast Concrete Plants

TDM Engineering Oy, Finland, specializes in the development of equipment for slipforming of precast concrete elements. The core technological unit of an automated production line is the extruder for hollow core slab production, ensuring an output speed from 1.4 to 3.5 linear meters per minute, depending on the density of the concrete mix used. The unit is integrated into casting beds at precast concrete plants and operates from a standard industrial power supply 3P + PE 400 V 50/60 Hz. These machines are serially operated at plants in Finland, the United Kingdom, Italy as well as in Asian countries and the CIS region.

Technology Concept: Reciprocating Concrete Compaction Under High Pressure

The production process is based on continuous extrusion technology. Low-slump concrete is fed from the hopper section into the compaction unit, where rotating augers force the material under extremely high pressure. The concrete is pressed and placed onto the casting bed, achieving precise and predefined geometry.

The compaction unit is mounted on a rigid steel frame with four guide wheels and equipped with an electronic gearbox. The standard hopper capacity is 1.5 m³, with an optional extended version up to 3.0 m³ available upon request. The machine moves along steel rails that also function as chamfer formers. Thanks to this design, the overall machine track width exceeds the product width by only 60 mm, optimizing workshop space utilization. The front section is engineered so that all working components are hermetically enclosed from above, protecting mechanisms from concrete contamination.

Industrial Application and Technical Parameters of TDM Platforms

The proprietary modular UniMould platform enables production not only of standard hollow core slabs, but also thin solid panels, piles, load-bearing beams, supports, and lintels. The extruder can be easily adapted for casting concrete over insulation layers and for precise configuration to manufacture elements with different fire-resistance classifications.

The equipment range includes three industrial modifications to meet various business requirements:

• S Series – Flagship line (maximum speed 3.0 m/min, product height 120–600 mm, width 1200, 1500, or 2400 mm). Equipped with an 11-inch color touchscreen monitor. The intensity of reciprocating compaction is automatically adjusted using machine-learning functions that analyze concrete properties in real time.
• N Series – High-performance unit with forming speed up to 2.2 m/min (product height 120–500 mm). Controlled via an 8-inch color display.
• L Series – Specialized forming machine for thin wall panels and partitions. Product height ranges from 80 to 220 mm, speed up to 1.8 m/min, width fixed at 1200 mm (8-inch monochrome monitor).

Structural Advantages: Cardan Shaft-Free Design

Finnish TDM extruders feature a well-engineered modular structure that completely eliminates complex gearboxes and cardan shaft drives. This engineering solution significantly enhances reliability during intensive and continuous forming of low-slump concrete mixes.

1. Independent auger drive – Ensures maximum concrete compaction density and allows dynamic adjustment of process parameters.

2. Reduced maintenance costs – Direct power transmission eliminates the need for cardan shaft lubrication and prevents costly repairs.

3. Low-noise high-frequency vibration beam – Evenly distributes vibration across the entire working area while maintaining minimal acoustic impact.

4. Wear-resistant components – Hopper, pallet, void formers, and shaping armor plates are manufactured from high-strength abrasion-resistant materials.

Adjustment of side shaping armor plates is performed quickly and precisely using external bolts in three planes. For process monitoring and operator safety, the compaction unit is equipped with a wide service platform with integrated ladders on three sides.

Integration and Ordering of a Precast Production Line

Implementation of Finnish TDM Engineering Oy systems fully automates slipforming production and significantly reduces plant operating costs.

The modular hollow core slab extruder requires minimal technical intervention, and its intuitive interface reduces operator training time.

To receive a detailed technical specification, configuration selection, and to order equipment directly from the factory in Finland, please contact TDM Engineering specialists via phone or email.