Spike Shaft

In the high-pressure environment of the extrusion hopper, the greatest enemy of consistency is bridging or uneven material flow. Before the concrete reaches the main roller, it must be aerated and distributed. The WELSCH high-performance spike shafts utilize a precision-engineered spike pattern that breaks up clusters and ensures a continuous, even curtain of concrete across the entire width of the pallet.

A spike shaft is only as effective as its reach. In the abrasive environment of concrete extrusion, standard spikes wear down rapidly, leading to a shadow effect where the concrete is no longer agitated. When standard spikes lose even a few millimeters of length, they lose the ability to reach the boundary layer of the concrete. This creates a stagnant dead zone where material becomes stationary, leading to inconsistent density and structural weak points in the final tile. Stagnant material can partially hydrate or break off in large, inconsistent chunks, causing slugs in the extrusion head and catastrophic defects in the final tile surface.

To combat the liquid sandpaper effect of high-speed extrusion, we offer two levels of premium armor for your spikes: hard metal coating for standard high-output requirements using specialized thermal-spray or cladding processes, and press-fitted hard metal sleeves for the most abrasive mixes, providing diamond-class hardness that maintains its original length and geometry for vastly extended service intervals.

Every concrete mix behaves differently. For mixes that require more aggressive feeding, we offer custom-welded paddles at the spike ends. These paddles are angled to act like an internal screw, creating a targeted down-leading pushing force that tunes the hopper to force material into the compression zone more effectively.