TL;DR

Clamp ring misalignment causes flash at the tire parting line and can damage the mold. Verify the ring actuator positions and mold segment alignment before re-clamping.

What you might see

visible flash at the tire bead area or parting line
clamp ring does not fully seat on the mold
clamp ring torque or force alarm on the controller
uneven engagement marks on the clamp ring after removal

Likely causes

Tap to mark as ruled out

Mold segment guide or slide worn causing a segment to sit low or tilted
Clamp ring actuator travel inconsistency between sides
Mold segments contaminated with rubber flash preventing full closure
Clamp ring or mold segment mounting bolt loose

Required tools

Scraper for flash removal
Mold release agent
Torque wrench for clamp ring bolts
Heat-resistant gloves
LOTO kit

Safety first

Lock out the press and steam supply before reaching near the mold or clamp ring.
Heavy mold segments and the clamp ring create crush hazards when the press cycles. Keep all personnel clear during any press closure in manual mode.
Steam and hot compound residue in the mold can cause burns. Wear heat-resistant gloves and a face shield.

Procedure

7 steps · ~45 min

1
Open the press and allow it to cool before inspecting the clamp ring and mold segments.
Warning: Press molds and clamp rings are at temperatures above 150 C immediately after a cure cycle. Allow cooling before contact.
2
Inspect the mold segments for rubber flash or compound buildup on the parting surfaces. Clean all flash and contamination with a scraper and approved mold release.[1]
3
Inspect the mold segment guide slides for wear or scoring. Worn guides allow segments to tilt and prevent the clamp ring from seating.[1]
4
Check the clamp ring actuator position sensors on both sides of the press. Confirm both sides reach the fully closed position simultaneously.
5
Inspect the clamp ring mounting for any loose bolts or damaged threads.
6
After cleaning and inspection, close the press slowly in manual mode and visually confirm the clamp ring seats evenly around the full mold circumference.
7
Run a cure cycle with a scrap tire and inspect the bead and parting line flash before returning to production tires.

Sources

HF TireTech (HF Group) HF B-Series / TPB Tire Curing Press general technical documentation, HF TireTech (HF Group)
HF TireTech B-Series / TPB tire press operator and maintenance documentation, mold and clamp ring maintenance (general)

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