Leaking head, poor mixing or a sticking piston? It may be time for an overhaul. Symptoms, daily care and the overhaul process.
The mixing head is the part of a high-pressure polyurethane machine where the two components are mixed and injected into the mould. Even wear of a fraction of a millimetre in the head directly affects mixing quality, part surface and material yield.
Signs that call for an overhaul
- Streaks, marbling or soft areas on parts
- Poor mixing at the start or end of the shot (bad first/last shot)
- The piston sticking or opening and closing late
- Leaks from the head body, chemicals getting into the hydraulic oil
- Unbalanced injector pressures
Daily and weekly maintenance
- Cleaning the outside of the head at the end of each shift
- Checking hydraulic and injector pressures
- Cleaning the filters periodically
- Visual checks of seals and gaskets
The overhaul process
The head is dismantled and the piston-to-body clearances are measured; parts are re-machined or newly made where needed. Seals, nozzles and injectors are replaced, and the head is tested before it goes back on the machine. Because MTS Otomasyon designs and makes its own mixing heads, parts are prepared quickly in our machining facility.
