Mould clamping system is machine agnostic

Edited by the Engineeringtalk editorial team Feb 28, 2005

When R-Tek was establishing a new injection moulding facility at its Merthyr Tydfil factory the company asked Staubli to advise on the optimum system for fast, efficient and reliable mould changing.

When R-Tek, specialist manufacturer of automotive interior components, was establishing a new injection moulding facility at its Merthyr Tydfil factory it asked Staubli to advise on the optimum system for fast, efficient and reliable mould changing.

R-Tek, a joint venture between Kasai and Visteon, operates five injection moulding lines at the Merthyr factory: four Negri Bossi machines of 300 to 800 tonne capacity and a 1600 tonne Krauss Maffei.

The company produces a wide range of mouldings from parcel shelves and boot linings to door casings, internal pillars and switch panels.

All components are produced on a strict JIT basis to detailed production schedules set by the end user, the automotive manufacturers.

The pattern of demand called for frequent changes of the mould tools; typical production runs average approximately 500 parts.

Staubli, the specialist in quick release connections, was asked to advise on the most suitable mould changing system for R-Tek.

The Plant Engineer at R-Tek Merthyr, responsible for the injection moulding development comments, said: "We considered both magnetic and hydraulic quick mould change systems for the machines".

"Staubli as a manufacturer of both types of system were able to objectively recommend the one most suitable".

Following Staubli's recommendation a decision was taken to install the QMC 100 single acting, hydraulic clamping system on all five machines.

A similar system was in use at R-Tek's sister factory in the North East and had proved to be efficient and reliable.

The installation went smoothly capable of being fitted to a machine within one day on most machines.

The injection moulding machines that were already at Merthyr were retrofitted while the remainder were ordered from the manufacturer with the Staubli equipment in place.

In both cases the operating systems for the hydraulic clamps were incorporated into the machine's controls.

All moulds were ordered complete with the required backplates to Staubli's specifications.

R-Tek regularly uses around 25 moulds, up to a maximum of 15 tonnes weight for the larger components such as bumper linings.

Staubli has two hydraulic clamping units for quick mould changing on injection moulding machines, QMC 100 single acting and QMC 101 a double acting unit.

Both clamps are of compact, robust design and are designed for operation on Euromap 11 standard backplates with parallel faces, no chamfer being required, any variation in backplate thickness tolerance is taken up by the clamping element.

The clamps can be connected directly to the hydraulics system on the machine or an independent hydraulic power pack can be installed.

Installations are adaptable for either vertical or horizontal mould changing.

The single acting QMC 100 unit, suitable for machines up to 2000 tonnes capacity, employs hydraulic power for unclamping while an irreversible automatic spring loaded system ensures failsafe clamping.

On the QMC 101 both clamping and unclamping use hydraulic power and this product is designed for larger capacity machines up to a clamping force up to 450 kN.

Clamping security is ensured by means of an integral thrust system.

Mould changeover times were reduced dramatically, from just over the hour using manual fixed clamping down to 15/20 minutes.

R-Tek's Plant Engineer comments: "75/80% of this reduction was obtained immediately on using the QMC 100 system and as the operators became more familiar with the procedure further reductions have been achieved".

"The Staubli system is robust and cost effective, we would certainly use the same system on all future injection moulding machines".