Upgraded PET stretch blow moulder offers multiple savings

The company said its InnoPET BloFill Series IV monoblock system eliminates the need for an air conveyor system – a move which saves both space and money. An economical cooling system also cuts water use.

The equipment is capable of processing a wide range of plastic bottle sizes and shapes, with PET bottles holding anything from 120 ml to three litres. The monoblock setup is able to process up to 72,000 PET bottles per hour, with typical efficiency levels exceeding 96 per cent, said KHS

One upgrade to the system is found directly downstream from the stretch blow moulding process. The new model uses just one modular transfer wheel in removing bottles from the blow station and adjusting the distance of finished PET containers to one another according to the configuration of the filling system.

Efficient cooling system​

The equipment also utilises an identically designed airlock as a second monoblock module. Where carbonated beverages are to be filled, the PET bottles are conveyed through a modular cooling system prior to reaching the filling system. This is a “highly efficient and economical”​ cooling process thanks to its minimisation of water use.

“A system of nozzles constantly sprays a mixture of water and air onto the bottle bases covering them with fine drops of mist. A maximum of nine nozzles is used in the system, with each nozzle spraying just one litre of water an hour,”​ said KHS.

The Series IV machines are equipped with a new heater, incorporating technology that almost halves the time required to heat preforms compared to the InnoPET Blomax Series III system.

This reduces the heater segment’s footprint by 50 per cent compared to previous models. Since the number of the preforms inside the heater element are therefore halved, this means “only half as many preforms need to be channelled out if an emergency stop is triggered within the monoblock as opposed to the previous set up”, ​said the company.

This development minimises the buffer area required between the monoblock and a downstream labeller. Start up time for the monoblock has been cut from two minutes to 15 seconds.

Servo motors​

A further key system upgrade has been made by the introduction of servo motors to the stretching process in the blow stations. This means the stretch speed is now independent of the machine speed, which facilitates adapting different bottle sizes to the filler.

The machine also realises an optimum distribution of material within PET bottles. This has the advantage that in a stretch process driven by servo motor, preforms can be used that has been optimized down to the last tenth of a gram of PET material.