Dosing control system

At the end of 2004 an important customer from the cosmetics industry made the decision to replace all classical piston filling machines with flowmeter-based machines. The aim was to increase productivity and ensure more consistent quality of the filled product shampoo and conditioner. The filling speed and filling accuracy were to be increased and production

downtimes avoided. 

The project concerned the conversion of one of several line fillers from piston filling to flowmeter-based filling machine.

Described by the customer as "particularly difficult”, the shampoo and conditioner to be bottled are prone to entrainment of air bubbles, resulting in overfilling and line shutdown if not recognized immediately. The 250 ml plastic containers were expected to be filled to an accuracy of ±0.5% or better. In addition, a substantial increase in throughput was planned.

The dosing system offered by Endress+Hauser had the following functions:

	Dosing control for up to 16 filling points
	Automatic, continuous correction of the excess volume
	Manual filter for correcting the leak flow volume
	Recognition and intelligent handling of air bubbles in the filling pipe
	Status monitoring of valves and flowmeters
	Control of the pressure in the product reservoir
	Communication with a supervisory system via PROFIBUS DP digital interface

The dosing system handles the filling process only. The mechanical parts of the filler, e.g. container feed, pumps, lowering of the filler nozzles etc, are controlled by the supervisory system, start commands being communicated via the PROFIBUS DP interface. The system is self-monitoring, adapting to changes in mechanical and physical flow conditions. When air bubbles are detected, the dosing is immediately reduced for the nozzle in question until the danger has passed, thus avoiding overfilling and shutdown of the entire line.

Features and benefits

According to the customer, the converted filler No. 1 is "the line with the highest productivity, the highest accuracy and the lowest downtime”. Further conversions are in planning.

	Control and automatic correction of fill-up quantity
	Possibility of manual corrections
	Detection and handling of air bubbles in the medium
	Filling time control and status monitoring

The dosing system installed comprised sixteen Coriolis mass flowmeters of type Dosimass DN08 with DN15 screwed pipe connections to DIN 11851, the reduction from DN15 to DN08, providing the required back-pressure.

The Coriolis mass flowmeters were connected to a fast Omron PLC that controlled 16 DN08 Gemü diaphragm valves. The dosing system is configured via a small 6” Omron touchpanel. The complete system communicates to a supervisory Simatic S7-315 system via a PROFIBUS DP interface. The integration was done by the customer's own engineers.

Dosing control system

Filling of shampoo and conditioner in the

production of hair care products

Case Study Engineering

CS004S/04/en

Dosing solutions for filling machines

Modular dosing solution for

flowmeter-based filling machines

Innovation Brochure

IN005S/04/en