Analysis of energy and material flows in the coating of body trims for automotive interiors

An analysis of energy and material flows showed that exploiting the energy content of the solvents can reduce the energy needed for the coating process and the waste generated in the paint shops.

Erwin Behr Automotive GmbH manufactures wood, fabric, aluminium etc. trims for the interiors of luxury cars.

The trims are coated using conventional application technologies (spraying) and a special patented curtain coating process.

Objectives of the project

• To achieve transparency regarding operating energy and material flows, particularly in the coating machine
• To draw up and assess a solvents balance
• To achieve transparency regarding operating energy and material cost
• To identify the potential for optimisation with measures integrated into the production process
• To present a concept for the thermal recovery of solvent emissions

The evaluations focused on solvent emissions and on the use of the energy contained in the solvents to supply the company.
A process flow chart and a detailed energy and material flow balance were used to simulate several scenarios and identify potential for optimisation.

Findings

Use of solvents:
Recovery of a high percentage of the solvent emissions could cover up to 23% of the heat required by the presses. At 40 tonnes of solvents each year, the savings potential amounts to EUR 18,000-22,000 p.a.

Recovery of solvents:
It should be possible to extract a high concentration of solvents by suction without too great an effort in the conventional application technologies and to introduce the recovered solvents into the heat generators for the presses.
This would facilitate compliance with the 50mg/m³ waste air threshold.

Coating process:
Increasing the efficiency of the coating process could lower the cost of buying the coating material and reduce the amount of waste produced (around EUR 6,000 p.a. for a 1% reduction in the amount of coating material needed).

Waste:
The extent of the contaminants present in the waste should be analysed in more detail.
This analysis may identify recovery options, e.g. at the solvent manufacturing plant. The cost of waste from the paint shops amounted to EUR 34,000 in 2003.

Curtain coating process:
The curtain coating process patented by Behr has already been optimised for economy and ecology. It minimises the exploitation of solvents and the resulting emissions considerably.
Source: Final report

Back to overview