Enameling Technology

Analysis of energy and material flows in the production of metal spindles

An analysis of energy and material flows identified measures to reduce the consumption of electricity and paint in the manufacture of lawn mower spindles, and to use the environmentally friendly resource of natural gas instead of fuel oil. 



The Niederstotzingen factory of GARDENA Manufacturing GmbH manufactures metal parts such as blades and shears for GARDENA gardening tools.

The energy used is primarily electrical, although the burner for the paint dryer is run on fuel oil.


Project objectives:

  • To provide a transparent presentation and analysis of the energy and material flows
  • To identify potential for optimisation
  • To achieve transferability of the results to other products

The production of spindles for the GARDENA reel mower was examined during the analysis of energy and material flows.

The following stages in the process were considered:

  • For the agitator: die-cutting, scouring, injection and welding
  • For the blades: laser cutting and spiralling
  • For the spindle: welding, washing, relaxing, PFTE coating, grinding



Proposed solutions:

  • Grinding machines: optimise energy consumption in new machines
  • PFTE coating unit: test whether robot technology would reduce paint losses
  • Recover heat from paint drying process and use for pretreatment
  • Paint drying: use natural gas instead of fuel oil
  • Reduce amount of unused mass in tempering furnace


Environmental benefit (based on total energy consumption in the manufacture of spindles, including generation of electricity):

  • Natural gas instead of fuel oil: 4% reduction in CO2 emissions, 9% less sulphur dioxide, 78% reduction in hydrocarbons
  • Optimisation of tempering furnace: Around 0.5% potential for electricity savings


Cost benefits:

  • 30% reduction in paint consumption possible for short spindles
  • Each percentage increase in the efficiency of the grinding machines affects 2/3 of total electricity costs

Participants of the project

Implementing Institution

GARDENA Manufacturing GmbH

Cooperation Partner

PE Europe GmbH

Promoting Institutions

Promoting Institutions

Landesanstalt für Umwelt Baden-Württemberg

Promotional program

Programm BEST (2003 - 2010)

More Project Information

Project period:: 2005 - 2007

Project region:: Germany (Baden-Württemberg)

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Source: Landesanstalt für Umwelt Baden-Württemberg