Since the first automatic washing machine for households in 1937, the minimization of the  purchasing costs (determinated by the design) and the operating costs (due to the water and energy requirements) have always been goals of the continuous development of all manufacturers.

Most of the energy required by a washing machine is used for heating up the water. It is determined by the laws of physics: the temperature increase of 1 liter of water by 1 degree Celsius always requires 1.16 watt-hours. This means that the energy requirement is primarily determined by the hot water quantity and temperature.

The achieved washing performance depends not only on the temperature but also on the mechanics, chemistry and washing duration. A reduction of the energy consumption by lowering the water temperature can be compensated, within a certain limit, by an elongation of the washing time or a corresponding detergent (“Sinner’s Circle”).

1937: First automatic washing machine “Bendix Home Laundry”
© Bendix Home Appliances

Development of energy and water consumption per wash cycle
Source: Own illustration based on IKW (2019) Sustainability in the washing, care and cleaning agent industry in Germany

Until the mid-1990s, a reduction in the energy and water requirements per wash can be observed. The clear flattening of the curves from this point on indicates that the technical limits for washing machines have already been reached.

To improve the sustainability of a product, it is necessary to reduce the total resource requirements per use.

Total resource requirements

The life cycle of a product consists mainly of three phases: Production, use, recycling & disposal. A washing machine requires about 1.9 tons of natural resources in its production.

In order to assess the sustainability of a product, the expense of production, recycling and disposal must be attributed to the use phase.

Resource requirements per use

A simple option to reduce the resource requirements per use is to design the machine for longevity, maintainability, and reparability.

For products where the technical limits have already been reached, this is often the most effective option.

Reduced resource requirements per use by extending the service life

The publicly accessible repair manuals and stocking of spare parts can improve the service life even without changing the design and be an important purchase decision when buying new ones. 

By aligning the design with digital manufacturing processes, it is possible to produce replacement parts as needed.

Digital manufacturing processes differ from all others in the aspect, that the shapes of the parts to be produced are available exclusively as digital data, which are used directly to control machine tools. As a result, the production costs of individual pieces are low, compared to industrial processes that require a costly mold and are only economical for high quantities.

Reibungsdämpfer, CNC lasergeschnitten

Required:

Manufacturing processes that are economically applicable even in small quantities, e.g. 

­— CNC milling & turning
— CNC laser cutting
— CNC punching & nibbling
— CNC bending
— All 3D printing processes

Additionally possible: 

Manufacturing processes that require costly tool making, e.g. 

­— Injection moulding
­— Punching
­— Deep drawing of sheet metal

Local service providers act as producers for repair shops because of the resulting digital spare parts storage.