The standard was published as VDA 19 and is still valid today in several updated versions. The international counterpart to VDA 19 is the ISO 16232 standard, the current 2018 version of which is fully compatible with VDA 19 Part 1.
VDA 19 describes, among other things, how components must be cleaned, tested and packaged in order to avoid contamination by particles or liquids. The regulations comprehensively define the requirements for the technical cleanliness of components in the automotive industry. Sectors outside the automotive industry, such as precision mechanics and the optical industry, also benefit from the suggestions on how to achieve clean production.
In order to achieve technical cleanliness, measures are taken to reduce the formation of particles in the process, among other things. The use of cleanrooms is an important aspect of VDA 19, as they provide a controlled environment for cleaning and testing components. In a CNC Cleanroom, particles are measured on surfaces to monitor cleanliness. In contrast to cleanroom production, the particle size to be avoided is usually in the visible range ( > 50 µm). The measurements are carried out using washing tests and optical methods. The particle sizes in production at CNC Cleanroom may be up to 600 µm or even larger depending on the process. More important than the size is often the type of particle that can affect production, e.g. the presence of metal particles.
Cleanliness levels and particle count in technical cleanliness according to VDA 19
The VDA defines four cleanliness levels for technical cleanliness in assembly. The higher the cleanliness level, the smaller the number and size of particles present on the parts. The four levels are:
SaS0: non-regulated area
In this area, no special measures are taken to prevent or minimize particle contamination. The ambient conditions correspond to those of a normal industrial hall.
SaS1: Clean zone
In this area, measures are taken to reduce the entry of particles from outside and the carry-over of particles via the process chain. The production environment is access-restricted and controlled.
SaS2: CNC Cleanroom
In this area, in addition to the measures for a clean zone, ventilation conditioning measures are also taken to reduce the entry of particles by means of filter systems.
SaS3: Cleanroom
The highest demands are placed on technical cleanliness in this area. Access is via airlocks. The environmental conditions correspond to those of a clean room in accordance with EN ISO 14644.
It should be noted that VDA 19 does not prescribe a specific level of cleanliness, but refers to the individual requirements of the respective cleanliness specification. The choice of cleanliness level depends on the type and degree of contamination of the components.
In most cases, cleanliness level 2 sufficiently fulfills the conditions for clean assembly if hazardous particles need to be reduced.
Cleanrooms in which the concentration of particles is monitored and regulated are therefore a key aspect of VDA 19, as they provide a controlled environment for cleaning and testing components. The permitted number of particles is measured and recorded in steps of 5 µm – 1000 µm on the surfaces using washing tests and optical methods (see table). The permitted number of particles is not defined by the VDA, but is determined for each process. More important than the size is often the type of particles that can affect production, e.g. the presence of metal particles.
The particle sizes significantly exceed the particle sizes permitted in a Cleanroom.
Clean rooms are therefore generally easier to set up and cheaper to operate than a regulated Cleanroom with complex filter and ventilation technology.
