Engineering plastics – The Manual - F.wood-supply.dk

Cleaning plastics
According to DIN 8592, cleaning is a chemical process
used in manufacturing to remove residues.
The following cleaning methods are particularly suitable
for plastic cleaning:
The four factors relevant to cleaning
Chemical
• Type of cleaning
• Cleaning chemical
• Concentration
Temperature
• Cleaning temperature
• Rinsing temperature
• Drying temperature
Mechanical
• Ultrasound
• Flow mechanism
• Spraying
• Brushing
• Geometry adjustment
Time
• Cleaning time
• Rinsing time
• Drying time
Depending on the type of soiling, the relevant areas have to
be adapted in order to achieve adequate cleanliness. Every
process must be taken in context with the input parameters
(material, geometry, contamination) and the output parameters
(cleanliness requirement)
Process is influenced by:
ˌˌContamination
(film, particulate, coating, germs)
ˌˌComponent geometry
(bulk material, single part, scooping, functional surface)
ˌˌComponent material (plastic)
ˌˌRequirements
(rough cleaning, cleaning, precision cleaning, ultraprecision
cleaning)
Wet chemical methods
ˌˌAlso suitable for components with ultra-complex
component geometries
ˌˌUsable for most plastics
ˌˌNo abrasive influence on components
ˌˌCaution in the case of materials which absorb
moisture (PA), due to tolerances
ˌˌCaution in the case of materials sensitive to stress
cracking (amorphous) such as PC, PSU, PPSU etc.
Mechanical processes
ˌˌPrimarily suitable for the rough cleaning of plastics
(brushing, wiping, …)
ˌˌCaution with soft plastics due to possible surface
damage (scratching)
CO 2 snow - dry ice blasting
ˌˌVery suitable, as blasted material is subjected
to practically no damage or influence.
ˌˌThe process is dry, non-abrasive and does not
result in transfer of heat to the component.
ˌˌIdeally suited also for soft materials and materials with
high moisture absorbing properties (PTFE, PA, …)
Plasma method
ˌˌSuitable for components with
ultra-complex component geometries
ˌˌSimultaneously exerts an activating effect
on the plastic surface
ˌˌNo abrasive influence on the surface,
no humidity in the system
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