Plastics react differently to solvents. What could be the influence of solvents on these materials?? By acting with a solvent on the plastic, you can them:
1) dissolve;
2) loosen;
3) unfold;
4) saturate with solvent, which will be absorbed by them and kept for a long time (solvent retention); the coating may blister as a result of the subsequent release of the solvent.
Plastics are more resistant to weather conditions than other substrates. Despite this, plastics also change with aging. What factors cause aging?
They cause aging of plastics:
1) physical impacts (also damage);
2) the impact of chemical factors;
3) UV;
4) oxidation (oxygen binding at the surface);
5) plasticizer diffusion;
6) static loads.
How the penetration of the plasticizer can occur?
1. The plasticizer can penetrate from the surface into deeper regions of the plastic. Because there are strong stresses on the surface, and the deeper zone is more flexible, scratches appear on the surface.
2. The plasticizer can penetrate the surface of the plastic. Due to the concentration of the plasticizer on the surface, it becomes soft and sticky. This leads to its soiling.
3. The plasticizer can penetrate from the plastic to another material. As a result, the material becomes brittle. The material taking up the plasticizer quickly becomes sticky and becomes dirty.
What are the necessary tests for plastic substrates?
Please list the relevant methods
Research of plastic substrates:
| Type of examination | Test method |
| Dirt | visual examination |
| Presence of oils and release agents | an attempt to moisten with water – if there are oils or release agents on the surface, then the water beats up |
| The presence of airing products | hand rubbing or scratching the material; recognition by identifying the formation of abrasive dust |
| Strength of the existing coating | scratch test or adhesive tape test; adhesion test |