As a kind of cultural relic protection and restoration technology and equipment, laser cleaning technology has been widely used in the world, especially in the cleaning, protection and restoration of ancient buildings and their various construction surfaces, with many successful cases.
Due to various environment and storage time and other reasons, cultural relics have been preserved for a long time. There will be a lot of dirt on the surface, such as soil spots, rust spots, oil stains, water stains, sweat stains, etc. due to the variety and different texture of the utensils, the cleaning methods are also different. This brings a lot of inconvenience to the cleaning of cultural relics. Now let’s take a look at the traditional ways of cleaning cultural relics?
1 Water Wash
For the general solid texture, not afraid of water immersion utensils, surface adhesion or contamination of dirt can be washed with distilled water.
The fixtures on the unearthed utensils are hard and difficult to wash off at one time. Do not use metal or hard objects when cleaning, so as not to damage the utensils.
2 Dry Cleaning
If there are stains on textile cultural relics, they may fade after washing;
Should use gasoline and other things to scrub, can also use dry cleaner spray directly in the stain;
Note: dry cleaner should be tested before use.
3 Dry Wipe
In order to preserve the natural color of some water fearing utensils and unearthed objects, it is not suitable to rinse them with water or medicine.
For this kind of utensils, gently wipe them with soft damp cloth.
4 Air Drying
For paper articles and some fabrics that are not suitable for washing or dry wiping, air drying method should be selected to blow away the dust and moisture on the surface.
Note: avoid strong sunlight, strong wind, dust pollution and pollen contamination.
5. Mechanical Dust Removal
For larger, bulky and irregular objects, mechanical dust removal such as vacuum cleaner can be used; For larger stone carvings and sculptures, high pressure air pump can be used to blow off the dust that is difficult to be removed by the vacuum cleaner.
6 Drug Cleaning
It is mainly used for antiques and unearthed cultural relics preserved in various harsh environments.
Note: due to the difference of the mixed substances in the unearthed materials from different places, experiments should be done first when using the self-made medicine solution, and different drugs and methods should be used.
The above six cleaning methods will cause irreversible damage to cultural relics, but it is only a matter of the extent of damage.
Laser cultural relic cleaning is different. Laser cleaning uses the characteristics of laser beam. Through the concentrating system, the laser beam can be concentrated into different spot diameters. Under the condition of the same laser energy, the energy density or power density generated by different spot laser beams are different. In this way, the laser energy required for cleaning can be easily controlled. Laser can achieve high concentration in time and space. Laser cleaning is the use of these features to effectively remove pollutants. The pollutant can be peeled off from the surface of the cultural relic instantaneously, so as to realize the cleaning of the cultural relic.
Another important aspect: it is a harmless way of cleaning – the material on the surface of cultural relics and the pollutants attached to it absorb different laser beams. This difference enables people to distinguish between the pollutants and the material on the surface of cultural relics, so as to accurately control the laser energy required for cleaning, so as not to damage cultural relics, but also to remove pollutants. At present, this technology has been widely used in stone relics, oil painting and other fields.
At present, the global laser industry is developing faster and faster, which promotes the rapid development of laser cleaning. Although the current laser cleaning technology can not replace the traditional cleaning technology, it is not even mature. However, many research institutions of laser cleaning have studied the conditions of laser technology and the complex interaction between updraft and mechanical factors, although these interactions have not been fully applied to practice. However, with the progress of process knowledge in theoretical model control strategy and the continuous development of laser cleaning technology, laser technology will overcome the disadvantages of traditional operation and provide more and more effective potential value in industrial development.
It can be predicted that laser cleaning with its strong adaptability, its application will continue to be expanded to new areas, bringing a green revolution for the cleaning industry.