Science and Technology of Cultural Famental | The dehydration and protection of the Tao Drum in the National Expo Pavilion

Author:National Museum Time:2022.09.22

The audience basically displayed in the National Museum "Ancient China" to enjoy the colorful pottery drums.

Photography | Under Dongshan Rie

【Editor's Note】

In the National Museum "Ancient China", there is a new stone pottery drum during the new stone period, which is a first -class cultural relics collected by the National Expo Museum. A few years ago, it had a long "fluff", and after the "mask" was treated by the Wenbao personnel, it was only "put on the job". This case was selected into the "Shi Yu Chonghui -National Museum Cultural Conservation Achievement Exhibition".

Now, please tell you the story behind this.

"Didn't expect the pottery to grow Mao?"

This Neolithic period was preserved in a large wooden box. One day in 2016, when the warehouse administrator opened the box again, the white "fluff" grew in the inner wall and speaker mouth of the cylinder -like cylinder.

Figure 1 Treatment of the white "fluff" at the edge of the front color pottery drum bell mouth

Figure 2 Treatment of a needle -shaped inner wall in the inner wall of the colorful pottery drum cylinder

Caimao Drum was unearthed in Leshanping, Yongdeng County, Lanzhou City in 1986, and has a history of more than 4,500 years. [2] Its texture is red pottery, 36.9cm long, 29.2cm in diameter, and 9.3cm in diameter of small mouth. The drum body is a cylindrical shape, one end is expanded to the outside, and the distance between the near -mouth is decorated with an equal nail. The other ends are slightly thicker. It is a small round mouth. The body is painted with black and red parallel strings and parallel strip lines (Figure 3). It has the characteristics of colorful pottery in a distinctive Neolithic era. It is a precious physical material to study the ancient culture and primitive life of my country.

Figure 3 National Museum of China

1. Detection and analysis

Cultural relics protection work often starts from analysis and detection, and the cause can be found in order to take the right medicine. Cultural security personnel first used the "white hairs" on the surface of the color pottery drum with the pupae, and put it under the microscope. The original "white hair" was actually a needle -shaped salt crystal (Figure 4).

Figure 4 Crystal form under the microscope (100 ×)

After analyzing the composition of these crystalline salt, the cultural security personnel further discovered that they were a needle -like crystalline salt called vinegar chloroccalite (

) (Figure 5). Through in -depth research, the acetic acid in the crystalline salt is mainly caused by the organic matter volatilized by the wooden cap box used for storing pottery (Figure 6). The acetic acid and the calcium ions contained in the chloride ions and pottery that were originally in the pot pores were in a certain temperature and humidity. Under the conditions, the crystal is precipitated, and the needle -shaped vinegar chlorine stones are finally formed [3].

Figure the XRD diagram of the five crystals

Figure Liulin and Sour Paper Box Volatile

Second, the dehydration of the color pottery drum

The treatment of the surface salt crystalline phenomenon of colorful pottery drums is not simply so simple to clean the surface. Because even if the surface crystalline salt is fully cleaned, the moisture in the environment will still carry soluble pollutants. The capillary is migrated in the ceramics through capillary, which makes the disease recur when the environmental humidity mutations are mutated, which will affect the "" Caimai Drum " healthy". Therefore, in order to effectively remove the soluble salt ions inside the ceramics, the cultural security personnel decided to make a whole body "deep cleaning" for the color pottery drum.

At this stage, the treatment method of pottery dehydration is: distilled water soaking and dehydration method, absorbing salinity and environmental control method [5]. However, because the painting layer of colorful pottery drums is very precious and traces of fracture repair in the middle of the body, the most traditional pulp dehydration method is finally used to mild salt dehydration treatment. The crystalline salt inside and outside the colorful pottery drum is gently pinching with the mule, and the surface is cleaned with a soft brush. This seemingly mysterious "dehydrated", in fact, is similar to the "mask" similar to the beauty of beauty. However, the "mask" of the "mask" of the colorful pottery drum is not ready, and the cultural security personnel need to be tailor -made.

The specific method is to tear the rice paper into a piece of pieces, put it in a container that soully distilled water, heat and stir to make it a pulp, add an appropriate amount of 1%NaOH aqueous solution to the soaked pulp, adjust the solution pH to 7-8, and this will be this. Put a layer of pulp evenly on the color pottery drum (Figure 7). The pulp dehydration method uses capillary to transfer the soluble salt inside the utensils to the pulp on the surface of the utensil, and crystallize on the paper. In this way, apply a part of the pulp to discharge a part of the soluble salt. Can remove soluble salts. The end point of the dehydration process is finally determined by the change of ion concentration in the slurry dissolved solution.

Figure Seven Paste Pottery Drum after Plasm

After nearly a year, after nine dehydration, the dehydration treatment of the color pottery drum was finally completed (Figure 8). In order to avoid the invasion of acidic gases such as acetic acid, cultural security personnel also customized a "new home" made of acid -free materials for color pottery drums (Figure 9). The current colorful pottery drums have re -"enrolled". In the basic display of the "ancient China" of the National Museum, it quietly shows the audience the mysterious ancient culture of our country.

Figure 8 The colorful pottery drum after treatment

Figure Jiucai Pottery Drum Acid -free material bag

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references:

[1] Li Mo, Cheng Xiaolin, Wu Na, etc.: "Analysis and treatment of crystalline salt on the surface of the neolithic Pottery Drum Survey", "Traditional Technology and Modern Technology -East Asia Cultural Heritage Protection Society, the sixth international academic seminar Conference Paper Collection, Fudan University Press, 2019, pp. 76-82.

[2] Wang Wenyuan: "Pottery Drum: The ancestor instrument from ancient times", "Oriental Collection", No. 3, 2013, pp. 41-42. [3] Gibson L T, Cooksey B G, Littlejohn D, et al. The mode of formation of the cotrichite, a widespread calcium acetate chloride nitrate efflorescence. Studies in Conservation, 2005,50(4):284-294.

[4] Alice B P, Michael S. Salt Efflorescence on Pottery in The Athenian Agora: A Closer Look. Studies in Conservation, 2015,60 (3): 172-184.

[5] Yang Ying: "Research on Deserting Salt in Frequent Salt Salt in Vulnerability", a master's degree thesis in Northwestern University, 2013, p. 13-16.

Cultural Security Small Encyclopedia

【Showing】

The dehydration of pottery is a way to reduce the soluble salt content inside the pottery. The slurry dehydration is a dehydration method that can be used for painting pottery. With the evaporation of the water in the pulp, under the influence of the capacity of the capillary, the soluble salt in the utensil will gradually transfer to the paper. After the pulp is dry, remove and replace it with a moist pulp to achieve repeatedly to achieve the purpose of dehydration dehydration. Essence

(Organize | Li Mo, hand book | Liu Jianhui)

【Related Exhibition】

Exhibition: Shi Yu Chonghui -National Museum Cultural Conservation Achievement Exhibition