KR20230106324A - Packaging method of cultural properties - Google Patents

Abstract

The present invention relates to a method for packaging cultural properties, which can safely pack cultural properties, such as pottery, that are easily damaged by impact, without damaging them and safely against impact. As for safe packaging, (1) a 3D scanning step of three-dimensionally scanning the cultural property to be packaged to obtain polygon data; (2) a 3D modeling step of three-dimensionally modeling the cushioning material based on the polygon data (external information of cultural properties) obtained in the 3D scanning step; and (3) a 3D printing step of three-dimensionally printing a cushioning material including a space capable of accommodating a cultural property based on the data obtained in the 3D modeling step.

Description

Packaging method of cultural properties}

The present invention relates to a method for packaging cultural properties, and more particularly, to a method for packaging cultural properties that can safely pack cultural properties that are easily damaged by impact, such as pottery, without damaging them and against impact.

From the viewpoint of conservation science of cultural properties, it is appropriate to regard packaging of cultural properties as a preventive measure. Protecting cultural properties from external shocks and preventing the cause of damage to cultural properties in advance is the most important purpose in packaging, and the purpose of prevention can be achieved by itself.

Packaging can be said to be a kind of cultural property protection device. The parts that come into direct contact with the relics are wrapped with soft materials such as neutral paper or cloth to prevent scratches, and these are wrapped with various cushioning materials to prevent direct impact from being transmitted to the cultural property. Finally, they are packaged in an outer box, which is the outermost protective device that prevents external physical shock and moisture penetration. All cultural property packaging is carried out on the basis of the above.

Packaged cultural properties can be damaged due to several factors. For example, in the process of moving cultural assets, they may be damaged due to physical shock and vibration due to an accident during transportation, and cultural assets stored in natural disasters may fall and be damaged. In order to prevent damage from external physical impact, it is necessary to remove the cause of damage to cultural properties by packaging them in an appropriate way.

Currently, the packaging method for cultural assets commonly used in domestic museums uses a rechargeable packaging method using Korean paper and cotton cloth inside a wooden box. Depending on the situation, an aluminum box is overlaid on the outside of the wooden box and the four-layer packaging is performed: neutral paper → cotton cloth → paulownia wood box → aluminum box. The wooden box uses a paulownia wood box that is effective in controlling humidity and is capable of mitigating shock.

Cotton cloth is a bag made by wrapping cotton with neutral Korean paper or Tyvek. The cotton acts as a buffer to protect cultural assets from physical impact and is convenient to use, so it is mainly used in various packaging processes. However, the material itself lacks resilience and resilience, and cotton cloth does not adhere to cultural properties, which can cause damage due to shock and vibration. In addition, when repackaging after release, the packaging performance is not uniform, resulting in poor reusability.

The method commonly used abroad uses a molded packaging method using neutral paper and plastic foam. Plastic foam has excellent waterproofing ability, so it can protect cultural properties from moisture, and because it is close to neutral, no chemical action on cultural properties occurs. However, there is a problem in that shock absorption ability and vibration protection ability are insufficient compared to cotton cloth, and ventilation is not performed smoothly.

Materials used for packaging of cultural heritage should be chemically stable and capable of effectively absorbing physical impact, and technical conditions should be considered in addition to material conditions. Although the same packaging material was used to wrap cultural properties, differences in packaging performance may occur depending on the packaging skill of the worker. Cultural heritage pavement workers should perform paving through skilled technology, but difficulties in paving are due to manpower problems.

In addition, the selection conditions for packaging materials should be selected in consideration of various factors such as workability, weather resistance, and chemical stability. Currently, in order to prevent the risk of damage during packaging of cultural assets, basic physical property tests and reliability evaluations of packaging materials, simplification of packaging processes, and research on the development of new packaging materials are being partially conducted, but standardized methods or studies are insufficient.

Therefore, the present inventors studied a new packaging method for cultural properties, especially ceramic cultural properties, to which 3D digital printing technology was applied, and obtained 3D shape information of ceramics through 3D scanning to produce a packaging box that completely adheres to ceramics. After modeling, a thermoplastic polyurethane filament (hereinafter referred to as “TPU Filament”) with elasticity and bendability is printed with a 3D printer to produce a ceramic packaging cushioning material, and then, physical properties are tested and reliability evaluated. Through this, the appropriate output options of the TPU Filament were confirmed, and the present invention was completed by confirming that it could replace the previously used cotton cloth.

A cultural heritage packaging method according to the present invention includes: (1) a 3D scanning step of obtaining polygon data by three-dimensionally scanning a cultural property to be packaged; (2) a 3D modeling step of three-dimensionally modeling the cushioning material based on the polygon data (external information of cultural properties) obtained in the 3D scanning step; and (3) a 3D printing step of three-dimensionally printing a cushioning material including a space capable of accommodating a cultural property based on the data obtained in the 3D modeling step.

1 is a photograph showing an example of neutral Hanji cotton cloth used as an interior material among packaging materials for cultural assets.
2 is a photograph showing an example of Tyvek cotton fabric used as an interior material among packaging materials for cultural assets.
3 is a photograph showing an example of a paulownia wood box used as an exterior material among packaging materials for cultural properties, particularly ceramics.
4 is a photograph showing another example of a paulownia box used as an exterior material among packaging materials for cultural assets, particularly ceramics.
5A to 5J are photographs sequentially taken of an exemplary cotton-filled packaging method among conventional cultural property packaging methods.
6a to 6f are photographs sequentially taken of an exemplary mold packaging method among conventional cultural property packaging methods.
7a to 7j are pictures sequentially showing an example of a method for packaging cultural assets according to the present invention.
8 is a graph of the transverse compressive strength of the octet pattern among the patterns filling the inside when 3D printing using the TPU filament used in the present invention.
9 is a graph of the vertical compressive strength of an octet pattern among patterns filling the inside when 3D printing using a TPU filament used in the present invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the present invention, packaging is performed with a cushioning material printed using cotton cloth and TPU Filament, which are generally used for packaging cultural assets, and evaluation of physical properties and reliability according to each packaging method is performed, and the packaging buffer produced and printed using TPU Filament is cotton. Powa replacement possibility was confirmed.

First, the packaging materials to be carried out in the present invention were selected by finding the currently researched cultural heritage packaging research cases and investigating the existing ceramic packaging methods and materials. It was investigated based on the cases of the papers and reports that have been studied in the past. For the packaging method, a cotton-filled packaging method, among which, a double packaging of a cushioning material → outer box was carried out, and Tyvek cotton cloth was selected as the packaging buffer material and a paulownia wood box was selected as the outer box.

Second, TPU filament, a material that has elasticity and can secure material resilience and vibration resistance, was selected as a comparative material to compensate for the disadvantages of the cotton fabric used previously. TPU Filament is made of polyurethane synthetic rubber resin and has elasticity and easily bendable properties, so it has the advantage of being able to produce flexible and elastic outputs.

Third, in order to solve the problems of cotton cloth, such as adhesion and insufficient recyclability, a packaging cushioning material was produced using 3D digital technology. The external information of the object was scanned with a 3D scanner, and the packaging buffer was modeled to create a packaging box, which was then printed using a 3D printer. 3D printers can print 3D model data, have excellent dissemination and accessibility of the device, and have the advantage of being able to easily produce 3D models.

Fourth, a physical property test was conducted to confirm the buffering and physical properties according to the inner grid and filling rate of the TPU Filament output. As for physical property tests, compressive strength test, permanent compression set test, and puncture impact behavior measurement test were conducted. For the production of the specimen, three types were selected through preliminary experiments: quarter cubic, cross-shaped 3D, and octet. The printing direction was selected horizontally and vertically, and the internal filling rate was set at 20%, 30%, and 40%. According to the results of the physical property test, the printing of the TPU filament packaging cushioning material was carried out by setting the options to be applied to the actual packaging.

Fifth, a reliability evaluation was conducted to evaluate the buffer performance of the printed TPU filament buffer material. Through a drop impact test, a vibration test, and a box compression test, the possibility of substitution was confirmed by comparing cotton and TPU filament cushioning materials.

First, we look at existing research cases.

A study was conducted to evaluate the reliability of the filling packaging method using cotton fabric, which is mainly used in Korea, and the mold packaging method using plastic EVA foam, which is mainly used in foreign countries. As for the contents of the study, after packaging was carried out according to each packaging method, a study was conducted to confirm the ability to mitigate temperature and humidity changes and the ability to absorb shock and vibration of the packaging material through temperature and humidity experiments and drop impact and vibration tests.

As a result of the experiment, the temperature insulation ability was similar, but the moisture absorption and desorption ability of the cotton fabric was superior. Both methods were excellent in the drop impact test, but the cotton-filled packaging method showed better results, and the vibration absorption ability showed almost similar results. Through this, it was confirmed that the packaging method using cotton fabric has better packaging performance than the mold packaging method using EVA foam.

Through 3D scanning and the Taguchi technique, a pavement support frame that fits the shape of the cultural property was produced. The Taguchi method is an experimental technique that minimizes the influence of uncontrollable factors through controllable factors. By applying this technique, the optimal processing conditions for packaging cultural properties of polyurethane foam were studied and actual packaging boxes were fabricated.

A reliability evaluation comparison experiment was conducted between the previously manufactured polyurethane foam pavement support frame and the previously used pavement method, and through this, the paveability of the polyurethane foam support frame was confirmed. As a comparison group, the rechargeable packaging method using hand-carved polyurethane foam and cotton cloth and the packaging method using air caps were set. The contents of the study were a drop impact experiment with an accelerometer attached and vibration waves that may occur during transportation of cultural assets 10 Vibration experiments were conducted using a frequency of 40 Hz to 40 Hz.

As a result of the experiment, the impact force received by the 3D polyurethane foam packaging method in the drop impact test was about 71% of the impact force of the air cap packaging method and about 68% of the impact force of the cotton filling packaging method. showed results.

In the vibration test, the 3D polyurethane foam support frame showed a large vibration level between 10 and 15 Hz, but then showed very stable support performance in the frequency range, while the air cap packaging method has a large amplitude range in the 10 to 20 Hz section, After , the vibration stabilized, but the vibration level rose temporarily within the 30 Hz section. In addition, it was confirmed that the cotton filling packaging method showed a large vibration level range over the entire frequency range.

In particular, the design of premium product packaging that can be produced through the 3D printer output system according to the present invention, rather than the mold manufacturing technology of existing product interior materials, was studied. In order to design and analyze a design that is more efficient than existing interior materials, customized interior materials were designed using a design design program and 3D printer. In the present invention, TPU Filament, which has excellent cushioning and elasticity, was selected as a standard material and printed in a grid-type and porous foam-type design.

As a result of the study, first, it was possible to shorten the completion time and post-process of the output interior material compared to the existing materials. The more complex the shape of the existing interior materials, the more difficult the unit price and production method are, but 3D printers can easily manufacture complex-shaped parts and shorten the manufacturing time.

Second, it was possible to print packaging materials suitable for the shape by manufacturing grid-type and porous foam-type packaging materials, and the recyclability of the printed interior materials was confirmed. Through this, it was judged that the efficiency of the packaging material was increased.

Third, it was possible to draw the conclusion that the buffering property was strengthened.

Hereinafter, packaging materials for packaging cultural properties, particularly pottery cultural properties, will be described.

In the selection of packaging materials for ceramic cultural assets, several criteria are considered.

First, materials in a chemically stable state must be used. Materials that chemically damage ceramics or materials containing harmful substances should not be used.

Paper boxes or wrapping paper containing general acidic chemicals should not be used as acidic substances may transfer to cultural properties and accelerate damage to cultural properties. In particular, in the case of newspaper, it is effective in preventing insect damage, so it is sometimes used as a wrapping paper for cultural assets, but it should be avoided because it can cause damage to cultural assets due to the transfer of acidic substances.

Second, a material with cushioning properties should be used. In the case of ceramics, the risk of damage due to external shock and vibration is relatively high, and more stringent buffering standards must be applied than other cultural property packaging. Third, economical materials should be used in consideration of recycling and cost issues, and lastly, materials that are stable against changes in external temperature and humidity should be used.

Considering these selection criteria, neutral paper, cotton cloth, ethylene foam (polyethylene foam), EVA foam (ethylene vinyl acetate foam), plastic foam, paulownia wood box, and aluminum box are mainly used as packaging materials currently used for packaging cultural assets. Neutral paper is chemically neutral to slightly basic paper in the range of pH 6.5 to 9 and is used to protect cultural properties from the external environment by wrapping them.

Cotton cloth is a buffer bag made of neutral paper, Korean paper, and cotton, and is used to protect cultural assets from shock and vibration. Plastic foam is produced in various ways, such as EVA foam and ethylene foam, depending on the content and material of internal bubbles, and is used to absorb external shock and vibration like cotton cloth. The paulownia wood box is used as the last outer packaging box, and the paulownia wood box is packed once more using an aluminum box outside the paulownia wood box.

In addition, various materials are used, divided into surface packaging materials, cushioning materials, inner skin boxes, and outer skin boxes, and the types and characteristics of each packaging material are shown in Table 1 below.

Neutral paper is a paper made of neutrality and weak alkalinity around pH 6.5, and refers to paper in which the components of the sizing solution are neutral. Right after the paper is manufactured, the hygroscopicity of the paper is large, so the ink spreads. In order to suppress such spreading, sizing treatment is performed, but most of the paper treated with acidic rosin has a problem in that deterioration proceeds. Accordingly, paper treated with a solution such as an alkyl ketene dimer, which is a neutral sizing treatment solution, is called neutral paper.

Neutralized paper used for packaging of cultural properties is used as a surface packaging material that protects the surface in direct contact with cultural properties. The surface packaging material protects cultural assets from scratches and prevents acid damage. Since it is a packaging material that directly touches the surface, traditional Korean paper and neutral paper made with chemical ingredients cannot be used, and traditionally manufactured Korean paper and neutral paper are mainly used.

Neutral paper is used by classifying physical properties such as thickness and basis weight according to the material and surface condition of the paper. Detailed physical properties and uses are shown in Table 2 below. As a characteristic, it is neutral, so there is no damage to cultural properties and it is convenient to use. In addition, it can be used for all cultural property materials and is cheaper than other surface packaging materials, but the physical properties of the material are weak.

Tyvek ^® is a fiber manufactured using high-density polyethylene (HDPE) fiber as a raw material, and is independently manufactured by Dupont. Tyvek has different types depending on the material of the fabric, and is divided into a hard type, which is a paper type, and a soft type, which is a cloth type. It has stronger physical properties than paper, but has a texture similar to paper and is ultra-light. In addition, due to antistatic treatment and corona coating treatment, dust and static electricity can be prevented, and the inflow of microorganisms and pests can be prevented.

Tyvek fabric used for packaging cultural assets uses a soft type. Since the surface is embossed and has elasticity like fabric and does not tear easily, it is used for surface packaging materials and cotton fabrics that must have excellent tensile strength. It has excellent abrasion resistance, waterproofing, and dustproofing, and can prevent damage due to deterioration and the habitation of lichens such as mold. It is also chemically inert and has high air permeability, making it safe from harmful gases.

Cotton cloth is the most commonly used cushioning material in Korea and has excellent insulation, moisture absorption and desorption capabilities, and shock absorption. Neutral Hanji (neutral Hanji cotton cloth; see Fig. 1) and Tyvek (Tyvek cotton cloth; see Fig. 2) are used for exterior materials, and natural cotton wool is used for the inner filling. It is made by wrapping an exterior material in a rectangular shape on the outside of cotton wool, and the neutral paper is finished with paper tape and the Tyvek is finished with cotton thread.

The size of the cotton cloth can be freely manufactured according to the size of the cultural property, and it is mainly produced and used in the size of 900 × 200 mm. Cotton cloth can be used for all materials of cultural heritage, and in particular, since cultural heritage packaging materials take a lot of cushioning properties into consideration, cotton cloth that can secure buffering properties is used in many packaging cases. In addition, it can be used for all cultural property materials and has the characteristics of being easy to manufacture and use.

However, if the cotton wool inside is exposed to the outside, it can adhere to the surface of the cultural property and generate a lot of dust. It lacks resilience and resilience, and the cotton cloth does not adhere to the cultural property, so damage by shock and vibration may occur.

Toilon (Polyethylene Foam) is a synthetic foamed resin that is produced in the form of a porous foam by foaming and compressing polyethylene synthetic resin, which is produced by polymerizing ethylene, at a high temperature. The name varies depending on the density, and 0.91 to 0.925 is called low density polyethylene (LDPE), 0.926 to 0.940 is called medium density polyethylene (MDPE), and 0.941 to 0.956 is called high density polyethylene (HDPE).

It is mainly used as a cushioning material in the packaging of cultural assets, and it is made thick by laminating 0.5 mm to 5 mm PE fabric by applying heat. It can be produced in various thicknesses to directly produce various three-dimensional objects, and because of its good elasticity, it is mainly used for packing hard cultural assets such as crowns or pottery or fixing them in storage boxes. In particular, it is the most commonly used material for three-dimensional fixation when transporting cultural assets or moving long distances.

It is inexpensive and can be carved and used according to the shape, so it can be applied to most forms of cultural properties. It has good moisture barrier properties, chemical resistance and low price, so it is used as a raw material for food packaging materials, transparent films for packaging buffers, and various wraps, in addition to packaging for cultural properties.

The box made of paulownia wood, which is widely used as an exterior material, is made of paulownia wood, which has excellent moisture control and insect repellent abilities. The older the tree, the better. Generally, it is produced with a thickness of about 12 mm and is customized according to the size of the cultural property. For example, after wrapping ceramics with cotton cloth, measure the value with a margin considering the thickness of the cotton cloth and the compressive stress caused by the cotton cloth. Usually, it is manufactured with a margin of about 15 to 20 mm, and the total height is manufactured with a margin of about 50 to 60 mm. The paulownia box is used as an inner skin box in the packaging of cultural properties and acts as a shock absorber and moisture proof. The paulownia box is divided into a lid-type box (see Fig. 3) and a slide-type box (see Fig. 4) according to the way the box is opened. Lid-type boxes are used for packaging general types of cultural properties, and slide-type boxes are used for mold and drawer-type packaging methods. Unlike other inner skin boxes, paulownia boxes are relatively robust and have the ability to control humidity, so they can protect cultural assets from the external atmospheric environment.

An aluminum box is a material that is used as an outer box in the packaging of cultural properties, and is a box that combines plywood and aluminum. The physical properties are solid and security can be increased by adding a locking device. In addition, it has excellent ability to block outside temperature and humidity, and once manufactured, it can be used semi-permanently.

In the following, the packaging method of cultural assets, especially ceramic cultural assets, is reviewed.

The packaging method for pottery cultural assets uses a cotton-filled packaging method and a molded packaging method. It is a particularly widely used packaging method in Korea, and the cotton-filled packaging method, which is a method of putting neutralized paper and cotton cloth in a paulownia box, is as follows, and an exemplary cotton-filled packaging method is shown in FIG. The pictures are shown sequentially.

Before packaging, observation for packaging is performed (Fig. 5a: Observation of weak parts of the object). For pavement observation, relatively solid areas and vulnerable areas at risk of damage are determined. The solid parts are the torso and the bottom, which have harder physical properties than other parts and are relatively free from breakage. Vulnerable parts are thin parts such as the mouthpiece, runner's inlet, outlet, handle, and spout, and packaging should be performed so that pressure or load is not directly transmitted to the weak parts.

Reinforce the uneven parts of ceramics or parts vulnerable to impact with cotton cloth (Fig. 5b: packaging of vulnerable parts, Fig. 5c: completion of reinforcement of weak parts). In the case of cultural assets with complex shapes, such as runners, they are wrapped to prevent direct transmission of impact to vulnerable parts, and the gaps between the body, jug, and handle are also filled with cotton cloth.

After that, the rim and the bottom are wrapped with a cotton cloth to make the overall shape rectangular. After placing the cotton cloth in a cross shape on the floor and placing the cultural property on it (Fig. 5d: installing the cotton cloth, Fig. 5e: placing the cultural property in the cotton cloth), lift the cotton cloth up and wrap the cultural property (Fig. 5f: cotton cloth wrapping). When wrapping the object, make a knot with cotton string to prevent the wrapping from unraveling (Fig. 5g: tie the cotton string). However, be careful as there is a risk of damage to the object when strong stress is applied.

Cotton cloth is added to the outer wall and bottom of the paulownia box to be packed (Fig. 5h: cotton cloth is installed inside the box), and the object is placed inside the box. After that, the cotton cloth is arranged on the object so that it can be placed inside the paulownia box. When the object is placed inside the box, the empty space is additionally filled with cotton cloth (Fig. 5i: cultural property placed inside the box is completed). The cultural property is filled with cotton cloth until it does not shake inside the box, and after filling, the cover is covered to complete the packaging (Fig. 5j: packaging complete).

When the ceramics are small in size or relatively simple in shape, several ceramics are packaged together in one box. The mold packaging method, which is a method of enshrining cultural properties by digging or sculpting polyethylene foam to suit the shape of pottery, is applied. The detailed method is as follows, and an exemplary mold packaging method is shown in FIG. 6f) are sequentially shown in photographs.

A polyethylene foam is prepared (FIG. 6a: preparation of polyethylene foam), and the cultural property is placed on the polyethylene foam, and a sketch is drawn on the foam to match the shape (FIG. 6b: confirmation of the part to be carved). According to the overall curvature of the cultural property, the inside of the foam is sculpted using a small tool such as a scalpel or removed using a wood burning tool (Fig. 6c: piece of polyethylene foam). Cultural assets are enshrined in the middle of the removal process and checked for shaking inside. If the carving is wider than the shape of the cultural property, shaking occurs inside, which leads to a decrease in pavement performance, so be careful. The depth of the foam is carved deeper than that of the cultural property, and the carving part of the cultural property does not rise above the foam. When the engraving is completed (FIG. 6d: Polyethylene foam fragmentation completed), the primary packaging is performed to protect the surface of the cultural property with neutral paper. After that, the wrapped cultural property is placed in the sculpted casting frame (Fig. 6e: cultural property placement), and then the mold is placed in the outer box to complete the packaging (Fig. 6f: packaging completion).

The method for packaging cultural assets according to the present invention is for safely packaging cultural assets that are easily damaged by external shocks, such as cultural assets, particularly pottery cultural assets. 3D scanning step to obtain; (2) a 3D modeling step of three-dimensionally modeling the cushioning material based on the polygon data (external information of cultural properties) obtained in the 3D scanning step; and (3) a 3D printing step of three-dimensionally printing a cushioning material including a space capable of accommodating a cultural property based on the data obtained in the 3D modeling step.

An example of a method for packaging cultural properties according to the present invention will be described in more detail based on the use of small-sized pottery as a cultural property for packaging.

The 3D scanning step of (1) consists of acquiring polygon data by three-dimensionally scanning the cultural property (FIG. 7a) to be paved. The first step in 3D digital packaging work is the process of acquiring 3D shape information of an object through 3D scanning. After scanning the upper and lower parts using an optical 3D scanner and a turntable (FIG. 7b), the point cloud data is completed by merging the data. Point cloud data is obtained by 3D scanning all surfaces of an object (ie, cultural property such as pottery), and a 3D polygon model is created through a meshing process, which is a process of converting the converted point cloud data into 3D surface data.

The 3D modeling step of (2) consists of three-dimensionally modeling the cushioning material (FIG. 7c) based on the external information of the cultural property obtained in the 3D scanning step. The acquired polygon data is loaded onto Freeform, a 3D modeling software, and sorted. Smooth modeling is possible only when the position of the object is set to 0, 0, 0 on the X, Y, and Z coordinates in the virtual space. After that, a 25 cm square box is fabricated outside the object (FIG. 7d). After creating the same shape as the object shape information inside the box, the data of the space where the object will be located is erased. When the data is erased, the shape of the data identical to that of the object remains inside the box like a mold. The box is cut in the virtual space so that the object can be placed inside (Fig. 7e). For cutting, after selecting a part to be cut with a virtual selection tool in the software, only the selected part is duplicated (FIG. 7f). Then, after removing the selected data, the copied data is pasted in the same place (Fig. 7g). The cutting direction is set differently according to the shape of the object. When the object is packed with the object, the cushioning material must enter well without strong pressure and shape deformation, and only minimal cutting must be performed so as not to degrade the performance of the cushioning material. In this study, it is manufactured by applying a method of vertically cutting from top to bottom by minimizing the cut surface. Accordingly, the number of cuts of the virtual box may be at least 1 time (particularly, when the object is symmetrical) to 4 times at most, but the present invention is not limited thereto, and the number of cuts is as many as necessary, but possible. It will be appreciated that it may be selected to form less. Data editing and modeling is performed in virtual modeling software (Freeform, 3D Systems, Inc., America) through a pen-shaped haptic device capable of sensing tactile feedback in a virtual space. Visually check the shape of the inside of the packaging cushioning material by comparing it with the actual packaging object. When visually confirmed, the area where the object may be caught during packaging and disassembly is removed using a virtual removal tool. After removal, the abnormal part of the data is finally checked before printing.

The 3D printing step of (3) consists of three-dimensionally printing a buffer material including a space capable of accommodating a cultural property based on the data obtained in the 3D modeling step. That is, when the production of the cushioning material is completed, printing is performed with a 3D printer (FIG. 7h). The output option is printed by setting the option of a cross-shaped 3D pattern, horizontal output, and internal filling rate of 20%, which is the result confirmed based on the results of the physical property experiment. As a result of the printing, the supporter that supports the output of the upper part is printed together, and it is removed using small tools. When the object is placed inside the cushioning material (FIG. 7i), no play occurs, and when the object is packed in a paulownia box (FIG. 7j), no gap is generated inside the box.

Preferred examples and comparative examples of the present invention will be described below.

The following examples are intended to illustrate the present invention and should not be construed as limiting the scope of the present invention.

Experimental Example 1

Before implementing the embodiments, several internal grids (ie, three types of quarter cubic, cross-shaped 3D, and octet) were prepared as specimens to set the optimal internal grid of the internal packaging cushioning material among 3D printing conditions, and the specimens Compressive strength was measured.

The size of the specimen was produced in the form of a square with a side length of 3 cm, and three types of internal grid structures were selected: quarter cubic, cross 3D, and octet among 13 output grids presented on the software. The internal structures of the other patterns are printed in the form of repeated two-dimensional stacking on the x and y axes, whereas the selected three types of structures are printed in the form of three dimensions (Table 3). As a result of the preliminary experiment, the three selected structures showed an insignificant difference of 1 to 3.4 kgf/cm2 in compressive strength between the horizontal and vertical output specimens. Considering this, in order to minimize the difference in compressive strength according to the output structure, quarter cubic, cross-shaped 3D, and octet patterns with similar results of compressive strength were selected. Examples of each pattern are shown in Table 3 below.

The internal filling rate is a value expressed as a percentage of how much the internal structure occupies the inside of the specimen, and the closer to 100%, the higher the filling rate density. As a result of the preliminary experiment, it was confirmed that there is no compression resistance because the compressive strength value is lowered or not measured at 20% or less, and the filling rate of 40% or more has too high a density, so the physical properties become hard and the shock absorption performance is poor (see Table 5 below) . Therefore, the internal filling rate was selected as 20%, 30%, and 40%. All specimens were printed using the horizontal printing method, which is a general printing method, and the vertical printing method, which is modeled by rotating 90° inside the software and printed vertically. Three copies were printed for each condition of each specimen, and the output results are as follows.

Example 1

The packaging object was selected as a blue natural flower incense burner with a diameter of about 10 cm and a height of about 9.5 cm. The selection criterion was selected as an object that has a complex structure with a relatively high risk of damage, has a size that does not exceed the maximum output size of the 3D printer, and can secure the part where the acceleration sensor for the experiment will be attached to the inside of the object.

For the outer packaging box, a paulownia wood box (Mandune Company, Korea), which is currently most commonly used for packaging cultural assets, was selected. As for the internal packaging buffer, a buffer made using Tyvek cotton (Samheung Science, Tyvek, Korea) and TPU filament (Stellamove, eLastic, China) was selected.

TPU Filament is composed of a polymer chain by the reaction of hexamethylene diisocyanate and 1,4-butanediol, and has a flexible and flexible chain covalent structure. has It is made of polyurethane synthetic rubber resin and has elasticity and easily bendable properties, so it is possible to produce flexible and elastic outputs. It is not easily damaged or worn even by external physical force, so it can be used in specialized fields such as packaging and medicine that require impact resistance and flexible physical properties.

A white light type 3D scanner (EinScan-Pro+, Shining 3D, China) was used to acquire the shape information of the packaging object. This scanner is a portable scanner with a precision of less than 1 mm, and the scanner reads and scans the image in which the white light emitted from the scanner is deformed according to the surface of the object. The scanning speed is fast and precise, so it is suitable for scanning medium and small cultural assets. It was used to acquire scan data of packaging objects, and all subject information of packaging objects was scanned in a portable mode.

A haptic device (3D Systems, Touch Haptic, U.S.A) was used for the modeling of the packaging cushioning material. The haptic device is a 3D Pen device that can directly feel tactile feedback and can directly feel objects in a 3D space. It is used for high-precision work and detailed sculpting because the user can feel a sense similar to real life. In the present invention, it was used in the modeling of 3D digital pavement cushioning materials.

The modeling data of the 3D digital packaging cushioning material was printed using an FDM-type 3D printer (Stellamove, B420, Korea). The maximum output size is 430 × 350 × 480 mm, and it is advantageous to produce high-quality output based on fast printing speed and accurate coordinate values through a position control system.

With the nozzle fastening of the direct connection method, even when using an elastic filament such as TPU filament, it is possible to print stably without stepping out, and by adopting a dual nozzle, it is possible to print two materials at the same time.

In order to manufacture a mold packaging cushioning material using 3D digital technology, the production of the cushioning material was carried out through the process of 3D scanning of the packaging object → 3D modeling of the cushioning material → 3D printing of the buffering material.

The first step in 3D digital packaging work is the process of acquiring 3D shape information of an object through 3D scanning. After scanning the upper and lower parts using an optical 3D scanner and a turntable, the point cloud data was completed by merging the data. Point cloud data was obtained by 3D scanning all surfaces of the object, and a 3D polygon model was created through the meshing process, which is the process of converting the converted point cloud data into 3D surface data.

The acquired polygon data was loaded into Freeform, a 3D modeling software, and aligned. Smooth modeling is possible only when the position of the object is set to 0, 0, 0 on the X, Y, and Z coordinates in the virtual space.

After that, a 25 cm square box was produced outside the object. After creating the same shape as the object shape information inside the box, the data of the space where the object will be located was erased.

When the data is erased, the shape of the data identical to that of the object remains inside the box like a mold. The box was cut in virtual space so that the object could be placed inside. For cutting, after selecting the part to be cut with the virtual selection tool in the software, only the selected part is duplicated. After that, the selected data was removed and the duplicated data was pasted in the same place.

The cutting direction is set differently according to the shape of the object. When the object is packed with the object, the cushioning material must enter well without strong pressure and shape deformation, and only minimal cutting must be performed so as not to degrade the performance of the cushioning material. In the present invention, it was produced by applying a method of vertically cutting from top to bottom by minimizing the cut surface.

Data editing and modeling were performed in virtual modeling software (Freeform, 3D Systems, America) through a pen-type haptic device capable of detecting tactile feedback in a virtual space.

The shape of the inside of the packaging cushioning material was visually checked by comparing it with the actual packaging object, and when visually confirmed, the area where the object could be caught during packaging and disassembly was removed using a virtual removal tool. After removal, the abnormal part of the data was finally checked before printing, and when the production of the buffer material was completed, printing was performed with a 3D printer.

The printing option was set to the options of cross-shaped 3D pattern, horizontal output, and internal filling rate of 20%, which were confirmed based on the results of the physical property experiment, and the printing time was about 346 hours and 20 minutes. As a result of the output, the supporter that supports the output on the upper part was printed together, and it was removed using small tools. When the object was placed inside the cushioning material, no play occurred, and a packaging structure was obtained by packaging in a paulownia wood box, and similarly, no gap was generated inside the box when packaging.

Example 2

Instead of making a 25 cm square box outside the object, make a 25 cm square box, and when printing with a 3D printer, except for printing on a 5 cm thick plate-shaped polyurethane foam in the 3D printer was performed in the same manner as in Example 1 above. The polyurethane used in preparing the plate-shaped polyurethane foam was the same as the polyurethane used in the manufacture of the TPU filament used in Example 1 to obtain a packaging structure.

Experimental Example 2

1) Compressive strength test

A compressive strength test was conducted to confirm the compressive strength and resistance capacity generated during transportation or packaging and loading by confirming the degree to which the pavement structure could withstand the pressure and load from the outside. The equipment used in the experiment was a universal material tester (Shimadzu, AGS-X, Japan). The measurement was carried out by setting the point where the compressive strength value first decreased as the maximum load, and the maximum load of the specimen was measured by compressing at a rate of 1 mm/min for each specimen. A total of three measurements were carried out with the previously prepared specimen, and the measured values were averaged.

2) Permanent compression reduction rate experiment

In order to measure the shrinkage rate according to room temperature compression of vulcanized rubber used in the part subjected to static compression or shear force of TPU filament material output, a permanent compression shrinkage rate test was conducted. Since there is no standardized standard for the corresponding experiment, the experiment was conducted with reference to the related KS standard.

It was conducted based on KS M ISO 815-1 (vulcanized or thermoplastic rubber - Part 1: room temperature, high temperature permanent compression shrinkage measurement method), and the specimen was manufactured in the form of a cylinder with a thickness of 12.70 ± 0.050 mm and a diameter of about 29.0 mm. The equipment used in the experiment was a permanent compression jig (Myungji Tech, Compression set, Korea).

The fabricated specimens were compressed in a compression jig for 24 hours at room temperature (23 ± 2 ° C) in the laboratory. When compression is applied, the applied compression set should be approximately 25 ± 2% of the original thickness of the specimen. After removing the specimen from the jig, the thickness of the specimen was measured after allowing it to recover for 30 ± 3 minutes at standard laboratory temperature. Then, it was converted into Equation 1 below and digitized. A total of three experiments were conducted and the measured values were averaged and calculated.

[Equation 1]

In the above formula,

C is the compression reduction rate (%),

t ₀ is the original thickness of the specimen (mm),

t ₁ is the final thickness of the specimen (mm), and

t ₂ is the thickness of the space bar (9.52 mm).

3) Puncture Impact Behavior Measurement Experiment

When the striking rod, which has fallen freely from a certain height, strikes the specimen, when an impact greater than a certain value is generated, the specimen is destroyed and penetrated. The amount of impact at which the specimen is not destroyed means that the specimen withstands the impact up to that value, and if the specimen is destroyed, it means that it cannot withstand the impact more than the impact amount recorded when the specimen is destroyed.

Therefore, in this experiment, impact behavior measurement was conducted to compare and analyze the buffering property according to the internal structure and filling rate of TPU filament material output. Since there is no standardized standard for the corresponding experiment, the experiment was conducted with reference to the related KS standard. The experiment was carried out with reference to KS M ISO 6603-2 (Plastic - Measurement of puncture impact behavior of hard plastics - Instrumental impact test), and the equipment used in the experiment was a drop impact tester (Instron, Drop Tester 9450, U.S.A) used

Prior to the experiment of the TPU filament output specimen, the experiment on the cotton cloth specimen was preceded in order to compare the buffering properties with cotton cloth, a previously used material. After finding the impact energy at the point where cotton fabric is punctured, the lowest experimental conditions of the device were set to test the TPU filament output specimen under the same conditions. Conditions were set to 1.0 m/s of impact velocity, 2.705 J of impact energy, and 50.986 mm of falling height. The specimen was manufactured in the form of a rectangle of the same size, 10 cm × 10 cm × 0.8 cm.

The experimental conditions of the TPU filament output specimen were set to an impact speed of 2.0 m/s, an impact energy of 10.820 J, and a drop height of 50.986 mm. The fabricated specimen was fixed to the test jig, and the impact rod was free-falled from a certain height using the impact rod drop device, and then the shock absorption behavior of the specimen was checked by recording whether or not it was destroyed and the amount of impact. The experiment was conducted a total of three times with the previously prepared specimens, and the measured values were averaged.

The reliability of the package structure obtained in Example 1 was evaluated as follows.

4) Drop impact test

Packaged cultural properties are at risk of falling when moving or when natural disasters such as earthquakes occur. When falling, when the packaging box collides with the ground, a fall shock is applied to the cultural property due to rapid acceleration and change in direction of force.

When an object falling freely from a certain height collides with the ground, potential energy is changed into kinetic energy, and the speed of the object at the moment of collision can be expressed as Equation 2 below.

[Equation 2]

In the above formula,

v is the velocity of the object at the moment of collision,

h is the drop height, and

g is the gravitational acceleration (9.8 m/s ² ).

According to Newton's second law, the amount of impact applied to the packaging box at the moment it falls and hits the ground is the same. According to Newton's second law, the magnitude of force is proportional to mass and acceleration. However, depending on the type and characteristics of the cushioning material, the amount of impact transmitted to the cultural property varies. Therefore, in this study, a 3-axis accelerometer is used to measure the change in acceleration that occurs during free fall and to compare the amount of fall impact applied to the pavement object.

The device used was a 3-axis accelerometer (Wit-motion, WT901C, China). After attaching the accelerometer to the inside of the packaging object, prepare the sample by packaging according to each packaging method. The fall proceeded with a horizontal fall in which the floor collided, and the height of the fall fell to the ground from a height of 2M, which is the average height of water towers in Korea. The experiment was conducted three times, and the average value was calculated and calculated.

5) Vibration experiment

Packaged cultural assets are constantly shaken inside the packaging box due to vibrations generated during transportation, and there is a risk of damage due to this. The transportation of cultural heritage is mainly carried out by land transportation by vehicle, air transportation by airplane, and transportation by ship. The vibration frequency band generated during land transportation is in the range of 70 to 200 Hz, and the vibration frequency band generated during air transportation is 20 to 200 Hz. 60 Hz, the vibration generated during ship transportation is 10 to 25 Hz. However, since ground transportation uses vibration-free vehicles, this study conducted experiments on vibration displacement that occurs during air transportation and ship transportation, and experiments were conducted in the range of 10 to 40 Hz to obtain measured values in the low frequency range of 40 Hz or less. proceeded

As for the experimental conditions, the experiment was conducted using method A, which is a sine wave sweep vibration method among the methods specified in KS A 1017 (vibration test method for packaged goods and containers). The experimental condition of Method A states that the set frequency is linearly changed over time and the rate limits the rising speed so that it does not exceed 7 Hz per minute.

Therefore, in this test, the following experimental conditions were set. The frequency was conducted in the range of 10 to 40 Hz, which is a low-frequency vibration band, and increased linearly for a total of 15 minutes by setting an increase range of 2 Hz per minute. The measured acceleration value was obtained by applying Equation 3 below to obtain an effective acceleration value for each section of Hz, and then the vibration level range was calculated using Equation 4 below and compared for each packaging method.

[Equation 3]

[Equation 4]

In the above expressions,

A _rms is the effective value of acceleration for each section,

A _m is the acceleration amplitude (㎨),

VAL (dB) is the vibration level range.

As for the direction of vibration, horizontal vibration vibrating on a plane and vertical vibration behavior vibrating up and down were performed. For each packaging method, a 3-axis accelerometer was attached to the inside of the object to determine the acceleration displacement due to vibration, and the amplitude of the box itself was measured by attaching an accelerometer to the outer upper part of the paulownia box in the same direction as the packaging object. Afterwards, the vibration displacement of the packaging object and the vibration displacement of the paulownia box were compared. The measurement was performed three times, and the measured value for each displacement was averaged.

6) Box Compression Experiment

In order to check the compressive strength and resistance capacity generated in the vertical direction of the packaging box after packaging the cultural assets, a box compression experiment is conducted. The test conditions were conducted by the method specified in KS T ISO 12048 (packaging - transport packaging - compression and loading test using compression tester), and the equipment used was a box compression tester (TEST ONE, box compressor, Korea). did Experimental samples were tested on the packaging structure of Example 1, and vertical compression was performed. The maximum load of the pavement structure was measured by compressing each specimen at a speed of 10 mm/min. The measurement was carried out by setting the point where the compressive strength value first decreased after increasing as the maximum load. The measurement was carried out a total of three times, and the measured values were averaged and calculated.

7) Results and discussion

7-1) Compressive strength test

The compressive strength test results are summarized in Tables 6 to 8 and FIGS. 8 and 9 below. 8 (octet pattern transverse compressive strength graph) and FIG. 9 (octet pattern longitudinal compressive strength graph) are graphs of changes in compressive strength behavior of octet pattern transverse and longitudinal output specimens. Due to the nature of the TPU material, there was no graph that rapidly decreased, and two turning points were observed at which the compressive capacity decreased or remained constant in the rising curve of the resulting graph of all specimens.

The first turning point is the same change value of about 1.2 kgf/cm2 for all specimens, which seems to be the process of buckling the outer wall of the specimen and compressing the empty space of the internal structure. Therefore, it was judged that it would be difficult to confirm the compressive resistance capacity of the specimen. The second turning point appears different for each specimen, which appears to be the part where the internal structure buckles beyond the maximum compressive load point. Therefore, the second turning point was judged to be the point at which the compressive resistance capacity could be confirmed, and the result value of the second turning point in the rising curve was presented.

The octet pattern appeared in the order of 40% 35.490 kgf/cm2 > 30% 21.048 kgf/cm2 > 20% 11.209 kgf/cm2 in the horizontal print specimen and 40% 29.724 kgf/cm2 > 30% 17.867 kg in the vertical print. f/cm2 > 20% 10.235 kgf/cm2 in order. The higher the compressive strength value, the higher the compressive resistance ability of the specimen, and the lower the compressive strength value, the lower the compression resistance, which means that it is difficult to protect the packaging object from compressive stress when applied to packaging cushioning material printing.

The quarter cubic pattern appeared in the order of 40% 28.760 kgf/cm2 > 30% 19.421 kgf/cm2 > 20% 10.396 kgf/cm2 in the horizontal print specimen and 40% 27.410 kgf/cm2 > 30% 17.867 in the vertical print specimen. kgf/cm2 > 20% 10.235 kgf/cm2 in order. The cross-shaped 3D pattern appeared in the order of 40% 20.316 kgf/cm2 > 30% 11.497 kgf/cm2 > 20% 8.243 kgf/cm2 in the horizontal print specimen and 40% 9.481 kgf/cm2 > 30% 7.914 in the vertical print specimen. kgf/cm2, > 20% and 5.297 kgf/cm2 in order.

In all specimen output conditions, the horizontal output specimens showed about 1.6 to 2.2 times higher compressive strength values than the longitudinal output specimens, and the compressive strength value increased as the internal filling ratio increased. The output direction of the internal structure of the horizontal and vertical output specimens was different, and this fact could be confirmed by the difference in the compressive strength results. It seems that the difference in the resistance capacity of the specimens occurred due to the difference in the structure output direction, and it was confirmed that the specimen printed horizontally had better compression resistance than the vertical output.

7-2) Permanent compression reduction rate experiment

The permanent compression reduction test results are summarized in Tables 9 to 11 below. In the horizontal output specimen of the octet pattern, the internal filling rate was 20% = 30% > 40% in order. At 20% and 30%, the highest resilience was found at 81%, and at 40%, a value of 77% was confirmed. In the vertical output specimen, the order of 30% > 40% > 20% was found. When the internal filling rate was 20%, the reduction rate was 72%, and the highest resilience was confirmed at 30% at 75%, and at 40%, the permanent compression reduction rate at 74% was confirmed.

In the horizontal output specimen of the quarter cubic pattern, the internal filling rate was 20% > 40% > 30% in order. The highest resilience was confirmed at 83% at 20% internal filling rate, and at 30% and 40%, values of 78% and 80% were confirmed, respectively. In the vertical output specimen, 30% = 40% > 20% appeared in the order. When the internal filling rate was 20%, the reduction rate was 72%, and the highest resilience was confirmed at 30% and 40% at 78%.

In the cross-shaped 3D-patterned horizontal output specimen, the internal filling rate was 20% = 30% > 40% in order. The internal filling rate of 20% and 30% was 91%, and the highest restoring force was confirmed, and the value of 90% was confirmed at 40%. In the longitudinal output specimen, the order of 40% > 30% > 20% was found. When the internal filling rate was 20% and 30%, the values of 69% and 75% were confirmed, respectively, and the highest resilience was confirmed at 40% at 76%.

Since the shrinkage rate measured in TPU under static compression under room temperature conditions means original stability or degree of recovery, it can be confirmed that the higher the result value of permanent compression shrinkage rate, the higher the stability after permanent compression. The lower the result value, the higher the compression resilience. When applied to packaging cushioning material printing, it can be interpreted that there is a possibility that the performance of the cushioning material may deteriorate over time.

When printed in a cross-shaped 3D pattern, it has excellent resilience after long-term compression, so that the packaging cushioning material maintains its intact shape during long-term storage and transportation, and the performance degradation of the cushioning material is relatively small. It is judged to be able to

7-3) Puncture Impact Behavior Measurement Experiment

As a result of the test of the cotton fabric specimen, the peak energy was found to be 1.484 J and no perforation of the specimen was observed. The peak energy is a value representing the maximum energy that a specimen can absorb when a free-falling additional specimen is struck, and represents the amount of shock absorption of the specimen. The higher the measured value is, the higher the shock absorption of the specimen is, which means that the shock resistance is excellent.

Since the cotton fabric specimen was not perforated under the lowest experimental condition of the device, the experiment was conducted by increasing the impact energy by increasing the impact speed by 2.0 m/s. As a result of the experiment, the peak energy was found to be 7.551 J and perforation of the specimen was observed. It can be seen that the cotton fabric specimen loses its function as a cushioning material because it does not absorb energy of 7.551 J or more and is perforated. Since the perforation of the cotton fabric specimen was confirmed, the impact speed was changed to 2.0 m/s and the TPU Filament printout was tested.

In the horizontal output specimen of the octet pattern, the internal filling ratio showed high values in the order of 30% 10.318 J > 40% 10.261 J > 20% 10.242 J. In the longitudinal output specimen, the internal filling ratio showed high values in the order of 30% 7.378 J > 40% 7.010 J > 20% 4.823 J. Both the horizontal and vertical output specimens of the octet pattern showed the highest value when the internal filling rate was 30%. The 40% output specimen showed a value similar to that of 30%, which can be seen as increasing the internal filling factor to 30% or more does not lead to an increase in shock absorption.

In the horizontal output specimen of the quarter cubic pattern, the internal filling ratio showed high values in the order of 30% 10.839 J > 20% 10.600 J > 40% 10.505 J. In the vertical output specimen, the internal filling ratio showed high values in the order of 30% 7.689 J > 40% 5.645 J > 20% 5.186 J. The quarter cubic pattern has an internal structure similar to that of the octet pattern, so the energy absorption behavior also showed similar results.

In the cross-shaped 3D-patterned horizontally printed specimen, the internal filling rate was 20%, 11.947 J > 30%, 10.739 J > 40%, and 10.325 J, respectively. In the longitudinal output specimen, the internal filling ratio showed high values in the order of 30% 6.784 J > 20% 3.764 J > 40% 3.712 J. The cross-shaped 3D, horizontal output, and 20% internal filling ratio options showed the best shock absorption among all output options, and in particular, showed 1.7 times better value than cotton cloth.

In all specimen output conditions, no perforation was observed in the horizontal output specimens after the experiment, and no perforation was observed in the vertical output specimens. These results can be seen that the horizontal output specimens have better shock absorption from the outside than the vertical output specimens. Summarizing the results of the previous experiments, the 20% option for horizontal output of the cross-shaped 3D pattern showed the best performance in the permanent compression set and puncture impact behavior tests. The option was selected as a cross-shaped 3D 20%.

7-4) Drop impact test

The results of the drop impact test are as follows. The average impact force of the TPU filament output buffer was 2.75 G and that of the cotton fabric was 2.55 G. The gravitational acceleration G represents the gravitational acceleration received by the object upon impact. It can be interpreted that the higher the measured value, the higher the gravitational acceleration applied to the object, and the higher the impact force.

The drop impact of the cotton fabric cushioning material showed an average value of 0.2 G higher than that of the TPU filament output buffer material, which seems to be due to the difference in the shock absorption performance of the TPU filament output buffer material and cotton fabric. In addition, in the case of the cotton fabric buffer material, damage was observed on the bottom of the object when dropped three times, and in the case of the TPU filament output buffer material, no damage was observed.

Since breakage was confirmed in the object of the cotton cushioning material, an additional drop experiment was conducted to quantitatively measure the piece breakage rate. Each packaging object was forcibly broken and separated into eight pieces. After bonding the separated pieces, they were repacked and dropped a total of three times under the same experimental conditions.

The drop impact test results are shown in Table 15, and the piece breakage test results are shown in Table 16, respectively.

As a result of the experiment, the cotton cushioning material was not damaged at the time of the first fall, but at the time of the second fall, two pieces were damaged at the bottom, and at the time of the third fall, it was damaged as a whole, resulting in a total of 19 pieces. The breakage rate of the cotton cushioning material was 125% for the 2nd fall and 237% for the 3rd fall. The TPU filament output buffer did not break during all dropping processes and maintained its intact shape. As a result of the experiment, it was confirmed that the TPU filament output buffer has excellent shock absorbency, as the impact amount of the TPU filament output buffer is lower by 0.2 G and the breakage rate is 2.4 times better.

7-5) Vibration experiment

The vibration level range is a value representing the degree of vibration. The peak value of the gravitational acceleration measured under the vibration displacement is converted into the effective value of the acceleration, and the result value is obtained using the measurement formula. It can be interpreted that the higher the measured value, the higher the gravitational acceleration and thus the greater the vibration applied to the packaging object, and the lower the measured value, the lower the degree of vibration applied to the packaging object, indicating excellent adhesion and vibration resistance of the packaging cushioning material.

Vibration test results are summarized in Tables 17-21 below.

The results of horizontal vibration of the TPU filament output buffer are as follows. In the range of 10 to 20 Hz, the average vibration level was 121 dB, and in this range, the displacement was larger than that of the paulownia box. An average vibration level of 114 dB was shown in the range of 20 to 30 Hz, and an average vibration level of 105 dB was shown in the range of 30 to 40 Hz. From 20 Hz, the vibration level range steadily decreased, and in the range of 22 to 40 Hz, a lower vibration level range than that of the paulownia box was confirmed.

The horizontal vibration results of the cotton-wrapped cushioning materials showed a constantly decreasing displacement in all Hz ranges. In the range of 10 to 20 Hz, the average vibration level was 116 dB, but the displacement was larger than that of the paulownia box. An average vibration level of 113 dB was shown in the range of 20 to 30 Hz, and an average vibration level of 108 dB was shown in the range of 30 to 40 Hz. In the range of 20 to 40 Hz, a lower vibration level range than that of the paulownia box was confirmed.

However, pitching on the Y-axis was observed in the vibration range of 10 to 30 Hz in the cotton-wrapped cushioning material. It was not observed in the TPU filament output cushioning material, but pitching of 5° on average was confirmed in the cotton-wrapped cushioning material. From this, it was found that the cotton packing cushioning material was not free from shaking of the object due to pitching, and it was judged that this could cause damage to the object to be wrapped.

Since vertical vibration is repeated up and down based on the Z-axis, 1 G of gravity always acts. Therefore, the reference point starts from 1 G, not 0 G. The results of vertical vibration of the TPU filament output buffer are as follows. In the range of 10 to 20 Hz, the average vibration level was 123 dB, and in this range, similar to the horizontal vibration, the vibration displacement was larger than the vibration level of the paulownia box. An average vibration level of 121 dB was shown in the range of 20 to 30 Hz, and an average vibration level of 119 dB was shown in the range of 30 to 40 Hz. It was confirmed that the change in the vibration level range was constantly reduced, but the change width was low.

The vertical vibration results of the cotton-wrapped cushioning material are as follows. An average vibration level of 137 dB was shown in the range of 10 to 20 Hz, an average of 130 dB in the range of 20 to 30 Hz, and an average of 121 dB in the range of 30 to 40 Hz. A large vibration level was confirmed in most of the ranges of 10 to 38 Hz, and the vibration level was 17 dB higher than the vibration level range of the paulownia box. It can be seen that the cotton fabric cushioning material is more vulnerable to vertical vibration than the TPU filament output cushioning material, and it is judged to have superior vibration resistance and adhesion compared to cotton fabric.

7-6) Box compression experiment

The box compression test results are shown in Table 22 below, and the results are as follows. Damage to the foam cushioning material packaging box was confirmed at 25.62 kN, and TPU filament output cushioning material packaging box was confirmed to be damaged at 30.88 kN. The measured value is the value that the paulownia box, which is the outer box, is damaged. The higher the measured value, the better the compression resistance of the cushioning material present inside the paulownia box, and the lower the measured value, the lower the compression resistance. .

For the TPU filament output buffer, buckling of the internal buffer was confirmed due to the compressive load from the time the paulownia box was damaged, and the cotton fabric buffer did not generate any compressive load after the paulownia box was damaged.

In the present invention, in order to solve the problem of cotton, which is a packaging cushioning material previously used, it was confirmed whether cotton fabric can be replaced by manufacturing an output packaging buffer using TPU Filament. As for the output options of the TPU Filament output, three types were selected: quarter cubic, cross-shaped 3D, and octet among the internal grid patterns presented on the 3D printing software. Specimen was produced by setting to . The physical properties and reliability were evaluated with the fabricated specimens, and the following results were derived.

For the physical property test, the appropriate output option of the TPU filament was set through the measurement test of compressive strength, permanent compression set, and puncture impact behavior, and basic physical properties that could replace cotton fabric were confirmed. As a result of the experiment, it was confirmed that the cross-shaped 3D pattern, horizontal output, and 20% internal fill option were the most appropriate options for output, and showed superior buffering performance compared to cotton.

As a result of the compressive strength test, the octet pattern, horizontal output, and internal filling ratio 40% option showed the highest value at 35.49 kgf/cm2. It was confirmed to have In all specimen output conditions, the horizontal output specimens show about 1.6 to 2.2 times higher compressive strength than the vertical output specimens, indicating that the internal filling ratio increases and high compressive strength values are displayed when printed horizontally.

As a result of the permanent compression reduction rate test, the cross-shaped 3D, horizontal output, and internal fill rate 20% option showed the highest value at 93%, and it was confirmed that the cross-shaped 3D pattern was about 1.1 times better than other patterns. When printed in a cross-shaped 3D pattern, it has excellent resilience after long-term compression, so that the packaging cushioning material maintains its intact shape during long-term storage and transportation, and the performance degradation of the cushioning material is expected to be relatively small. It is judged to be able to

As a result of the measurement of the puncture impact behavior, the cross-shaped 3D, horizontal output, and 20% internal filling rate option showed the highest value at 11.947 J, and in particular, the value was 1.7 times better than cotton cloth, the existing material. When the additional falling specimen was hit, the horizontal output specimen was not perforated, but the vertical output specimen was perforated, and it can be seen that the horizontal output specimen has better shock absorption capacity from the outside.

Reliability evaluation compared the packaging performance of the TPU filament print buffer and cotton fabric buffer through drop impact test, vibration test, and box compression test, and evaluated the possibility of replacing the cotton fabric used previously. As a result of the experiment, it was confirmed that the TPU Filament has superior performance in buffering, vibration resistance against vertical vibration displacement, and adhesion than cotton cloth, which is a previously used packaging cushioning material.

The drop impact test results confirmed that the fall impact of the cotton cushioning material was about 1.1 times higher. In the case of the TPU filament output buffer, the object inside was not damaged, but in the case of the cotton fabric buffer, damage was observed on the bottom of the object when dropped three times, and the piece breakage rate was about 2.4 times higher. It was confirmed that the cushioning property of the TPU filament output buffer was excellent, considering that the foam cushioning material had a higher fragmentation rate.

As a result of the vibration test, in the horizontal vibration range, the cotton fabric buffer was 1.05 times higher in the range of 10 to 30 Hz, but the TPU filament output buffer material was 1.02 times higher in the range of 30 to 40 Hz. Pitching on the Y-axis was observed in the foam buffer material, and the pitching value was about 5.2 times higher than that of the TPU filament output buffer material. In the vertical vibration range, the TPU filament output buffer showed 1 to 1.2 times higher results in the range of 10 to 40 Hz. This shows that the vibration resistance of the TPU filament output buffer is excellent in vertical vibration, although it has similar vibration resistance in horizontal vibration, and it is judged that pitching on the Y-axis can be effectively reduced due to excellent adhesion.

The results of the box compression test showed that the TPU filament cushioning material packaging box was 1.2 times better than the cotton fabric. In the case of the TPU filament buffering material packaging box, the buckling of the cushioning material was confirmed after the paulownia box was damaged, but the cotton fabric buffering material was not observed. These results seem to be the difference in the performance of enduring compression resistance of the packaging cushioning material inside the paulownia box, and the compression resistance performance of the TPU filament buffer material seems to be better.

In order to solve the problems of cotton cushioning materials used in existing packaging, experiments were conducted to optimize output options and confirm the applicability as a new packaging cushioning material. As a result of the study, it was concluded that an appropriate output option for the cushioning material was selected and that it could be applied as a substitute for cotton cloth. However, it did not show much better physical properties compared to cotton, and it seems that research on the material of TPU filament is needed to improve the physical properties more. It is considered that it can be applied to actual cultural heritage packaging if the harmful substances generated in the printing process and the hazard evaluation of the material itself are conducted later.

In conclusion, in the storage and transportation of cultural properties, a packaging process that can safely protect cultural properties is carried out. Packaging provides physical stability to cultural properties during transportation and serves to protect cultural properties from external shocks and vibrations. Cotton cloth, which is currently the most widely used ceramic packaging cushioning material in Korea, lacks resilience, material resilience, and adhesion, which can cause damage to cultural properties due to shock and vibration. In addition, there is a problem that the performance of the packaging material varies depending on the packaging skill of the worker, and there is a problem that the recyclability is insufficient because the packaging performance is not uniform.

Therefore, in order to solve these problems, 3D scanning and 3D printing technology were applied to solve the packaging instability according to the operator, and the applicability as a packaging buffer material to replace cotton fabric was confirmed through physical property tests and reliability evaluation. Therefore, in order to compare with a new material with buffering properties, the experiment was conducted by selecting TPU Filament printouts with bendable properties as a comparison group. As a result of the experiment, the following research results were derived.

First, the simplification of the packaging process was confirmed.

As a result of the packaging material production, it was possible to easily obtain the external information of the object with a 3D scanner, and the packaging buffer material made of TPU Filament was printed. In the existing cotton filling packaging method, the method of adding cotton fabric was different depending on the shape of the object and the weak part, and it was not completely adhered to the object, but it was confirmed that the printed packaging cushioning material was completely adhered to the object.

However, according to Example 1, there is a problem that the output time is long (about 346 hours and 20 minutes), but instead of producing a 25 cm square box outside the object as in Example 2, a 25 cm square box When manufacturing and outputting with a 3D printer, the output time was about 27 % (about 252 hours and 15 minutes), and there was no significant difference in tests such as compressive strength or shock absorption, and the breakage rate was also found to be the same. This is considered to be due to the fact that the polyurethane used in preparing the plate-shaped polyurethane foam is the same as the polyurethane used in the manufacture of the TPU filament used in Example 1, and exhibits almost similar physical properties.

In addition, in the packaging process after output, the packaging process was simplified because the cushioning material was manufactured and output as an integral type compared to cotton cloth packaging.

Second, the reusability of the TPU filament output buffer was confirmed.

Since it was printed according to the shape of the packaging object, the packaging performance was uniform and reusability was excellent when repackaging after unpacking, so the same buffering performance could be expected during the storage process as well as packaging. Modeling and output of the cushioning material seems to require a certain level of training in the manufacturing process, but anyone who is not an expert in the packaging process can derive the same packaging performance, which is considered to be able to solve the absence of packaging experts to some extent.

Third, optimization of TPU filament output options was confirmed.

As a result of the experiment, the cross-shaped 3D pattern, horizontal output, and 20% internal filling rate output options showed the best results, but the output options derived were only applied to the options suggested by the 3D printer used in this study, and other companies' devices were used. If so, it seems necessary to optimize the output options accordingly. Compared to cotton cloth, which is a conventional material, it has been confirmed that the impact absorption energy of TPU Filament is about 1.7 times better, and the cross-shaped 3D pattern with excellent permanent compression recovery and cushioning, horizontal output, and 20% internal filling rate output option are the most optimized output. appears to be an option.

Fourth, the possibility of replacing the TPU filament output buffer was confirmed.

In the drop impact test, sectional breakage of the cotton cushioning material was observed. In the vibration experiment, the vibration resistance of the TPU filament was confirmed, and the pitching on the Y-axis was effectively reduced, and the adhesion to the packaging material was quantitatively confirmed. The compression resistance performance of the packing material also showed better results than cotton cloth, and through reliability evaluation, the possibility of replacing the TPU filament output cushioning material was confirmed. As the experimental results showed similar or slightly better performance, it was determined that the TPU filament output buffer material had properties similar to that of cotton cloth and could be replaced and mixed with cotton cloth in the packaging process.

In the present invention, in order to solve the problems of cotton cloth, which is a material used for packaging ceramic cultural assets, it was intended to investigate basic physical properties and applicability through physical property and reliability evaluation. Summarizing the conclusions of the study, the printed packaging material to which the 3D digital technology was applied perfectly fits the shape of the object, does not shake, and simplifies the packaging process. It was confirmed that the effect was improved or improved, and it is considered to be possible to replace the cotton cloth.

Although the present invention has been described in detail only with respect to the specific embodiments described above, it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical idea of the present invention, and it is natural that such changes and modifications fall within the scope of the appended claims.

(No drawing designator)

Claims (7)

It is intended to safely pack cultural assets that are easily damaged by external shocks, such as cultural assets, especially ceramic cultural assets,
(1) a 3D scanning step of obtaining polygon data by three-dimensionally scanning a cultural property to be paved;
(2) a 3D modeling step of three-dimensionally modeling the cushioning material based on the polygon data (external information of cultural properties) obtained in the 3D scanning step; and
(3) a 3D printing step of three-dimensionally printing a buffer material including a space capable of accommodating cultural assets based on the data obtained in the 3D modeling step;
Cultural heritage packaging method comprising a. The method according to claim 1, wherein the 3D modeling step comprises three-dimensionally modeling the cushioning material based on polygon data (external information of the cultural property) obtained in the 3D scanning step. The method of claim 2, wherein the 3D modeling step loads and arranges the polygon data (external information of cultural properties) obtained in the 3D scanning step on 3D modeling software, and accommodates all external information of cultural properties outside the external information of cultural properties. After producing a rectangular box of the size that can be accommodated, creating a shape identical to the external information of the cultural asset inside the box, and then erasing the data of the space where the external information of the cultural heritage is located, Cultural property characterized in that it is performed by leaving the shape of the data, selecting and duplicating the part to be cut in the virtual space so that the object can be placed inside, removing the selected data, and then pasting the duplicated data in the same place. packaging method. According to claim 3, the cutting direction of the virtual box proceeds with only minimal cutting so that the cultural heritage can be entered without entangled parts when wrapping the cultural heritage with a cushioning material without applying strong pressure or shape deformation to the cultural heritage according to the shape of the cultural heritage. Cultural heritage packaging method characterized by. [Claim 5] The method of claim 4, wherein the number of cuts of the virtual box is within a range of 1 to 4 times. The cultural property according to claim 2, characterized in that data editing and modeling are performed in virtual modeling software through a pen-shaped haptic device capable of sensing tactile feedback in a virtual space. packaging method. According to claim 1, Cultural heritage packaging method characterized in that the printing on the plate-shaped polyurethane foam in the 3D printing step.

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