KR20210103232A - Non heat insulation and refractory duct or panel of corrugated sheets and molding method therof - Google Patents

Abstract

The present invention relates to a non-insulation and fireproof duct or panel related to the transport of various gas fluids such as air conditioning, air supply, and exhaust. More specifically, the present invention relates to a corrugated cardboard duct or panel which ensures fireproof, smoke-free, and non-toxic properties by coating a mixture of 90-95% water glass and 5-10% expanded graphite on corrugated cardboard, and which also, secures insulation and is lightweight according to the composition of multiple layers of corrugated cardboard. Therefore, safe evacuation is possible with fireproof, smoke-free, and odor-free properties in case of fire, and also, effects of energy-saving, construction cost reduction, resolving the shortage of manpower in the construction market, and environmental preservation according to the use of eco-friendly materials occur. In addition, the panel of the present invention can be used as a building material or interior material.

Description

Non-heat insulation and refractory duct or panel of corrugated sheets and molding method therof

The present invention relates to a duct used for transporting various gas fluids such as air conditioning and air supply/exhaust ducts, and more particularly, to a corrugated cardboard duct or panel made by coating a mixture of water glass and expanded graphite on corrugated cardboard and a method for forming the same.

Existing ducts are manufactured using galvanized steel sheets or stainless steel sheets, and if thermal insulation is required, glass fiber, cross-linked foam insulation materials, or rubber foam insulation materials are used to insulate.

Because the metal duct is heavy, it is difficult to manufacture, transport, and install, and there are many difficulties with punching and scissors cutting when drilling at the site. Also, there is a possibility of a safety accident due to the sharpness of the cut surface. In addition, when heat loss is reduced and insulation is required for the smooth functioning of the duct, insulation materials must be purchased and insulation work must be carried out. In case of fire, rubber foamed and crosslinked foam insulation materials are difficult to evacuate due to lack of fire resistance and generation of smoke and odors. .

Phenolic duct is a duct made by bonding aluminum sheets on both sides of phenolic. It is light and easy to assemble. However, the strength of the phenolic material, corner joint, and connecting flange between ducts is weak, so there are many difficulties in medium and large ducts. In addition, it is vulnerable to moisture, and there is a lot of difficulty in evacuation due to the generation of smoke and odor from phenolic in case of fire.

As another prior art, as disclosed in Patent Registration No. 10-1029559, by using corrugated cardboard as a material for the duct, it is eco-friendly and has low thermal conductivity to increase the thermal barrier effect and to propose a corrugated cardboard duct that can be used for air conditioning at the same time. However, here, in order to reinforce the structure of the corrugated cardboard, an aluminum sheet and an iron sheet are attached to the inner and outer surfaces of the corrugated cardboard, and hemp and cotton are used for heat retention. The duct made in this way is weak in strength, fire resistance, and moisture resistance, so it is not currently commercially available.

The present invention is to solve the above problems, by coating or mixing corrugated cardboard and a special mixture to increase insulation, light weight, reduce construction cost, fire safety (fireproof, smoke-free, odor-free), eco-friendliness, moisture resistance, printability It is to provide a corrugated duct or panel that can meet customer requirements such as

The main object of the present invention is to provide a corrugated cardboard duct or panel that can be used without using a separate insulating material for thermal insulation, which is the main function of the duct or panel.

Another object of the present invention is to provide a corrugated cardboard duct or panel comprising at least one layer of hardened corrugated cardboard in which a mixed solution of 90-95% water glass and 5-10% expanded graphite is coated on the original cardboard and corrugated core of the corrugated cardboard. .

Another object of the present invention is to provide a corrugated cardboard duct or panel with increased fire resistance and waterproofness by placing stone paper on the corrugated cardboard.

Another object of the present invention is to provide a method for manufacturing a straight pipe corrugated duct.

Another object of the present invention is to provide a method for manufacturing a corrugated cardboard panel.

The non-heating fireproof corrugated cardboard duct or panel of the present invention for achieving the above object is a mixture of 90-95% water glass and 5-10% expanded graphite coated on the original cardboard and corrugated core of the corrugated cardboard to form at least one hardened corrugated cardboard. contains more than one layer.

In a preferred embodiment of the present invention, three layers of the corrugated cardboard coated with the mixed solution are arranged as a lower layer and an upper layer, respectively, based on a single original cardboard.

In a preferred embodiment of the present invention, the stone paper is adhered to the outer paper and/or the inner paper.

In a preferred embodiment of the present invention, the single original cardboard coated with the mixed solution is attached to the stone paper again.

In a preferred embodiment of the present invention, ceramic is additionally coated on the stone paper.

In a preferred embodiment of the present invention, when corrugated cardboard coated with a mixed solution is arranged in multiple layers, they are arranged symmetrically to each other.

In a preferred embodiment of the present invention, at least two or more layers of corrugated cardboard coated with a mixed solution are laminated, and at least one of the corrugated cardboard layers is a corrugated core in an orthogonal direction.

As another embodiment of the present invention, as a continuous pipe manufacturing method, as a continuous forming method of straight pipe corrugated duct, a plurality of corrugated cardboard rollers coated with a mixture of 90-95% water glass and 5-10% expanded graphite on flat corrugated cardboard Preparing, winding at least one layer of corrugated cardboard with at least one layer spirally coated on the base mold so that the original is upward, winding at least one layer into a single original cardboard spirally, at least one layer of coated corrugated cardboard Including the step of spirally winding to come down, and spirally winding at least one layer of stone paper.

In a preferred embodiment of the present invention, the step of coating the single original cardboard and the stone paper with the mixed solution in advance.

As another embodiment of the present invention, the method for forming a corrugated cardboard panel comprises at least two or more corrugated cardboard layers coated with a mixed solution of 90-95% water glass and 5-10% expanded graphite on a flat corrugated cardboard, at least among the corrugated cardboard layers It includes the step of stacking one layer so that the orthogonal corrugated core is placed.

As a preferred embodiment of the present invention, the step of laminating the first layer by transferring the corrugated cardboard coated with a mixture of 90-95% water glass and 5-10% expanded graphite on the flat corrugated cardboard between the conveyors rotating up and down, the first layer Laminating a second layer with corrugated cardboard coated with corrugated paper in an orthogonal direction on top, laminating a third layer with corrugated cardboard coated on the second layer, laminating a single original cardboard on the third layer, the single original cardboard Laminating a fourth layer with corrugated cardboard coated on a layer, laminating a fifth layer with corrugated cardboard coated with orthogonal corrugated paper on the fourth layer, Laminating a sixth layer with corrugated cardboard coated on the fifth layer includes steps.

In a preferred embodiment of the present invention, the corrugated cardboard of the first layer to the third layer is arranged so that the original cardboard is downward, and the corrugated cardboard of the fourth layer to the sixth layer includes the step of arranging the original cardboard so that the original cardboard is located upward.

In a preferred embodiment of the present invention, it further comprises laminating the mixed solution-coated stone paper on the outermost inner layer.

In a preferred embodiment of the present invention, it includes the step of laminating a single original paper coated with the mixture on the stone paper.

In a preferred embodiment of the present invention, a composite panel is formed by bonding a thin metal plate to the inside and outside of the corrugated cardboard panel manufactured by the present invention.

By using the corrugated cardboard duct according to the present invention as described above, it is possible to secure the heat insulation property, thereby reducing the energy of the building, reducing the cost and securing the fire safety (fireproof, smoke-free, odor-free) through weight reduction and non-heat insulation. In addition, it has the effect of expressing the diversity of space by applying various designs to the duct surface, and it has the effect of contributing to environmental conservation through recycling of materials during demolition.

1 is a cross-sectional view of the thickness of a corrugated duct according to one preferred embodiment of the present invention.
2 is a cross-sectional view of the thickness of a corrugated cardboard panel according to a preferred embodiment of the present invention.
3 is a schematic diagram of an apparatus for coating a mixed solution on a corrugated cardboard according to a preferred embodiment of the present invention.
Figure 4 is a schematic view for explaining the continuous molding process of the straight pipe corrugated duct according to a preferred embodiment of the present invention.
5 is a schematic diagram for explaining a continuous molding process of a corrugated cardboard panel according to a preferred embodiment of the present invention.

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

Corrugated cardboard is a cardboard made by bonding a corrugating medium to a liner with an adhesive. Depending on the composition, single faced corrugated fiberboard, double faced, single wall, or double wall ), is divided into triple-sided corrugated cardboard (triple wall). The original paperboard provides resistance to mechanical shock and climatic conditions, and the backing board is used for printing. The corrugated wick gives the corrugated cardboard its thickness and increases its rigidity and flexibility, while at the same time providing relative elasticity against compression during impact. Corrugated cardboard exhibits high compressive strength while using a relatively low weight material. In a preferred embodiment of the present invention, flat corrugated cardboard is used, but other types of corrugated cardboard may also be used.

The mixture to be coated on the corrugated cardboard of the present invention is a mixture of 90-95% water glass and 5-10% expanded graphite.

The water glass used in the present invention is a liquid glass, an aqueous solution of sodium silicate (Na2SiO3), which is a representative silicate, and is used as a fixing agent due to its strong adsorption property, and is used as a building material due to its waterproofness and nonflammability. Water glass is not flammable, so it is used as an adhesive to attach fire-fighting materials to the wall. But it takes a little longer to harden.

Expanded graphite used in the present invention expands hundreds of times when it exceeds a certain temperature due to its own crystal structure of carbon, forms a heat insulating layer (Char) to secure physical flame retardancy, and has excellent flame retardant effect with less material, heavy metal If there are no problems, environmental problems or odor problems, the price is also low.

Stone paper (mineral paper) used in the present invention has the printability and degradability of wood paper, and at the same time has characteristics such as waterproof durability and heat workability of a plastic film.

The gist of the present invention is characterized by a corrugated cardboard duct using the properties of corrugated cardboard, water glass, expanded graphite and stone paper. In order to solve the problems in the existing ducts, the present inventors coated or mixed a mixture of water glass and expanded graphite on corrugated cardboard while researching ducts of corrugated cardboard, plastic, and metal straight pipe to increase insulation, reduce weight, reduce construction costs, and improve fire safety (fire resistance, It was possible to obtain a corrugated cardboard duct with smoke-free, odor-free), eco-friendliness, and moisture resistance.

In contrast, FIG. 1 shows the thickness of the duct as a partial cross-section of a straight pipe duct, and the corrugated cardboard of the present invention uses a single faced corrugated fiberboard. A stone paper 5 is placed on the top to make a good ceramic paint coating (not shown) on the stone paper, and a designation design can be drawn thereon through screen printing. The flat corrugated cardboard coated with the mixed solution from the bottom of the stone paper (5) is adhered in three layers with the original paper (3) facing upward, and the single original cardboard (4), which is an intermediate paper coated with the mixed solution below, achieves smoothness. It is arranged to secure, and three layers of flat corrugated cardboard coated with a mixed solution under it are adhered with the original cardboard 3 facing down, and finally the stone paper 5 is arranged to form the inner surface of the duct. have. Based on the single original cardboard (4), three layers of corrugated cardboard are arranged symmetrically with each other.

Coating the corrugated cardboard with a mixture of water glass, which has adhesion, waterproofness and non-combustibility, and expanded graphite, which expands hundreds of times to increase flame resistance when heated, to increase insulation, light weight, and fire safety (fireproof, smoke-free, non-flammable) odor), eco-friendliness, and moisture resistance, and additionally laminated stone paper to provide waterproofness and printability. In addition, several layers of corrugated cardboard are laminated to give warmth and hardness. And if the conventional duct has to be constructed by covering an additional insulating material, the corrugated cardboard duct of the present invention is guaranteed to have sufficient thermal insulation without a separate insulating material.

In addition to the straight pipe corrugated duct having the thickness shown in FIG. 1, a curved corrugated duct is also required, and in order to use it in the field, a flange for connecting them in series and joints for connecting vertically are required. In this regard, the present inventors have focused on the fact that it is desirable to manufacture a panel having strong structural hardness for such a curved pipe, a flange, and a joint, and to use it by bending it.

The structure of this panel is shown in FIG. 2, and for the purpose of explanation, the arrangement of the corrugated paper 2 of the corrugated cardboard is arranged in the front and rear directions on the drawing as shown in FIG. Those aligned in the left and right directions will be referred to as orthogonal corrugations here. Referring to FIG. 2 for a cross-section of the panel of the present invention, the mixed solution coated stone paper 5, the mixed solution coated flat corrugated cardboard thereon, and the original paper 3 are arranged with the first layer 11 facing down. ), a flat corrugated cardboard coated with a mixed solution thereon, a second layer 12 arranged as a corrugated core in an orthogonal direction with the original paper 3 facing down, a flat corrugated cardboard coated with a mixed solution thereon, the original cardboard 3 A fourth layer ( 14), a flat corrugated cardboard coated with a mixed solution thereon, a fifth layer 15 arranged as a corrugated core in an orthogonal direction with the original paper 3 facing upward, a flat corrugated cardboard coated with the mixed solution thereon, the original cardboard (3) It includes a sixth layer (16) arranged with an upward direction, and a stone paper (5) coated with a mixed solution thereon.

The cross-sectional configuration of the corrugated cardboard panel shown in FIG. 2 is a preferred embodiment of the present invention, but the present invention includes stacking corrugated core paper alternately in the forward and orthogonal directions in the corrugated cardboard coated with the mixed solution, and includes a single original cardboard that is a stone paper and an intermediate paper It is clear that the composition of all combinations to be included in the right of the present invention. As shown in Figure 2, when the corrugated paper is laminated orthogonally, the structural strength of the panel is much stronger.

In this regard, the strength of the panel in which the corrugated core is laminated in the same direction, the panel in which the corrugated core is laminated symmetrically, and the panel in which the corrugated core is alternately laminated in the forward and orthogonal directions, is stronger toward the latter. The panel of the present invention can be utilized as a building material and an interior material. In this case, a composite panel is formed by bonding a thin metal plate to the inside and outside of the corrugated cardboard panel of the present invention, and it can be constructed on the inside and outside walls or ceilings of buildings.

3 is a schematic diagram for explaining a method of coating a mixed solution of 90-95% water glass and 5-10% expanded graphite on corrugated cardboard or stone paper.

As an example, when the flat corrugated cardboard 1 wound on the supply roller is passed through the container 20 containing the mixed solution 10, the mixed solution is coated on the corrugated paper 2 and the original cardboard 3 of the flat corrugated cardboard 1, After passing the heater 30 to harden the coated mixture, it is wound on a take-up roller to make a roll corrugated cardboard. Here, the degree of hardening of the coated mixed solution is appropriate to the extent that the mixed solution-coated corrugated cardboard can be unwound after being wound on a roller.

Figure 4 is a schematic view for explaining a method for manufacturing a straight pipe corrugated duct shown in Figure 1.

The apparatus and method for manufacturing a straight pipe corrugated duct of the present invention is a continuous manufacturing method of a reinforced plastic pipe using a transfer film of Patent Application No. 10-2018-0109952 applied for a patent by the inventor of the present invention. can be manufactured with As the related description will be incorporated herein, if you have any doubts about the continuous molding process, please refer to the above-mentioned patent literature.

Here, in the preferred embodiment, a straight pipe is manufactured in a cylindrical shape, but a polygonal straight pipe including a square is also possible. A roller on which a corrugated cardboard coated with the mixture prepared in FIG. 3 is wound, a roller on which a stone paper is wound, and a roller on which a single original paper as intermediate paper is wound are prepared in advance.

In order to manufacture a straight pipe corrugated cardboard duct including the cross-sectional thickness shown in Fig. 1, the first roller 41 on which the stone paper is wound, the first roller 42 on which the corrugated cardboard coated with the mixed solution is wound, the mixed solution coated The second roller 43 on which the corrugated cardboard is wound, the third roller 44 on which the corrugated cardboard coated with the mixed solution is wound, the roller 45 on which the single original cardboard as intermediate paper is wound, the fourth roller with the corrugated cardboard coated with the mixed solution is wound ( 46), a fifth roller 47 on which the mixed solution-coated corrugated cardboard is wound, a sixth roller 48 on which the mixed solution-coated corrugated cardboard is wound, and a second roller 49 on which stone paper is wound are arranged, and forming A shaft tube 53 is aligned along the rollers, and a motor 52 capable of rotating the shaft tube 53 is connected to one end of the shaft tube 53 . In the base mold 57 that rotates integrally with the shaft tube 53 with the shaft tube 53 as the central axis in the form of a circular tube, the sheet wound on each roller (collectively referred to as) is arranged in the order of the base mold 57 ), a cross section of the thickness shown in FIG. 1 can be obtained. When continuously wound in this way, the wound straight tube corrugated cardboard duct 100 is cured while passing through the heater 54 and adheres to each other and continues to grow through the conveyor belt 56 (which is a circular tube shape with the shaft tube 53 as the central axis). (53) and covers the longitudinal outer circumferential surface of the base mold 57, which rotates integrally, and is cut to a predetermined length by the transfer film 58 that is in close contact from the rear to the front) and the cutter 55. Here, the first to third corrugated cardboard rollers are wound around the base mold 57 so that the original cardboard comes upward, and the fourth to sixth corrugated cardboard rollers are wound around the base mold 57 so that the original cardboard comes downward.

In a preferred embodiment, the step of coating the single original paper and the stone paper with the mixed solution in advance.

5 is a schematic view for explaining a method for manufacturing the flat corrugated cardboard panel shown in FIG.

A roller on which a corrugated cardboard coated with the mixture prepared in FIG. 3 is wound, a roller on which stone paper is wound, and a roller on which a single original cardboard is wound are prepared in advance.

In order to manufacture a corrugated cardboard panel including the cross-sectional thickness shown in FIG. 2, the first roller 41 on which the stone paper is wound, the first roller 42 on which the corrugated cardboard coated with the mixed solution is wound, the mixed solution coated corrugated cardboard The second roller 43, the third roller 44 on which the mixed solution coated corrugated cardboard is wound, the single original cardboard roller 45, the fourth roller 46 on which the mixed solution is coated corrugated cardboard is wound, A fifth roller 47 on which the mixed solution-coated corrugated cardboard is wound, a sixth roller 48 on which the mixed solution-coated corrugated cardboard is wound, and a roller 41 on which stone paper is wound are prepared.

The arrow in FIG. 5 indicates the direction in which the sheet moves due to the rotation of the conveyor belt and the roller, and the other indicates the feeding direction of the corrugated cardboard in the orthogonal direction.

Transferring the stone paper 5 coated with the mixed solution wound on the roller to the conveyor, arranging the first layer 11 with the flat corrugated cardboard coated thereon and the original cardboard 3 facing down, of the conveyor Stop the transfer and place the flat corrugated cardboard coated with the mixed solution from the means 60 thereon, the original cardboard 3 downward and the second layer 12 as a corrugated core in the orthogonal direction, while starting the transfer of the conveyor again The step of arranging the third layer 13 with the flat corrugated cardboard coated with the mixed solution coated thereon, the original cardboard 3 facing down, the step of arranging the single original cardboard 4 which is an intermediate paper coated with the mixed solution thereon, the The step of arranging the fourth layer 14 with the flat corrugated cardboard coated with the mixed solution on top of the original cardboard 3 facing upward, stopping the conveying of the conveyor, and using the flat corrugated cardboard coated with the mixed solution thereon, the original cardboard (3) The step of arranging the fifth layer 15 as a corrugated core in an orthogonal direction, with the flat corrugated cardboard coated with the mixed solution thereon while restarting the transfer of the conveyor, the sixth layer 16 with the original cardboard 3 facing upward ) includes the step of placing and placing the mixed solution coated stone paper (5) thereon. Through these steps, a seamless and continuously long panel is formed, and the formed panel is cured and bonded by a heater and can be cut to a predetermined length by a cutter.

In place of the stone paper coated with the mixed solution, just stone paper can be used, and in this case, the step of forming the upper and lower surface layers by further laminating the mixed solution-coated original paper on the stone paper layer is additionally included.

By using the panel made in this way, various types of corrugated cardboard ducts can be made by cutting, bending, folding and gluing cylindrical and rectangular straight pipes as well as curved pipes, and members connecting the ducts can be made.

In another embodiment, the stone paper and the coated corrugated cardboard are placed on a conveyor, and the sheet to which the coated corrugated cardboard of the orthogonal direction is adhered is wound on one roller, and the adhesive sheet wound on the roller is symmetrically overlapped to make the stone paper , comprising the step of producing a corrugated cardboard panel laminated with a coated corrugated cardboard, orthogonal corrugated core-coated corrugated cardboard and stone paper. A corrugated cardboard panel can be manufactured in various other combinations.

Ceramic coating can be additionally applied to the surface layer of the corrugated duct or panel, and the design can be printed using screen printing to make the appearance of the duct beautiful.

The present invention has been described above based on the preferred embodiment, but this is intended to illustrate the present invention. Those of ordinary skill in the art will be able to change or modify the above embodiment in other forms. However, since the scope of the present invention is defined by the claims, such variations or modifications may be construed as being included in the claims below.

2: bone core
3: original paper
4: single disc
5: stone paper
10: mixed solution
53: shaft tube
54: burner
55: cutter
57: base mold

Claims (15)

A non-insulated fireproof corrugated duct or panel comprising:
A non-heating fireproof corrugated cardboard duct or panel comprising at least one layer of hardened corrugated cardboard by coating a mixed solution of 90-95% water glass and 5-10% expanded graphite on the original corrugated cardboard and corrugated core. According to claim 1,
A non-heating fireproof corrugated cardboard duct or panel in which three layers of the mixed solution-coated corrugated cardboard are arranged as a lower layer and an upper layer, respectively, based on a single original cardboard. According to claim 1,
A non-heating fireproof corrugated cardboard duct or panel in which stone paper is adhered to the outer and/or inner original of the corrugated cardboard. 4. The method of claim 3,
A non-heating fireproof corrugated cardboard duct or panel in which a single original cardboard coated with the mixed solution is again adhered to the stone paper. 4. The method of claim 3,
A non-heating fireproof corrugated cardboard duct or panel in which the stone paper is additionally coated with ceramic. 3. The method of claim 2,
When arranging the corrugated cardboard coated with the mixed solution in multiple layers, the non-heating fireproof corrugated cardboard duct or panel arranged symmetrically with respect to the single original cardboard. According to claim 1,
At least two or more layers of corrugated cardboard coated with the mixture are stacked, and at least one of the corrugated cardboard layers is a corrugated core in an orthogonal direction. A method of forming a straight pipe corrugated duct by continuously forming a straight pipe corrugated duct by a continuous pipe manufacturing method, the method comprising:
Preparing a plurality of corrugated cardboard rollers coated with a mixture of 90-95% water glass and 5-10% expanded graphite on flat corrugated cardboard;
Winding at least one layer of the above-mentioned nameplate corrugated cardboard in a spiral on the base mold so that the original cardboard comes upward;
spirally winding at least one layer with a single original cardboard;
The step of spirally winding at least one layer of the coated cardboard so that the original cardboard comes down;
A method of forming a straight pipe corrugated duct comprising the step of spirally winding at least one layer of stone paper. 9. The method of claim 8,
Method of forming a straight pipe corrugated cardboard duct comprising the step of coating the single original paper and the stone paper with the mixed solution in advance. A method of forming a corrugated cardboard panel, comprising:
It includes at least two corrugated cardboard layers coated with a mixture of 90-95% water glass and 5-10% expanded graphite on a flat corrugated cardboard, and laminating at least one of the corrugated cardboard layers so that the corrugated core in the orthogonal direction is placed A method of forming a corrugated panel comprising a. 11. The method of claim 10,
Laminating the first layer by transferring the corrugated cardboard coated with the mixed solution between the conveyors rotating up and down,
Laminating a second layer with corrugated cardboard coated with corrugated paper in an orthogonal direction on the first layer,
Laminating a third layer with corrugated cardboard coated on the second layer;
Laminating a single original cardboard on the third layer,
Laminating a fourth layer with corrugated cardboard coated on the single original cardboard layer;
Laminating a fifth layer with corrugated cardboard coated with corrugated paper in an orthogonal direction on the fourth layer;
A method of forming a corrugated cardboard panel comprising the step of laminating a sixth layer with corrugated cardboard coated on the fifth layer. 12. The method of claim 11,
The corrugated cardboard of the first layer to the third layer is arranged so that the original cardboard is placed downward, and the corrugated cardboard of the fourth layer to the sixth layer is arranged so that the original cardboard is located upward. 12. The method of claim 11,
In addition, the method of forming a corrugated cardboard panel comprising the step of laminating the mixed solution-coated stone paper on the outermost layer. 12. The method of claim 11,
A method of forming a corrugated cardboard panel comprising the step of further laminating a single original cardboard coated with the mixture on the stone paper. A composite panel in which a thin metal plate is adhered to the inside and outside of a corrugated cardboard panel manufactured by the method of any one of claims 10 to 15.

Images