Flaky gathering material, preparation device of flaky gathering material and cigarette filter stick

Abstract

The invention discloses a flaky gathering material which is formed by gathering flaky materials (1), a plurality of convex frames (101) are arranged on the flaky materials (1), and a through hole (102) is formed in each convex frame (101); the convex frame (101) is circular, elliptical or polygonal; and the shape of the through hole (102) is the same as that of the convex frame (101). The invention further discloses a preparation device of the flaky gathering material and a cigarette filter stick containing the flaky gathering material.

Description

Technical Field

[0001] The invention belongs to the technical field of cigarettes, and in particular relates to a sheet-like gathering material, a preparation device of the sheet-like gathering material and a cigarette filter rod. Background Art

[0002] As people in various countries pay more and more attention to health, heated cigarettes have gradually entered the public eye due to their low harm. Heated cigarettes are a product that produces aerosols by cooperating with heated tobacco devices. The heating temperature generally reaches 200℃-400℃, and since there is no combustion and no high-temperature cracking process, the release of harmful substances is greatly reduced. In order to give consumers a good consumption experience, the smoke inlet temperature needs to be low and the aroma is full and full. This requires the full volatilization of the heated cigarette core, and the cigarette has a certain aroma-carrying capacity and a good cooling effect.

[0003] At present, the cooling methods generally used for heated cigarette products include: using wrinkled and gathered films, designing spiral structures to increase the length of the airway, and using hollow tubes to use the Venturi effect to cool down. The existing cooling methods mainly have problems such as complex processing technology, high production cost, large aroma interception, and poor cooling effect. In terms of flavoring heated cigarettes, the current mainstream method is mainly to add burst beads to the filter rods of heated cigarettes, or directly mix flavors in the core material. However, the production cost of burst beads is high, and the aroma release is uneven, and mixing flavors in the core material is likely to cause poor aroma release stability and affect the aroma release of the core material. Patent CN109846084A reports the use of polylactic acid filament composite filter rods for cooling, the gaps between the polylactic acid filaments are filled with fillers, and the circumferential surfaces of the polylactic acid filaments and fillers are evenly coated with plasticizers or tow adhesives for filter rod molding. However, the fillers between the polylactic acid filaments may evaporate with the smoke during the smoking process, bringing a bad smoking experience. Patent CN210043187U reports that the purpose of fragrance enhancement and cooling is achieved by gathering the polylactic acid film and placing a non-woven fabric in the middle. However, the fragrance carrying capacity of the non-woven fabric is limited, and the processing technology is complicated and the processing cost is high. Patent 202420931398X reports the use of polylactic acid films containing through holes to form a columnar structure as a cooling or / and fragrance adding section; however, since the polylactic acid film is in sheet form, after the polylactic acid film containing through holes is gathered, the through holes cannot be kept unobstructed well, the ventilation rate cannot be improved, and the cooling effect is poor; on the other hand, the fragrance enhancing material is directly carried on the surface of the cooling film, and the polylactic acid film is gathered to produce wrinkles or gaps to increase the fragrance carrying capacity; in fact, the fragrance carrying capacity in the wrinkles or gaps will not be greatly increased.

[0004] The present invention is proposed for this purpose. Summary of the invention

[0005] The invention discloses a sheet-like gathering material, a preparation device of the sheet-like gathering material and a cigarette filter rod. The sheet-like material of the invention has a plurality of convex frames, each of which has a through hole; the obtained sheet-like material is gathered and used in the cooling section, the flavoring section or / and the supporting section of the cigarette filter rod to achieve a better effect.

[0006] The technical solution of the present invention is as follows:

[0007] The present invention discloses a sheet-like gathering material, which is formed by gathering sheet-like materials 1. The sheet-like material 1 has a plurality of convex frames 101, and each convex frame 101 has a through hole 102. The convex frames 101 are circular, elliptical or polygonal, and have a height of 0-5mm. The shape of the through hole 102 is the same as or different from that of the convex frame 101.

[0008] Preferably, the convex frames 101 are evenly arranged in parallel on the sheet material 1 , and the convex frames 101 in each column are staggered with the convex frames 101 in adjacent parallel columns.

[0009] Preferably, the base material of the sheet material 1 is polylactic acid.

[0010] The second aspect of the present invention discloses a device for preparing the sheet-like gathering material, which comprises: a sheet-forming component 2, a coating component 3 and a gathering component 4; wherein the sheet-forming component 2 is upstream of the coating component 3, and the gathering component 4 is downstream of the coating component 3.

[0011] Preferably, the sheet forming assembly 2 includes an upper roller 21 and a lower roller 22 , the upper roller 21 is provided with a plurality of grooves 211 on its surface, the lower roller 22 is provided with a boss 221 matched with the grooves 211 on its surface; the grooves 211 correspond to the convex frame 101 ; the boss 221 corresponds to the through hole 102 .

[0012] Preferably, the coating assembly 3 includes a coating device and a material storage and guiding device; the coating device includes a first roller 31, and the material storage and guiding device includes a material guide plate 301; the mouth of the material guide plate 301 is attached to the roller surface of the first roller 31.

[0013] Preferably, the coating device further comprises: a mounting plate 32, a first roller shaft 31, a second roller shaft 33, a first tensioning shaft 34 and a second tensioning shaft 35 mounted on the mounting plate 32, the second roller shaft 35 and the first tensioning shaft 34 being arranged on the left and right sides of the lower part of the first roller shaft 31 respectively, and the second tensioning shaft 35 being arranged on the lower right side of the first tensioning shaft 34; on the outer side of the mounting plate 32, the first roller shaft 31 is connected to a synchronous pulley 36, and the synchronous pulley 36 is connected to a reduction motor 38 through a synchronous belt 37;

[0014] The material storage and guiding device further comprises: a material storage bin 302, a baffle 303 and a seat spring 304. The material storage and guiding device is fixedly mounted on the mounting plate 32 via a bin mounting plate 305. The material storage bin 302 is arranged such that its bin opening faces the roller surface of the first roller 31. The material guide plate 301 is arranged at the bottom of the material storage bin 302. The mouth of the material guide plate 301 is a curved surface that fits the roller surface of the first roller 31. The upper part of the material guide plate 301 near the mouth is provided with a baffle 303. The baffle 303 The two ends are arranged in the rectangular grooves 3021 at the two ends of the opening of the storage bin 302; there are two seat springs 304, and the base of each seat spring 304 is installed in the rectangular groove 3021 and is interference fit, and the upper end of each seat spring 304 is against the lower wall of the baffle 303; a baffle threaded hole 3031 is provided at the center of the baffle 303, and a guide plate threaded hole 3011 is provided on the guide plate 301; the baffle threaded hole 3031 and the guide plate threaded hole 3011 are adapted to the adjusting screw 306.

[0015] Preferably, the gathering component 4 comprises: a conical tube 41 , the conical tube 41 is trumpet-shaped, and the large opening 411 of the conical tube faces the applying component 3 .

[0016] The third aspect of the present invention discloses a cigarette filter rod, which comprises the sheet-like gathering material.

[0017] Preferably, the cigarette filter rod comprises: a gathering section 11 made of sheet-like gathering material and a wrapping member 12; the wrapping member 12 is a cylindrical structure, which wraps around the gathering section 11 of the sheet-like gathering material; and the inner surface of the wrapping member 12 has an anti-permeability layer.

[0018] Effects of the present invention:

[0019] 1. The sheet material of the present invention is provided with a convex frame 101, and a through hole 102 is provided in the convex frame 101. The sheet-like gathering material of the present invention is gathered into a desired shape such as a cylindrical shape, a rod shape, etc., and can be used for cigarette filter rods, especially for heat-not-burn cigarette filter rods, such as the cooling section, flavoring section, and support section of the heat-not-burn cigarette filter rod. When used as a support section, in addition to the through hole 102 for ventilation, the convex frame 101 separates the surface of the sheet material, increasing the air permeability while ensuring the support. When used as a cooling section (rod), the base material of the sheet material can be a material such as polylactic acid, and the convex frame 101 with the through hole 102 separates the adjacent surfaces of the sheet material. In addition to the through hole 102 for ventilation, the convex frame 101 can increase the air permeability to reduce smoke retention, and at the same time use the physical properties of the material itself (such as polylactic acid has a cooling performance) to cool down. When used as a scenting segment, flavors and fragrances can be directly applied to the surface of the sheet material through the application component. Due to the isolation of the adjacent sheet materials by the convex frame 101, it has a larger fragrance-carrying space, that is, the setting of the convex frame 101 can significantly increase the fragrance-carrying capacity of the sheet material. At the same time, the convex frame 101 can also provide a certain support force to the scenting segment, so that the scenting segment has good stability after scenting. The present invention requires that the height of the convex frame be 0-5mm; generally, the greater the height of the convex frame, the higher the ventilation rate, but the worse the support, the lower the fragrance carrying rate, so the height of the convex frame is not the higher the better. Compared with conventional technology, the sheet-like gathering material of the present invention is used as a scenting segment, and its fragrance-carrying capacity is 2 to 3 times higher than that reported in patent CN202420931398X, and the use of substrate is reduced, the cost is reduced, and the stability is improved.

[0020] 2. In the preparation device for sheet-like gathered materials of the present invention, the surface of the upper roller 21 is provided with a plurality of grooves 211 corresponding to the convex frame 101 of the sheet-like material; the surface of the lower roller 22 is provided with a convex platform 221 corresponding to the through hole 102 of the sheet-like material. The frame height, shape, number, and arrangement of the convex frame 101 can be designed according to actual needs; the shape of the through hole 102 can also be changed according to requirements. The surface structure of the upper roller and the lower roller of the preparation device of the present invention can be changed and designed according to the needs of the sheet-like material.

[0021] 3. The preparation device of the present invention includes: a sheeting component, a coating component and a gathering component. The device has a simple structure, and each component is a common component, which can be installed by oneself and is easy to implement. The preparation device of the present invention takes the polylactic acid film sheet substrate as an example, and the upper roller 21 and the lower roller 22 of the sheeting component are used to roll and form the polylactic acid film sheet; the smoke-generating agent and / or flavors can be evenly applied to the surface of the polylactic acid film sheet by the coating component, and the amount of the smoke-generating agent and / or flavors can be controlled by adjusting the size of the gap between the baffle 303 and the guide plate 301; and then the gathering component gathers and forms the gathered section, which has both cooling and flavoring functions when used in heated cigarettes. The entire process flow of the preparation device of the present invention is simple and the preparation cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the sheet material of the present invention.

[0023] Figure 2 for Figure 1 Partial enlargement

[0024] Figure 3 It is a schematic diagram of the cigarette filter rod of the present invention.

[0025] Figure 4 It is a schematic diagram of the overall appearance of the preparation device of the sheet-like gathering material of the present invention.

[0026] Figure 5 It is a schematic diagram of the sheet assembly of the present invention.

[0027] Figure 6 It is a schematic diagram of the spreading component and the gathering component of the present invention.

[0028] Figure 7 It is a schematic diagram of the material storage and guiding device of the present invention.

[0029] Figure 8 It is an exploded view of the material storage and guiding device of the present invention.

[0030] The accompanying drawings are marked as follows: 1. sheet material; 101. convex frame; 102. through hole; 11. gathering section; 12. wrapping piece; 2. sheeting assembly; 21. upper roller; 211. groove; 22. lower roller; 221. boss; 3. smearing assembly; 301. material guide plate; 3011. material guide plate threaded hole; 302. material storage bin; 3021. rectangular groove; 303. baffle; 3031. baffle threaded hole; 304. seat spring; 305. bin mounting plate; 306. adjusting screw; 31. first roller shaft; 32. mounting plate; 33. second roller shaft; 34. first tensioning shaft; 35. second tensioning shaft; 36. synchronous pulley; 37. synchronous belt; 38. reduction motor; 4. gathering assembly; 41. tapered tube; 411. large mouth of tapered tube. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0033] In addition, the terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features.

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix", "bond" and the like should be understood in a broad sense, for example, it can be connected, detachably connected, or integrated. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In this specification, the schematic representation of the above terms should not be understood to necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0036] The sheet-like gathering material of the present invention is gathered by a sheet-like material 1, wherein the sheet-like material 1 has a plurality of convex frames 101, each of which has a through hole 102; the convex frames 101 are circular, elliptical or polygonal; the shape of the through hole 102 is the same as or different from that of the convex frames 101; wherein the convex frames 101 are evenly arranged in parallel on the sheet-like material 1, and each row of convex frames 101 is staggered with the convex frames 101 of the adjacent parallel rows, such as Figure 1 and Figure 2The frame height, shape, quantity, arrangement, etc. of the convex frame 101 can be designed and replaced according to actual needs. The present invention requires that the height of the convex frame 101 is 0-5 mm.

[0037] If the gathering section 11 is used as a cooling section of a cigarette filter rod, the base material of the sheet material 1 may be polylactic acid, because polylactic acid can be used as a cooling material.

[0038] like Figure 3-Figure 8 As shown, the device for preparing the sheet-like gathering material of the present invention comprises: a sheet-forming component 2, a coating component 3 and a gathering component 4; wherein the sheet-forming component 2 is upstream of the coating component 3, and the gathering component 4 is downstream of the coating component 3.

[0039] like Figure 5 As shown, the sheet forming assembly 2 includes an upper roller 21 and a lower roller 22. The upper roller 21 has a plurality of grooves 211 on its surface, and the lower roller 22 has a boss 221 matched with the grooves 211 on its surface; the grooves 211 correspond to the convex frame 101; and the boss 221 corresponds to the through hole 102.

[0040] like Figure 6 As shown, the coating assembly 3 includes a coating device and a material storage and guiding device; the coating device includes a first roller 31, and the material storage and guiding device includes a material guide plate 301; the mouth of the material guide plate 301 is attached to the roller surface of the first roller 31.

[0041] The coating device further comprises: a mounting plate 32, a first roller 31, a second roller 33, a first tensioning shaft 34 and a second tensioning shaft 35 mounted on the mounting plate 32, the second roller 35 and the first tensioning shaft 34 being arranged on the left and right sides of the lower part of the first roller 31 respectively, and the second tensioning shaft 35 being arranged on the lower right side of the first tensioning shaft 34; on the outer side of the mounting plate 32, the first roller 31 is connected to a synchronous pulley 36, and the synchronous pulley 36 is connected to a reduction motor 38 through a synchronous belt 37;

[0042] The material storage and guiding device also includes: a material storage bin 302, a baffle 303 and a seat spring 304. The material storage and guiding device is fixedly installed on the mounting plate 32 through a bin mounting plate 305. The material storage bin 302 is arranged so that its bin opening faces the roller surface of the first roller 31; the material guide plate 301 is arranged at the bottom of the material storage bin 302, and the mouth of the material guide plate 301 is a curved surface, which is attached to the roller surface of the first roller 31; the material guide plate 301 is used to guide the coating material such as smoke generating agent and / or flavor and fragrance from the material storage bin 302; the material guide plate 301 near the mouth is There is a baffle 303 at the upper part, and the two ends of the baffle 303 are arranged in the rectangular grooves 3021 at the two ends of the opening of the storage bin 302; there are two seat springs 304, and the base of each seat spring 304 is installed in the rectangular groove 3021 and has an interference fit, and the upper end of each seat spring 304 abuts against the lower wall of the baffle 303; a baffle threaded hole 3031 is provided at the center of the baffle 303, and a guide plate threaded hole 3011 is provided on the guide plate 301; the baffle threaded hole 3031 and the guide plate threaded hole 3011 are adapted to the adjusting screw 306; Figure 7 and Figure 8 shown.

[0043] like Figure 6 As shown, the gathering component 4 includes: a conical tube 41 , which is trumpet-shaped, and its large opening 411 faces the smearing component 3 .

[0044] like Figure 3 As shown, the cigarette filter rod using the sheet-like gathering material of the present invention comprises: a gathering section 11 formed of the sheet-like gathering material and a wrapping member 12; the wrapping member 12 is a cylindrical structure, which is wrapped around the outer periphery of the gathering section 11 of the sheet-like gathering material; the inner surface of the wrapping member 12 has an anti-permeability layer.

[0045] Example 1: Use Figure 3-Figure 8 The preparation device shown is used to prepare a polylactic acid film sheet-shaped gathering material. The convex frame 101 is rectangular, and the height of the convex frame 101 is 2 mm; the through hole 102 is also rectangular.

[0046] The polylactic acid sheet substrate enters from the gap between the upper roller 21 and the lower roller 22 of the sheet forming assembly 2, and is extruded by the upper roller 21 and the lower roller 22 to form a polylactic acid sheet, so that the convex frame 101 and the through hole 102 are both rectangular sheet materials such as Figure 1 and Figure 2As shown, it then enters the coating component 3; at this time, the reduction motor 38 works, and the first roller 31 is driven to rotate through the cooperation of the synchronous belt 37 and the synchronous pulley 36. The polylactic acid sheet film from the sheet forming component 2 enters from the top of the second tensioning shaft 35, and then passes through from the bottom of the first tensioning shaft 31 and enters the gap between the curved surface of the guide plate 31 and the roller surface of the first roller 31, and then goes around from the upper end of the first roller 31 to the right side of the second roller 35, and then enters the tapered tube 41 from the lower end of the second roller 35 through the large mouth 411 of the tapered tube 41 tube 41; at the same time, the smoke-generating agent and / or flavor in the storage bin 302 is evenly spread on the surface of the polylactic acid sheet by the curved surface of the mouth of the guide plate 301. According to product requirements, the adjusting screw 306 can be rotated to adjust the gap between the baffle 303 and the guide plate 301 with the cooperation of the seat spring 304 to control the amount of smoke-generating agent and / or flavor applied; the polylactic acid sheet after application is gathered and curled through the conical tube 41 to form a sheet-like gathered material, which is roughly a cylindrical segment; after cutting, it can be used in cigarette filter rods.

[0047] Example 2: The gathered segments 11 cut from the sheet-like gathered material obtained in Example 1 are used as the flavoring segments of the cigarette filter rods of the heated non-combustion cigarettes, such as Figure 3 shown.

[0048] When the gathered segments 11 cut from the sheet-like gathered material obtained in Example 1 are used as the flavoring segments of the cigarette filter rods for heating non-combustion cigarettes, Figure 3 As shown. When inhaling, the cigarette core section is heated by the heating device to release aerosol. When passing through the flavoring section of the present invention, the flavor gel mixture loaded in the gathering section 11 releases the aroma. Because the fragrance-carrying space of the sheet-like gathering material of the present invention is larger and the fragrance-carrying amount is higher, the gas fragrance entering the oral cavity from the filter section is fuller and fuller. At the same time, after the sheet-like materials are gathered, the rectangular convex frame 101 separates the surfaces of adjacent sheet-like materials. Due to the presence of the through hole 102, there are more pores and higher air permeability, which greatly reduces the interception of the heated cigarette smoke. In addition, the base material of the sheet-like material of this embodiment is polylactic acid. Since polylactic acid can also be used as a cooling material, the flavoring section of this embodiment has both the effects of flavoring and cooling. In this way, only one cylindrical section of the sheet-like gathering material of the present invention is needed to have the effects of cooling and flavoring. While the flavoring section of this embodiment has a good cooling effect, it increases the stable release of aroma, reduces the processing steps of heated cigarettes, and reduces costs.

[0049] The above embodiments are not limitations of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the essential scope of the present invention also fall within the protection scope of the present invention.

Claims

1. A sheet-like gathering material, characterized in that: The sheet-like gathering material is formed by gathering sheet-like materials (1), the sheet-like materials (1) are provided with a plurality of convex frames (101), each convex frame (101) having a through hole (102) therein; the convex frames (101) are circular, elliptical or polygonal, and have a height of 0-5 mm.

2. The sheet-like gathering material according to claim 1, characterized in that: The convex frames (101) are evenly arranged in parallel on the sheet material (1), and the convex frames (101) in each column are arranged in a staggered manner with the convex frames (101) in the adjacent parallel columns.

3. The sheet-like gathering material according to claim 1, characterized in that: The base material of the sheet material (1) is polylactic acid.

4. The device for preparing the sheet-like gathered material according to any one of claims 1 to 3, characterized in that: It includes: component (2), a smearing component (3) and a gathering component (4); wherein the sheeting component (2) is upstream of the smearing component (3), and the gathering component (4) is downstream of the smearing component (3).

5. The preparation device according to claim 4, characterized in that: The sheet forming assembly (2) comprises an upper roller (21) and a lower roller (22); the surface of the upper roller (21) is provided with a plurality of grooves (211); the surface of the lower roller (22) is provided with bosses (221) adapted to the grooves (211); the grooves (211) correspond to the convex frame (101); and the bosses (221) correspond to the through holes (102).

6. The preparation device according to claim 4, characterized in that: The smearing assembly (3) comprises a smearing device and a material storage and guiding device; the smearing device comprises a first roller (31), and the material storage and guiding device comprises a material guide plate (301); the mouth of the material guide plate (301) is attached to the roller surface of the first roller (31).

7. The preparation device according to claim 6, characterized in that: The coating device further comprises: a mounting plate (32), a first roller (31), a second roller (33), a first tensioning shaft (34) and a second tensioning shaft (35) mounted on the mounting plate (32), wherein the second roller (35) and the first tensioning shaft (34) are respectively arranged on the left and right sides of the lower part of the first roller (31), and the second tensioning shaft (35) is arranged on the lower right side of the first tensioning shaft (34); on the outer side of the mounting plate (32), the first roller (31) is connected to a synchronous pulley (36), and the synchronous pulley (36) is connected to a reduction motor (38) via a synchronous belt (37); The material storage and guiding device further comprises: a material storage bin (302), a baffle (303) and a seat spring (304); the material storage and guiding device is fixedly mounted on the mounting plate (32) via a material bin mounting plate (305); the material storage bin (302) is arranged such that its bin opening faces the roller surface of the first roller (31); the material guide plate (301) is arranged at the bottom of the material storage bin (302); the opening of the material guide plate (301) is a curved surface which fits the roller surface of the first roller (31); the upper portion of the material guide plate (301) close to the opening is provided with a baffle (303); the baffle (303) The two ends are arranged in the rectangular grooves (3021) at the two ends of the opening of the storage bin (302); there are two seat springs (304), the base of each seat spring (304) is installed in the rectangular groove (3021) and is interference fit, and the upper end of each seat spring (304) is against the lower wall of the baffle (303); a baffle threaded hole (3031) is provided at the center of the baffle (303), and a guide plate threaded hole (3011) is provided on the guide plate (301); the baffle threaded hole (3031) and the guide plate threaded hole (3011) are adapted to the adjusting screw (306).

8. The preparation device according to claim 4, characterized in that: The gathering component (4) comprises: a conical tube (41), the conical tube (41) is trumpet-shaped, and the large opening (411) of the conical tube faces the smearing component (3).

9. A cigarette filter rod, characterized in that: It comprises the sheet-like gathering material according to any one of claims 1-3.

10. The cigarette filter rod according to claim 9, characterized in that: The cigarette filter rod comprises: a gathering section (11) formed of a sheet-like gathering material and a wrapping piece (12); the wrapping piece (12) is in a cylindrical structure and is wrapped around the periphery of the gathering section (11) of the sheet-like gathering material; and the inner surface of the wrapping piece (12) is provided with an anti-permeation layer.

Images