Glass forming system and method for producing two or more glass products from one glass blank

Abstract

Glass forming system (1) for producing two or more glass products from a glass blank (2), comprising - a transport unit (4) for transporting the glass blank (2), which has a grid structure (6) with two or more processing recesses (12), wherein the grid structure (6) is arranged and designed to hold the glass blank (2) vertically above the processing recesses (12), - a forming device (13) with two or more forming units (16), each having an upper forming element (18) and a lower forming element (20), each forming a cavity (22) for forming the glass blank (2), - wherein the transport unit (4) can be arranged on the forming device (13) in such a way that the forming units (16) can each be moved through one of the process recesses (12) in order to press a glass blank (2) held by the lattice structure (6) into the cavities (22).

Description

[0001] The invention relates to a glass forming system for producing two or more glass products from one glass blank, a transport unit for use in such a glass forming system and a method for producing two or more glass products from one glass blank.

[0002] Glass forming systems are generally well known. Multi-cavity molds are increasingly being used to produce glass products, such as optics, by hot forming. During heating, the glass blank already rests on the lower forming tool, meaning that a significant portion of the tool's service life is not used for the value-adding activity of forming. Furthermore, this arrangement results in long cycle times. In addition, the heating of the blank exposes the forming tool to significant temperature fluctuations. As a result, tool wear is increased and tool life is reduced. The lower forming tool is usually coupled to the glass temperature, so that individual temperature control of the glass blank and the lower forming tool is not possible or only possible to a limited extent.An upper mold, on the other hand, can be tempered, although the correct tempering of the glass blank, lower and upper molds can usually only be achieved with an iterative process.

[0003] A frequently used method in the prior art to avoid heating the glass blank on the lower forming tool is to preheat the glass blank externally and move it from the heating station to the forming tool using a handling process. For example, DE 10 2019 117 756 A1 describes the external heating of a glass blank, which is then placed on rod-shaped support elements of a forming device. Handling locally influences the glass blank through gripping marks. Furthermore, the glass blank can become contaminated by dust and other particles during handling.

[0004] DE 21 35 697 A discloses a device for bending glass panes of any shape, comprising an elongated furnace, a heating bed, and a transport device for transporting the glass panes through the furnace. DE 11 2012 005 570 T5 discloses a molding device and a molding method for glass housings. DE 10 2016 113 827 A1 discloses a method for producing a plurality of glass elements.

[0005] Furthermore, dimensionally stable transport of the glass blank is required to ensure safe handling of the blank with its low viscosity, which is caused by the high temperature. Maintaining the shape of the glass blank during preheating and handling is essential for the production of high-quality glass products.

[0006] The external preheating of the glass blank also requires a comprehensive system design. In particular, the provision of a handling unit with a sensitive gripper to reduce gripping marks is prone to technical malfunctions, costly, and requires regular and usually extensive maintenance.

[0007] A further disadvantage of external preheating is that the grip marks on the glass blank are only partially predictable.

[0008] In particular, the complex relationships between gripping force, temperature, and glass material mean that gripping marks can only be determined statistically, which often results in unsatisfactory quality of the manufactured glass products. Furthermore, the process is characterized by low efficiency, as the manufactured glass products must undergo extensive quality control.

[0009] It is therefore an object of the present invention to provide a glass forming system and a method for producing two or more glass products from a glass blank, as well as a transport unit for use in such a glass forming system, which reduce or eliminate one or more of the aforementioned disadvantages. In particular, it is an object of the invention to provide a solution that enables high-quality production of glass products. Furthermore, it is an object of the invention to provide a solution that enables the provision of a glass blank without grip marks.

[0010] This object is achieved with a glass forming system, a transport unit, and a method according to the features of the independent patent claims. Further advantageous embodiments of these aspects are specified in the respective dependent patent claims. The features listed individually in the patent claims and the description can be combined with one another in any technologically expedient manner, with further embodiments of the invention being demonstrated.

[0011] According to a first aspect, the object mentioned at the outset is achieved by a glass forming system for producing two or more glass products from a glass blank, comprising a transport unit for transporting the glass blank, which has a grid structure with two or more process recesses, wherein the grid structure is arranged and designed to hold the glass blank vertically above the process recesses, a forming device with two or more forming units, each having an upper forming element and a lower forming element, each forming a cavity for forming the glass blank, wherein the transport unit can be arranged on the forming device in such a way that the forming units can each be moved through one of the process recesses in order to press a glass blank held by the grid structure into the cavities.

[0012] The invention is based, among other things, on the finding that the gripping process can be avoided if the glass blank is first heated on the transport unit using a tempering device and the glass blank is then inserted into the forming device with the transport unit.

[0013] As a result, no gripping of the glass blank is required for movement from the tempering device to the forming device, but only a transfer of the transport unit, which leaves no gripping marks on the glass blank. Transferring the transport unit is preferably carried out with a tempered gripper,

[0014] A further advantage of the transport unit, which is usually heated to 400 °C to 700 °C during normal operation, is that the shape of the glass blank is essentially retained and no sagging of the heated glass blank is to be expected.

[0015] The invention is further based on the finding that the transport unit is arranged on the forming device in such a way that the forming process is essentially unaffected by the transport unit. This is achieved in the present case by allowing the forming units, in particular the lower forming elements of the forming units, to move through the process recesses of the lattice structure. In other words, the transport unit can be lowered into the forming device so that the forming device can perform the forming process.

[0016] The glass forming system is designed to produce two or more glass products from the glass blank. "From a glass blank" specifically means at least one glass blank, since two or more glass blanks can be arranged side by side on the transport unit and can be heated, transported, and molded accordingly. The glass products can be wafers, for example.

[0017] The glass forming system comprises the transport unit. The transport unit is designed to transport the glass blank, in particular from a tempering device to the forming device. The transport unit comprises the grid structure. The grid structure has two or more processing recesses.

[0018] The lattice structure preferably comprises two or more lattice struts aligned to form the process recesses. The lattice struts are preferably aligned parallel and / or orthogonally to one another. For example, two lattice struts aligned orthogonally to one another form a total of four process recesses. The process recesses preferably have a rectangular, furthermore preferably a square, opening cross-section. Furthermore, the process recesses preferably have a honeycomb-shaped opening cross-section.

[0019] It is further preferred that the lattice structure has a lattice structure frame that surrounds the lattice struts. The lattice structure can also be designed such that two forming units can be moved through a process recess.

[0020] The forming device has two or more forming units. A forming unit has an upper forming element and a lower forming element. The upper forming elements are preferably formed on an upper forming device of the forming device. Furthermore, the lower forming elements are preferably arranged on a lower forming device of the forming device. The upper forming device and / or the lower forming device can be formed in one piece, in particular monolithically, or in multiple parts.

[0021] An upper forming element and a corresponding lower forming element are configured to form a cavity. For this purpose, the upper forming element preferably has a concave region in a section facing the lower forming element and / or the lower forming element preferably has a concave region in a section facing the upper forming element.

[0022] The forming units are preferably arranged side by side. The forming units can be arranged, for example, in a line or in a matrix. Typically, the glass blank is placed on the lower forming elements of the forming units.

[0023] To enable the arrangement of the glass blank between the upper forming element and the lower forming element, it is provided that the transport unit can be arranged on the forming device in such a way that the forming units can each be moved through one of the process recesses in order to press a glass blank held by the lattice structure into the cavities. The transport unit is thus arranged on the forming device with the glass blank so that the forming units, for example the lower forming elements of the lower forming units, can be moved through the process recesses. By moving through, the glass blank is transferred from the lattice structure to the lower forming elements. The glass blank can then be pressed in the cavities.

[0024] The transport unit preferably has no influence on the pressing process. Alternatively, the transport unit can be designed and arranged in such a way that it has a predefined influence on the pressing process. This can be achieved, for example, by contacting the glass of the glass blank with the transport unit during pressing. Furthermore, it is preferred that gaps be established between the transport unit and the forming units. Alternatively, the upper forming element can also be moved through the process recesses.

[0025] The fact that the glass blank held by the grid structure is pressed in the cavities also means that a portion of the glass blank is pressed. Typically, a portion of the glass blank is not actually pressed in sections between two forming units. The transport unit is therefore arranged on the forming device in such a way that the glass blank held by the grid structure is pressed in the cavities while the transport unit is arranged on the forming device. Removing the transport unit before pressing is not necessary.

[0026] A preferred embodiment of the glass forming system is characterized in that the transport unit is designed to transport the glass blank between the forming device and a tempering device. For this purpose, the transport unit comprises, in particular, a material that essentially does not form a chemical bond with the glass during the preheating of the glass blank in the tempering device and is essentially dimensionally stable at high temperatures.

[0027] Furthermore, the transport unit preferably has at least one handling section arranged and configured to interact with a transport means. The handling section is preferably configured as a flat projection.

[0028] A preferred development of the glass forming system is characterized in that the grid structure is formed by grid struts. The grid struts are preferably aligned parallel and / or orthogonal to one another. Furthermore, the grid struts are preferably formed in one piece. Alternatively or additionally, the grid structure can be formed by or comprise at least one wire. The grid structure can also be formed by two or more wires. It is preferred that the transport unit has one, two, or more pins for fastening and / or deflecting the wire. The pin(s) can, for example, project from an underside of the transport unit.

[0029] A further preferred embodiment of the glass forming system is characterized in that the grid structure has at least one support element, so that a glass blank can be supported on the at least one support element. The grid structure preferably comprises a plurality of support elements, which are further preferably evenly distributed. For example, the support elements can be encompassed by the grid struts. Each process recess is preferably surrounded by at least three, preferably four, support elements to enable advantageous support of the glass blank. Thus, the contact surface of the glass blank on the transport unit is reduced, further improving quality.

[0030] It is preferred that the at least one support element be arranged so that it can be replaced. Due to the regular heating and contact with the heated glass blank, the at least one support element is exposed to stresses that cause wear.

[0031] A preferred development of the glass forming system is characterized in that the forming device has a recessed area surrounding the two or more forming units and the grid structure can be sunk at least partially into the recessed area in such a way that the cavities can be completely closed.

[0032] As soon as the forming units are moved through the process recesses, the grid structure can, for example, be moved into the recessed area, so that it essentially does not impair the pressing process. The recessed area can, for example, have one, two, or more recessed channels between the forming units. It is particularly preferred that the recessed area has a geometry corresponding to the grid structure and / or the transport unit, so that the grid struts of the grid structure can be arranged in the recessed channels of the recessed area.

[0033] In a further preferred development of the glass forming system, it is provided that the lower forming elements have a lower truncated pyramid-shaped section and / or the upper forming elements have an upper truncated pyramid-shaped section, so that glass flow cavities influencing a glass flow are formed adjacent to the cavities when the cavities are closed.

[0034] If the upper and lower forming elements each have a truncated pyramid-shaped section, the glass flow cavities can, for example, have a hexagonal cross-section. Furthermore, the glass flow cavity can have a diamond-shaped cross-section. The glass flow cavities influence the glass flow, thus improving the production of glass products. In particular, by adjusting the angles of the truncated pyramid-shaped sections, the friction of the glass on the forming unit can be adjusted.

[0035] It is preferred that a lower limit of this angle be selected between 20-30° relative to the horizontal, and an upper limit of this angle be selected between 60-70° relative to the horizontal. The truncated pyramid-shaped sections can also have freeform surfaces that approximate a pyramid shape. This can be formed, for example, with a spherical, aspherical, or polynomial-shaped section.

[0036] A further preferred embodiment of the glass forming system is characterized by the fact that a convex glass flow element is arranged between the upper truncated pyramid-shaped sections, which protrudes into one of the glass flow cavities when the cavities are closed. The glass flow element can, for example, have a pyramid-shaped or conical cross-section, with the apex of the pyramid facing downward during normal operation. Such a glass flow element can further influence the glass flow in the glass flow cavity.

[0037] In a further preferred embodiment of the glass forming system, the lower forming elements each have a lower cuboid section, and the cuboid sections form one side of the recessed region, in particular one side of the recessed channel(s). A cuboid section can also be understood as a cube-shaped section. The cuboid sections are preferably arranged vertically below the truncated pyramid-shaped sections. Consequently, the lower forming elements preferably initially extend vertically straight upwards and, due to the truncated pyramid-shaped sections, then taper towards the cavity.

[0038] A further preferred embodiment of the glass forming system comprises two or more, preferably four, positioning elements for positioning the glass blank in a predetermined position on the grid structure.

[0039] Preferably, four fixing elements are provided in each inner corner of the transport unit facing the grid structure. Alternatively or additionally, four fixing elements are preferably provided on each side of the grid structure and / or an inner side of the transport unit. The fixing elements preferably have a cross-section that tapers upwards, so that the spacing between two oppositely arranged fixing elements decreases downwards.

[0040] A further preferred embodiment of the glass forming system is characterized in that it comprises a centering means that centers the transport unit relative to the forming device. It is preferred that the recessed area has the centering means, and the centering means is designed to position the transport unit by means of a positioning section. For example, the recessed area or the recessed channels can be tapered, so that positioning of the transport unit within the recessed area or within the recessed channels is achieved by means of a tight tolerance.

[0041] A further preferred embodiment of the glass forming system is characterized in that the forming device and the transport unit each have at least one corresponding alignment opening, which have a common passage axis during normal operation and are arranged such that the forming device and the transport unit can be aligned by means of the alignment opening and an alignment element that can be arranged in the alignment opening.

[0042] A further preferred embodiment of the glass forming system is characterized in that the transport unit has a collar surrounding the grid structure. The collar can, for example, surround the grid structure frame. The collar is arranged in such a way that, during normal operation, it is located outside the forming device when the forming units are brought together.

[0043] A further preferred embodiment of the glass forming system is characterized in that the lattice structure has a cooling system arranged and configured to cool the lattice structure. It is particularly preferred that the cooling system comprises cooling channels embedded within the lattice struts of the lattice structure, through which a cooling fluid can flow.

[0044] According to a further aspect, the object mentioned above is achieved by a transport unit for use in a glass forming system according to one of the aforementioned embodiments, which is designed to transport a glass blank, comprising a grid structure with two or more processing recesses, wherein the grid structure is arranged and configured to hold the glass blank vertically above the processing recesses. The aforementioned features, properties, and advantages of the transport unit of the glass forming system according to the first aspect apply analogously to the transport unit according to this aspect.

[0045] According to a further aspect, the object mentioned at the outset is achieved by a method for producing two or more glass products from a glass blank, in particular with a glass forming system according to one of the embodiments described above, comprising the steps of: heating a glass blank held vertically via process recesses of a lattice structure of a transport unit by means of a heating unit; moving the transport unit from the heating unit to a forming device with two or more forming units, each having an upper forming element and a lower forming element, each forming a cavity for forming the glass blank; and moving the upper forming elements and / or the lower forming elements towards one another through the process recesses in order to press the glass blank held by the lattice structure into the cavities.

[0046] Moving the transport unit from the heating unit to the forming device also includes, in particular, a corresponding arrangement of the transport unit on the forming device. This arrangement may, for example, include arranging the grid structure in a recessed area, in particular in recessed channels.

[0047] After the glass blank has been pressed in the cavities, the pressed glass blank is removed from the forming device using the transport unit. The glass blank can then be moved to a cooling station, which may include a cooling annealing furnace.

[0048] The method and its possible further developments have features or process steps that make them particularly suitable for use with the glass forming system and its further developments. For further advantages, design variants, and details of the other aspects and their possible further developments, please refer to the above description of the corresponding features and further developments of the glass forming system.

[0049] Preferred embodiments are explained using the accompanying figures. They show: Fig. 1: a schematic, two-dimensional cross-sectional view of an exemplary embodiment of a glass forming system; Fig. 2: a schematic, three-dimensional view of the Fig. 1 shown glass forming system; Fig. 3: a schematic, three-dimensional view of an exemplary embodiment of a transport unit; Fig. 4: a schematic, two-dimensional plan view of the Fig. 3 transport unit shown; Fig. 5: a schematic, three-dimensional detailed view of the Fig. 3 shown transport unit; Fig. 6: a schematic, two-dimensional view of the Fig. 3 shown transport unit; and Fig. 7: a schematic view of a process.

[0050] In the figures, identical or essentially functionally identical or similar elements are designated by the same reference numerals.

[0051] The Fig. 1 and Fig. 2 shows a glass forming system 1 for producing 25 glass products from a glass blank 2. For this purpose, the glass forming system 1 comprises a transport unit 4, which, through a clever design, can be arranged on a forming device 13. The forming device 13 presses the glass blank 2 in the cavities 22, while the transport unit 4 is arranged on the forming device 13.

[0052] The forming device 13 comprises an upper forming device 14 and a lower forming device 15. The forming device 13 comprises a total of 25 forming units 16. Each forming unit 16 comprises an upper forming element 18 and a lower forming element 20, each forming a cavity 22. The recess region 34 is provided between the forming units 16. The recess region 34 is formed by recess channels. The recess channels are formed, among other things, by cuboid sections 44 of the lower forming elements 20. Vertically adjacent to the cuboid section 44 of each lower forming element 20 is a truncated pyramid-shaped section 42, which forms part of the cavity 22 and a glass flow cavity 48.

[0053] The transport unit 4 has a grid structure 6 with grid struts 8, 10. The grid struts 8, 10 can each be arranged in the recessed area 34. By arranging the grid structure 6 in the recessed area 34, the forming units 16 can each be moved through one of the process recesses 12. This advantageously allows the glass blank 2 held by the grid structure 6 to be pressed in the cavities 22.

[0054] During normal operation, the forming device 13 is open before pressing a glass blank 2, which means in particular that the upper forming device 14 is spaced apart from the lower forming device 15. In this state, the glass blank 2 is moved by the transport unit 4 from a tempering device to the glass forming system 1. There, the transport unit 4 is arranged on the lower forming device 15 such that the lattice structure 6 is moved into the recessed area 34. As a result of this movement, the lower forming elements 20 of the forming units 16 pass through the process recesses 12. As a result, the glass blank 2 is transferred from the lattice structure 6 to the lower forming elements 20. This state is shown in the Fig. 1. Subsequently, the upper and lower forming elements 18, 20 move toward each other in the vertical direction V, so that the glass blank 2 is pressed into the cavities.

[0055] The glass components are then removed from the upper forming device 14 using a vacuum gripper or a vacuum mechanism. Furthermore, the glass components can be pushed out of the transport unit 4, in particular vertically upwards.

[0056] It is particularly in Fig. 1 shows that the grid structure 6 is arranged within the recessed area 34. A collar 36 of the transport unit 4 is arranged outside the forming area. The collar 36 results in heat shading. Furthermore, the transport unit 4 comprises an alignment opening 28. Furthermore, the forming device 13 has alignment openings 26, 28. The alignment openings 26, 28 on one side have a common movement axis 24, 24'. Thus, the various components of the glass forming system 1 can be moved in alignment with one another.

[0057] In addition to the lattice struts 8, 10, the lattice structure 6 has a cooling system formed, among other things, by cooling channels 40 embedded in the lattice structure 6. A cooling fluid can flow through the cooling channels 40.

[0058] Glass flow cavities 48 are formed by the truncated pyramid-shaped sections 42 of the forming units 16. The glass flow cavities 48 improve the glass flow. Glass flow elements 46 can extend into the glass flow cavities 48 to further improve the glass flow.

[0059] The Fig. The transport unit 4 shown in Figures 3-6 comprises, in addition to the grid structure 6 and the collar 36, a handling section 38. The handling section 38 is provided on four sides of the transport unit 4. The handling section 38 enables advantageous movement of the transport unit 4 from a tempering device to the forming device 13.

[0060] The grid structure 6 further comprises a plurality of support elements 30. The support elements 30 reduce the contact surface between the glass blank 2 and the grid structure 6. The support elements 30 are preferably arranged in an interchangeable manner. It is also shown that a plurality of process recesses 12 are formed by the grid structure 6.

[0061] Positioning elements 32 are also arranged on the sides of the grid structure 6, which is surrounded by a grid structure frame. The positioning elements 32 position the glass blank 2 in a predetermined position on the grid structure 6. In particular, Fig. 5 shows that the positioning elements 32 have a section tapering upwards, so that the positioning of the glass blank 2 is improved.

[0062] Fig.7 shows a schematic view of a method for producing two or more glass products from a glass blank 2. The method comprises heating 100 a glass blank 2 held vertically above the process recesses 12 of the lattice structure 6 of the transport unit 4 by means of a heating unit. Furthermore, the method comprises moving 102 the transport unit 4 from the heating unit to the forming device 13 having two or more forming units 16, each having an upper forming element 18 and a lower forming element 20, each forming a cavity 22 for forming the glass blank 2.

[0063] Furthermore, the method comprises moving 104 the upper forming elements 18 and / or the lower forming elements 20 through the process recesses 12 towards each other in order to press the glass blank 2 held by the lattice structure 6 in the cavities 22.

[0064] The glass forming system 1 described above, as well as the transport unit 4 and the corresponding method, enable high-quality production of glass products, since the glass blank 2 on which the glass products are based has essentially no imprints. Furthermore, the method is efficient because no sensitive gripping process is required. REFERENCE SYMBOL 1 glass forming system 2 glass blanks 4 transport unit 6 Lattice structure 8 lattice strut 10 lattice strut 12 Process recess 13 Forming device 14 upper forming device 15 lower forming device 16 Forming unit 18 upper forming element 20 lower forming element 22 Cavity 24, 24' movement axis 26 Alignment opening 28 Alignment opening 30 support elements 32 Positioning element 34 Advanced study area 36 collars 38 Handling section 40 cooling channel 42 truncated pyramid section 44 cuboid section 46 Glass flow element 48 glass flow cavities V Vertical direction

Claims

[1] Glass forming system (1) for producing two or more glass products from a glass blank (2), comprising - a transport unit (4) for transporting the glass blank (2), which has a grid structure (6) with two or more processing recesses (12), wherein the grid structure (6) is arranged and designed to hold the glass blank (2) vertically above the processing recesses (12), - a forming device (13) with two or more forming units (16), each having an upper forming element (18) and a lower forming element (20), each forming a cavity (22) for forming the glass blank (2), - wherein the transport unit (4) can be arranged on the forming device (13) in such a way that the forming units (16) can each be moved through one of the process recesses (12) in order to press a glass blank (2) held by the lattice structure (6) into the cavities (22). [2] Glass forming system (1) according to claim 1, wherein the lattice structure (6) is formed by lattice struts (10) and / or by a wire. [3] Glass forming system (1) according to one of the preceding claims, wherein the grid structure (6) has at least one support element (30) so that a glass blank (2) can be supported on the at least one support element (30). [4] Glass forming system (1) according to one of the preceding claims, wherein the forming device (13) has a recessed region (34) surrounding the two or more forming units (16) in each case and the lattice structure (6) can be sunk at least partially into the recessed region (34) in such a way that the cavities (22) can be completely closed. [5] Glass forming system (1) according to one of the preceding claims, wherein the lower forming elements (20) have a lower truncated pyramid-shaped section (42) and / or the upper forming elements (18) have an upper truncated pyramid-shaped section, so that glass flow influencing glass flow cavities are formed adjacent to the cavities (22) upon closing of the cavities (22). [6] Glass forming system (1) according to the preceding claim 5, wherein a convex glass flow element (46) is arranged between the upper truncated pyramid-shaped sections, which protrudes into a glass flow cavity when the cavities (22) are closed. [7] Glass forming system (1) according to one of the preceding claims, wherein the lower forming elements (20) each have a lower cuboid-shaped section (44) and the cuboid-shaped sections form one side of the recessed area. [8] Glass forming system (1) according to one of the preceding claims, comprising two or more positioning elements (32) for positioning the glass blank (2) in a predetermined position on the grid structure (6). [9] Glass forming system (1) according to one of the preceding claims, comprising a centering means centering the transport unit (4) relative to the forming device (13). [10] Glass forming system (1) according to the preceding claim 9, wherein the recessed region (34) has the centering means and the centering means is designed to position the transport unit (4) by means of a positioning section. [11] Glass forming system (1) according to one of the preceding claims, wherein the transport unit (4) has a collar surrounding the grid structure (6). [12] Glass forming system (1) according to one of the preceding claims, wherein the grid structure (6) comprises a cooling system arranged and configured to cool the grid structure (6). [13] Glass forming system (1) according to the preceding claim 12, wherein the cooling system comprises cooling channels (40) embedded within lattice struts of the lattice structure (6), through which a cooling fluid can flow. [14] Transport unit (4) for use in a glass forming system (1) according to one of the preceding claims 1-13, which is designed to transport a glass blank (2), comprising - a lattice structure (6) with two or more process recesses (12), - wherein the grid structure (6) is arranged and designed to hold the glass blank (2) vertically above the process recesses (12). [15] A method for producing two or more glass products from a glass blank (2), comprising the steps: - heating a glass blank (2) held vertically over process recesses (12) of a grid structure (6) of a transport unit (4) by means of a heating unit; - moving the transport unit (4) from the heating unit to a forming device (13) having two or more forming units (16), each having an upper forming element and a lower forming element, each forming a cavity for forming the glass blank (2); and - moving the upper forming elements (18) and / or the lower forming elements (20) towards each other through the process recesses (12) in order to press the glass blank (2) held by the lattice structure (6) into the cavities (22).

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