Method and apparatus for hot-forming semi-finished glass products and hot-formed glass containers

Abstract

To provide a hollow glass product that is manufactured by a device for manufacturing a glass product having a defined internal shape and external shape.SOLUTION: A hollow glass product is a container or a container part including a neck region or a shoulder region and a wall. The glass product includes a container wall and a neck region or a shoulder region. The wall has a circular cross section or an elliptical cross section. The container includes a characteristic surface region 320 on an outside glass surface of the hollow glass. As to a ratio between a tangential direction 35 slope average value and an axial direction 34 slope average value in the characteristic surface region, the hollow glass satisfies the expression of tangential direction slope average value / axial direction slope average value<0.6.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to a method and an apparatus for forming glass semi-finished products in a hot process. In particular, the present invention relates to a method and an apparatus for such a forming process, which allows for an increased production of good products by extending the cleaning intervals. Furthermore, the present invention relates to hollow glass articles.

[0002] Background of the Invention The prior art is known for producing glass articles from semi-finished products, also known as intermediate materials, by a deformation process. For example, glass vials for pharmaceutical applications are produced from glass tubes by heating one end of a short tube section to the forming temperature of the glass and then forming the desired shape using a suitable forming tool in one or more forming steps. The internal shape is usually formed by a pin inserted into the end of the tube. During the forming process, the semi-finished product rotates. The shape and dimensions of the pin define the internal shape of the glass vial. Deformation is performed by an outer forming tool that presses the glass tube against the pin and simultaneously forms the outside of the glass tube. The glass tube and the outer forming tool rotate. The outer forming tool includes a forming roller with a forming surface.

[0003] Thus, German Utility Model No. 202004004560 describes a method and device for hot forming using freely rotatably mounted forming rollers that are driven by the rotating semi-finished product and rotate synchronously with the glass, i.e., there is no relative movement between the glass and the forming rollers.

[0004] The deformation is preferably carried out using a so-called rotary transfer machine, whereby the deformation can take place in several steps, i.e. at several stations on the rotary transfer machine.

[0005] During contact with the tool, the glass semi-finished product is cooled by the forming tool. Therefore, between forming steps, the semi-finished product may need to be heated again. The temperature is adjusted so that after the last forming step, the glass reaches a temperature at which the semi-finished product is dimensionally stable.

[0006] Contact with the hot glass exposes the forming tools, in particular the forming surfaces of the forming rollers, to high temperature loads, where the glass may have temperatures of up to 1000° C. During the deformation process, the forming surfaces may therefore become hot, i.e. have temperatures of >250° C.

[0007] Furthermore, direct contact of the forming tools with the hot glass must be avoided, because this causes the glass to adhere to the surface of the forming tools. Therefore, in the hot forming of glass, a lubricant, also called a release agent, such as oil or paste, is usually used. The lubricant is applied to the forming tools by, for example, spraying, spraying, or pouring the lubricant onto the forming tools during the intermediate cycles of the forming process, when the tools are not in contact with the glass. Each tool is lubricated again before each contact with the glass.

[0008] Due to the high temperature, reaction products of the lubricant are produced during the deformation process, i.e., soot formation occurs. Therefore, soot deposits form on the forming surfaces of the forming rollers during operation. This is troublesome because the soot comes into contact with the hot glass and can therefore become incorporated into or bond with the formable glass. This causes significant cosmetic problems. For example, when producing glass vials, this can lead to staining in the neck area of ​​the bottle being deformed. The affected glass vials must be rejected.

[0009] In addition to soot stains, the contours of the uneven soot deposits on the forming rollers can be transferred to the glass. The unevenness is then imprinted on the glass surface like a stamp, again resulting in cosmetic defects, i.e., the corresponding vials being rejected. Furthermore, lubricant inclusions can occur between the glass surface and the rotating forming rollers. The trapped oil film is trapped between the glass surface and the tool surface during the rotation process, imprinting a pattern on the still-formable glass surface. This results in a mottled structure of varying heights on the corresponding glass surface in the final product. In this case, there is no fundamental difference in the direction of pattern formation; that is, there is no fundamental difference between the intensity of the pattern in the direction of rotation, i.e., the tangential direction, and the intensity of the pattern in the direction of the rotation axis, i.e., the axial direction.

[0010] Therefore, forming tools must be cleaned at appropriate intervals, typically every two to three hours. Cleaning the forming rollers requires shutting down the production machine, which reduces production. Furthermore, shutting down the production machine can lead to startup problems, which impair the manufacturing process beyond the shutdown period.

[0011] Problem to be solved by the invention The object of the present invention is to provide an apparatus for producing glass articles having defined internal and external shapes that does not have the above-mentioned disadvantages of the prior art. A further object of the present invention is to provide a corresponding production method and a hollow glass article.

[0012] Description of the invention The problem of the present invention is already solved by the subject matter of the independent claims. Advantageous embodiments and developments of the invention are the subject matter of the dependent claims.

[0013] In this case, the device according to the invention comprises at least the following components: - a device for heating glass until it softens, - at least one inner and one outer forming tool for forming the semi-finished product, the outer forming tool comprising a forming roller with a forming surface and serving to form the outer flank of the semi-finished product, and a device for accommodating the forming rollers, - a forming station having a device for applying lubricant to the forming surface of the forming roller, the device having an outlet for discharging the lubricant; (However, the forming rollers are supported in a receiving device so as to be freely rotatable, and can be or are immobile during the forming process by means of a locking fixing device.) It has.

[0014] The forming of the semi-finished product into the specific shape or dimensions of the desired product can then be a direct result of the forming process. In particular, the method according to the invention can be used to form the crimp neck or the outer surface of the crimp neck of a vial or carpule, or the outer surface of the syringe cone tip of a syringe.

[0015] However, forming the semi-finished product into the product shape can also be achieved by a number of different forming processes. In addition to the inner and outer sides of the semi-finished product, for example, in the production of glass bottles, glass vials, or glass containers, the shape of the neck and vial mouth can also be formed.

[0016] With the device according to the invention, cleaning intervals can be significantly extended, and at the same time, rejects due to production are reduced, which is guaranteed by the individual components of the device.

[0017] The device is particularly designed for forming tubular semi-finished products, where the inner and outer sides are determined by the shape of the tube. In a preferred embodiment of the invention, the inner forming tool is designed as a pin. The device is particularly suitable for producing glass containers, such as pharmaceutical primary packaging, for example vials, carpules or syringes, by deforming glass tubes.

[0018] Due to the stationary outer forming roller, the outer forming roller is not driven or rotated by the rotating semi-finished product during the deformation process. Therefore, there is a relative movement between the outer forming roller and the semi-finished product. This relative movement causes shear forces to act on the semi-finished product. Surprisingly, it has been found that, if the forming roller is sufficiently lubricated, the shear forces do not have a detrimental effect on the quality of the semi-finished product being deformed. Instead, it has been found that the shear forces have a beneficial effect. The material to be formed is guided by the shear forces to the forming tool in a particularly advantageous manner and pressed against the forming tool, facilitating the forming of the semi-finished product.

[0019] The forming rollers are fixed by removable connections, so that they can be removed between individual forming steps and rotated by an angle α in the fixing device. The angle α can be predefined in one embodiment. Thus, by rotating the forming rollers by the angle α between hot forming steps, the subsequent hot forming steps are performed by adjacent surface sections of the forming surface. This means that only a small fraction of the forming roller's surface is used per deformed semi-finished product. The rotation of the forming rollers between the individual forming steps ensures that the forming surface is worn evenly across the entire surface of the forming roller.

[0020] Another advantage of the clamping device according to the invention is that the rotation of the forming rollers between the individual forming steps allows the use of cooler areas of the forming tool for each forming step or each semi-finished product to be deformed. Therefore, the forming rollers do not heat up or heat up only slightly during production. This is particularly advantageous because it significantly reduces soot formation due to combustion or thermal decomposition of the lubricating oil. Furthermore, wear on the forming tool is reduced, which can extend the life of the forming tool.

[0021] The apparatus includes a device for applying lubricant to the forming surface of the forming roller, wherein the lubricant is applied to only a portion of the forming surface at any one time per application step, and preferably the lubricant is applied to a portion of the forming roller once per cycle.

[0022] One embodiment provides for the device for releasing the lubricant to be fixedly mounted within the device, i.e., the distance from the spray nozzle to the surface of the forming tool to be sprayed is constant. In this case, for example, the spray nozzle may be integrated into the forming station or the outer forming tool. Mounting on the underside of the outer forming tool is also possible.

[0023] According to one embodiment, the application of the lubricant is carried out by means of a drip lubricator. Drip lubricators with automatic constant oil release have proven to be particularly advantageous.

[0024] Preferably, the lubricant applicator is arranged in the apparatus so that its outlet and the forming tool are spaced at an angular distance of at least 45° around the rotation axis of the semi-finished product. Thus, only a small amount of lubricant is in contact with the hot glass. Preferably, the angle β is in the range of 90 to 270°, particularly preferably in the range of 160 to 200°, i.e., the lubricant applicator is arranged in the apparatus opposite the glass-contacting surface.

[0025] According to one embodiment, the amount of oil released per application is in the range of 0.01 to 0.1 g, particularly preferably in the range of 0.03 to 0.05 g. The small amount of lubricant applied significantly reduces contamination of the product, forming tools, and the production environment. At the same time, however, the device according to the invention achieves sufficient lubrication.

[0026] As lubricants, in the device according to the invention, a viscosity of <600 mm 2 Any oil can be used which has a / s and a flash point and / or thermal decomposition point >200° C., preferably >250° C. Thus, the same oils can be used here as in known standard processes.

[0027] The device is particularly designed for forming tubular semi-finished products, where the inner and outer sides are determined by the shape of the tube. In a preferred embodiment of the invention, the inner forming tool is designed as a pin. The device is particularly suitable for producing glass containers, such as pharmaceutical primary packaging, for example vials, carpules or syringes, by deforming glass tubes.

[0028] The forming roller has a rotationally symmetrical cross section. According to one embodiment of the present invention, the forming roller has a cylindrical cross section in a central plane perpendicular to the axis of rotation of the forming roller. In this embodiment, the forming roller is therefore circular. This has the advantage that the angle by which the forming roller is rotated in step c) can be freely selected or no precise adjustment of the rotation angle α is required.

[0029] Alternatively, the forming roller has a polygonal cross section with multiple forming surfaces in a central plane perpendicular to the rotation axis of the forming roller. In the case of a forming roller with a polygonal cross section, the rotation angle α to be maintained in step c) depends on the number of forming surfaces. Preferably, the forming roller has 6 to 18 forming surfaces.

[0030] In one development of the embodiment, the edges of the forming surface are formed flat, convex or concave.

[0031] The rotation of the forming rollers after each forming process according to the invention ensures that the cold areas of the forming tool are used for every semi-finished product to be deformed, and the forming rollers heat up less overall during production. According to one development of the invention, the device has an additional cooling device for the forming rollers, whereby cooling can take place by active or passive heat conduction.

[0032] One embodiment of the present invention envisions that the device has a cooling body that is directly or indirectly connected to the forming roller receiving device. The forming rollers are in thermal contact with the cooling body, which preferably has an internal coolant so that process heat can be removed. In this case, the coolant is only in indirect contact with the forming rollers via the cooling body. Alternatively or additionally, the device has air cooling for cooling the forming rollers.

[0033] Preferably, the device is configured so that the temperature of the forming tool surface is, through heat dissipation, at most 250°C, preferably at most 180°C, and particularly preferably at most 100°C. By "forming tool surface" is meant, in particular, the part of the forming tool that comes into contact with the hot glass during the deformation process. The surface temperature of the forming roller is measured sporadically using a contact surface thermometer immediately adjacent to the glass contact point. Due to the low temperature, almost no oil is burned, which significantly reduces soot generation and results in no or very little accumulation of combustion residues on the forming surface of the forming roller.

[0034] The device according to the invention therefore preferably has a cleaning interval of at least 8 h, or even at least 12 h, by which is understood the time interval between two downtimes of the device for cleaning the forming tools.

[0035] The present invention also relates to a method for forming glass semi-finished products using fixed forming rollers, the method comprising at least steps a) to c), including: a) heating the semi-finished product until it softens; b) forming the outer and inner surfaces of the semi-finished product in at least one forming step with at least one forming tool having forming rollers; and c) removing the locking device, rotating the forming rollers by a predefined angle α, and fixing the forming rollers again, so that when steps a) to b) are repeated, another part of the forming surface of the forming rollers comes into contact with the semi-finished product. Preferably, the semi-finished product is formed by an inner forming semi-finished product and an outer forming semi-finished product. Preferably, the semi-finished product is formed as a tube, in particular as a tube with a circular or ellipsoidal cross section. In particular, the method according to the present invention can be used to produce, for example, vials, neck regions or crimp neck regions of carpules, or syringes.

[0036] In step a), the semifinished product is first heated to a temperature close to the forming temperature of the glass used, and in step b), it is formed by contact with a forming tool. Preferably, in step b), the semifinished product is formed by inserting an inner forming tool into the semifinished product and attaching an outer forming tool onto the semifinished product for forming. The inner forming tool is preferably configured as a pin. The outer forming tool has at least one forming roller with at least one forming surface. The forming roller is fixed to the receiving device by a removable locking device. The semifinished product is placed on the inner forming tool and performs a rotational movement around its center point. Because the forming roller of the outer forming tool is fixed, the forming roller does not rotate, and relative movement occurs between the forming surface and the semifinished product during the forming process. At least the part of the forming surface that comes into contact with the semifinished product during the forming process is covered with a lubricant oil, which prevents the glass from adhering to the forming surface.

[0037] The application of oil to the forming surface region that forms the contact surface with the glass in step b) is carried out during one of method steps a) to c). The oil is applied to a portion of the forming surface that is not in contact with the semi-finished product at the time of application. According to one embodiment of the present invention, lubricating oil is applied to a portion of the forming surface of the forming roller in each cycle. A drip oil dispenser, in particular a drip oil dispenser with automatic, constant release, has proven particularly advantageous. One embodiment of the present invention provides for applying 0.01 to 0.1 g, preferably 0.03 to 0.05 g, of oil to the forming roller in each oil release step.

[0038] In step c), the locking device is removed. The forming roller is rotated by an angle α and then re-fixed in the locking device. According to one embodiment of the present invention, the angle α is predefined, i.e., the forming roller is rotated by a predetermined angle α. Step c) therefore ensures that when steps a) to b) are repeated, another part of the forming surface of the forming roller comes into contact with the semi-finished product. As a result, heating of the entire forming roller is prevented, and a cooler forming surface is provided for each forming step. This significantly reduces soot generation.

[0039] According to one variant of the method according to the invention, the surface temperature of the forming surface, which forms the contact surface with the glass during the forming process, is at most 250° C., preferably at most 180° C., particularly preferably at most 100° C., during the deformation process, i.e., even when in contact with the heated semi-finished product. The forming rollers may then be cooled during the forming process. In particular, heat may be removed from the forming rollers during the forming process by means of heat conduction.

[0040] According to one embodiment of the present invention, the heat is dissipated passively by heat dissipation, in which case the forming roller is in contact with a cooling body, which may also have active cooling: one development provides for the cooling body to be thoroughly rinsed with a cooling medium, preferably a cooling liquid.

[0041] Alternatively or additionally, the part of the forming surface which is in contact with the semi-finished product to be deformed is cooled by blowing in a gas stream, preferably by blowing in a stream of air.

[0042] According to one embodiment, in step b), the outer side of the semi-finished product is formed by a forming roller with a circular cross section. In this embodiment, the forming roller is rotated in step c) by an angle a preferably in the range of 2 to 10°, particularly preferably in the range of 3 to 5°. Alternatively, the forming roller has a polygonal cross section. Preferably, the forming roller has a polygonal cross section with 6 to 18 forming surfaces, where the number of forming surfaces is determined by the number of sides of the polygon.

[0043] One development of the invention provides for step d) of cleaning the forming roller after step c). The forming process is stopped and the forming roller is cleaned during the stoppage. According to one embodiment of the invention, the cleaning step is performed at the earliest after 10,000 repetitions of process steps a) to c), i.e., after 10,000 semi-finished products have been deformed. Alternatively, cleaning step d) is performed at the earliest after the device has been operated for 4 hours, preferably 8 hours, particularly preferably 15 hours, and especially preferably 24 hours. This allows for a significant increase in the cleaning interval. Preferably, the operating time between two cleaning steps d) is greater than 24 hours.

[0044] According to another development of the invention, after step c), a cleaning step e) for cleaning the forming rollers is carried out while steps a) to c) are repeated with a new semi-finished product. In this development, cleaning is therefore carried out during the ongoing process, so that no interruption of the manufacturing process is necessary. In each case, only a portion of the forming surface is cleaned, preferably the portion of the forming surface that was in contact with the semi-finished product in the preceding step b). Preferably, cleaning of the forming rollers is carried out after each forming process according to steps a) to c).

[0045] The present invention further relates to a hollow glass article produced or producible using the method according to the invention, wherein the glass article is a container or container part and includes a container wall and a neck or shoulder part, and the hollow glass article is, at least in part, cylindrical with a circular or elliptical cross section.

[0046] The outer surface of the container is subjected to high pressure during the manufacturing process and has a characteristic surface structure in the areas formed using the outer forming tool and the internal forming tool, for example, in the form of a pin. The surface area of ​​the outer surface of the container is also referred to as the characteristic surface area below. In this context, the characteristic surface is understood to mean the surface area of ​​the outer glass surface that is formed in one forming step using the internal pin and the outer forming tool. Preferably, the forming step for forming the characteristic surface area is the final forming step in the overall forming method for producing the container in question.

[0047] According to one embodiment, the container is a vial or carpule. In this case, the characteristic surface area is understood to be the outer surface of the crimp neck. In another embodiment of the present invention, the container is a syringe. In this embodiment, the characteristic surface area is understood to be the outer surface of the cone tip. In this case, the characteristic surface area of ​​the container has a surface structure with undulations in which the gradient in the height profile is anisotropic. In this case, the height profile has a tangential gradient and an axial gradient.

[0048] Tangential gradient is understood to mean the gradient of the height profile in the tangential direction, where the direction of the surface structure that corresponds to the direction of rotation of the semi-finished product during the forming process is called tangential direction, whereas axial gradient is understood to mean the gradient of the height profile in the axial direction, i.e. in a direction parallel to the axis of rotation of the semi-finished product.

[0049] In this case, the mean value of the tangential gradient, i.e. the mean tangential gradient value, as well as the mean value of the axial gradient, i.e. the mean axial gradient value, are calculated according to the invention from the height profile of the characteristic surface area as follows:

[0050] Three measurement areas, each measuring 1.0 mm x 1.0 mm, are arranged on the characteristic surface of the container so that the measurement areas are evenly distributed around the periphery of the characteristic surface area, with a tangent distance of 120° between each other. At the same time, each measurement area is positioned at the axial center of the characteristic surface area. Because the container has a rotationally symmetric or cylindrical shape, all characteristic surface areas have a cylindrical curvature in the tangential direction. This cylindrical curvature is automatically corrected after measuring the height profile, which is easily possible with a measurement area size of 1.0 mm x 1.0 mm. Possible systematic axial curvature of the characteristic surface area, i.e., due to the molding of the container, is also automatically corrected. Therefore, the macroscopic influence of the container shape is not taken into account in calculating the relief and in the evaluation described below.

[0051] The undulations of individual measurement areas of the characteristic surface area can be determined using a white light interferometer. At each point of the undulations within the measurement area, the tangential and axial gradients are measured. The undulations are then corrected in the axial and circumferential directions by calculations based on the macroscopic container shape. The local tangential or axial gradients are then calculated from the respective directional derivatives. The absolute height values ​​of the surface undulations deviate because the height differences between the valleys and peaks are replaced by regions with approximately constant gradients. Depending on the absolute height differences between the peaks and valleys, these constant regions extend with different widths across the measurement area. Therefore, the average tangential and axial gradient values ​​for each measurement area are obtained as the average of the local tangential or axial gradient values ​​across the measurement area. The corresponding average gradient values ​​for each measurement area are also arithmetically averaged, so that the average tangential or axial gradient values ​​are calculated by averaging them across the three measurement areas. In the following, unless otherwise specified, the tangential gradient average value and the axial gradient average value are understood to mean the gradient average value calculated over the three measurement regions, as described above.

[0052] In this case, the container according to the present invention has a characteristic surface area in which the average tangential gradient is smaller than the average axial gradient. This can be explained by the fact that when producing containers using fixed forming rollers, particularly in the production method according to the present invention, the formable semi-finished glass surface is ground against the fixed tool surface of the outer forming tool, so that the lubricant or oil film present on the surface of the forming tool is scraped off or abraded by the glass surface. Thus, the relative movement between the glass surface and the tool surface produces a groove pattern similar to that in a turning process.

[0053] In contrast, the height profile of a container produced by a method known from the prior art using a moving forming roller does not exhibit anisotropy, or at least not a significant anisotropy, with respect to the gradient of the height profile, which depends on the respective directional derivative. In this case, the lack of a preferred direction can be explained by the fact that, in the method known from the prior art, the tool surface rotates in the direction of rotation with respect to the glass surface of the semi-finished product under pressure at the tool contact point (although there is a lubricating oil film of various thicknesses between the tool and the glass surface). This difference in the thickness of the lubricating oil film is imprinted like a stamp on the glass surface, which is still formable, during the rotational movement. In this case, there is no difference, or at least not a significant difference, in how the pattern is formed in the direction of rotation, i.e., tangentially, and in the direction of the rotation axis, i.e., axially.

[0054] According to the disclosure, the method also includes a hollow glass article that is produced or can be produced using the method of the present invention, wherein the glass article is a container or container portion having a neck or shoulder region and a wall, the glass article including the container wall and the neck or shoulder region, the wall having a circular or elliptical cross-section, the container having a characteristic surface region on an outer glass surface of the hollow glass article, the characteristic surface region having a tangential direction and an axial direction, the tangential direction corresponding to the circumferential direction and the axial direction being perpendicular to the tangential direction, the height profile of the characteristic surface region having a tangential gradient having a tangential gradient average value and an axial gradient having an axial gradient average value, respectively, the tangential gradient being the gradient of the height profile in the tangential direction, the axial gradient being the gradient of the height profile in the axial direction, and the tangential gradient average value is calculated by integrating the values ​​of the local tangential gradient values ​​of the height profile within a measurement area within the characteristic surface region, and the axial gradient average value is calculated by integrating the values ​​of the local axial gradient values ​​of the height profile within a measurement area within the characteristic surface region.

[0055] According to one embodiment of the present invention, the characteristic surface of the container has a surface structure with undulations, whereby the ratio between the mean tangential gradient and the mean axial gradient is: Tangential gradient average / axial gradient average <0.60 applies.

[0056] Particularly preferably, with respect to the ratio between the mean tangential gradient and the mean axial gradient: Tangential gradient average / axial gradient average <0.45 applies.

[0057] According to one development of the invention, the outer side of the characteristic surface area has a surface roughness Rz measured at the height of the wall in a direction transverse to the longitudinal axis of the container, i.e. in the range of 85 to 95°, preferably 90°. 接線方向 The surface roughness Rz measured in the longitudinal direction of the container is greater than 軸方向 Preferably, the pieces have a circumferential groove or score.

[0058] The depth of the groove or groove is the maximum single surface roughness Rzi of the corresponding piece. 軸方向 In this case, the single surface roughness Rzi 軸方向 is measured in accordance with the standard DIN EN ISO 4768:1990.

[0059] In one development of the invention, the characteristic surface area of ​​the container has at least two, preferably at least three, circumferential grooves, the spacing between the individual grooves being variable.

[0060] According to one embodiment, the hollow glass article is a bottle, a vial, a syringe part, or a carpule part. In particular, the hollow glass article is a part of a pharmaceutical primary packaging, for example a medicine vial.

[0061] Also included in the present invention is a hollow glass article, wherein the glass article is produced by hot forming of a glass tube and / or has a tubular section with a constant wall thickness along its height, the section having a standard deviation in wall thickness of less than 0.05 mm.

[0062] Also included in the present invention is a hollow glass article as described above, wherein the characteristic surface area is located outside the tubular segment and is located in an end region of the glass article, and wherein the diameter of the glass article within the characteristic surface area is smaller than the diameter of the tubular segment.

[0063] The glass of the hollow glass article may in particular be borosilicate glass.

[0064] Detailed Description In the following, the invention will be explained in more detail with the aid of exemplary embodiments and figures 1 to 17. [Brief explanation of the drawings]

[0065] [Figure 1] 1 shows a hot forming device known from the prior art in a side view. [Figure 2] 1 shows a hot forming device known from the prior art in a top view; [Figure 3] 1 illustrates, in side view, one embodiment of a hot forming apparatus according to the present invention. [Figure 4] 1 illustrates, in top view, one embodiment of a hot forming apparatus according to the present invention; [Figure 5] 1 illustrates one embodiment of a manufacturing method according to the present invention. [Figure 6] 1 shows an embodiment of the device according to the invention in a side view with an outer shaping roller having a polygonal cross section; [Figure 7] 1 shows an embodiment of the device according to the invention in a top view with an outer shaping roller having a polygonal cross section; [Figure 8] 1 illustrates a glass vial according to the present invention. [Figure 9] 1 illustrates a glass vial according to the present invention. [Figure 10] 2 shows the 2D relief of the surface structure of a characteristic surface area of ​​a container known from the prior art. [Figure 11] 1 illustrates the 2D contours of the surface structure of a characteristic surface region of one embodiment. [Figure 12] 1 shows the 3D relief of the surface structure of a characteristic surface area of ​​a container known from the prior art. [Figure 13] 1 illustrates the 3D contours of the surface structure of a characteristic surface region of one embodiment. [Figure 14] 1 shows a tangential gradient analysis of a characteristic surface area of ​​a container known from the prior art; [Figure 15] 1 shows an axial gradient analysis of a characteristic surface area of ​​a container known from the prior art; [Figure 16] 1 illustrates a tangential gradient analysis of a characteristic surface area of ​​an exemplary embodiment; [Figure 17] 1 illustrates an axial gradient analysis of a characteristic surface area of ​​an exemplary embodiment;

[0066] 1 and 2 illustrate a hot-forming apparatus 1 known from the prior art, where FIG. 1 shows a side view and FIG. 2 shows a top view. The apparatus has an inner forming tool 40, which forms the inner lateral surface of the glass vial. The outer forming roller 20 is rotatably supported on a suspension 60. Furthermore, the apparatus has an air cooler 70 for cooling the glass tube 30. During the forming process, the glass tube 30 undergoes a rotational movement. The forming tools 40 and 20 move toward the semi-finished glass tube to be formed. Since the outer forming tool 20 is rotatably supported, it also rotates due to the rotational movement of the glass tube 30. Therefore, the outer forming roller 20 and the glass tube 30 do not move relative to each other. Furthermore, when forming the outer lateral surface of the glass tube 30, the entire lateral surface of the outer forming roller 20 comes into contact with the hot glass tube 30. The glass tube is cooled using the air cooler 70.

[0067] Figures 3 and 4 illustrate one embodiment of a hot forming apparatus 2 according to the present invention, with Figure 3 showing a side view and Figure 4 showing a top view of the apparatus. The apparatus has an inner forming tool 40 for forming the inner side of a glass tube 30, as well as two outer forming tools 21 for forming the outer side. The glass tube 30 rotates, and its rotational movement is represented by arrows.

[0068] The outer forming tool 21 is formed as a forming roller with a circular cross section and is supported so as to be freely rotatable by means of a suspension 61. However, during the deformation process, the forming roller 21 is fixed by a fixing device 82, which prevents the forming roller 21 from rotating. Therefore, the forming roller 21 is not rotated by the rotating glass tube 30, but remains fixed in position by the device 82. Therefore, the glass tube 30 and the forming roller 21 exhibit relative movement with each other. Because the forming roller 21 is fixed by the fixing device 82 during the deformation process, only a small fragment of the side surface of the forming roller 21 comes into contact with the hot glass tube 30, while the other side surfaces of the forming roller 21 do not come into contact with the glass tube. Therefore, only a small portion of the side surface of the forming roller 21 is available as a contact surface with the glass tube.

[0069] The apparatus 2 according to the invention further comprises a lubricant applicator 90 on the outer forming roller 21. The outlet of the lubricant applicator 90 and the forming tool are arranged at an angular distance of at least 45° around the rotation axis of the semi-finished product. This arrangement of the apparatus 90 ensures that the lubricant is applied not to the contact surface of the forming roller 21 with the hot glass tube 30, but to a separate, cooler area of ​​the forming roller 21. In the illustrated embodiment, the apparatus 2 according to the invention further comprises a forming roller cooling device 100. This prevents thermal decomposition of the lubricant. This reduces soot formation and therefore contamination of the semi-finished product.

[0070] Figure 5 illustrates an embodiment of the deformation method according to the invention, whereby the device 2a corresponds to the device 2 according to the invention shown in Figures 3 and 4. For the sake of clarity, only one outer forming roller 21 is shown.

[0071] In step a), a glass preform 30 is prepared and placed on the inner forming tool 40, the preform having been heated until the glass softens. The outer forming tool 21 is configured as a forming roller with a circular cross section and is rotatably supported by means of a suspension 60. The forming roller is fixed by means of a fixing device 82.

[0072] In step b), the semi-finished product 30 is shaped. To do this, the semi-finished product 30 undergoes a rotational movement around its center point, which is represented by the arrows. The inner flank of the semi-finished product 30 is shaped by an inner forming tool 40. The outer flank of the semi-finished product 30 is shaped by the contact surface 22 of the outer forming tool 21, which is covered with a lubricant during the shaping process.

[0073] After the forming process, in step c1), the semi-finished product 30 is removed from the device 2a. The fixing device 82 is removed and the forming roller 21 is rotated by a predefined angle α, preferably corresponding to the angle of the contact surface 22. Subsequently, in step c2), the position of the forming roller 21 is fixed by locking the fixing device 82.

[0074] Furthermore, in step c), the device 90 applies lubricant to a partial region 91 of the side of the forming roller 21. In doing so, the lubricant is applied to the partial region 91 of the forming roller 21 that was not part of the contact surface 22 in the preceding step b), thereby ensuring that the partial region 91 has not been or is no longer heated by contact with the hot glass 30 during the application of the lubricant.

[0075] When steps a) and b) are repeated with a new semi-finished product 31, a new partial region 23 of the side of the forming roller 21 comes into contact with the semi-finished product 31. Therefore, since deformation is carried out for each semi-finished product using a different partial region of the side of the forming roller 21 as the contact or forming surface, the respective forming surface is not heated by the previous forming process, but a cold forming surface is present in each forming process. A cold forming surface is understood in particular to mean a forming surface having a surface temperature of less than 250°C.

[0076] 6 and 7 illustrate an exemplary embodiment with a forming roller 25 having a polygonal cross section. The forming roller shown here has a cross section in the shape of a dodecagon. Accordingly, twelve forming surfaces 26 are present as contact surfaces. The rotation angle α shown in FIG. 5 is therefore 30° for this forming roller.

[0077] FIG. 8 shows a diagram of a deformed glass vial 31, where the surface roughness Rz in the measurement area 32 is plotted against the longitudinal axis 33 of the glass vial. 縦方向 and Rz 横方向 The measurement directions are indicated by arrows 34 and 35, with arrow 34 indicating the axial direction and arrow 35 indicating the tangential direction. Measurement area 32 is located within characteristic surface area 320. In the exemplary embodiment shown in Figure 8, characteristic surface area 320 corresponds to the outer surface of the crimp neck.

[0078] The measurement area 32 is shown in Figure 9, where the characteristic surface area 320 of the glass vial, i.e., the crimp neck, has a plurality of circumferential grooves 36, 37, 38, and 39. The grooves 36, 37, 38, and 39 are aligned transversely to the longitudinal axis of the glass vial.

[0079] FIG. 10 shows, as a comparative example, a 2D height profile of the surface structure of a characteristic surface area of ​​a glass vial known from the prior art. The measurement area has a size of 2 mm x 2 mm and was taken from the area of ​​the crimp neck. The 2D height profile is shown in gray scale. The abscissa indicates the tangential direction and the ordinate indicates the axial direction. It is clear from FIG. 10 that the pattern imprinted during the manufacturing process does not have a preferred direction. That is, the pattern or height profile in the rotational direction, i.e., the tangential direction, is as prominent as in the direction of the rotation axis, i.e., the axial direction.

[0080] Figure 11 shows a 2D height profile of a characteristic surface area of ​​one exemplary embodiment. Again, the measurement area has a size of 2 mm x 2 mm and was taken from the crimp neck area. The 2D height profile is shown in grayscale, with the abscissa representing the tangential direction and the ordinate representing the axial direction. Unlike the height profile shown in Figure 10, the height profile of this exemplary embodiment has an anisotropic distribution. Segments with the same axial value have the same or nearly the same height, whereas measurement points with the same tangential value but different axial values ​​have different undulation heights.

[0081] This is because, in the method according to the present invention, the formable glass surface grinds against the fixed tool surface, scraping away the oil film of undefined thickness, creating a groove pattern in the tangential direction. This is also evident from Figure 13, which shows the 3D relief of the glass surface in a grayscale representation of a measurement area of ​​2 mm x 2 mm, with the x-axis representing the tangential direction and the y-axis representing the axial direction. A grinding pattern with grooves or striations in the tangential direction appears.

[0082] In contrast, the 3D height profile shown in FIG. 12 shows the characteristic surface area of ​​the comparative example. Unlike the exemplary embodiment, the comparative example does not show a preferred direction in the height profile. Rather, there is no difference in how the imprinted pattern is formed in the tangential or axial direction. To quantitatively understand the structure of the characteristic surface area, three measurement areas, each measuring 1 mm x 1 mm, were selected and undulations were created using a Zygo NexView Nx2 white light interferometer. The individual measurement areas were spaced 120° apart from each other at a tangent distance, thus evenly distributed around the entire circumference of the characteristic surface area. Furthermore, the individual measurement areas were adjusted so that they were centered axially within the characteristic surface area. The undulations were measured and corrected for the cylindrical shape of the measurement area due to the macroscopic container shape. From the obtained undulations, local gradients were measured in both the tangential and axial directions at each point of the undulations. To calculate the average tangential and axial gradients for each measurement area, the corresponding local gradient values ​​were averaged over the entire measurement area. The corresponding mean gradient values ​​of the individual measurement areas were again arithmetically averaged to calculate the mean tangential gradient and the mean axial gradient as average values ​​across the three measurement areas.

[0083] 14 and 15 show the gradient analysis in the tangential direction (FIG. 14) and the axial direction (FIG. 15) of the comparative example, with the local gradient values ​​shown as grayscale. In the comparative example, the tangential and axial gradient values ​​are barely different from each other, i.e., there is no preferred direction or anisotropy in the gradient distribution over the measurement area.

[0084] 16 and 17 show gradient analyses of an exemplary embodiment, where FIG. 16 shows the local gradient in the tangential direction and FIG. 17 shows the local gradient in the axial direction. From FIGS. 16 and 17, the anisotropy of the gradient values ​​is clearly discernible. While the gradient in the tangential direction is roughly constant, the gradient values ​​in the axial direction are clearly different.

[0085] The value of the gradient also depends on the diameter of the characteristic surface, which is always present on the outside of a rotationally symmetrical container. The smaller the diameter of the surface area used for the measurement, the greater the gradient that occurs. This applies to the gradient in the axial direction as well as the gradient in the tangential direction. Table 1 below shows the measured values ​​for vials with different crimp neck diameters.

[0086] [Table 1]

[0087] The gradient values ​​listed in Table 1 are arithmetic average values ​​for multiple samples, where each sample value was calculated by arithmetic averaging of measurements at three measurement areas on the outer surface of the crimp neck, each measuring 1 mm x 1 mm. The measurement areas were centered in the axial direction. The three measurement areas of one measurement were positioned at a tangential distance of 120° from each other. One gradient analysis was performed for each of the three measurement areas of one sample, both in the axial direction and in the tangential direction, and the gradients thus obtained were averaged by integration over each measurement area. The comparative example was produced by a method known from the prior art using a moving outer forming roller, while the exemplary embodiment was produced by the method according to the present invention.

[0088] All samples were produced using a forming roller whose contact surface had an average surface roughness Ra of 1.6 μm, which is the finest degree of machining that can be achieved by simple turning.

[0089] Table 1 reveals that the value of the average gradient increases with decreasing crimp neck radius for both the exemplary embodiment and the comparative example. However, unlike both comparative examples, the exemplary embodiment exhibits anisotropy with respect to the average gradient value, i.e., the average gradient value is significantly smaller in the tangential direction than in the axial direction. Accordingly, the exemplary embodiment also has a much smaller ratio of the average tangential gradient to the average axial gradient than the comparative example.

Claims

1. A hollow glass article, the glass article being a container or container portion having a neck or shoulder region and a wall, the glass article including the container wall and the neck or shoulder region, the wall having a circular or elliptical cross section, the container having a characteristic surface region on an outer glass surface of the hollow glass article having striations or grooves in the circumferential direction of the surface, and with respect to the ratio between the average tangential gradient and the average axial gradient in the characteristic surface region: Tangential gradient average value / axial gradient average value < 0.6 applies, where the tangential direction corresponds to the circumferential direction of the hollow glass article, and the axial direction corresponds to the height direction of the hollow glass article. Hollow glass products.

2. With respect to the ratio between the average tangential gradient and the average axial gradient in the characteristic surface area, Tangential gradient average value / axial gradient average value < 0.45 2. The hollow glass article of claim 1, wherein:

3. The hollow glass article of claim 1 or 2, wherein the height profile of the characteristic surface region has an anisotropic gradient.

4. The characteristic surface area has an increased average surface roughness Rz measured parallel to the longitudinal axis of the glass article. 軸方向 and a piece having an increased average surface roughness Rz 軸方向 4. The hollow glass article according to claim 1, wherein the segment having the following structure extends around the entire periphery of the characteristic surface region.

5. At least one increased average surface roughness Rz 軸方向 5. The hollow glass article of claim 4, wherein the piece having the groove or score has a circumferential groove or score.

6. The hollow glass article of claim 5 , wherein the at least one fragment has a plurality of striations or grooves.

7. The characteristic surface area has an average surface roughness Rz measured parallel to the longitudinal axis of the glass article. 軸方向 and at least one piece having an average surface roughness Rz 軸方向 is the average surface roughness Rz measured at the wall height in a direction transverse to the longitudinal axis of the glass article. 接線方向 2. The hollow glass article of claim 1, wherein the hollow glass article is greater than 100 mm.

8. 8. The hollow glass article of claim 7, wherein the at least one fragment has at least one circumferential score or groove.

9. 9. The hollow glass article of claim 8, wherein the at least one fragment has a plurality of striations or grooves.

10. 9. The hollow glass article according to claim 1, wherein the glass article is a bottle, a vial, or a portion of a carpule, and the characteristic surface region is formed by the outer surface of a crimped neck, or the glass article is a syringe, and the characteristic surface region is formed by the outer surface of a cone tip.

11. A hollow glass article according to any one of claims 1 to 10, wherein the glass article is a part of a pharmaceutical primary packaging, preferably a pharmaceutical vial.

12. 12. The hollow glass article of claim 1, wherein the glass article is a borosilicate glass.

13. A hollow glass article according to any one of claims 1 to 12, wherein the glass article has a tubular section along its height.

14. 14. The hollow glass article of claim 13, wherein the glass article has a tubular section with a constant wall thickness along its height, the section having a standard deviation in wall thickness of less than 0.05 mm.

15. 15. The hollow glass article of claim 14, wherein the characteristic surface area is located outside the tubular segment and at a terminal region of the glass article.

16. 16. The hollow glass article of claim 15, wherein the diameter of the glass article at the area of ​​the characteristic surface region is smaller than the diameter at the tubular section.

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