DE102008018042B4 - Method for producing raised and / or drawn structures on hollow bodies, preferably of glass - Google Patents

Abstract

Method for producing raised (102) and / or drawn-in structures (104) on hollow bodies (10) with the steps:
Detecting the position and / or contour of the hollow body (10) by means of an optical detection device;
Calculating a predetermined path of a heat source based on the sensed location and / or contour of the hollow body (10);
Applying a pressure difference between the interior of the hollow body and the exterior of the hollow body;
Tracing the predetermined path with the heat source to locally heat the hollow body (10) to a softening temperature of the hollow body (10) by means of the heat source to cause local deformation of the hollow body; and
Cooling of the hollow body (10).

Description

The present invention relates to a method for producing raised or retracted structures on hollow bodies as well as a corresponding device.

Glass products are partially provided with projections, shoulders, protrusions, etc. (raised structures) and / or depressions, depressions, grooves, etc. (drawn-in structures) during production. In the process, these raised and drawn-in structures are produced simultaneously with the production of the glass body, for example by introducing an overpressure into a cavity of the molten glass (fixed blowing). The quality, d. H. Dimensions, roughness, etc. of the raised and retracted structures thus produced is relatively low. The glass product thus produced gives the user the impression of a cheap or low quality. There is thus a need for an improvement of the raised structures with respect to their quality.

US 4,057,409 A describes a device for the manufacture of cathode ray tube screens with integrally formed contoured fasteners. US 2 722 086 A describes a method for forming openings in glass products with the step of spot heating of side walls of the glass product. JP 62202828 A discloses a method for producing glass products in which parts to be deformed are locally heated. US 5 737 126 A discloses microlenses and other optical elements made by laser heating of doped semiconductors and other absorbent glasses.

The object of the invention is thus to provide a method for producing raised and drawn structures with which high-quality products can be produced. In addition, a corresponding device is to be made available.

This object is solved by the features of the independent claims. Advantageous developments of the invention are defined in the dependent claims.

This object is achieved by a method for producing raised and / or drawn structures on hollow bodies or walls of lumens with the following steps:
Detecting the position and / or contour of the hollow body by means of an optical detection device;
Calculating a predetermined path of a heat source based on the detected location and / or contour of the hollow body;
Applying a pressure difference between the interior of the hollow body and the exterior of the hollow body;
Traversing the predetermined path with the heat source for locally heating the hollow body to a softening temperature of the (material of) the hollow body by means of the heat source to cause a local deformation of the hollow body; and
Cooling the hollow body.

By merely locally heating the hollow body of an already blown glass product to cause local deformation, the raised structure can be subsequently produced on an already pressed or blown glass product. In addition, the inventive method provides a high degree of freedom, because due to the only local heating of the hollow body arbitrary structures can be shaped or designed. A degree of deformation can also be determined or controlled by applying a corresponding pressure difference. In other words, a high degree of deformation can be generated by a high pressure difference, while a low degree of deformation can be generated by a low pressure difference. Alternatively or additionally, by controlling the heating temperature of the hollow body, the degree of deformation can be controlled. That is, by generating a relatively low temperature, the degree of deformation can be reduced, while by generating a higher heating temperature, a degree of deformation can be increased.

In summary, it can be said that a degree of deformation can be determined on the one hand by controlling the pressure difference and on the other hand by controlling the local heating temperature. Cooling may be done passively by exposure of the product to ambient temperature or actively by cooling.

Preferably, the step of heating by means of laser beam, is best carried out by means of a CO ₂ laser. A laser device has the advantage that the energy for heating can be bundled very strongly in order to subject very precise and targeted specific areas of the hollow body of a strong heating. Thus, even very finely structured structures can be produced on the glass product.

In order to produce specific elevation or depression trains on the glass body, the heat source is moved according to the invention along a predetermined path on the hollow body. As a result, the user has another way to control the energy input into certain local areas of the hollow body. Such can be qualitative high-quality and very well reproducible structures are produced on the hollow body.

Preferably, the heat source power and / or the web speed of the heat source is controlled by means of a corresponding control or regulating device. Thus, there is a further possibility for controlling or designing the producible structures on the hollow body.

Furthermore, according to the invention, the position and / or contour of the hollow body is detected by means of an optical detection device such as a 2D scanner optics or a 3D scanner optics or any other optical detection device such as a light barrier, an optical sensor, a CCD camera or the like. Thus, the predetermined path of the heat source can be calculated and traversed based on the sensed position and / or contour of the hollow body, thus producing the desired raised structures at predetermined locations on the hollow body having predetermined heights and / or depths.

Preferably, the wall thickness of the hollow body is measured with the aid of the same optical detection device or a separate optical detection device, and the web speed and heat source power are corrected on the basis of the measured wall thickness. Thereby, the shape of the raised or retracted structures and the entire finished hollow body can be further improved, because the deviations of the wall thickness of the hollow body to be processed are taken into account. In areas of thinner wall thickness, less heat source power is needed and / or the web speed may eventually be increased to produce a predetermined bump or depression on the hollow body. Conversely, in areas of increased wall thickness, higher heat source performance or possibly lower line speed or both is required to create a predetermined structure on the hollow body. Accordingly, by measuring the wall thickness and correspondingly correcting web speed and / or heat source power, the structure can be produced with higher precision to give a high-quality impression.

Preferably, the degree of deformation of the hollow body with the same or another optical measuring device is continuously measured during the forming in order to provide a further correction possibility for correcting web speed and / or heat output. This has the advantage that a predetermined degree of deformation is measured directly and a corresponding intervention can be made on the control or regulation in order to control web speed and / or heat source power so that the predetermined degree of deformation is achieved.

In addition, the hollow body can be selectively cooled by applying a gas stream to cause a predetermined solidification of the structures produced. The gas used is preferably nitrogen or air.

To apply the pressure difference, an opening of the hollow body is preferably closed, for example with a silicone-coated aluminum plate. However, any other plate or shutter may be used as long as the interior of the hollow body is sufficiently sealed against an outside to apply a desired pressure difference between the inside and outside of the hollow body. The silicone-coated aluminum plate offers the advantage of a good seal and a good heat dissipation without being deformed when introducing the heat.

Preferably, a cup of a drinking glass is provided as a hollow body with the raised or retracted structures with the inventive method. It will be understood, however, that any other glass product may be provided with such structures by the method of the invention. The inventive method is further not limited to the processing of glass, but can also be used for other materials such as sheet metal or plastic.

The invention further relates to an apparatus for carrying out the method described above with a pressure difference generating device and a suitable heat source.

Preferably, a laser, preferably a CO ₂ laser is used as a heat source, so that the introduced heat energy can be very concentrated and very precisely targeted to predetermined locations can be introduced.

According to the invention, the device further has a movement device for moving the heat source along a surface of the hollow body.

Further preferably, a control and regulating device for controlling or regulating the heat source power and / or the web speed of the heat source is provided.

Furthermore, an optical detection device for detecting the position is provided according to the invention and / or contour of the hollow body and a calculation device for calculating the predetermined path of the heat source on the basis of the detected position and / or contour of the hollow body.

Furthermore, a measuring device for continuously measuring the wall thickness of the hollow body and a correction device for correcting the web speed and / or the heat source power on the basis of the measured wall thickness are furthermore preferably arranged.

Preferably, there are further provided a measuring device for continuously measuring a degree of deformation of the hollow body and a correction device for correcting the web speed and / or the heat source power on the basis of the measured degree of deformation.

Further preferably, a gas supply means for cooling the hollow body by applying a gas stream is provided.

The invention will now be explained in more detail with reference to the accompanying figure.

The figure shows a wine glass as an exemplary hollow body, which is to be provided with the inventive method with corresponding raised and / or drawn structures.

This in 1 shown drinking glass 1 has a floor 30 , a stalk 20 and a goblet 10 , This drinking glass 1 is made by known compression molding and blowing and cooled. Subsequently, raised and / or confiscated structures 102 . 104 at the goblet 10 formed by the method according to the invention. This is done inside the cup 10 creates an over or under pressure by opening 106 of the cup 10 is closed and a vacuum pump and / or a pressurizing device (not shown) to the interior of the cup 10 is connected.

Thus, a differential pressure between the interior of the cup 10 and the exterior of the cup 10 generated. By locally heating the wall 108 of the cup 10 becomes the wall 108 locally heated to the softening temperature of the glass. Due to the applied pressure difference becomes at elevated pressure in the interior of a raised or projecting structure 102 on the wall 108 generated. In the opposite case, at negative pressure in the interior of the cup 10 a retracted structure 104 (Recess, groove, etc.) on the wall 108 of the cup 10 generated. After cooling down the wall 108 locally heated places 102 . 108 become these bodies 102 . 104 hardened in the deformed form. This leaves a permanent deformation 102 . 104 on the wall 108 of the cup 10 ,

As the heat source, a laser device (not shown) such as a CO ₂ laser is preferably used, because thus the introduced energy for heating the glass can be bundled very strongly and very fine and high-quality structures on the wall 108 of the glass 1 can be generated. Preferably, the laser device is coupled to a moving means (not shown) to move the laser beam along a predetermined path on the wall 108 of the cup 10 to move. In this way, lines, elevations, depressions, depressions, grooves, patterns, etc. can be applied to the wall as desired 108 be formed. The differential pressure generating device is preferably controllable or adjustable between a negative pressure of 0.02 bar up to an overpressure of 5 bar, preferably between a negative pressure of 0.02 bar up to an overpressure of 2 bar.

More preferably, both the laser device and the movement device are coupled to a central control and regulating device (not shown) in order to be able to control or regulate the heat source power and the path speed in accordance with the predetermined pattern or the desired structure.

Preferably, an optical detection device is further provided to detect the contour and position of the product to be processed prior to processing. In this way, it is preferable to use the central control and regulating device to calculate the predetermined path of the heat source on the basis of the detected position and contour of the hollow body. However, it is not necessary to provide a central control and regulating device for this purpose, the optical detection device can rather be controlled and regulated separately if it is coupled with the control and regulating device for the heat source power and path speed of the heat source.

The optical detection device is preferably a 2D laser optics or a 3D laser optics. However, any other optical detecting means such as a photointerrupter, an optical sensor, a CCD camera, or the like may be used, if predetermined known lines are detected on the glass, for example. Such lines may, for example, the upper and lower edge line 32 . 34 of the soil 30 or the opening 106 of the cup 10 be. In other words, by detecting the location of these known lines 32 . 34 on the ground 30 or at the opening 106 of the cup 10 can the contour and location of the known glass 1 be detected precisely. Based on the detected contour and position of the glass 1 Then, the predetermined path of the heat source for generating the raised or drawn-in structure 102 . 104 be calculated.

Preferably, the wall thickness of the cup 10 Also measured by the optical detection device, because the wall thickness over the circumference and the height of the glass 1 varied. If in this way before forming the raised or contracted structure 102 . 104 on the wall 108 the wall thickness in the area to be worked on the wall 108 of the cup 10 is determined, the heat source power and the web speed can be corrected on the basis of the measured wall thickness to the precision in the processing of the wall 108 of the cup 10 continue to increase.

Alternatively or additionally, the degree of deformation is measured by the optical detection device if an even higher precision is to be achieved. By measuring the degree of deformation, the web speed and energy input or heat source power can be correspondingly increased or decreased by a predetermined target value of the deformation of the structure 102 . 104 to achieve.

To further a flow of softened structure 102 . 104 By preventing too slow cooling, a cooling process is preferably performed by applying a gas flow to the deformed sites 102 . 104 accelerated. In this way, the precision of the deformation can be further increased. Nitrogen is preferably used for the gas stream, but any other inert gas or air may be used to cool the structure accordingly fast.

For applying the pressure difference inside the cup 10 must the opening 106 be closed. This is preferably done by a silicone coated aluminum plate. Aluminum has the advantage of good heat dissipation to prevent deformation such as corrugation of the plate due to the introduced heat. Silicone offers the advantage of a good seal and at the same time high heat resistance. However, any other plate material may be used.

The invention is not limited to the formation of raised and drawn structures 102 . 104 at the goblet 10 a glass 1 limited. Rather, the structures shown 102 . 104 also be formed on any other glass body, such as a hollow lens, a lamp, etc. Furthermore, the inventive method can also be applied to other materials such as sheet metal or plastic.

By the method according to the invention, for example, lettering or logos and the like can be attached to hollow bodies made of glass, plastic, metal, etc. with very high precision. Above all, it offers the advantage of a very precise design of the structures 102 . 104 that give the impression of high quality. In particular, in high-quality glass series as they are used for wine glasses, champagne flutes, etc., the high-quality appearance of extraordinary importance.

LIST OF REFERENCE NUMBERS

1

drinking glass

10

chalice

20

stalk

30

ground

32

upper edge line

34

lower border line

102

sublime structure

104

retracted structure

106

opening

108

wall

Claims (15)

Method for producing raised ( 102 ) and / or confiscated structures ( 104 ) on hollow bodies ( 10 ) with the steps: detecting the position and / or contour of the hollow body ( 10 ) by means of an optical detection device; Calculating a predetermined path of a heat source on the basis of the detected position and / or contour of the hollow body ( 10 ); Applying a pressure difference between the interior of the hollow body and the exterior of the hollow body; Departure of the predetermined path with the heat source for local heating of the hollow body ( 10 ) to a softening temperature of the hollow body ( 10 ) by means of the heat source to cause local deformation of the hollow body; and cooling the hollow body ( 10 ). The method of claim 1, wherein the step of heating is performed by laser beam. The method of claim 2, wherein the laser beam is generated by a CO ₂ laser. Method according to one or more of the preceding claims, further comprising the step of controlling the heat source power and / or the web speed of the heat source. Method according to one or more of the preceding claims, further comprising the step of continuously measuring the wall thickness of the hollow body ( 10 ) and correct the Web speed and / or heat source power based on the measured wall thickness. Method according to one or more of the preceding claims, further comprising the step of continuously measuring a degree of deformation of the hollow body ( 10 ) and correcting the web speed and / or heat source performance based on the measured degree of deformation. Method according to one or more of the preceding claims, wherein the step of cooling by means of applying a gas stream to the hollow body ( 10 ) is carried out. Method according to one or more of the preceding claims, further comprising the step of closing an opening of the hollow body ( 10 ) by means of a plate, preferably a silicone-coated aluminum plate. Method according to one or more of the preceding claims, wherein the hollow body ( 10 ) a goblet of a drinking glass ( 1 ). Device for carrying out a method according to one or more of the preceding claims, comprising: optical detection means for detecting the position and / or contour of the hollow body ( 10 ); a calculation device for calculating a predetermined path of a heat source on the basis of the detected position and / or contour of the hollow body ( 10 ); a pressure difference generating means; a heat source; and a movement device for moving the heat source along a surface of the hollow body ( 10 ). Apparatus according to claim 10, wherein the heat source is a laser, preferably a CO ₂ laser. Device according to one or more of the preceding claims 10 to 11, further comprising a control and regulating device for controlling or regulating the heat source power and / or the path speed of the heat source. Device according to one or more of the preceding claims 10 to 12, further comprising a measuring device for continuously measuring the wall thickness of the hollow body ( 10 ) and correcting means for correcting the web speed and / or the heat source power based on the measured wall thickness. Device according to one or more of the preceding claims 10 to 13, further comprising a measuring device for continuously measuring a degree of deformation of the hollow body ( 10 ) and correcting means for correcting the web speed and / or the heat source power on the basis of the measured degree of deformation. Device according to one or more of the preceding claims 10 to 14, further comprising a gas supply device for cooling the hollow body ( 10 ) by applying a gas stream.

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