Device and method for applying lubricant to the internal surfaces of a mold for forming hollow glass bodies

Abstract

Lubricant application device, on the internal surfaces of a forming mold (1, 10) for hollow glass bodies, such as bottles, the device being capable of applying the lubricant to a portion of the forming surfaces of a main mold such as a roughing mold or a finishing mold, and to the forming surfaces of a bottom mold located in a lower part of the main mold such as a ring mold or a finishing bottom mold, the device comprising a wand (5) provided with first spray holes (6) and second spray holes (7), one or more of the first holes spraying a lubricant in a first radial or axial direction, towards the mold or towards the bottom of the mold, one or more of the second holes spraying a lubricant in a second radial direction, the first spray holes and the second spray holes being arranged in the extreme lower part of the wand,The cane includes two lubricant distribution networks capable of providing simultaneous or sequential supply to the first and second spray holes. Figure for the abbreviation: Figure 1,

Description

Title of the invention: Device and method for applying lubricant to the internal surfaces of a mold for forming hollow glass bodies

[0001] The invention relates to the lubrication of molds for the glass industry, and more particularly but not exclusively concerns spray lubrication of finishing molds.

[0002] The invention is of particular interest in the manufacture of hollow glass products, such as bottles, flasks or jars.

[0003] After melting and refining, the glass undergoes thermal conditioning and is conveyed to production machines in feeders to be cut into gobs. The gobs are then transformed into jars or bottles by forming machines.

[0004] Manufacturing techniques have been developed according to the types of products to be made, in particular the process called blow-and-blow process for narrow-ring hollow bodies such as food and beverage bottles, and the process called press-and-blow process for wider-ring hollow bodies such as large capacity pots.

[0005] Reference can be made, for example, to the documents Biosca et al, Numerical and experimental study of blow and blow for perfume bottles to predict glass thickness and blank mold influence, International Journal of Applied Glass Science, 2019, Vol. 10 Issue 4, p569-583; Doumenc, Surface heat transfer coefficients: determination by inverse methods in transient two-dimensional conduction, 1993.

[0006] Reference can also be made to documents WO2017032883 (Socabelec, 2017), EP3800166 (Nihon Yamamura Glass, 2021).

[0007] For the vocabulary of manufacturing glass containers, reference can be made to the ISO7348:1992 standard.

[0008] According to this standardized vocabulary, in a press-blown process for manufacturing hollow glass, the blank and the ring are pressed, then the blank is blown into its final shape in a finishing mold, the blank being formed in a roughing mold. The ring is the upper part of a container neck designed to receive the closure, the ring being formed by a mold portion called the ring mold.

[0009] According to this standardized vocabulary, in a blow-blown process, the initial and final shapes are obtained by blowing air under pressure.

[0010] In a press-blown process, the parison is introduced into the blank mold, the punch of which obstructs the opening of the ring mold. The punch is then The glass is moved upwards, forcing it to conform to the contours of the blank mold and the ring mold. At the end of the pressing process, the blank mold is opened and the blank is transferred to the finishing mold, where the glass is blown. Once the blowing is complete, the finishing mold is opened and the bottle is removed from the mold.

[0011] In the blow-blown process, the parison enters the roughing mold, then Compressed air is injected, and the glass is pushed downwards onto the punch and into the ring mold. The punch descends, the blank retracts, and air is blown through the base of the punch, pressing the glass against the walls of the blank mold. The blank is then transferred to the finishing mold, where compressed air blows it to give the final shape of the hollow object, such as a bottle.

[0012] These two processes, press-blown and blow-blown, are most often implemented in IS (Individual Section, Ingle-Smith) machines, comprising several sections (usually up to 20 sections), each section having from one to four cavities. Each cavity includes a ring mold, a roughing mold, and a finishing mold. A central distribution system ensures the allocation of the parisons to the different sections of the IS forming machine.

[0013] In a conventional IS machine, each parison is received and processed in a roughing mold and then a finishing mold, the roughing mold comprising two half-molds defining a vertical parting line. At the lower end of the roughing mold, the two half-molds close onto a ring mold.

[0014] In older techniques, the lubrication of metal surfaces in contact with glass is carried out manually on the molds by operators. A thin film of lubricant, most often a graphite-filled grease, is periodically deposited on the walls of the roughing mold, facilitating the penetration of the parison into the roughing mold, as well as the removal of the blank from the mold.

[0015] The lubrication of the metal surfaces of the mold, called mold greasing (swabbing, doping) can lead to marking or grease stains on the surface of the hollow glass product (carbon mark), in particular on the ring or on the neck.

[0016] Manual lubrication has many disadvantages: risk to the operator who performs the lubrication without stopping the machine, need for the operator to be present and perform the lubrication regularly, for example every twenty minutes.

[0017] To overcome these problems, it is known to carry out the spray lubrication of a mold for forming hollow glass bodies, by means of a rod mounted movable relative to the mold.

[0018] Document WO2007 / 138226 (Saint-Gobain, 2007) describes spray lubrication of a mold by a moving nozzle, carried by an arm of a robot mounted to move in translation on a rail running along the side of the roughing molds of a On the IS machine, lubrication of the finishing molds is also possible. The spray nozzle moves downward between the two mold halves of a roughing mold, continuously spraying oil in an axial direction, along a 45° cone, during this downward movement. When the nozzle reaches its lowest position, the two mold halves are separated, exposing the ring mold, and the spray nozzle is raised, spraying oil towards the ring mold. The spraying then stops, and the nozzle rises to its highest position.

[0019] Document WO 2016 / 132236 (Is Eng, 2016) describes spray lubrication of a roughing mold or a finishing mold, by a spray gun, in an IS machine. The spray gun performs a spray in a radial direction, towards the inner surfaces of the molds, while remaining stationary or moving upwards or downwards between the two mold halves.

[0020] Document EP3689832 (Nihon Yamamura Glass, 2020) describes the application of a lubricant by spraying a finishing mold using a spray gun that sprays laterally in a horizontal direction and downwards in a vertical direction. The spray gun has first spray holes at its lower end for axial spraying, for example, a full cone, and second spray holes for lateral spraying, for example, a full cone. The second spray holes are located in the middle section of the spray gun. Lateral spraying is performed simultaneously with axial spraying.

[0021] Document EP4129940 (Ernhart Glass, 2023) describes a lubrication method for a blank mold, using a spray gun that applies spray in a radial and axial direction, before opening the blank mold, with the spray angle between 45 and 90 degrees. The upper surface of the neck ring and its circumferential inner surface are then lubricated after the two halves of the blank mold are separated.

[0022] Despite the numerous developments proposed in the prior art for spray lubrication means, it is estimated that 2% of the yield of glass hollow body forming machines is lost following mold lubrication (Orzol et al, Tribological investigations of the glass-to-metal contact during glass forming at an industrial scale, International journal of applied glass science, 2021).

[0023] The invention aims to overcome the disadvantages of prior art devices and methods for spray lubrication of molds for forming hollow glass bodies.

[0024] According to a first aspect of the invention, a device for applying lubricant to the internal surfaces of a mold for forming hollow glass bodies, such as bottles, is proposed, the device being capable of applying the lubricant to a part forming surfaces of a main mold such as a roughing mold or a finishing mold, and on the forming surfaces of a bottom mold located in a lower part of the main mold such as a ring mold or a finishing bottom mold, the device comprising a rod or lance having first spray holes and second spray holes, one or more of the first holes spraying lubricant in a first radial or axial direction, towards the mold or towards the bottom of the mold, one or more of the second holes spraying lubricant in a second radial direction, the first spray holes and the second spray holes being arranged in the extreme lower part of the rod.

[0025] By arranged in the extreme lower part of the cane, we mean here that the first holes and the second spray holes are placed at substantially the same height, along the length of the cane, and close to the lower free end of the cane.

[0026] Advantageously, the cane comprises two lubricant distribution networks, a first network connecting the first spray holes to a first lubricant reservoir, a second network connecting the second spray holes to a second lubricant reservoir or to the first lubricant reservoir, the device comprising control means for each of the two distribution networks, the control means being capable of ensuring simultaneous or sequential supply of the first spray holes and the second spray holes.

[0027] Advantageously, pressurizing each lubricant reservoir allows each lubricant to circulate through separate channels internal to the can, and a radial or axial spray of a first lubricant, simultaneous or not with a radial spray of a second lubricant.

[0028] In some implementations, the two separate lubricant distribution networks are connected to a single reservoir of the same lubricant.

[0029] The first lubricant and the second lubricant may be identical or different. The lubricants are, for example, sprayable graphite greases, or graphite-free release greases.

[0030] According to a second aspect of the invention, a machine for manufacturing hollow glass bodies is proposed, comprising at least one forming mold and a lubricant application device as presented above, the machine comprising a drive mechanism enabling the lubricant application device to move back and forth in the axial direction.

[0031] The spray lance or nozzle undergoes a substantially vertical, axial movement between an extremely high position and an extremely low position. In position At its highest point, the rod is out of the mold and inactive. At its lowest point, the rod is at a predetermined distance from the bottom of the mold.

[0032] The drive mechanism can be mechanical, such as a roller rolling on a cam. The drive mechanism may include means such as cylinders. The nozzle can be mounted on a robot arm. Depending on the number of molds to be lubricated, several nozzles can be mounted on the same drive mechanism.

[0033] According to a third aspect, a method for applying lubricant to the internal surfaces of a mold for forming hollow glass bodies, such as bottles, is proposed, suitable for applying the lubricant to a portion of the forming surfaces of a main mold such as a roughing mold or a finishing mold, and to the forming surfaces of a bottom mold located in a lower part of the main mold such as a ring mold or a finishing bottom mold, the method comprising moving a rod provided with first spray holes and second spray holes within the mold, one or more of the first holes spraying lubricant in a first radial or axial direction, towards the mold or towards the bottom of the mold, one or more of the second holes spraying lubricant in a second radial direction,The first and second spray holes are located at the extreme lower part of the cane.

[0034] Advantageously, the cane comprises two lubricant distribution networks, a first network connecting the first spray holes to a first lubricant reservoir, a second network connecting the second spray holes to a second reservoir or to the first lubricant reservoir, control means for each of the two distribution networks being capable of ensuring simultaneous or sequential supply to the first spray holes and the second spray holes.

[0035] Other objects and advantages of the invention will become apparent from the description of embodiments given below with reference to the accompanying drawings in which:

[0036] [Fig. 1] is a cross-sectional view of a roughing mold, with a grease gun in the upper position and performing radial spray lubrication;

[0037] [Fig.2] is a cross-sectional view of the roughing mold of [Fig.1], the two half-molds being separated, the grease tube being in a low position and performing axial spray lubrication;

[0038] [Fig.3] is a cross-sectional view of a finishing mold, with a grease gun in the high position and performing radial spray lubrication;

[0039] [Fig.4] is a cross-sectional view of the finishing mold of [Fig.3], the two halves- with the molds moved aside, the grease gun is in a low position and performs lubrication by axial spraying.

[0040] The upper and lower positions of the grease fitting can be fixed according to requirements, and the positioning examples shown in the figures are not limiting.

[0041] In the remainder of this description, the expression spray lance will be used, for the sake of simplicity, to refer to the grease lance, which could also be called a lubrication lance, a spray lance.

[0042] By cane is designated a slender, elongated piece, typically cylindrical and of small diameter, advantageously of the order of 8 mm.

[0043] By spraying, we mean here the reduction of a liquid into a mist (or the reduction of a viscous or liquid mixture containing a powder into very fine particles), as well as the action of projecting these very fine particles of liquid by means of pressure.

[0044] Figures 1 and 2 schematically represent a roughing mold 1 comprising two half-molds 2, 3 and a ring mold 4. In [Fig. 1], the roughing mold 1 is in the closed position, with the two half-molds 2, 3 in contact. The spray nozzle 5 is in the raised position and performs radial spray lubrication.

[0045] In [Fig. 2], the blank mold 1 is in the open position, with the two mold halves 2 and 3 separated from each other. The spray nozzle 5 is in the lowered position and performs axial spray lubrication of the ring mold 4.

[0046] The spray wand 5 is provided with first spray holes 6 and second spray holes 7, one or more of the first holes 6 spraying a lubricant in a first axial direction, towards the bottom of the mold, one or more of the second holes 7 spraying a lubricant in a second radial direction.

[0047] The first spray holes 6 and the second spray holes 7 are arranged in the extreme lower part of the spray wand 5.

[0048] Figures 3 and 4 show a finishing mold 10, comprising two half-molds 11, 12 and a finishing bottom 13.

[0049] In [Fig. 3], the finishing mold 10 is in the closed position, with the two mold halves 11 and 12 in contact. The spray lance 5 is in the raised position and performs radial spray lubrication through the second spray holes 7.

[0050] In [Fig. 4], the finishing mold 10 is in the open position, with the two mold halves 11 and 12 separated from each other. The spray nozzle 5 is in the lowered position and performs axial spray lubrication through the first spray holes 6.

[0051] Spraying is obtained for example by injecting compressed air into a stream of sprayable grease, or into a stream of liquid such as an oil.

[0052] Spraying can be achieved by placing a narrowing of the passage section of a fluid in a nozzle.

[0053] Different jet shapes can be obtained: flat jets, solid cone, hollow cone jet, and axial flow. Advantageously, the jets are variable, that is, subject to variations, depending on the time or requirements.

[0054] The angle of the nozzle outlets can be adjusted, for adaptation to complex hollow body shapes.

[0055] The device has many advantages.

[0056] Axial spray lubrication and radial spray lubrication can be carried out in a totally simultaneous, partially simultaneous, or sequential and non-simultaneous manner.

[0057] For example, in a first step, the spray lance enters the closed mold for radial spray lubrication in predefined areas of the mold walls. During this first step, the spray lance can be held in position or moved, for example, downwards within the mold.

[0058] Then, in a second step, the mold is opened and the mold bottoms are subjected to axial spraying, the extreme free part of the spray wand being brought closer to the mold bottom.

[0059] The device thus allows great flexibility and variability of uses, for adaptation to different geometries of hollow bodies to be formed.

[0060] Specific areas of the finishing molds can be lubricated by spraying, while other specific areas can be protected from the application of grease or oil, in order to avoid contamination of the formed containers.

[0061] Thus, for example, the neck area, the shoulder area, and the engraved areas are advantageously and precisely lubricated by radial spraying. The engraved areas contain customization elements for the hollow bodies, as well as the mold number.

[0062] The bottom plate of the finishing molds can be fully lubricated by axial spraying.

Claims

Demands

1. A device for applying lubricant to the internal surfaces of a forming mold (1, 10) for hollow glass bodies, such as bottles, the device being capable of applying lubricant to a portion of the forming surfaces of a main mold such as a roughing mold or a finishing mold, and to the forming surfaces of a bottom mold located in a lower portion of the main mold such as a ring mold or a finishing bottom mold, the device comprising a wand (5) having first spray holes (6) and second spray holes (7), one or more of the first holes (6) spraying lubricant in a first radial or axial direction, towards the mold or towards the bottom of the mold (1, 10), one or more of the second holes (7) spraying lubricant in a second radial direction,the device being characterized in that the first spray holes (6) and the second spray holes (7) are arranged in the extreme lower part of the cane (5).

2. Lubricant application device according to claim 1, characterized in that the wand (5) comprises two lubricant distribution networks, a first network connecting the first spray holes (6) to a first lubricant reservoir, a second network connecting the second spray holes (7) to a second lubricant reservoir or to the first lubricant reservoir, the device comprising control means for each of the two distribution networks, the control means being capable of ensuring simultaneous or sequential supply of the first spray holes (6) and the second spray holes (7).

3. Machine for manufacturing hollow glass bodies comprising at least one forming mold and a device according to claim 1 or 2, and a drive mechanism enabling the lubricant application device to move back and forth in the axial direction.

4. A method for applying lubricant to the internal surfaces of a forming mold (1, 10) for hollow glass bodies, such as bottles, suitable for applying the lubricant to a portion of the forming surfaces of a main mold such as a roughing mold or a finishing mold, and on the forming surfaces of a bottom mold located in a lower part of the main mold such as a ring mold or a finishing bottom mold, the method comprising moving in the mold a rod (5) provided with first spray holes (6) and second spray holes (7), one or more of the first holes (6) spraying a lubricant in a first radial or axial direction, towards the mold or towards the bottom of the mold (1, 10), one or more of the second holes (7) spraying a lubricant in a second radial direction, the first spray holes (6) and the second spray holes (7) being arranged in the extreme lower part of the rod (5).

5. Method of applying lubricant to the internal surfaces of a glass hollow body forming mold according to claim 4, characterized in that the wand (5) comprises two lubricant distribution networks, a first network connecting the first spray holes (6) to a first lubricant reservoir, a second network connecting the second spray holes (7) to a second lubricant reservoir or to the first lubricant reservoir, control means for each of the two distribution networks being capable of ensuring simultaneous or sequential supply to the first spray holes (6) and the second spray holes (7).

Images