阅读说明：本技术 制造玻璃产品的方法和装置 (Method and apparatus for manufacturing glass products ) 是由 米科·阿罗马 于 2021-06-16 设计创作，主要内容包括：一种制造玻璃产品的方法,包括：由熔融玻璃(100)形成玻璃物体,在所述形成(120)之后,在对所述物体进行冷却的同时将包含具有抗菌特性的金属的流体施用在玻璃物体上,以及在所述施用(130)之后,对玻璃物体进行退火以获得最终的抗菌玻璃产品。一种玻璃制造装置,包括：喷雾施用单元(1),其构造成将包含具有抗菌性能的金属的流体施用在玻璃物体(14)上,其中,喷雾施用单元包括用于使玻璃物体(14)移动的运输单元(10)、框架(11)和附接至框架(11)的喷嘴(13),喷嘴构造成将具有抗菌特性的金属喷射到玻璃物体(14)上。(A method of making a glass product comprising: forming a glass object from molten glass (100), after said forming (120), applying a fluid comprising a metal having antimicrobial properties on the glass object while cooling said object, and after said applying (130), annealing the glass object to obtain a final antimicrobial glass product. A glass manufacturing apparatus comprising: a spray application unit (1) configured to apply a fluid containing a metal having antimicrobial properties onto a glass object (14), wherein the spray application unit comprises a transport unit (10) for moving the glass object (14), a frame (11) and a nozzle (13) attached to the frame (11), the nozzle being configured to spray the metal having antimicrobial properties onto the glass object (14).)

1. A method of making a glass product, the method comprising:

forming a glass object from molten glass (100),

applying a fluid comprising a metal having antimicrobial properties on the glass object while cooling (120) the object after the forming, and

after the applying (130), annealing the glass object to obtain a final antimicrobial glass product.

2. The method of claim 1, wherein the method further comprises: a step (110) of flame polishing the surface of the glass object after the forming (100).

3. The method of claim 1 or 2, wherein in the step of applying (120), the applied fluid comprises at least one of silver, copper and zinc or a compound thereof in the form of pure metal particles.

4. The method of claim 3, wherein the silver compound comprises at least one of silver chloride, silver sulfide, silver sulfate, silver nitrate, silver hydroxide, silver phosphate, silver carbonate, and an organometallic compound of silver.

5. The method of claim 3, wherein the copper compound comprises at least one of copper chloride, copper sulfide, copper sulfate, copper nitride, copper nitrate, copper hydroxide, copper phosphate, copper phosphide, copper carbonate, and an organometallic compound of copper.

6. The method of claim 3, wherein the zinc compound comprises at least one of zinc chloride, zinc sulfate, zinc sulfide, zinc nitrate, zinc nitride, zinc hydroxide, zinc phosphate, zinc phosphide, zinc carbonate, and an organometallic compound of zinc.

7. The method according to any one of claims 3 to 6, wherein the concentration of the compound in the fluid is 0.1 to 2kg/l at room temperature.

8. The method according to any one of claims 3 to 7, wherein during the applying step (120), a metal compound is applied to the surface of the glass object by spraying from a nozzle.

9. The method according to claim 8, wherein the droplet has a size of 10nm to 10 μm when deposited on the surface of the glass object during ejection from the nozzle.

10. A method according to claim 8 or 9, wherein the nozzle is arranged to eject the fluid at a flow rate of 0.1 to 10 l/h.

11. A glass manufacturing apparatus, comprising:

a spray application unit (1), the spray application unit (1) being configured to apply a fluid comprising a metal having antibacterial properties on a glass object (14), the spray application unit (1) comprising:

a transport unit (10), the transport unit (10) being used for moving the glass object (14),

a frame (11), and

a nozzle (13) attached to the frame (11), the nozzle (13) configured to spray metal having antimicrobial properties onto the glass object (14).

12. The glass manufacturing apparatus according to claim 11, wherein the spray application unit (1) further comprises a conveyor (12), the conveyor (12) being movable by the transport unit (10).

13. The glass manufacturing apparatus according to claim 12, wherein the conveyor (12) further comprises a rotatable platform on which the glass object (14) is placed.

14. Glass manufacturing apparatus according to any of claims 11 to 13, wherein the nozzle (13) is located in a pressurized system or an ultrasonic evaporator.

15. The glass manufacturing apparatus of any of claims 11 to 14, wherein the fluid comprises at least one of silver, copper, and zinc, or compounds thereof, in the form of pure metal particles.

Technical Field

The present invention relates to apparatus and methods for making glass products, and more particularly to antimicrobial glass products.

Background

Conventional glass manufacturing processes include: forming a glass object from molten glass; flame polishing a glass object to obtain a smooth surface; the glass object is then annealed at 300 ℃ to 700 ℃ for 1 hour to 12 hours to prevent the formation of internal stresses due to an uncontrolled cooling process of the surface and bulk before cooling to room temperature. Even a slight vibration or impact of the object may cause internal stresses within the glass object to relax, causing breakage or minor stress cracking.

Metals such as silver (Ag), gold (Au), copper (Cu) and zinc (Zn) are known to have antimicrobial effects, for example in the medical device industry, as these metals can kill or prevent the growth of microorganisms. Most conventional antimicrobial glass has an antimicrobial metal layer on the surface of the glass. Several methods are used to form such layers, for example: the final non-antimicrobial glass product is coated with metal by adding metal compounds to the glass-forming raw materials, or the metal is added to an ion exchange bath. Followed by another annealing step and removal of excess metal from the surface.

Since some of these metals are relatively expensive, the most cost-effective and longer-lasting method of forming the antimicrobial layer is by ion-exchange. Conventional ion exchange processes are used to chemically strengthen the annealed glass object and typically involve immersing the glass object in a molten salt containing ions having a larger ionic radius than the ions present in the glass that are susceptible to exchange reactions, such that the smaller ions present in the glass are replaced by the larger ions in the molten salt solution.

Some of the disadvantages associated with metal salt baths are the relatively long immersion time and the characteristic color of the metal, which appears to the human eye as yellow, for example, for silver. The conventional ion exchange process may take 30 minutes to several hours to obtain the desired antibacterial layer. If the concentration of metal ions is reduced, the antibacterial performance is also reduced. For example, the yellow/amber color of silver is caused by absorption of visible light (except for yellow wavelengths), and this is an undesirable feature in transparent products.

Another disadvantage associated with ion exchange is that ion exchange is a separate process that requires additional time, space, and effort. In some cases, the glass object is heated below the glass transition temperature to activate ion exchange on the glass object. The size of the ion exchange bath is a determining factor when impregnating the 3D product. The larger the salt bath, the more salt and energy are required. For some 3D products, such as bowls, it is necessary to take into account the flow of the salt bath and fill the entire inner surface of the bowl. The glass articles may be so large that only one product can be impregnated at a time. The ion exchange process for a batch of bowls can be very time consuming and energy intensive given the conventional impregnation times.

Disclosure of Invention

It is an object of the present invention to provide a method and apparatus that overcomes the above-mentioned disadvantages. The object of the invention is achieved by a method and an arrangement which are characterized by what is stated in the independent claims. Preferred embodiments of the invention are disclosed in the dependent claims.

The invention is based on the following idea: during the manufacturing process, in particular after the forming step and before the annealing step, a fluid containing a metal with antimicrobial properties is applied onto the surface of the glass object, so that ion exchange will take place during annealing, which will shorten the total manufacturing time and prevent the characteristic color of the metal from being visible.

Drawings

The invention will be described in more detail below by means of preferred embodiments with reference to the accompanying drawings, in which:

FIG. 1 illustrates a flow diagram of a method of making a glass product according to some embodiments;

FIG. 2 shows a schematic view of an apparatus according to an embodiment; and

fig. 3 shows a schematic view of an apparatus according to another embodiment.

Detailed Description

Fig. 1 illustrates a flow diagram of a method for manufacturing a glass product, according to some embodiments. The method of the present invention involves making an antimicrobial glass product directly from molten glass without adding an antimicrobial material to the molten glass raw materials or without ion exchange of the annealed objectAdditional post-processing steps. For example, the most common raw material for soda-lime glass is Silica (SiO)₂) Calcium oxide (CaO) and sodium oxide (Na)₂O), these raw materials are fed to a glass melting furnace.

The present invention relates to the production of glass, wherein the production comprises a forming step 100 for forming a glass object from molten glass, which, depending on its composition, is between 1000 ℃ and 1500 ℃. For example, for dishware, temperatures of 1000 ℃ to 1200 ℃ are preferred. During the forming step 100, molten glass is placed into a mold where the glass object is formed into an initial shape by pressing or blowing, or both. The forming step may be performed by machine, by hand, or by a combination of both. The glass is given its shape and the object reaches a temperature at which the viscosity of the glass largely prevents the glass from flowing under the influence of gravity. The object is further cooled after exiting the mold. In some embodiments, no mold is needed, but rather the shape is obtained by collecting molten glass onto a blow tube and manually molding.

In some embodiments, the forming step 100 is followed by a flame polishing step 110, in which flame polishing step 110 the surface of the glass object becomes smooth and polished while removing the visible marker after forming. The temperature of the glass object before polishing should generally be as high as possible, but not allowed to change too much in viscosity to destroy the shape of the glass object. Polishing is accomplished with as efficient a flame as possible to introduce sufficient energy to the surface to re-melt and smooth the surface. However, this step may not be necessary when polishing the surface is not required.

Following the flame polishing step 110 or the forming step 100 is an application step 120, in which a fluid comprising a metal having antimicrobial properties is applied to a glass object having a surface temperature of 500 ℃ to 950 ℃. In this temperature range, the glass object is still soft and easy to surface treat. The applying step may last less than 200 seconds, or in some embodiments, even less than 30 seconds, and may be accomplished by spraying on the surface of the glass object, dipping the glass object into a bath, or other application techniques that cause the fluid to at least partially deposit on the surface of the glass object. The application time refers to the time when the fluid is actively deposited on the surface of the glass object. The fluid deposited on the surface may have a very small droplet size, so that the solvent evaporates on the way out of the nozzle and only the metal or metal mixture contacts the surface, since the high volatility of the solvent at ambient temperature is increased by the specific surface area of the droplets. This is preferred because no additional energy is transferred from the hot surface to evaporate the liquid, which results in a faster cooling of the surface.

In some embodiments, the applying step 120 may be combined with the flame polishing step 110, where the oxidizing or reducing agent further comprises metal particles or metal salts deposited on the surface of the glass object in the flame polishing step 110. This step may be performed immediately after the forming step 100.

Spraying may be achieved by at least one nozzle and the system may be customized to the desired product shape. Herein, "jetting" means: droplets or particles containing solvent and dissolved metal compounds are produced in the form of a spray, mist, fog, jet or the like and deposited onto the surface of the object. System parameters can be designed including spray characteristics, droplet size distribution, spray impact, spray pattern, spray coverage, and spray angle. The residence time of the particles before deposition on the surface may be so long that all of the solvent evaporates from the droplets, but is not so limited.

The droplet size in the mist from the atomizer is one of the key parameters for obtaining particles of the appropriate size for ion exchange to take place in the appropriate manner and ultimately to achieve the desired effect. I.e. on the one hand to avoid too fast an ion exchange leading to diffusion of the metal in the glass matrix and on the other hand to avoid the colouring effect of the metal, the cooling effect of excessively large particles and the absence of materials having a very small particle size and concentration combination. There are several types of nozzles in which gas-assisted spraying typically produces smaller droplet sizes than nozzles that use only liquid pressure as atomization. Both types provide an initial velocity to the droplets, as opposed to ultrasonic spraying, which tends to produce droplets without sufficient energy of motion if not assisted by external acceleration. By increasing the pressure, the average value of the particle size distribution from the hydraulically operated nozzle can be shifted towards smaller particle sizes. However, as the velocity difference of the liquid and the gas increases, the gas-assisted nozzle ejects smaller droplets, i.e. increasing the gas pressure is the main factor for a given orifice size. Furthermore, the smaller the liquid feed opening, the smaller the particle size is generally.

The design of the nozzle may affect the type of spray pattern. There are several spray pattern types, such as flat fan, solid cone, hollow cone, spiral solid cone, solid stream, and mist, and the spray pattern type will affect the droplet size, but even if kept in one pattern type, the degree of atomization may vary. For example, the best pattern for a tumbler (tubbler) is a flat fan that covers the entire side when the tumbler is rotated about its axis, and one nozzle can cover the entire periphery. For rotating plates, a full cone pattern provides the best coverage.

In one embodiment, when the droplets are deposited onto the surface of the glass object, the droplet size may be in the range of between 10nm to 1000 μm and dispersed into smaller droplets, for example 10nm to 10 μm droplets. The nozzles can eject fluid at a flow rate of 0.1l/h to 10l/h, depending on the type and size of the nozzle. For example, for an unheated fluid, the flow rate may be 1l/h, while for a heated fluid, the flow rate may decrease as the concentration increases. The fluid may be heated to below its boiling temperature, depending on the composition. The spray time is preferably 5 to 60 seconds to obtain the desired coverage of the object, but in some embodiments a spray time of even 5 to 30 seconds is sufficient.

There are different techniques to generate the spray. The two most common techniques are pressurized systems and ultrasonic evaporators. The pressurized system may be a gas-assisted atomizer which uses its special design and pressurized air or gas to atomize the liquid and break it up into tiny droplets. The ultrasonic evaporator may be an ultrasonic atomizer which generates high frequency oscillation using energy of high speed impact to atomize liquid droplets finely. This particular design produces tiny and uniform droplets. The ultrasonic atomizer has two atomization stages. Stage one: the liquid mixes with the pressurized air and produces tiny droplets for ejection. And a second stage: when the atomized droplets impact the ultrasonic generator, the atomized droplets are micro-atomized to produce smaller droplets.

In the application step 120, the amount of fluid to be applied may be varied to obtain the desired antimicrobial characteristics. Generally, metals considered to have antibacterial properties are typically transition metals (V, Ti, Cr, Co, Ni, Cu, Zn, Tb, W, Ag, Cd, Au and Hg) and some other metals located in the d-block, As well As metalloids of groups 13 to 16 of the periodic table (Al, Ga, Ge, As, Se, Sn, Sb, Te, Pb and Bi). The most commonly used antimicrobial metals are titanium (Ti), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), gold (Au), and aluminum (Al). The term "metal having antibacterial properties" refers to any of the pure metals described above, or compounds or ions thereof. For example, the pure metal may be in the form of nanoparticles. In some embodiments, the metal may be submicron nanoparticles made of pure metal encapsulated in a polymer or protected by a carbon shell.

In some embodiments, the fluid comprises at least one of a silver compound, a copper compound, and a zinc compound. The silver compound may be a silver salt, and include at least one of silver chloride, silver sulfide, silver sulfate, silver nitrate, silver hydroxide, silver phosphate, silver carbonate, and an organometallic compound of silver. The copper compound may be a copper salt, and include at least one of copper chloride, copper sulfide, copper sulfate, copper nitride, copper nitrate, copper hydroxide, copper phosphate, copper phosphide, copper carbonate, and an organometallic compound of copper. The zinc compound may be a zinc salt, and includes at least one of zinc chloride, zinc sulfate, zinc sulfide, zinc nitrate, zinc nitride, zinc hydroxide, zinc phosphate, zinc phosphide, zinc carbonate, and an organometallic compound of zinc.

Depending on the solubility of the metal compound, the fluid containing the compound may be in an aqueous solution or an organic solvent. For example, silver nitrate is relatively soluble in distilled water, but is extremely insoluble in alcohol. Anhydrous copper sulfate is also soluble in water and insoluble in ethanol, and copper sulfate pentahydrate is very soluble in methanol. In addition, zinc chloride is also soluble in water, ethanol and acetone.

The concentration of the metal compound in the fluid is 0.1kg/l to 2kg/l at room temperature, or 0.1kg/l to 20kg/l when the fluid is heated to a temperature above room temperature but below its boiling point. The concentration required to produce an antibacterial effect after ion exchange depends on the time of application. The longer the application time, the lower the concentration required. For example, an application time of 60 seconds can achieve sufficient concentration when 0.1kg/l of silver nitrate is applied at a rate of 1l/h, whereas an application time of 5 seconds can produce a similar impregnation when the same concentration of silver nitrate is applied at a feed rate of 10 l/h. After the fluid containing the metal having the antibacterial property is deposited on the surface, the aqueous solution or the organic solvent in the fluid is evaporated, leaving only the metal compound on the surface of the glass object, which is converted into the metal ion. This applies to the case where the solvent does not evaporate completely before contacting the surface of the glass object, but as previously disclosed, in some embodiments the solvent evaporates on the way out of the nozzle and only the metal compound contacts the surface.

An annealing step 130 follows the application step 120. The annealing step 130 may be performed in an annealing furnace or any other type of furnace to provide an initial temperature of 500 ℃ to 950 ℃ depending on the glass transition temperature (Tg) of the glass, and then to reduce the initial temperature in a controlled manner to near ambient temperature. Annealing prevents the formation of tension due to simultaneous cooling of the body and the surface, thereby reducing internal stresses, which reduces brittleness and the probability of fracture. The annealing time and temperature depend on the size and composition of the glass object. Thus, the invention should not be limited by any particular annealing time or temperature. For example, a small marble requires little controlled annealing, a flat bottom cup with a thickness of 1cm can be annealed in a few hours, while a complex artwork with a maximum wall thickness of 10cm may require one or two days to anneal properly.

Annealing allows for ion exchange reactions, which are chemical reactions between two species. Each species consists of positively and negatively charged species, called ions, which are involved in the exchange of one or more ionic components. The larger metal ions, i.e., charged particles in the metal compound, migrate to the surface of the glass, replacing the smaller ions originally in the glass. Depending on the chemistry of the ions to be exchanged, ions in the metal compound on the surface can penetrate to the glass surface. As the glass cools, the reaction rate decreases until no ion exchange occurs. The cooling needs to be controlled to prevent the exchanged metal ions from penetrating into the bulk, but rather to leave the exchanged metal ions on the exposed surface so that the ion leaching can actively kill the bacteria in the final product. The metal ions obtained may even be unevenly distributed and cover less than 100% of the surface, as long as the distance of the islands (also called domains) is in the same range as the size of the bacterial cells to be acted on. The thickness of the obtained layer may be less than 10nm, which is transparent to the human eye, rather than the yellow color that appears in the case of silver. However, if the obtained particle size exceeds 10nm, the concentration of the particles is important because the human eye cannot detect a faint yellow color when the islands are far apart. In order to obtain complete surface coverage and to ensure that the bacterial cells are always in contact with silver ions, these islands may even be spaced 1 μm apart, since typical bacterial cell sizes are typically in the range of 1 μm to 5 μm.

And annealing to obtain the finished antibacterial glass product, and then naturally cooling, wherein the natural cooling means that the glass object is automatically cooled to the ambient temperature without extra help. Ambient temperature may refer to room temperature. The glass object may be cooled in an open space outside the annealing furnace or in a furnace, the furnace being cooled together with the glass object while the glass object is in the furnace.

Fig. 2 and 3 show schematic views of a spray application unit 1 of a glass manufacturing apparatus according to some embodiments. The apparatus comprises a spray application unit 1 configured to apply a fluid containing a metal having antimicrobial properties to a glass object 14. The glass object 14 shown in fig. 2 and 3 may be, for example, a flat-bottomed cup. The spray application unit 1 comprises a transport unit 10 for transporting the glass objects 14, a frame 11 and at least one nozzle 13 attached to the frame 11, which nozzle 13 is configured to spray a fluid containing a metal having antimicrobial properties onto the glass objects 14.

Fig. 2 shows a side view of the device according to an embodiment, wherein the nozzles 13 are attached to the ceiling of the frame 11 and arranged to spray from above towards the glass objects 14.

Fig. 3 shows a top view of the device according to another embodiment, wherein the nozzles 13 are attached to the side walls of the frame 11 and arranged to spray from both sides towards the glass object 14. In some embodiments, the nozzles 13 may be attached to the ceiling and the sidewalls of the frame 11.

The transport unit 10 is arranged to transport the glass objects 14 to the spray application unit 1 and to transport the glass objects 14 from the spray application unit 1 or within the spray application unit 1. The transport unit 10 may be, for example, a robot for gripping glass objects or an actuator for moving the conveyor 12 with a belt or chain. The conveyor 12 may be located within the frame 11 with the glass objects 14 disposed through the frame 11. Conveyor 12 may also include a rotatable platform on which glass objects 14 are placed. When the glass object 14 reaches the vicinity of the nozzle 13, the platform is arranged to rotate, thereby rotating the glass object 14 around the central axis of the glass object 14 such that the side of the glass object 14 is uniformly sprayed.

The nozzle 13 is located in a pressurized system or an ultrasonic evaporator. The nozzles 13 are arranged to eject fluid at a flow rate of 0.1 to 10 l/h. The preferred spray time is 5 seconds to 60 seconds, most preferably 5 seconds to 30 seconds. The pattern type of the nozzle 13 in fig. 2 may be a solid cone shape, and the pattern type of the nozzle 13 in fig. 3 may be a flat fan shape. The applied fluid comprises at least one of a silver compound, a copper compound, and a zinc compound, and more preferably comprises silver nitrate.

The apparatus for antimicrobial glass products may also include a forming unit configured to form the glass object. The forming unit may be machine-assisted or manually-assisted and includes at least a melting furnace for heating the glass batch material to or above a melting temperature and a forming device for imparting a shape to the glass object. The forming means may be a die or a blow tube or the like using manual forming.

A flame polishing unit may be disposed after the glass forming unit, and the flame polishing unit is configured to smooth a surface of the glass object. The flame polishing apparatus includes a flame polishing machine that can generate a flame in a range of 2400 ℃ to 3300 ℃. This can be achieved, for example, by combining oxygen with hydrogen and feeding the combination to a precision flame nozzle. However, in some embodiments, a flame polishing unit is not necessary, or is combined with the spray application unit 1.

The annealing unit may be arranged after the application unit and comprises an annealing furnace or furnace configured to reduce the surface temperature of the glass object from slightly above Tg to ambient temperature in a controlled manner. The lehr may be electrically powered and include a conveyor belt and an entrance and an exit. The time that the glass object passes from the entrance to the exit defines the annealing time. The annealing furnace may also be closable with one opening.

A metal compound, such as silver nitrate, is dissolved in 5% to wt in deionized water. When the glass object comes out of the flame polishing unit, a liquid containing a metal having an antibacterial property is atomized at a rate of 1l/min by pneumatic air in the nozzle 13, and a metal compound is deposited on the surface of the rotating glass object 14. There may be six individual nozzles 13 (as shown in fig. 3) in three consecutive stations, wherein one station includes one nozzle 13 on one side and another nozzle 13 on the opposite side. The nozzle 13 is placed 10cm from the surface of the glass object 14 so that the spray is deposited on the entire outer surface of the glass object 14. The glass object 14 is rotated about its central axis by the rotatable platform for 5 seconds at each station. After deposition, the glass object 14 is placed on an annealing lehr. The temperature and residence time of the lehr are adjusted according to the wall thickness of the glass objects 14 so that the objects can be properly annealed.

In some embodiments, additional cooling units may be provided. The cooling unit may be a storage space to provide convective heat exchange from the glass object to ambient temperature. In some embodiments, the cooling unit and the annealing unit may be combined such that the glass object is cooled within the annealing furnace as the furnace cools.

The final glass product has a thin antimicrobial layer that is transparent to the human eye. The disclosed method is faster and more cost effective than conventional methods for making antimicrobial glass products from molten glass.