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Title:
A METHOD AND APPARATUS FOR 3D PRINTING OF QUARTZ GLASS
Document Type and Number:
WIPO Patent Application WO/2018/002001
Kind Code:
A1
Abstract:
The present invention provides a method for 3D printing of quartz glass, the method at least comprising the steps of: (a) feeding solid quartz glass (5) as a (semi-)continuous phase such as a rod or a wire through a nozzle (2) having an inlet (3) and an outlet (4), wherein the nozzle (2) is cooled during the feeding of the glass therethrough; (b) melting the solid glass (5) after exiting the outlet (4) of the nozzle (2) using one or more heaters (7), thereby obtaining melted glass (5A); (c) depositing a first layer of melted glass on a surface (11); (d) allowing the first layer of melted glass as deposited in step (c) to at least partly solidify; (e) depositing a second layer of melted glass on the at least partly solidified first layer; and (f) repeating the steps of depositing of melted glass thereby obtaining a pre-defined quartz glass object.

Inventors:
DE MARIE JOHANNES CHRISTIAAN (NL)
MIZEE ALBERTUS PAULUS (NL)
VAN DER MEER RIK (NL)
Application Number:
PCT/EP2017/065776
Publication Date:
January 04, 2018
Filing Date:
June 27, 2017
Export Citation:
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Assignee:
SHELL INT RESEARCH (NL)
SHELL OIL CO (US)
International Classes:
C03B19/01; B33Y10/00; B33Y30/00; C03B19/02; C03B20/00; C03B23/20
Foreign References:
US20040116269A12004-06-17
US6216492B12001-04-17
US5578227A1996-11-26
GB2134896A1984-08-22
ES2368079A12011-11-14
US20160031159A12016-02-04
EP0426363A21991-05-08
US5578227A1996-11-26
US20040116269A12004-06-17
Other References:
WANG P W ET AL: "Glass and hot extrusion by ME module for 3D additive manufacturing", 2016 IEEE INTERNATIONAL CONFERENCE ON INDUSTRIAL TECHNOLOGY (ICIT), IEEE, 14 March 2016 (2016-03-14), pages 1167 - 1171, XP032904083, DOI: 10.1109/ICIT.2016.7474920
Attorney, Agent or Firm:
MATTHEZING, Robert, Maarten (NL)
Download PDF:
Claims:
C L A I M S

1. A method for 3D printing of quartz glass, the method at least comprising the steps of:

(a) feeding solid quartz glass (5) as a (semi-) continuous phase such as a rod or a wire through a nozzle (2) having an inlet (3) and an outlet (4), wherein the nozzle (2) is cooled during the feeding of the glass therethrough;

(b) melting the solid glass (5) after exiting the outlet (4) of the nozzle (2) using one or more heaters (7), thereby obtaining melted glass (5A) ;

(c) depositing a first layer of melted glass on a surface (11) ;

(d) allowing the first layer of melted glass as deposited in step (c) to at least partly solidify;

(e) depositing a second layer of melted glass on the at least partly solidified first layer; and

(f) repeating the steps of depositing of melted glass thereby obtaining a pre-defined quartz glass object.

2. The method according to claim 1, wherein the solid glass (5) as fed in step (a) melts at a temperature of at least 800°C (at atmospheric pressure), preferably at least 1000°C, more preferably at least 1500°C.

3. The method according to claim 1 or 2, wherein the solid glass (5) as fed in step (a) comprises at least 75 vol.% silica (S1O2) , preferably at least 90 wt.%, more preferably at least 95 vol.%, even more preferably at least 99 vol.%.

4. The method according to any of the preceding claims, wherein the solid glass (5) is melted in step (b) in a focal heating zone (6) defined by two or more heaters

(7) .

5. The method according to claim 4, wherein the focal heating zone (6) is placed at a distance of less than 2.0 cm from the outlet (4) of the nozzle (2), preferably less than 1.0 cm, more preferably less than 0.5 cm.

6. The method according to any of the preceding claims, wherein during the depositing of the second layer of melted glass on the at least partly solidified first layer in step (e) , the first layer is at least partly re- melted .

7. An apparatus (1) for performing the method according to any of the preceding claims for 3D printing of quartz glass, the apparatus (1) at least comprising:

- a nozzle (2) for feeding solid quartz glass (5), the nozzle (2) having an inlet (3) and an outlet (4), wherein the nozzle (2) comprises a coolant channel (8) to allow heat exchanging contact with a coolant flowing through the channel (8) during use of the apparatus (1); and

- a focal heating zone (6) for melting glass, wherein the focal heating zone (6) is arranged downstream of the outlet (4) of the nozzle (2) and wherein the focal heating zone (6) is defined by two or more heaters (7) .

8. The apparatus (1) according to claim 7, wherein the focal heating zone (6) is placed at a distance of less than 2.0 cm from the outlet (4) of the nozzle (2), preferably less than 1.0 cm, more preferably less than

0.5 cm .

9. The apparatus (1) according to claim 7 or 8, wherein the two or more heaters (7) comprise hydrogen burners.

Description:
A METHOD AND APPARATUS FOR 3D PRINTING OF QUARTZ GLASS

The present invention relates to a method for 3D printing of quartz glass.

In recent years, 3D printing of materials has

attracted a lot of attention. In 3D printing successive layers of material are formed and deposited, typically under computer control, to create a pre-defined object. These objects can be of a variety of shapes or geometries and are typically produced from a 3D model or electronic data source.

There is a continuous desire for providing new methods of 3D printing, in particular for materials such as quartz glass that are difficult to process otherwise.

US5578227 discloses a prototyping system that is based on fusion of a thin feedstock of metal and non- metal materials which have various profiles, for example a rectangular wire. Quartz glass has not been mentioned.

US20040116269 discloses a process for producing a highly durable silica glass ingot (i.e. a cast into a shape) comprising simultaneously falling a finely divided silica powder and a finely divided zirconium-containing substance in a furnace using oxyhydrogen flame as heat source to form an accumulated layer of zirconium- containing silica on a bottom of the furnace; and

extending the accumulated layer to outwardly radial directions, to form an ingot wherein zirconium is

uniformly dispersed in a silica glass matrix.

A problem associated with 3D printing of materials such as quartz glass is that high temperatures are needed. As a result, the printer components also need to be able to withstand such conditions. Consequently, objects made from materials such as quartz glass are typically still formed using conventional glassblowing techniques .

It is an object of the present invention to overcome or minimize the above problem.

It is a further object of the present invention to provide an alternative method of 3D printing of glass, in particular quartz glass .

One or more of the above or other objects can be achieved by providing a method for 3D printing of quartz glass, the method at least comprising the steps of:

(a) feeding solid quartz glass as a (semi-) continuous phase such as a rod or a wire through a nozzle having an inlet and an outlet, wherein the nozzle is cooled during the feeding of the glass therethrough;

(b) melting the solid glass after exiting the outlet of the nozzle using one or more heaters, thereby obtaining melted glass;

(c) depositing a first layer of melted glass on a surface;

(d) allowing the first layer of melted glass as deposited in step (c) to at least partly solidify;

(e) depositing a second layer of melted glass on the at least partly solidified first layer; and

(f) repeating the steps of depositing of melted glass thereby obtaining a pre-defined quartz glass object.

It has surprisingly been found according to the present invention that the method allows for 3D printing of temperature-resistant materials such as quartz glass.

An advantage of the method according to the present invention is that 3D shapes or geometries can be obtained that cannot be achieved by conventional glassblowing techniques. A further advantage is that such shapes or geometries may be obtained in a quick and reproducible manner. Also, the method according to the present invention is particularly suited for glass objects having a small size, which are typically difficult to obtain using conventional glassblowing techniques.

An even further advantage of the method according to the present invention is that any toxic vapours that may occur during the heating of the quartz glass can be removed very locally, and in a simple manner, thereby improving the safety.

Also, it has been surprisingly found according to the present invention that the obtained quartz glass objects are less prone to thermal stress, which is in particular an issue for larger glass objects.

In step (a) , solid quartz glass is fed through a nozzle having an inlet and an outlet.

The nozzle according to the present invention is not particularly limited, but will typically be heat- resistant .

According to the present invention, the solid quartz glass is fed as a (semi-) continuous phase such as a rod or (possibly spooled) wire. Preferably, the solid glass as fed in step (a) is a glass rod.

The composition of the solid quartz glass is not particularly limited. Preferably, the solid quartz glass as fed in step (a) melts at a temperature of at least 800°C (at atmospheric pressure), preferably at least 1000°C, more preferably at least 1500°C. Further, it is preferred that the solid quartz glass as fed in step (a) comprises at least 75 vol.% silica (Si02) , preferably at least 90 vol.%, more preferably at least 95 vol.%, even more preferably at least 99 vol.%. According to the method of the present invention, the nozzle is cooled during the feeding of the glass

therethrough. This, to avoid melting of the nozzle in view of the proximity of the heaters. The person skilled in the art will readily understand that the cooling of the nozzle may be achieved in various ways. Preferably, the cooling of the nozzle is achieved by heat exchanging contact with a coolant such as water.

In step (b) , the solid glass is melted after exiting the outlet of the nozzle (i.e. outside the nozzle) using one or more heaters, thereby obtaining melted glass.

The person skilled in the art will readily understand that the one or more heaters are not particularly limited and can be selected from e.g. a laser, a CH4/O2 or H2/O2 burner, plasma, etc. Preferably at least a H2/O2 burner is present. Preferably, the solid glass is melted in step (b) in a focal heating zone defined by two or more heaters. According to an especially preferred embodiment, the focal heating zone is placed at a distance of less than 2.0 cm from the outlet of the nozzle, preferably less than 1.0 cm, more preferably less than 0.5 cm.

In step (c) , a first layer of melted glass is deposited on a surface. This surface may be any surface, but is typically chosen to allow easy removal of the pre- defined glass object as obtained in step (f ) . Suitable examples of surfaces are e.g. sintered glass, porous glass, ceramic, etc. Typically, the surface will have the same or similar thermal expansion coefficient as the glass that is deposited thereon. The depositing is typically done using computer control, as is common in 3D printing .

In step (d) , the first layer of melted glass as deposited in step (c) is allowed to at least partly solidify. Subsequently, in step (e) , a second layer of melted glass is deposited on the at least partly

solidified first layer.

Preferably, during the depositing of the second layer of melted glass on the at least partly solidified first layer in step (e) , the first layer is at least partly re- melted (using the one or more heaters) . Hereby, a good fusion of the first and second layers can be achieved; this good fusion of layers may be required for e.g. glass equipment as used in labs.

In step (f), the step of depositing of melted glass (as a fresh layer on the surface or on already deposited layers) is repeated thereby obtaining a pre-defined quartz glass object. The person skilled in the art of 3D printing will readily understand that this repeating in step (f) can be done as desired to obtain the pre-defined end shape of the glass object, including depositing fresh layers on the surface and/or further ( 'subsequent' ) layers on already deposited ( 'previous' ) layers. It goes without saying that, dependent on the shape of the pre ¬ defined quartz glass object, a subsequent (third, fourth, fifth, etc.) layer may be deposited on any of the previous (first, second, third, etc.) layers. Also, as above, the previous layer (s) may at least partly be re- melted (using the one or more heaters) when depositing a subsequent layer to achieve a good fusion of the previous and subsequent layers.

As the person skilled in the art of 3D printing is familiar with how to repeat the depositing steps

(typically using conventional computer control) , this is not further discussed here in detail.

In a further aspect, the present invention provides an apparatus for performing the method according to any of the preceding claims for 3D printing of quartz glass, the apparatus at least comprising:

- a nozzle for feeding solid glass, the nozzle having an inlet and an outlet, wherein the nozzle comprises a coolant channel to allow indirect heat exchanging contact with a coolant flowing through the channel during use of the apparatus; and

- a focal heating zone for melting glass, wherein the focal heating zone is arranged downstream of the outlet of the nozzle and wherein the focal heating zone is defined by two or more heaters.

Preferably, the focal heating zone is placed at a distance of less than 2.0 cm from the outlet of the nozzle, preferably less than 1.0 cm, more preferably less than 0.5 cm.

Further, it is preferred that the two or more heaters comprise hydrogen (H2/O2) burners.

Hereinafter the invention will be further illustrated by the following non-limiting drawing. Herein shows:

Fig. 1 schematically a cross-sectional view of (part of) an apparatus suitable for performing the method for 3D printing of quartz glass according to the present invention .

Figure 1 shows a cross-sectional view of (part of) a 3D printer generally referred to with reference number 1.

The 3D printer 1 comprises a nozzle 2 (with an inlet 3 and an outlet 4) for feeding solid (i.e. quartz) glass 5 and a focal heating zone 6. The nozzle 2 comprises a coolant channel 8 for supplying and removing a coolant (such as water) to allow heat exchanging contact between the coolant and the nozzle 2 during use of the nozzle 2 (and thereby cooling the nozzle 2) . The focal heating zone 6 is defined by two or more heaters 7. In the embodiment of Fig. 1, the heaters comprise hydrogen (H2/O2) burners. To this end, the H2/O2 is fed through fuel inlet 9 and supplied to the focal heating zone 6 by means of fuel supply channels 10.

During use of the apparatus 1, the solid glass is fed as a quartz glass rod 5 through the nozzle 2 via inlet 3 and outlet 4 to a focal heating zone 6. Then, the solid glass 5 is melted after exiting the outlet 4 of the nozzle 2 using the heaters 7, thereby obtaining melted glass 5A, which is deposited on a surface 11. In the situation shown in Figure 1, already various layers of glass have been deposited on the surface 11, in line with steps (c)-(f) of the method according to the present invention. After further repeating of these steps, a pre- defined quartz glass object is eventually obtained.

As the person skilled in the art of 3D printing is familiar with how to repeat the depositing steps

(typically using conventional computer control) , this is not further discussed here in detail. When depositing further ( 'subsequent' ) layers, the already deposited

('previous') layer (s) may at least partly be re-melted (using the one or more heaters) when depositing a subsequent layer to achieve a good fusion of the previous and subsequent layers.

The person skilled in the art will readily understand that many modifications may be made without departing from the scope of the invention.