Claims:WE CLAIM:

1. A double chamber apparatus 100 for three-dimensional printing comprising:
a build chamber 106 configured to print three-dimensional prints in a heated environment, wherein, the build chamber 106 allows diffusion of a controlled amount of air into the said build chamber 106 and wherein, the build chamber 106 comprises an extrusion system;
an outer chamber 103 configured to diffuse the controlled amount of air into a build chamber 106 and maintain the temperature of air in the outer chamber 103 at a specified lower value compared to the temperature of air in the build chamber 106, wherein the build chamber 106 is inside the outer chamber 103, and wherein the outer chamber 103 comprises of a gantry system 104, 105;
an environment control system 101 configured to adjust the incoming air from the ambient for predefined environmental parameters, wherein said environment control system 101 draws in air from the ambient and supplies the air to the outer chamber 103;
a raw material compartment 102 configured to feed raw material into the build chamber 106; and
an electronic bay 107 configured to provide electronic input to the apparatus 100 and thereby control the operation of said apparatus 100, and wherein the electronic bay 107 comprises various electronic components including a processor coupled with a memory;
wherein, the memory is fed with a plurality of executable instructions and information along with other parameters, about a part to be three dimensionally printed and wherein, the processor coupled with the memory is configured to execute said instructions in order to create the required three-dimensional print inside the build chamber 106;
wherein, the environment control system 101 adjusts the incoming air from the ambient to predefined environmental parameters and sends the air to the outer chamber 103 through an air compressor 406;
wherein, the air from the outer chamber 103 is diffused into the build chamber 106 and heated in the build chamber 106 via plurality of heating elements and wherein, the raw material compartment 102 feeds the raw material into the build chamber 106 and further, the extrusion system extrudes the raw material after melting and lays down the raw material, with the help of the gantry system 104, 105, in the build chamber 106, to create the required part of the three-dimensional print; and
wherein, such a double chamber formed of the outer chamber 103 and build chamber 106, facilitates temperature balancing in the three-dimensional printing apparatus 100 and allowing various components in the outer chamber 103 to operate optimally, preventing damage and wherein such controlling of environment in the three-dimensional printing apparatus 100 also facilitates in preventing a large host of issues including warping of the three dimensional printed parts and impurities getting added into said three dimensional printed parts, thereby allowing the apparatus 100 to create various high-grade three dimensional prints.

2. The double chamber apparatus 100 for three-dimensional printing of claim 1, wherein the heating elements comprise one or more ceramic heaters placed along the inner three vertical sides of the build chamber 106

3. The double chamber apparatus 100 for three-dimensional printing of claim 1, wherein the environment control system 101 comprises multiple components such as a dehumidifier 403, air filters 402, 404 for filtering dust, germs and gaseous contaminants.

4. The double chamber apparatus 100 for three-dimensional printing of claim 3, wherein the environment control system 101 is connected to the outer chamber 103 with transfer air duct 407 or air duct 405 through an air compressor 406 and inlet valve 401 and wherein, the environment control system 101 facilitates in preventing damages to internal and external components of the apparatus 100 while operating at high temperatures for an extended period of time.

5. The double chamber apparatus 100 for three-dimensional printing of claim 3, wherein the components of environment control system 101 are optionally off-the-shelf components designed for use in ambient temperature as opposed to more expensive components designed for use in high temperature, thereby effectively reducing the cost of the equipment.

6. The double chamber apparatus 100 for three-dimensional printing of claim 1, wherein the predefined environmental parameters comprise humidity, air purity and pressure.

7. The double chamber apparatus 100 for three-dimensional printing of claim 1, wherein the raw material compartment 102 holds raw material either in the form of filaments, pellets or like forms.

8. The double chamber apparatus 100 for three-dimensional printing of claim 7, wherein the raw material compartment 102 is environmentally controlled based on the predefined information fed in the memory, for ensuring the raw material is being kept at required environmental conditions before and during printing, thereby protecting the raw material from undergoing change in properties during printing due to exposure to moisture, temperature gradients, extended printing cycles and like parameters.

9. The double chamber apparatus 100 for three-dimensional printing of claim 1, wherein the air inside the outer chamber 103 is taken in from the ambient via an inlet valve 401 connected to the environment control system 101 and said air is released to the ambient via a pressure relief cum vent valve, connected to the outlet vent 303.

10. The double chamber apparatus 100 for three-dimensional printing of claim 9, wherein the outer chamber 103 is kept at a specified higher pressure compared to the ambient as a safety system to ensure a relatively positive leak to ambient if it happens in order to avoid dust/germs/impurities entering the print chamber or the build chamber 106.

11. The double chamber apparatus 100 for three-dimensional printing of claim 9, wherein the outer chamber 103 comprises air circulation systems 407, 303 and X and Y gantry system 105 and a Z axis gantry system 104 comprising of motors and linear guides.

12. The double chamber apparatus 100 for three-dimensional of claim 9, wherein walls of the outer chamber 103 are metallic such as of stainless steel or aluminum which can provide structural rigidity and airtightness and can also help radiate heat away from the air inside the outer chamber 103.

13. The double chamber apparatus 100 for three-dimensional of claim 9, wherein one or more air circulation vents or ducts 303 located on the outer chamber 103 allows travel of air to the outer chamber 103 from the environment control system 101 and from the outer chamber 103 to the ambient.

14. The double chamber apparatus 100 for three-dimensional of claim 1, wherein the air compressor 406 pumps in the air taken from the outlet of the environment control system 101 and further, pressurize and pump said air via a transfer duct 407 into the outer chamber 103 and wherein, the air compressor 406 is activated during the operations of the machine as per requirement to maintain the optimal pressure via a one-way valve between the air compressor 406 and outer chamber 103.

15. The double chamber apparatus 100 for three-dimensional printing of claim 9, the air from the outer chamber 103 is vented out to ambient via a one-way vent cum relief valve.

16. The double chamber apparatus 100 for three-dimensional printing of claim 1, wherein the moment when the air temperature in the outer chamber 103 goes beyond nominal settings, control of temperature is either done by venting hot air out via the pressure relief cum vent valve 303 and taking in fresh colder air or by removing heat by radiation and convection directly into ambient via radiators 408.

17. The double chamber apparatus 100 for three-dimensional printing of claim 1, wherein the build chamber 106 is thermally insulated to the outer chamber 103, excluding small diffusion leaks and wherein the build chamber comprises a base for laying the three-dimensional printed parts and insulated build chamber 106 can be heated up to 250°C.

18. The double chamber apparatus 100 for three-dimensional printing of claim 17, wherein the build chamber 106 is double walled 302 on four sides with a double walled chamber door in front and covered with a covered but retractable mechanism to allow the movement of gantry system 105 to contain air and heat.

19. The double chamber apparatus 100 for three-dimensional printing of claim 17, wherein the build chamber 106 comprise thermal insulation 301, along and in between two walls 302 of the build chamber 106 and on the top of the build chamber, wherein the thermal insulation 301 is deformable and has a reflective coating on the inner side of chamber 106 and insulative coating on outer side.

20. A double chamber method 500 for three- dimensional printing comprising:
feeding, via input means a plurality of executable instructions information about the three-dimensional part to be printed and other parameters to be used in a memory unit of apparatus 100, wherein a processor is coupled with the memory unit and wherein the processor is configured to execute instructions to perform required printing;
adjusting, via an environment control system 101, the incoming air from the ambient to predefined environmental parameters;
sending, via a transfer vent or duct 407 and air compressor 406, the air from the environment control system 101 to an outer chamber 103;
diffusing, via small diffusion leaks the air from the outer chamber 103 to a build chamber 106;
heating, via plurality of heating elements, the build chamber 106 as per requirement, thereby allowing heating the diffused air in the build chamber 106;
controlling, the temperature and pressure inside the apparatus 100 by allowing the air in outer chamber 103 to be maintained at a pre-set temperature, wherein the pre-set temperature is maintained by allowing the hot air to exit via pressure relief cum vent valve 303 and taking in cold air via inlet and/or radiating heat away from inside via radiators 408;
feeding, via a raw material compartment 102, raw material into the build chamber 106 for three-dimensional printing;
extruding, via an extrusion system, said raw material after the raw material reaches the melting temperature; and
moving, a gantry system 104, 105, to create a required three-dimensional print by laying down the melted raw material, layer by layer, on a base in the build chamber 106;
wherein, such a double chamber formed of the outer chamber 103 and build chamber 106, facilitates temperature balancing in the three-dimensional printing apparatus 100 and allowing various components in the outer chamber 103 to operate optimally, preventing damage and wherein such controlling of environment in the three-dimensional printing apparatus 100 also facilitates in preventing a large host of issues including warping of the three dimensional printed parts and impurities getting added into said three dimensional printed parts, thereby allowing the apparatus 100 to create various high-grade three dimensional prints.

Dated this 8th day of August, 2018

Priyank Gupta
Agent for the Applicant
IN/PA- 1454
, Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003
(As Amended by Patents Amendment Rules-2006)

COMPLETE SPECIFICATION

(See Section 10 and Rule 13)

Title of invention:
A DOUBLE CHAMBER APPARATUS AND METHOD FOR THREE-DIMENSIONAL PRINTING

APPLICANT:
Fabheads Automation Pvt. Ltd.
An Indian entity having address at:
IITM Incubation Cell, Third Floor,
IIT Madras Research Park, Kanagam Road,
Taramani, Chennai – 600113 (INDIA)

The following specification particularly describes the invention and the manner in which it is to be performed.
CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY

The present application does not claim priority from any other patent application.

TECHNICAL FIELD

The present subject matter described herein, in general, relates to a field of three-dimensional printing apparatus. In particular, the present subject matter is related to a three-dimensional printing apparatus and method with a double chamber process.

BACKGROUND

The three-dimensional (3D) printing industry encompasses many forms of technologies and materials. When most people think of 3D printing they are thinking of a simple desktop FDM (fused deposition modelling) printer but that’s not the entire picture. 3D printing can be divided into metal, fabrics, bio and a whole host of other industries. For this reason, it’s important to see it as a cluster of diverse industries with a myriad of different applications.
Manufacturers have long used 3D printers in their design process to create prototypes. Most common 3D printers build parts on heated beds with the parts exposed to ambient air during the process. These versions are simple and inexpensive. There exist some versions of printers which print parts inside a heated chamber. These setups solve most of the printing issues caused due to difference in temperature like ‘warping’ of parts that are being printed, a critical issue associated with ambient air printing.
But, when a higher grade part is to be made – like bioimplant grade or aerospace grade, the materials/parts are to be printed in an even more specialised controlled environment than just heating air to control dust and other impurities, control germs, control humidity, control temperature, and maintain precision. The current heated chamber setups lack such additional environmental controls which restrict it from being used for critical parts in fields such as biomedical and aerospace. To overcome this drawback there are two options:
• Require the equipment to be placed and work only in a clean room environment
• Or incorporate the environment control systems directly into the heated chamber with air of very high temperature
But, both of these options are very expensive because:
• Setting up a clean room just to print a small part inside a machine is of course extremely cost intensive
• An environment control system like air purifier, humidity control, germ removal, etc on a hot air environment is not really an easily available off-the-shelf component and tend to be expensive to be custom developed.
Therefore, there is a long-standing need of a three-dimensional printing apparatus and method which is inexpensive and can cater to niche requirements like in biomedical, aerospace, etc.

SUMMARY
This summary is provided to introduce concepts related to a double chamber apparatus and method for three-dimensional printing. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.
In one implementation, a double chamber apparatus for three-dimensional printing is illustrated in accordance with the present subject matter. In one embodiment, the three-dimensional printing apparatus may comprise a build chamber configured to print three-dimensional prints in a heated environment, wherein, the build chamber allows diffusion of a controlled amount of air into the said build chamber. Further, the apparatus may comprise an outer chamber configured to diffuse the controlled amount of air into a build chamber and maintain the temperature of air in the outer chamber at a specified lower value compared to the temperature of air in the build chamber. The build chamber may be inside the outer chamber, and wherein the outer chamber may comprise a gantry system. The apparatus may further comprise an environment control system configured to adjust the incoming air from the ambient for predefined environmental parameters. The environment control system draws in air from the ambient and supplies the air to the outer chamber. The apparatus may furthermore comprise a raw material compartment configured to feed raw material into the build chamber, and wherein the build chamber comprises an extrusion system. Further, the apparatus may comprise an electronic bay configured to provide electronic input to the apparatus and thereby control the operation of said apparatus. The electronic bay may comprise various electronic components including a processor coupled with a memory. The memory is fed with a plurality of executable instructions and information along with other parameters, about a part to be three dimensionally printed. The processor coupled with the memory is configured to execute said instructions in order to create the required three-dimensional print inside the build chamber. The environment control system may adjust the incoming air from the ambient to predefined environmental parameters and sends the air to the outer chamber through an air compressor. The air from the outer chamber may be diffused into the build chamber and heated in the build chamber via plurality of heating elements. The raw material compartment may feed the raw material into the build chamber and further, the extrusion system may extrude the raw material after melting and lays down the raw material, with the help of the gantry system in the build chamber, to create the required part of the three-dimensional print. Such a double chamber formed of the outer chamber and build chamber, may facilitate temperature balancing in the three-dimensional printing apparatus and allowing various components in the outer chamber to operate optimally, preventing damage. Such controlling of environment in the three-dimensional printing apparatus also facilitates in preventing a large host of issues including warping of the three-dimensional printed parts and impurities getting added into said three dimensional printed parts, thereby allowing the apparatus to create various high-grade three-dimensional prints.
In another implementation, a double chamber method for three- dimensional printing apparatus comprising is illustrated in accordance to the present subject matter. The method may comprise feeding, via input means a plurality of executable instructions information about the three-dimensional part to be printed and other parameters to be used in a memory unit of apparatus, wherein a processor is coupled with the memory unit and wherein the processor is configured to execute instructions to perform required printing. The method further may comprise adjusting, via an environment control system, the incoming air from the ambient to predefined environmental parameters. The method may furthermore comprise sending, via a transfer vent or duct and air compressor, the air from the environment control system to an outer chamber. The method further may comprise diffusing, via small diffusion leaks the air from the outer chamber to a build chamber. The method furthermore may comprise heating, via plurality of heating elements, the build chamber as per requirement, thereby allowing heating the diffused air in the build chamber. The method may further comprise controlling, the temperature and pressure inside the apparatus by allowing the air in outer chamber to be maintained at a pre-set temperature, wherein the pre-set temperature is maintained by allowing the hot air to exit via relief cum vent valve and taking in cold air via inlet and/or radiating heat away from inside via radiators. The method may comprise feeding, via a raw material compartment, raw material into the build chamber for three-dimensional printing. The method may further comprise extruding, via an extrusion system, said raw material after the raw material reaches the melting temperature. The method may furthermore comprise moving, a gantry system to create a required three-dimensional print by laying down the melted raw material, layer by layer, on a base in the build chamber. Such a double chamber formed of the outer chamber and build chamber, facilitates temperature balancing in the three-dimensional printing apparatus and allowing various components in the outer chamber to operate optimally, preventing damage. Such controlling of environment in the three-dimensional printing apparatus also facilitates in preventing a large host of issues including warping of the three-dimensional printed parts and impurities getting added into said three-dimensional printed parts, thereby allowing the apparatus to create various high-grade three-dimensional prints in a very economical way.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.
Figure 1 illustrates, a double chamber apparatus 100 for three-dimensional printing, in accordance with the present subject matter.
Figure 2 illustrates, a block diagram 200 of a double chamber apparatus 100 for three-dimensional printing, in accordance with the present subject matter.
Figure 3 illustrates, a detailed view 300 of the various components and parts of a double chamber apparatus 100 for three-dimensional printing.
Figure 4 illustrates, an internal block diagram 400 of the components and related processes involved in the environmentally controlled 3D printing process of the double chamber apparatus 100 for three-dimensional printing.
Figure 5 illustrates, a double chamber method 500 with the included steps for the for three-dimensional printing.

DETAILED DESCRIPTION

Reference throughout the specification to “various embodiments,” “some embodiments,” “one embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment,” or “in an embodiment” in places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.
Referring now to figure 1, a double chamber apparatus 100 for three-dimensional printing is illustrated in accordance to the present subject matter. Existing three-dimensional printing apparatuses comprise heated chamber setups but lack in additional environmental controls such as control of dust, impurities, germs, humidity, etc. along with temperature. This restricts the existing 3D printing devices from being used for critical parts in fields such as biomedical and aerospace. The existing devices have to be either placed and operated only in a clean room environment which is extremely cost-intensive, or such control systems have to be incorporated into the existing heated chamber but have to be custom developed as the air inside is in elevated temperature and is therefore again expensive. The present double chamber apparatus 100 for three-dimensional may comprise of all these environment controls which can be purchased off-the-shelf for not so high temperatures and incorporated into a double chamber process, thereby avoiding the need of placing the machine in a clean room environment or using very expensive components.
In one embodiment, the double chamber apparatus 100 for three-dimensional printing may comprise an environment control system 101, raw material compartment 102, outer chamber 103, Z gantry 104, X and Y gantry 105, build chamber 106 and electronic bay 107. Said figure 1 may illustrate a double chamber concept, where, inside the outer chamber 103, all environment control may be performed by dehumidifying, purifying and pressurizing the air in the inner chamber 106. Further, heating of air alone may be performed and in effect by controlling the direction of air flow from one chamber to another may offer an extremely simple and inexpensive apparatus that offers huge possibilities. In one embodiment, the environment control system 101 may be located on top of the outer chamber 103. The environment control system 101 may comprise of multiple components like a dehumidifier, air filters (for dust, germs and gaseous contaminants), compressor, etc. which are connected to the outer chamber 103 via an inlet air duct. The raw materials may be fed from a separate raw material compartment 102, wherein said raw material compartment 102 may also be environment controlled. Raw material compartment 102 holds raw material in form of filaments, pellets, etc. The raw material compartment 102 may be located above the outer chamber 103 and adjacent to the environment control system 101. Further, the electronic bay 107 may be located below the outer chamber 103. The electronic bay 107 consists of all the electronic components which can include the processors coupled with memory storage, controllers, drivers, power distributors, etc. which facilitate in providing electronic input and control for operating of the apparatus. The locations of all components of the three-dimensional printing apparatus 100 with a double chamber process including the environment control system 101, the raw material compartment 102 and the electronic bay 107 can be changed as per requirement and is not necessarily fixed to the locations shown in the illustration.
As previously described, for environmental control systems to be integrated into a single chamber 3D printing setup which exists presently, components may be required for control of predefined environmental parameters such as humidity, air purity and air pressure. These components of an environment control system 101 will be very expensive as they would need to be designed to be operated at elevated temperatures for extended periods of time. In the three-dimensional printing apparatus 100, the effective cost of these components is significantly lower as they need not be operated at elevated temperatures and need not be designed for such. These, optionally off-the shelf components which are part of the environment control system 101 may be placed outside the heated build chamber 106 and is therefore, not subjected to higher temperatures. This may enable the use of environment control systems 101 designed for ambient temperature use, which are not cost-intensive and effectively lowers the cost of the equipment. Referring now to figure 2 and figure 3, a block diagram 200 and various components/parts of a double chamber apparatus 100 for three-dimensional printing are illustrated in accordance with the present subject matter. In one embodiment, the block diagram 200 comprises an inner chamber or build chamber 106 which may provide a heated environment, and an outer chamber 103 which may facilitate controlled humidity, purity and other environmental aspects as required. The outer chamber 103 may be a component which is coupled with multiple environment control systems. The outer chamber 103 may be leak proof to ambient but can lose heat to ambient easily which allows the air inside the outer chamber 103 to be at a specified lower temperature compared to the inner chamber 106, wherein the three-dimensional printing actually happens in the inner chamber 106, wherein a higher temperature may be maintained in the inner chamber 106. The environment control system 101 may draw air from the ambient and supply said air to the outer chamber 103 as required, and thereby avoids the needs for the environment control systems 101 to be compatible for operation with air of high temperature. Now referring to figure 3, when the apparatus 100 may be turned on and used for 3-dimensional printing, the outer chamber 103 may be configured to diffuse the air (via many air gaps to the inner chamber segment 106) into the inner chamber or build chamber 106. Further, the air from the build chamber 106 may also diffuse into the outer chamber to some extent. The outer chamber 103 may be tightly leak proofed with seals on its edge surfaces to ambient. All the air inside the outer chamber 103 may be taken in from the ambient only via an inlet valve 401 (shown in figure 4) connected to the environment control system 101 and can be released to the ambient only via a pressure relief cum vent valve 303 coupled with the outlet vent 303. The outer chamber 103 may be kept at a specified higher pressure compared to ambient as a safety system to ensure a relatively positive leak to ambient if it happens in order to avoid dust, germs and impurities from entering the print chamber or the build chamber 106. The outer chamber 103 can easily radiate heat away into the ambient, thereby, the temperature of air in the outer chamber 103 may be at a specified lower value compared to the inner chamber or build chamber 106. Such lower temperature in the outer chamber may allow effective use of off-the-shelf environment control systems offering economical advantage.
In one embodiment, the inner chamber or the build chamber 106 may be kept relatively less leak proofed wherein only a controlled amount of air can diffuse to the outer chamber 103. Therefore, the inner chamber’s 106 air may always be one which has been environmentally controlled. Any loss of heat by losing hot air into the outer chamber 103 may be replenished by more heat being added from the heaters inside the inner chamber or build chamber 106. The build chamber 106 may be thermally insulated to the outer chamber 103 excluding very small diffusion leaks. Therefore, the inner chamber 106 offers an economical advantage. Therefore, both the outer chamber 103 and build chamber 106 may be configured to form a double chamber system wherein said double chamber system may offer a much higher efficiency and allows 3D printing to proceed in a much more economical way. The 3D Printing may occur inside an insulated build chamber 106 (inner chamber) which can be heated up to 250°C. Said chamber 106 may be double walled 302 on four sides with a double walled chamber door in the front and covered with a retractable mechanism to allow for the movement of gantry system 105 to contain air and heat. In one embodiment, the build chamber 106 may comprise of one or more heating elements and thermal insulation 301. The thermal insulation may be along the walls wherein, an air gap or any insulating material may be placed between the two walls 302 of the build chamber 106. Along the top of the build chamber 106, there may be a deformable thermal insulation 301 to cover the build chamber 106 from top, wherein the deformable thermal insulation 301 may have a reflective coating on the inner side of chamber 106 and insulative coating on outer side. In one embodiment, heating elements in the chamber 106 may comprise of one or more ceramic heaters placed along the inner three vertical sides of the chamber 106 (except the side with the door access). The build chamber 106 may comprise an extrusion system which melts and extrudes the raw material.
In one embodiment, the outer chamber 103 may comprise of an X and Y gantry system 105 and an Z axis gantry system 104 comprising of motors and linear guides. The outer chamber 103 further may comprise of the inner (Build) chamber 106, and air circulation systems 407, 303. The walls of the outer chamber 103 may be metallic such as of stainless steel or aluminum which can provide structural rigidity and airtightness and can also help radiate heat away from the air inside the outer chamber 103.
The air in the outer chamber 103 may undergo humidity control, germ control and air impurities control based on the information fed into the apparatus 100 directly or through a storage media. The outer chamber 103 may be assembled onto the frame of the apparatus 100 and may be ensured to be air tight with seals/sealants as per requirement. In one embodiment, one or more air circulation vents or ducts 303 on the top of the outer chamber 103 may allow travel of air with the environment control systems 101 placed outside the chamber 103 and with the ambient. The outer chamber 103 may significantly reduce flow of heat from the build chamber 106 directly into ambient air. The average temperature in the outer chamber 103 may be much lower compared to the temperature inside the inner chamber 106. This temperature balancing may allow components in the outer chamber 103 like motors and linear guides to operate optimally.
Referring to figure 4, an internal block diagram 400 of the components and related processes involved in the environmentally controlled 3D printing process of the double chamber apparatus 100 for three-dimensional printing is illustrated in accordance to the present subject matter. In one embodiment, the air inlet to the apparatus 100 may be taken into the entry of environment control system 101 comprising dust filter 402, further a dehumidifier 403, furthermore any other special air filters 404. The output of the system 101 may be directly connected to the input of an air compressor 406 with an air duct 405. The air compressor 406 may drive the air from ambient through the environment control systems 101. The air compressor 406 may pump in the air taken in from the outlet of the environment control systems 101 and pressurise and pump said air via a transfer duct 407 into the outer chamber 103. The air compressor 406 can be activated anytime during the operations of the machine as per requirement to maintain the optimal pressure and the pressure is maintained via a one-way pressure relief cum vent valve 303 between the air compressor 406 and outer chamber 103.

The air from the outer chamber 103 can be vented out to ambient at any time via a one-way pressure relief cum vent valve 303 from the outer chamber 103 to ambient directly. Said valve can be activated anytime electronically. As a safety, the valve also vents the air out beyond a certain pressure as a relief mechanism.

When the air temperature in the outer chamber 103 may go beyond nominal settings, control of temperature can be done by two mechanisms – (a) by venting hot air out via the pressure relief cum vent valve 303 and taking in fresh colder air; and (b) by removing heat by radiation and convection directly into ambient via radiators 408 which may or may not be aided by heat conducting liquid to transfer heat from outer chamber 103 to radiators 408.
Fabrication of a part will only begin once the required environmental conditions of temperature, pressure, humidity, purity, etc. may be reached. As the raw material compartment 102 can also be environmentally controlled if required, and it ensures that the raw material itself is kept at the required conditions before and during printing. This protects the raw material from undergoing change in properties during printing due to exposure to moisture, temperature gradients, etc. Such an environmental control is a very important feature of the machine which helps protect the raw material during extended printing cycles, without which, they have to be separately packed and protected under certain conditions before printing.

During printing, the double chamber process only allows environmentally controlled air to be in contact with the part or object being 3D printed. This prevents a large host of issues such as warping of parts and dimensional changes due to temperature gradients, impurities getting lodged into the part, moisture trapped inside voids or other internal spaces, etc. The environmental controls allow the apparatus to create high-grade parts which is equal to the standards achieved if the fabrication was done inside of a clean room environment.

A secondary benefit of using an environment controlled outer chamber 103 is the protection of critical internal components from external elements. As the machine operates at high temperatures for extended periods of time, there is a high chance of mechanical components such as bearings, rails, guides, etc. along with electrical and electronic components such as motors, encoders, connectors, etc. from getting affected due to the temperature itself, and due to the presence of moisture and impurities. The environmental controls prevent damage to such components by keeping them at optimal operating conditions as printing proceeds. This reduces the amount of preventive maintenance required and chances of corrective maintenance requirements, thereby reducing maintenance expenses considerably.
Referring now to figure 5, a double chamber method 500 for three-dimensional printing is illustrated in accordance with the present subject matter. In a preferred embodiment, once the double chamber apparatus 100 for three-dimensional printing is started, at step 501, a memory unit in the apparatus 100 may be fed, via input means such as a portable media storage or like means, with plurality of executable instructions and information about the part to be printed and other parameters to be used, wherein a processor may be coupled with the memory unit and the processor is configured to execute instructions to perform required printing. For example, in the case of using ABS (Acrylonitrile Butadiene Styrene) as the raw material for 3D printing, extrusion temperature may be around 210 to 260°C, temperature of the base on which a part is printed may be ranging from 90-120°C and the build chamber 106 temperature may be 50-70°C. The pressure, in the chamber 106 may be set at 1.1 bar, and humidity at 30% via the information fed in the memory unit. Based on the information fed, the build chamber 106 and the constituent base may be heated. These temperature settings may be different for different materials that will be printed and different for even different grades of the same material which will be calibrated for different print settings. The environment control system 101 may be connected to the outer chamber 103 with transfer air ducts 407 or vents. At step 502, in the environment control system 101, the incoming air from the ambient may be adjusted to predefined environmental parameters such as but not limited to, humidity, purity and pressure with regard to different systems. Once the required conditions are met, at step 503, the air may be sent into the outer chamber 103 via the transfer vent or duct 407 and the air compressor 406. At step 504, the air may then diffuse into the build chamber 106, through small diffusion leaks (not shown in the figure). At step 505, the build chamber 106 may be heated as per requirement, with heating elements such as ceramic heaters, thereby heating the diffused air in the build chamber 106. In one embodiment, the build chamber 106 may be thermally insulated but may not be completely air tight. At step 506, in case optimal environmental settings are exceeded in the outer chamber 103, an electronically controlled pressure relief cum vent valve connected to an outlet duct or vent 303 may be activated to reduce and control temperature and pressure. Temperature in the outer chamber 103 may also be reduced by the use of radiators 408 which can dissipate heat into the ambient air. Once all the required environmental conditions of temperature, pressure, humidity and purity are met and an operable steady state achieved, at step 507, the raw material may be fed from the raw material compartment 102 into the build chamber 106 for three-dimensional printing. At step 508, said raw material is then heated via the extrusion system (not shown in figure) in the build chamber 106 until the raw material may reach the melting temperature and is then extruded. At step 509, the gantry systems 104 and 105 may move the attached extrusion system according to the fed information and may lay down material layer by layer to create a part of the 3D print.
Although implementations of an apparatus 100 and method 500 for three-dimensional printing have been described in language specific to structural features and/or methods, it is to be understood that the appended claims are not necessarily limited to the specific features or methods described. Rather, the specific features are disclosed as examples of a double chamber apparatus and method for three-dimensional printing.