Patent Description:
Various features of the present disclosure will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate features of the present disclosure, and wherein:.

As shown in <FIG>, a three-dimensional (3D) printing system <NUM> (also referred to as an additive manufacturing system) according to one example comprises: a build unit, <NUM>, a 3D printer <NUM> and a material management station <NUM>. The material management station <NUM> may manage build material for one or more 3D printers and/or for one or more build units.

The build unit <NUM> is arranged to slot into a docking position in the printer <NUM> to allow the printer <NUM> to generate a 3D object within the build unit. The build unit is also arranged to also slot (at a different time) into a docking position <NUM> in the material management station <NUM>. The build unit <NUM> may be docked in the material management station <NUM> prior to a 3D printing process to load the build unit with build material in preparation for a subsequent 3D printing process that will be performed by the 3D printer <NUM>.

The build material loaded into the build unit may include recycled or otherwise recovered build material from one or more previous printing processes, fresh build material, or a mix of fresh and recovered build material. Some build materials may be non-recyclable and hence in this case no recovered build material will be used to load the build unit. The build material may be or include, for example, powdered metal materials, short fiber materials that may, for example, have been cut into short lengths from long strands or threads of material, powdered composited materials, powder ceramic materials, powdered glass materials, powdered resin material, powdered polymer materials and the like. In some examples where the build material is a powder-based build material, the term powder based materials is intended to encompass both dry and wet powder based materials, particulate materials and granular materials. In one example, the build material may be a powdered semi-crystalline thermoplastic material. It should be understood that the examples described herein are not limited to powder-based materials, and may be used, with suitable modification if appropriate, with other suitable build materials. In other examples, the build material may be in the form of pellets, or any other suitable form of build material, for instance.

Returning to <FIG>, the build unit <NUM> may also be docked in, or otherwise connected to, the docking position <NUM> in the material management station <NUM> (shown without the build unit <NUM> docked in <FIG>) to clean up at least some components of the build unit <NUM> after it has been used in a 3D printing production process. The clean-up process may involve recovery and storage in the material management station <NUM> of non-solidified build material from the previous print job for subsequent reuse. During a 3D printing process a portion of the supplied build material may be fused or otherwise bound to form the 3D object, whilst a remaining portion of the supplied build material may remain non-solidified or unbound and potentially recyclable, depending upon the type of build material used. Some processing of the non-solidified build material may be performed by the material management station <NUM> prior to storage for recycling, to reduce any agglomeration for example.

One material management station <NUM> can be used to service one or more different 3D printers, using one or more build units <NUM>. A given 3D printer may interchangeably be connected with one or more build units <NUM>, for example, utilizing different build units for different build materials. The material management station <NUM> can purge a build unit <NUM> of a given build material after a 3D printing production process, allowing it to be filled with a different build material for a subsequent printing production run. Purging of the build unit <NUM> may also involve purging of the material management station <NUM> or alternatively, it may involve separation of different build materials in the material management station <NUM> to limit contamination of one build material type with another.

The build unit <NUM> in this example has a build platform <NUM> on which an object being manufactured is constructed. The build unit <NUM> also comprises a build material store <NUM>, which is situated beneath a build platform <NUM> in this example. The build platform <NUM> may be arranged to have an actuation mechanism (not shown) allowing it, when it is docked in the printer <NUM> and during a 3D printing production process, to gradually move down, such as in a step-wise manner, towards the base of the build unit <NUM> as the printing of the 3D object progresses and as the build material store <NUM> within the build unit <NUM> becomes depleted. This provides progressively more distance between the base level of the build platform <NUM> and the print carriages (not shown) to accommodate the 3D object being manufactured. The size of an object being printed may increase progressively as it is built up layer-by-layer in the 3D printing process in this example.

The 3D printer <NUM> of this example can generate a 3D object by using a build material depositor carriage (not shown) to form layers of build material onto the build platform <NUM>. Certain regions of each deposited layer are solidified by the printer <NUM> to progressively form the object according to object-specifying data. The object-specifying data are based on a 3D shape of the object and may also provide object property data such as strength or roughness corresponding to the whole object or part(s) of the 3D object. In examples, the desired 3D object properties may also be supplied to the 3D printer <NUM> via a user interface, via a software driver or via predetermined object property data stored in a memory.

After a layer of the build material has been deposited on the build platform <NUM> by the printer <NUM>, a page-wide array of printheads on a carriage (not shown) of the 3D printer <NUM> can traverse the build platform <NUM> to selectively deposit an agent in a pattern based on where particles of the build material are to be solidified together. Once the fusing agent has been applied, the layer of build material may be exposed to fusing energy using one or more heating or curing elements (not shown) of the 3D printer <NUM>. The build material deposition, fusing agent and fusing energy application process may be repeated in successive layers until a complete 3D object has been generated. The material management station <NUM> may be used with any additive manufacturing technique and is not limited to printers using printheads on a carriage to deposit a printing agent as in the example described above. Chemical binder systems, such as BinderJet™, or metal type 3D printing may also be used. For example, the material management station <NUM> may be used with a selective laser sintering additive manufacturing technique.

According to one example, a suitable fusing agent may be an ink-type formulation comprising carbon black, such as, for example, the fusing agent formulation commercially known as V1Q60Q "HP fusing agent" available from HP Inc. In one example such a fusing agent may additionally comprise an infra-red light absorber. In one example such an ink may additionally comprise a near infra-red light absorber. In one example such a fusing agent may additionally comprise a visible light absorber. In one example such an ink may additionally comprise a UV light absorber. Examples of inks comprising visible light enhancers are dye based colored ink and pigment based colored ink, such as inks commercially known as CE039A and CE042A available from HP Inc. According to one example, a suitable detailing agent may be a formulation commercially known as V1Q61A "HP detailing agent" available from HP Inc. According to one example, a suitable build material may be PA12 build material commercially known as V1R10A "HP PA12" available from HP Inc.

<FIG> schematically illustrates the material management station <NUM> of the example of <FIG>, with the build unit <NUM> of <FIG> docked therein.

As shown in the example of <FIG>, the material management station <NUM> has two ports for receiving supply containers 114a, 114b, which may be releasably connectable to the material management station <NUM>. In one example, supply containers 114a, 114b may be of a first type such as a type referred to herein as "single-use", these being prefilled and non-user refillable supply containers (which may also referred to as cartridges) intended for a single dispensing of its contents, and/or a second type such as a type referred to herein as "bulk-refillable", these being refillable supply containers (which may also referred to as hoppers) that can be refilled from a larger bulk supply container, and dispense their contents many times over. A bulk-refillable supply container which may be refillable from a bulk supply of fresh build material, for example from a package of build material storing at least a multiple of times larger than the volume of the bulk-refillable supply container. The bulk-refillable supply container may include a refill port whereby fresh material can be introduced from one or more larger bulk supply containers or time and thus refilled.

The provision of two supply containers ports allows "hot swapping" to be performed such that if a currently active container becomes empty or close to empty of build material when the build unit <NUM> is being filled with build material by the material management station <NUM> in preparation for an additive manufacturing process, a fresh build material supply source can be dynamically changed to the other of the two containers. The fresh build material from the containers 114a, 114b, may be consumed, for example, when loading the build unit <NUM> with build material prior to the build unit <NUM> being installed in the printer <NUM> for a 3D printing production run.

A build unit use time, namely a time required for printing of a 3D object before build unit <NUM> can be reused, may depend upon both a printing time of a 3D object whilst the build unit <NUM> is in the printer <NUM> and a cooling time of the contents of the build volume of the build unit <NUM>. It will be understood that the build unit <NUM> can be removed from the printer <NUM> after the printing operation, allowing the printer <NUM> to be re-used for a further printing operation using build material within a different build unit before the total build unit use time has elapsed. The build unit <NUM> can be moved to the material management station <NUM> at the end of the printing time. A vacuum system can be used, in some examples, to promote more rapid cooling of the contents of the build volume following a 3D print production process than would otherwise occur without the vacuum system.

The material management station <NUM> in this example has a recovered build material tank <NUM> (see <FIG>), located internally, where build material recovered from the build unit <NUM> by the vacuum system is stored for subsequent reuse, if appropriate. Some build materials may be recyclable whilst others may be non-recyclable. In an initial 3D printing production cycle, <NUM>% fresh build material may be used. However, on second and subsequent printing cycles, depending upon build material characteristics and user choice, the build material used for the print job may comprise a proportion of fresh build material (e.g. <NUM>%) and a portion of recycled build material (e.g. <NUM>%). Some users may elect to use mainly or exclusively fresh build material on second and subsequent printing cycles, for example, considering safeguarding a quality of the printed object. The internal recovered build material tank <NUM> may become full during a post-production clean-up process, although it may become full after two or more post-production clean up processes have been performed, but not before. Accordingly, an overflow tank in the form of an external overflow tank <NUM> can be provided as part of the material management station <NUM> to provide additional capacity for recovered build material for use once the internal recovered build material tank <NUM> is full or close to full capacity. Alternatively, the external overflow tank <NUM> can be a removable tank. In this example, one or more ports are provided as part of the material management station <NUM> to allow for output of or reception of build material to and/or from the external overflow tank <NUM>. A sieve <NUM> or alternative build material refinement device may be provided for use together with the internal recovered build material tank <NUM> to make non-solidified build material recovered from a 3D printing production process for recycling more granular, that is, to reduce agglomeration (clumping).

The material management station <NUM> in this example has a mixing tank (or blending tank) <NUM> comprising a mixing blade (not shown) for mixing recycled build material from the internal recovered build material tank <NUM> with fresh build material from one of the supply containers 114a, 114b for supply to the build unit <NUM> when it is loaded prior to a printing production process. The mixing tank (or blending tank) <NUM>, in this example, is provided on top of the material management station <NUM>, above the location of the build platform <NUM> when the build unit <NUM> is docked therein. The mixing tank <NUM> may be connected to a mixer build material trap <NUM> for input of build material into the mixing tank <NUM>.

The supply containers 114a, 114b, the external overflow tank <NUM> and the main body of the material management station <NUM> may be constructed to fit together in a modular way, permitting a number of alternative geometrical configurations for the fully assembled material management station <NUM>. In this way, the material management station <NUM> is adaptable to fit into different housing spaces in a manufacturing environment.

The supply containers 114a, 114b may be releasably connected to the main body of the material management station <NUM> via respective supply container connectors 134a, 134b.

<FIG> schematically illustrates a management station <NUM> in the form of material management station <NUM>. The material management station <NUM> can be used in conjunction with the build unit <NUM> of <FIG>.

Material management station <NUM> in this example includes a build material loading system arranged to receive build material from one or more supply containers <NUM>. In one example the build material loading system <NUM> of the material management station <NUM> can include a conduit network and a pump to provide a pressure differential across the network to transport non-solidified build material between different components, such as mixing tanks, waste purging containers, build unit <NUM>, or other components. The pump may be a suction pump which operates to create a pressure differential across the suction pump to produce air flow from an air inlet at substantially atmospheric pressure through the conduit network towards an upstream side of the suction pump (at a pressure below atmospheric pressure or at "negative pressure"). The pump may be provided as an integral part of the material management station <NUM> in one example, but in another example, the material management station <NUM> provides a negative/reduced pressure interface, via which a suction pump may be detachably coupled or coupled in a fixed configuration. When the pump is active, a differential pressure can be provided between different parts of the material management station <NUM> that can enable build material to be transported around the station.

The build material loading system <NUM> may include a series of valves controlled by a controller <NUM>, for example a programmable logic controller, forming a part of processing circuitry of the build material management station <NUM>. The controller <NUM> may electronically open one or more valves to open one or more paths in the conduit system based on the material transport operation being performed. The controller <NUM> may also electronically close one or more valves to close one or more paths in the conduit system. The valves may be, for example, butterfly valves and may be actuated using compressed air. In another example, one or more valves may be opened and closed manually by a user.

<FIG> shows one supply container <NUM> releasably connected to the material management station <NUM>. In other examples a plurality of supply containers can be connected to the material management station <NUM>. In this example the supply container is connected to the material management station with a hose <NUM> connected to a build material loading system <NUM>. The build material loading system <NUM> in this example operates via the conduit network described above.

Each supply container <NUM> has a supply valve (not shown) for isolating the supply container from the environment, which may be opened when the container is connected to the build material loading system <NUM>. Each supply container <NUM> also includes a piping system (not shown) for transporting build material from the base of the supply container <NUM> to the supply valve, and an air inlet valve (not shown) to ensure air can enter the supply containers to maintain air pressure within the supply container <NUM>.

To transport build material from the supply container <NUM> to the material management station, valves separating the supply container <NUM> and the build material loading system <NUM> can be opened. When the pump is active a differential pressure can be provided from the build material loading system <NUM> to the supply container <NUM>. This enables a flow of air and material from the supply container <NUM> to be transported into the build material loading system <NUM>.

The build material loading system may contain or be connected to a collection tank into which material from the supply container <NUM> is dispensed as outlined below with reference to <FIG>.

The collection tank may include, or be connected to, a metering system <NUM> for metering the amount of build material that has been transported from the supply container <NUM> into the material management station <NUM> using the build material loading system <NUM>. This metering system may comprise a weight sensor as described below with reference to <FIG> or other means of metering the amount of material transported. The metering system <NUM> of the material management station can be configured to produce digital usage data <NUM>, which may comprise, for example weight data, volume data, or data relating to other measurements, indicating a measure of the amount of build material that has been loaded from the supply container into the build material loading system.

In this example the material management station <NUM> is connected to a data communication interface <NUM> configured to allow communication via a data communication network <NUM>.

The material management station <NUM> also contains a processor <NUM> which, when executing software instructions held in storage (not shown) in the management station, is configured to control the operation of the material management station <NUM> and has access to various operational data generated and stored in the management station <NUM>, including, for example, usage data <NUM> generated by the metering system <NUM>. The processor <NUM> may also be configured to communicate with the supply container <NUM>.

The processor <NUM> is configured to communicate with an administration system <NUM> via the data communication network <NUM>. Administration system <NUM> is run on a data processing platform located remote from the material management station <NUM>, for example in a control center. Alternatively, or in addition, functions of the administration system may be distributed across data processing platforms in a number of different physical locations or on any other system connected to the data communication network. The processor <NUM> is configured to send usage data <NUM> generated by the metering system <NUM> to the administration system <NUM> via the data communication network <NUM>.

The processor <NUM> may also be configured to receive management data, including control messages intended for the material management station <NUM>, from the administration system <NUM> via the data communication network <NUM>.

The management station <NUM> in this example may contain equipment (not shown) capable of providing a human-machine interface, for example a touch-screen display. The touch-screen display can be configured to display some or all of the content of messages received by the processor <NUM> from the administration system <NUM>. Such messages may relate to the amount of build material that has been consumed from supply container <NUM>, the amount of build material remaining in supply container <NUM>, notifications or alerts relating to the consumption of build material from supply container <NUM> or any messages pertaining to the data sent from the material management station <NUM> to administration system <NUM>. The processor <NUM> may also be configured to locally generate messages in relation to messages received from the administration system <NUM>.

The processor <NUM> may be configured to constantly or periodically monitor the administration system <NUM> via the data communication network <NUM> for data generated by the administration system <NUM>, and to retrieve data relevant to the operation of management station <NUM>. It may include an automated shutdown function which prevents the management station <NUM> from operating one or more functions relating to loading of build material unless it is connected to data communication network and receiving communication from administration system <NUM>. Administration system <NUM> may transmit heartbeat messages periodically to the management station <NUM> in order to prevent shutdown. The shutdown function may be delayed by a predetermined grace period after disconnection from the data communication network <NUM> and/or the administration system <NUM> in order to allow for data network maintenance periods and problems.

The data generated by the administration system <NUM> in this example contains control messages, that control operations of the material management station. Such control messages may include, for example, instructions intended for implementation by a build material usage controller <NUM>, which may include one or more physical components such as a motor and/or a valve, to enable or disable functions of the material management loading system including blocking transport of build material from the supply container <NUM> to the material management station <NUM> by preventing operation of part, or all, of the build material loading system <NUM>. Control messages generated by the administration system <NUM> may cause the controller <NUM> to enable or disable functions of the material management loading system <NUM> indeterminately, or for a predetermined period of time.

The processor <NUM> may also be configured to perform such control operations on the material management station <NUM> in the absence of control messages from the administration system. In the example where the control messages generated by the administration system <NUM> cause the processor to restrict use of or disable functions for a predetermined period of time, following receipt of such a message these functions may be controlled according to the control message for the predetermined time period in the event that no more messages are received due to, for example, loss of communication with the data communication network <NUM>.

<FIG> shows an example of an additive manufacturing material management station <NUM>.

In this example, the material management station <NUM> includes a collection tank <NUM> for receiving fresh and/or recyclable build material within the main body of the material management station. The collection tank <NUM> includes an inlet <NUM> for receiving fresh build material <NUM> from a supply container <NUM>. The collection tank <NUM> may also include an outlet <NUM> for transferring build material out of the collection tank <NUM> into a container <NUM>. The container <NUM> may be a build unit as described in relation to <FIG> and <FIG>. Alternatively, the container <NUM> may be a separate box or tank for holding build material. An outlet conduit <NUM> may be connected between the outlet <NUM> and the container <NUM>, to help transport build material from the collection tank <NUM> to the container <NUM>.

A supply conduit <NUM> may connect between the inlet <NUM> to the collection tank <NUM> and the supply container <NUM>. The supply conduit <NUM> may be provided with a tank connector <NUM> for detachably connecting to the fresh build material tank port <NUM> of the supply container <NUM>. The supply conduit <NUM> may detachably connect to the inlet <NUM> to the collection tank <NUM>. The further end of the conduit <NUM> (e.g. the tank connector <NUM>) may be disconnected from the supply container <NUM> so that the supply container <NUM> can be replaced. For example, when it is empty, an empty supply container <NUM> may be replaced with a full supply container <NUM>. In another example, the supply container <NUM> may be replaced with a different supply container <NUM> containing a different fresh build material <NUM>.

The supply container <NUM> may be provided with a data memory chip <NUM>, and read-only (one-way electrical communication) or read-write electrical communication (two-way electrical communication) may be established between the management station <NUM> and the data memory chip of the supply container <NUM> when the supply container is mechanically connected to the supply conduit <NUM>. The electrical communication between the material management station <NUM> and data memory chip <NUM> on the supply container <NUM> may be encrypted. The data memory chip of the supply container <NUM> may be a secure memory chip, and the data recorded onto the data memory chip, may be encrypted.

Read-write communication between the material management station <NUM> and the supply container <NUM> may alternatively be provided, for example, by providing a two way radio frequency (RF) connection between the material management station <NUM> and supply container <NUM>. The use of an RF connection may simplify the mechanical connection between the material management station <NUM> and the fresh build material supply tank <NUM>.

In one example the supply container <NUM> is a single-use supply container and its memory chip contains data indicating that a type of the container is single-use, an identity of the container to verify its authenticity, and a secure updateable record of contents, indicating a current amount of fresh build material in the container.

In another example the supply container <NUM> is a bulk-refillable supply container which may include a data memory chip that may store less, and/or less secure, data than that stored on a single-use container memory chip, or may, in some examples, contain no such data memory chip at all. In one example a bulk-refillable supply container memory chip contains data indicating that a type of the container is refillable, an identity of the container, which may be used to verify its authenticity, and no secure updateable record indicating a current amount of fresh build material in the container. It should be noted that, even if no secure updateable record may be included, a less secure record may be included.

In this example the lack of a secure updateable record of contents, as provided in the single-use supply container's memory chip, may be obviated, ameliorated, or improved, by functionality provided in the management station which enables the management station to interact securely with the remote administration system, and which when combined with updates sent to, and remote control commands received from, in administration system. This system provides restrictions in use of bulk-refillable material to an amount of bulk-refillable material authorized in the administration system, as will be described below, but nevertheless allows the management station to use single-use supply containers interchangeably with the bulk-refillable supply containers, or after authorized use of the bulk-refillable supply containers has been restricted or ended.

In the example shown in <FIG>, a supply container connector <NUM> has a chip reader <NUM> configured to connect electrically to a data memory chip <NUM> on the supply container <NUM> by contacting electrode pads (not shown) in the supply container port <NUM> with resiliently deformable electrodes (not shown)(e.g. sprung-electrodes) in the supply container connector <NUM>. The electrode pads are electrically connected to the data memory chip <NUM> of the supply container <NUM>. The data communication cable <NUM> communicates data between the chip reader <NUM> and a data processor <NUM> of the material management station <NUM>, which may or may not be the same processor as processor <NUM>.

When the supply container connector <NUM> of the supply conduit <NUM> is mechanically coupled to the supply container <NUM>, the material management station <NUM> may read data that has been permanently stored, or has previously been written onto, the data memory chip <NUM> of the supply container.

In the example of a single-use container, the previously written data may record a container identifier for the supply container <NUM>, may record the type of fresh build material <NUM> within the supply container, and may record the initial quantity of fresh build material <NUM> contained in the supply container prior to first post-manufacturing use and/or the recorded residual quantity of fresh build material <NUM> remaining within the supply container after prior use. Additionally, the material management station <NUM> may write data to the data memory chip <NUM> of the supply container <NUM>. For example, data may be written to the data memory chip <NUM> to update the record of the recorded residual quantity of fresh build material <NUM> therein, as (or after) fresh build material is drawn out up the supply conduit <NUM>.

Where applicable, some of the data recorded on the data memory chip <NUM> may be read-only data (e.g. the type of fresh build material <NUM>), and some of the recorded data may be over-writable by the material management station <NUM> (e.g. a quantity of fresh build material <NUM>). The data memory chip <NUM> may be encrypted, to prevent or hinder reading from and/or writing to the data memory chip, except by a compatible material management station <NUM> (e.g. with communication being established after a hand-shaking protocol has been successfully completed). Additionally, the data memory chip <NUM> may be protected by a restriction that limits the recorded data corresponding to a residual quantity of fresh build material to counting monotonically, corresponding with a decreasing recorded residual quantity (e.g. a one-way counter).

A data processor <NUM> of the material management station <NUM> may read the container identifier recorded on the data memory chip <NUM> of the supply container <NUM>, and, in the example of a single-use supply container, use the container identifier to identify the type of fresh build material <NUM> contained in the supply container (e.g. by consulting a look-up table of the data processor). If the type of fresh build material <NUM> identified by reading the container identifier is incompatible with the 3D printer <NUM> of the 3D printing system <NUM>, the data processor prevents fresh build material <NUM> from being drawn into the material management station <NUM>, e.g. preventing the fresh build material from being drawn into the supply conduit <NUM>, e.g. to protect the 3D printer from damage arising through the use of incompatible build material.

If the data processor <NUM> detects that the recorded residual quantity of fresh build material <NUM> in the single-use supply container <NUM> is at or below a threshold level (e.g. zero) the data processor prevents fresh build material <NUM> from being drawn into the material management station <NUM> from the supply container. For example, the material management station <NUM> may fully extract the contents of a supply container <NUM> and write data (e.g. a status flag) to the data memory chip <NUM> of a single-use container to indicate that the supply container should no longer be used. Accordingly, in the event that a single-use supply container <NUM> has been re-filled subsequent to manufacture, the data processor <NUM> may prevent the withdrawal of further build material, in excess of the initial quantity of fresh build material with which the manufacturer filled the supply container <NUM> (i.e. prior to first use).

In the example of a bulk-refillable supply container the management station <NUM> may restrict use of or disable transfer of the build material according control messages received from a remote administration system, as described below. The residual quantity of fresh build material that can be added from a bulk-refillable container to the material management station can be monitored and controlled by the remote administration system.

The withdrawal of fresh build material from a bulk-refillable supply may be prevented by closing one or more valves that connect the supply container to the material management station <NUM>, thereby preventing coupling of the supply container <NUM> to negative pressure from the pump.

If the administration system detects that the recorded residual quantity of fresh build material <NUM> in a bulk supply package is at or below a threshold level (e.g. zero), due to refilling of bulk-refillable supply containers, the data processor prevents fresh build material <NUM> from being drawn into the material management station <NUM> from the bulk-refillable supply container. For example, the material management station <NUM> may stop loading build material from the supply container irrespective of its fill state, or partly or fully extract the contents of a supply container <NUM>, and thereafter prevent further loading from any bulk-refillable supply container, whilst loading from a single-use supply container may remain enabled.

If the data processor <NUM> is unable to read a container identifier from supply container <NUM>, the data processor may prevent fresh build material <NUM> from being drawn into the material management station <NUM> from the supply container, which may protect the printer from damage arising through the use of an incompatible supply container.

In the example of a bulk-refillable supply container, data stored on a chip in the container may record the type of container in use to indicate that the contents are bulk-filled material, and not record data describing the type or quantity of material stored within the supply container. A determined residual quantity of bulk-supplied fresh build material allocated to the management station, or a grouped set of management stations, may be recorded locally by the material management station <NUM> and/or by the administration system, such as the administration system, on which the recorded data is correlated with a unique identifier for the bulk-refillable supply container, and material management station.

The collection tank <NUM> includes a metering system for measuring a total quantity of build material within the collection tank <NUM>. In the illustrated example, the metering system utilizes a weight sensor <NUM>. The weight sensor <NUM> may include a load cell placed within the collection tank <NUM>. Alternatively, a weight sensor may be provided that weighs the fresh build material supply tank, e.g. with a weight sensor in a bay of the material management station <NUM>, upon which the supply container sits, in use. In a further alternative, the quantity sensor may be a volume sensor.

The weight sensor <NUM> may form part of a data processing system <NUM>, as shown in <FIG>. In this example, the data processing system <NUM> comprises the weight sensor <NUM>, a data processor <NUM>, a supplementary data memory chip <NUM> in the material management station <NUM>, and an output display <NUM>. The weight sensor <NUM> is configured to transmit weight data to a data processor <NUM>, which may be connected to the weight sensor via suitable circuitry, for example. The data processor <NUM> receives weight data from the weight sensor <NUM> to allow the data processor <NUM> to determine the weight of fresh build material <NUM> drawn out of the supply container <NUM>. By knowing the quantity of fresh build material <NUM> in in the supply container <NUM>, e.g. by reading the recorded initial quantity or recorded residual quantity of fresh build material <NUM> in a single-use supply container <NUM> from the data memory chip <NUM>, this allows the data processor <NUM> to compute an updated residual value of the weight of fresh build material <NUM> remaining in the supply container <NUM>. The data processor <NUM> may then write the updated residual value to the data memory chip <NUM> of the supply container <NUM>. Further, if the data processor <NUM> detects that the computed updated residual quantity of fresh build material <NUM> in the supply container <NUM> is at or below a threshold level (e.g. zero), the data processor prevents fresh build material <NUM> from being drawn into the material management station <NUM> from the single-use supply container.

For example, a portion of fresh build material <NUM> may be transferred to the collection tank <NUM> via the conduit <NUM> from an initially full supply container <NUM>. The weight sensor <NUM> in the collection container <NUM> (or alternatively, a weight sensor beneath the supply container <NUM>) may measure the weight of fresh build material <NUM> withdrawn from the fresh build material supply tank and added to the collection tank. The data processor <NUM> can receive weight data from the weight sensor <NUM> corresponding to the weight of fresh build material <NUM> added to the collection tank <NUM> and can subtract the weight of fresh build material <NUM> added to the collection tank <NUM> from the recorded initial weight of build material <NUM> within the single-use supply container <NUM>. Thus, the data processor <NUM> can calculate a remaining weight of fresh build material <NUM> within the supply container <NUM>, which may then be updated onto the data memory chip <NUM>.

In the example where the container is a bulk-refillable container that does not store build material usage data, the metering system of the collection tank as described above is configured to provide usage data <NUM>, describing the amount of build material that has been transported into the collection tank, to the processor <NUM> to be transmitted to a remote administration system, as described below with reference to <FIG>.

The initial weight of a single-use fresh build material <NUM> in the supply container <NUM> can be controlled or measured during manufacture of the supply container <NUM>. Thus, the initial weight of fresh build material <NUM> in a supply container <NUM> may be stored on the data memory chip <NUM> of single-use supply containers prior to the first post-manufacturing use. Alternatively, if the initial weight of fresh build material <NUM> in the supply container <NUM> is not already known, the initial weight of build material can be measured, for example using weight sensors (not shown) prior to connecting the supply container <NUM> to the conduit <NUM> of the material management station <NUM>.

A supplementary secure data memory chip <NUM> may be included in the data processing system <NUM> and may be integral with the material management station <NUM>. The supplementary data memory chip <NUM> can store the weight of fresh build material <NUM> remaining in the supply container <NUM> and the weight of build material in the collection tank <NUM>. The data processor <NUM> can write and/or update the calculated remaining weight of fresh build material <NUM> within the single-use supply container <NUM> to the data memory chips <NUM> and <NUM>. Alternatively or additionally, the data processor <NUM> may write and/or update the total weight of fresh build material <NUM> removed from the single-use supply container <NUM> to the data memory chips <NUM> and <NUM>. The supplementary data memory chip <NUM> may record data relating to the supply container <NUM> and the withdrawal of fresh build material from the build material supply tank. The data recording may occur after the withdrawal of fresh build material <NUM> has been completed or may occur during the withdrawal of fresh build material, e.g. as a real-time update.

Further portions of fresh build material may be transferred to the collection tank <NUM> from the supply container <NUM>. Further portions of fresh build material <NUM> may be added to an empty or substantially empty collection tank <NUM> or may be added to the collection tank <NUM> in addition to build material already within the collection tank <NUM>. The data processor <NUM> can obtain further weight data from the weight sensor <NUM> corresponding to a weight of a further portion of fresh build material within the collection tank <NUM> and can process the further weight data to calculate a total weight of fresh build material remaining in the single-use supply container <NUM>.

For example, if the further portion of fresh build material is added to an empty or substantially empty collection tank <NUM>, the weight sensor can measure the total weight of build material within the collection tank. The data processor may receive the weight data from the weight sensor <NUM> and can use the weight data to calculate a remaining weight of build material <NUM> within a single-use supply container <NUM>. Alternatively, in the example of a bulk-refillable supply tank the weight data may be transmitted to a remote administration system.

To calculate a residual weight of fresh build material <NUM> in the single-use supply container <NUM>, that was provided by the tank manufacturer, the data processor may obtain data corresponding to the total weight of fresh build material previously transferred to the collection tank <NUM> from the data memory chip <NUM>. The data processor <NUM> may then add the weight of build material previously transferred to the weight of the further portion of build material within the collection tank <NUM> (as measured by the weight sensor <NUM>), to thereby calculate a total weight of fresh build material that has transferred from the supply container <NUM> to the collection tank <NUM>. The data processor <NUM> may then write this updated residual weight data to the data memory chip <NUM> for use in further calculations.

The data processor <NUM> may subtract the total weight of fresh build material that has transferred from the single-use supply container <NUM> from the initial weight of fresh build material <NUM> in the supply container <NUM> to thereby calculate a remaining weight of fresh build material <NUM> in the supply container <NUM>.

In another example, the data processor <NUM> may obtain data corresponding to the weight of fresh build material <NUM> remaining in the single-use supply container <NUM> from the data memory chip <NUM>. This data may have been written to the data memory chip <NUM> by the data processor <NUM> after a previous calculation. The data processor <NUM> may then subtract the weight of the further portion of fresh build material transferred to the collection tank <NUM> (as measured by the weight sensor <NUM>), and subtract this weight data from the remaining weight of fresh build material <NUM> previously recorded in the supply container <NUM>, to calculate a new remaining weight of fresh build material <NUM> in the supply container <NUM>.

The material management station <NUM> may include, for example, an output display <NUM>, for example an LED screen, which may display the residual weight of fresh build material <NUM> determined to be in the supply container <NUM> and/or the total weight of build material within the collection tank <NUM> and/or the remaining allowance of bulk material that may be supplied through bulk-refillable supply tanks. The output display <NUM> may form part of the data processing system <NUM> as shown in <FIG>. The data processor <NUM> may be connected to the output display <NUM> to transmit weight data to the output display <NUM>.

The supply container <NUM> may be disconnected and replaced with a different fresh build material supply tank at any time. For example, the supply container <NUM> may be replaced when the data processor <NUM> calculates there is no fresh build material <NUM> remaining in a single-use supply container <NUM>. When the supply container <NUM> is replaced (e.g. with a full single-use fresh build material supply tank), the data processor may read data from the corresponding data memory chip <NUM> of the fresh build material supply tank to obtain the quantity of fresh build material <NUM> recorded to be contained therein (which may differ from the actual quantity of fresh build material contained in the tank, if the tank has been subject to an unauthorized re-fill).

Some material management stations may include two or more supply containers <NUM> as described above. In this case, the data processor <NUM> may switch the source of fresh build material to a second fresh build material supply tank when it calculates or otherwise receives data indicating that a first fresh build material supply tank is empty or that an allowance for use has been exhausted. This allows continuous transfer of fresh build material to the mixing tank whilst the first fresh build material supply tank is replaced. The data processor <NUM> can measure or receive data indicating the remaining weight of fresh build material in the second fresh build material supply tank in the same way as described above.

<FIG> shows an example of an administration system configured for controlling additive manufacturing processes. Such processes may include those described above. The system is suitable for use with a bulk-refillable supply container that does not contain a single-use data memory chip capable of storing data describing the amount of material it contains. The administration system <NUM> in this example corresponds to administration system <NUM> of <FIG>.

In this example the administration system <NUM> contains a management system <NUM> capable of recording information relating to the consumption of an allowable usage of a resource, such as bulk supplied build material, and a configuration service <NUM> capable of generating control messages that can cause a processor to alter operation of material management stations. It is to be understood that the administration system may contain more data processing elements that perform other functions than that shown.

The administration system <NUM> of <FIG> is configured to communicate with a management station <NUM>, corresponding to management station <NUM> of <FIG>, which is remote from the administration system, via a data communications network <NUM>.

In one example the management system <NUM> of the administration system <NUM> is configured to receive and store supply update data <NUM> indicative of an initial allocation of usage of bulk-supplied build material to be granted to at least one material management station <NUM> and associate the granted allocation with a level-of-usage record held the at least one material management station <NUM>. In one example the supply update data describes an allocation of build material that may be received from one or more bulk-refillable supply containers <NUM>, into the material management station <NUM>. The supply update data <NUM> may also be indicative of an increase, decrease, or other alteration to a level-of-usage already stored by the management system. Amendments may be made to the granted allocation following, for example, purchase of more bulk-supplied build material.

The management system <NUM> is also configured to receive data <NUM> from the material management station <NUM>, via a data communication network <NUM>. Such data contains usage data indicative of the amount of build material loaded from at least one supply container <NUM> into the material management station <NUM>. The management system can update the level-of-usage record so as to remove the used amount of material described in the usage data <NUM> from a stored allocation to create a new current level-of-usage record.

A configuration service <NUM> within the administration system <NUM> is configured to communicate with the management system <NUM> to generate one or more control messages based on the currently stored allocation. Control messages may be configured to enable features such as loading of build material from bulk-refillable supply containers to the material management station in response to the management system current usage allocation indicating an allowable usage amount within an expected range, such as any amount above zero. The control messages are configured to disable loading from a bulk-refillable supply container in response to the management system's current allocation indicating an amount of usage outside an expected range.

It is to be understood that where control messages may for example disable the loading of bulk supplied build material, the disabling may also be conducted in response to detection of a period of time since a periodic re-enabling control message is received.

An amount of material previously loaded by the build material loading system may remain usable according to the control message generated by the configuration service. In addition, loading of recycled or recovered material from the recovered build material tank <NUM> may be enabled whilst loading of fresh build material is disabled.

The control messages generated by the configuration service <NUM> may contain digital permission grants or permission revocations that cause the processor <NUM> to enable, or alternatively restrict use of or disable at least one of the operational features of the material management station <NUM>. Such operational features may include the transport of build material from a supply container such as a bulk-refillable supply container, to the material management station <NUM>.

The control messages may contain information that causes the processor <NUM> to restrict use of or disable operational features of the material management station for an indeterminate period, or may grant a temporal amount of usage of the operational features. In the example where the control messages contain a grant of a temporal amount of usage of the operational features the control of such features extends until the temporal amount of usage expires. In this way the grant of usage cannot be bypassed in the event of a loss of connection between the material management station <NUM> and the data communication network <NUM>.

In one example, the configuration service <NUM> can periodically receive information from the management system <NUM> indicating that a level-of-usage falls within an expected range. The configuration service can then periodically generate a control message granting a temporally-limited permission to receive build material from a bulk-refillable container into the material management station. This control message is periodically communicated to the material management station via a data communication network while the level-of-usage is within an expected range. Upon receipt by the material management station the control message will cause the processor <NUM> to temporarily enable such features until another control message is received or the temporal period expires.

In another example, the configuration service <NUM> can receive information from the management system <NUM> indicating that a material management station has currently recorded level-of-usage that falls out of an expected range. The configuration service can then generate a control message that causes the processor <NUM> of the material management station to disable usage of the build material loading system <NUM> receive material from a bulk-refillable supply container into the material management station. The features may remain disabled until a control message is received granting usage, indicating that an additional allocation of supply has been received in the administration system as supply update data.

In the example where a material management station does not have an associated allocation of bulk supply, the configuration service <NUM> can generate a default control message wherein the default control message disables usage of build material loading system to load material from a bulk-refillable supply container.

<FIG> shows a flow diagram outlining an example of a method of controlling an additive manufacturing process.

The method of <FIG> comprises, at block <NUM>, loading build material into material management station from one or more supply containers.

The method further comprises, at block <NUM>, metering the amount of build material that was loaded from the one or more supply containers and generating usage data.

The method further comprises, at block <NUM>, transmitting the usage data indicative of the usage amount, generated at block <NUM>, to an administration system remote from the material management station.

The method further comprises, at block <NUM>, receiving one or more control messages from the administration system.

The method further comprises, at block <NUM>, controlling the usage of build material in the additive manufacturing process in response to the at least one control message.

<FIG> shows an example of a non-transitory computer readable storage medium according to an example. The storage medium <NUM> stores instructions which when executed by a processor <NUM> cause the processor to perform the actions shown in the blocks of <FIG>.

At block <NUM> the processor monitors an amount of build material for use in an additive manufacturing process that is loaded from one or more supply containers by reading build material usage data <NUM> from a metering system.

At block <NUM> the processor transmits the usage data indicative of the monitored amount of build material usage to an administration system <NUM>.

At block <NUM> the processor receives one or more control messages <NUM> generated by administration system in response usage data transmitted by the processor. The control messages contain processor readable instructions instructing the processor to control features of the additive manufacturing process.

At block <NUM> the processor controls usage of a build material in the additive manufacturing process in response to the at least one control messages by controlling features of the additive manufacturing process.

An example of the above disclosure will now be described in relation to an additive manufacturing system that provides for the control of the use of bulk-supplied build material. In this example the build material is supplied in bulk quantities and dispensed into bulk-refillable supply containers, similar to bulk-refillable supply container <NUM>, for use with a 3D printing system, similar to printing system <NUM>. The control of bulk-supplied build material is performed by an administration system similar to administration system <NUM>.

In this example, a network-based management system, similar to management system <NUM>, capable of storing information relating to the bulk-supplied build material consumption of a management station, similar to management station <NUM>, stores an level-of-usage record for bulk-supplied build material. The management system forms part of a network-based administration system similar to administration system <NUM>. When bulk-supplied build material is purchased, the management system receives and stores an update to the level-of-usage record in accordance with a new allocation associated with a management station. The update may be performed by supplying data similar to supply update data <NUM>.

A remaining amount of build material that a management station may load is calculated by the management system using the level-of-usage record and usage data from the management station loading the build material, such as usage data <NUM>, provided via a data communication network.

The management system can identify devices that are over loading build material when the level-of-usage record indicates a usage level outside of an expected range, such as below zero, and communicate this to a configuration service capable of generating control messages, similar to configuration service <NUM>, which can prevent further loading of a management station as described below. When the level of usage is outside of an expected range, a notification from the management system is sent to a communication interface associated with the management station consuming bulk-supplied build material, such as data communication interface <NUM>, that can be displayed on a display of the management station. In this way users of the system are notified that a bulk supplied build material allocation is exhausted and they are to purchase more build material to continue loading bulk-supplied build material. Upon the purchase of more bulk-supplied build material, the management system increases the amount indicated in the level-of-usage record as described above, and the bulk supplied build material is separately delivered to the facility in which the management station operates.

The configuration service within the administration system may be configured to generate a bulk configuration profile ("BCP") based on the currently stored level-of-usage record and a BCP uniform resource locator (URL). The BCP and URL are communicated to the management station as part of a control message. The BCP includes a control parameter that defines a quantity of time for which a management station is permitted to continue loading bulk-supplied build material. In this example a single control parameter is used to control allowance of build material loading, but it is to be understood that a plurality of parameters could be used which may or may not be temporal. The configuration service may also supply other configuration profiles that control other operations of the 3D printing system. The configuration profile URL is communicated to a data communication interface of the 3D printing system with a data communication network, such as the Internet, either directly or via a network-based storage service. Such communications are similar to the control messages described above.

Usage data indicative of an amount of build material loaded from a bulk-refillable supply container is transmitted from the management station to the administration system via the data communication network. The management system uses this usage data to update the bulk-supplied build material allocation by subtracting the amount of build material that has been loaded from the previous allocation, and in response the administration system may stop a periodic transmission of BCPs to the management station, may transmit a default BCP containing information indicating that further loading from refillable storage containers should be disabled. Alternatively, the default BCP may contain no information indicating that further loading from refillable storage containers should be enabled.

A control parameter of a BCP controlling the loading of build material may be a temporal allowance, for example an integer value of the number of minutes, that a management station may continue to load build material. A time-stamp and unique device identifier for a management station (for example, a serial number) is also included in the BCP that to allow a management station to identify the most recent BCP that was addressed to it. The unique device identifier, along with an in-built validation process in a management station to ensure that the unique device identifier matches with an internally-stored device identifier, ensures that BCPs cannot be re-used or shared among management stations.

The duration of a temporal allowance may be longer than an average interval between the periodic transmission of updated BCPs to a given management station, in order to provide robustness against network issues.

A control parameter specifying an initial allowance of bulk-supplied build material consumption may be provided by means of a setting securely held within each management station, for example a firmware setting. Such a setting may allow a limited period of build material loading for initial set up and configuration of the management station, after which build material loading will be disabled until a first, or new, BCP is received.

A default BCP may be associated with a management station by the configuration service in the absence of any association with a bulk-supplied build material allocation. A control parameter in the default profile may prevent loading of bulk-supplied build material. The control parameter may for example be a non-positive value of temporal allowance, for example zero. Once a level of usage falls outside an expected range, the configuration service may remove the association of the management station with the bulk allocation and the management station is associated with a default profile. Once an allocation has been associated with a management station, as a first or subsequent instance, the configuration service may stop supplying the default BCP and supply a BCP with a temporal allowance for the management station to consume bulk-supplied build material until the bulk-supplied build material allocation is exhausted.

It is to be understood that the loading of other non-bulk-supplied build material for example from a non-user refillable supply container, may remain enabled while loading from bulk-refillable supply containers is disabled.

The data communication interface of with the management station may be configured to monitor and retrieve from the administration system the configuration profiles generated by the configuration service and forward them to one or more other associated devices, including forwarding the BCP to a printing station, in order to control usage.

The configuration profiles may be retrieved as they are generated or periodically retrieved form a network based storage service. Where the communication interface retrieves the profiles on a periodic basis, the parameter defining the period of retrieval may be provided by the configuration service.

The management station receives and stores the BCP from the communication interface and enables or disables loading from bulk-refillable supply containers according to the control parameter. A BCP may be accepted by the management station if the unique device identifier in the BCP is that of the management station and the time-stamp is more recently generated that the currently stored BCP. If these conditions are not met, the management station may not accept the BCP. Once a BCP is received and accepted the management station may store the control parameter value and re-initialize a countdown timer with the most recently stored value of time units remaining. In this example the value is a quantity of minutes. Thus, build material loading may be enabled for the generated temporal allowance or until a further BCP is received specifying a different temporal allowance.

When a user of a management station attempts to load bulk-supplied build material from a bulk-refillable supply container, the management station checks the countdown timer prior to commencing the loading operation. While a positive value of remaining time units is stored the management station may continue to load the bulk-supplied build material until the countdown timer reaches zero or a default BCP is received, at which point it will stop loading bulk-supplied build material. If the control parameter does not contain a positive value or otherwise indicates the bulk-supply allocation is exhausted, the management station will not load bulk-supplied build material. The management station may report an alert to the communication interface if a user attempts to load bulk build material while build material loading is disabled, which in turn may be communicated to the administration system.

Data describing the amount of build material that has been loaded, or is pending to be uploaded, is communicated to the administration system by the management station, for use by the management system in determining a remaining allocation of bulk-supplied build material. This may be done directly or through a network-based storage system. These details may be encrypted by the management station or the communication interface for communication over a data communication network.

It is to be understood that while one management station is described in the examples above, a plurality of management stations can be assigned to a single bulk-supplied build material allocation and/or level-of-usage record stored in the management system.

Where in the above examples, control is performed in relation to a refillable supply container, it should be understood that the same, or similar, control techniques may alternatively, or in addition, be applied in relation to non-user refillable supply containers.

Claim 1:
An administration system (<NUM>) for an additive manufacturing process, the process comprising:
loading build material from one or more supply containers (114a, 114b), for use in the additive manufacturing process; and
metering an amount of build material loaded from the one or more supply containers (114a, 114b),
wherein the administration system (<NUM>) is configured to communicate with a management station (<NUM>), remote from the administration system (<NUM>), over a data communications network (<NUM>), and wherein the administration system (<NUM>) is configured to:
receive usage data indicative of an amount of build material loaded from the one or more supply containers (114a, 114b);
receive first update data indicative of an initial amount of usage granted and monitor the usage data with respect to the initial amount;
receive second update data indicative of an additional amount of usage granted and monitor the usage data with respect to the initial and additional granted amounts; and
transmit one or more control messages, the one or more control messages comprising a control message for disabling loading of build material from the one or more supply containers (114a, 114b) in response to the amount of build material loaded from the one or more supply containers (114a, 114b) exceeding the initial and the additional amounts of usage granted.