阅读说明：本技术 3d打印材料阻断 (3D printed material blocking ) 是由 B·埃瓦尔德 M·罗德 T·度迪克 J·盖勒 于 2017-04-21 设计创作，主要内容包括：一种3D打印材料阻断设备包括：排放开口隔离器,其设置在3D打印机的第一区域中；以及打印材料料斗,其包括处于所述打印材料料斗的底部处的排放开口,以在所述3D打印机的与所述第一区域相邻的第二区域中从所述打印材料料斗排放打印材料。当所述打印材料料斗处于所述第一区域中时,所述排放开口隔离器阻塞所述打印材料料斗的所述排放开口。(A 3D printed material blocking apparatus comprising: a discharge opening isolator disposed in a first region of the 3D printer; and a printing material hopper comprising a discharge opening at a bottom of the printing material hopper to discharge printing material from the printing material hopper in a second region of the 3D printer adjacent to the first region. The discharge opening isolator blocks the discharge opening of the printing material hopper when the printing material hopper is in the first region.)

1. A 3D printed material blocking device, comprising:

a discharge opening isolator disposed in a first region of the 3D printer; and

a printing material hopper comprising a discharge opening at a bottom of the printing material hopper to discharge printing material from the printing material hopper in a second region of the 3D printer adjacent to the first region, an

Wherein the discharge opening isolator blocks the discharge opening of the printing material hopper when the printing material hopper is in the first region.

2. The device of claim 1, wherein the second area comprises a print area of the 3D printer.

3. The apparatus of claim 1, wherein the second area comprises a feed plate adjacent to a print area of the 3D printer.

4. The apparatus of claim 3, wherein the discharge opening isolator includes an upper surface having an area greater than an area of the discharge opening.

5. The apparatus as set forth in claim 4, wherein,

characterized in that a first reference extends along the bottom of a first lateral side of the printing material hopper and a second reference extends along the bottom of a second lateral side of the printing material hopper, an

Wherein the first and second references are arranged to contact the feedshoe when the printing material hopper is moved relative to the feedshoe to define first and second lateral boundaries, respectively, for printing material discharged from the discharge opening.

6. The apparatus as set forth in claim 5, wherein,

characterized in that a third reference extends along the bottom of the front side of the printing material hopper and a fourth reference extends along the bottom of the rear side of the printing material hopper, an

Wherein the third datum and the fourth datum are spaced from the first datum and the second datum by a first height to define a height of printing material discharged from the discharge opening when the printing material hopper moves along the feedshoe with the first datum and the second datum contacting the feedshoe.

7. The apparatus of claim 6, wherein an upper surface of the discharge opening isolator is disposed at a second height from the feedshoe.

8. The apparatus of claim 7, wherein the second height is greater than the first height.

9. The apparatus of claim 8, wherein the discharge opening isolator includes a ramp extending from the feedshoe to the second height along a path of the printing material hopper from the feedshoe to the discharge opening isolator.

10. The apparatus of claim 9, wherein a width between a first lateral side and a second lateral side of the discharge opening isolator is less than a width between the first lateral side and the second lateral side of the printing material hopper, and wherein the first lateral side and the second lateral side of the printing material hopper slide outside of the first lateral side and the second lateral side of the discharge opening isolator during movement of the printing material hopper along the discharge opening isolator.

11. The apparatus of claim 10, wherein the first lateral side and the second lateral side of the printing material hopper abut first lateral side and second lateral side of the discharge opening isolator during movement of the printing material hopper along the discharge opening isolator.

12. The apparatus of claim 11, wherein the first height is between about 1.0-4.0mm, and wherein the second height is between about 0.0-1.5mm higher than the first height.

13. The apparatus of claim 8, wherein the second height of the drain opening isolator is adjustable to a selected second height, wherein the first height of the drain opening isolator is adjustable to a selected first height, and wherein the selected second height is greater than the selected first height.

14. A method of isolating flow from a printing material hopper, comprising:

setting a feed shoe in a second area of the 3D printer;

providing a drain opening isolator in a first area of the 3D printer adjacent to the second area at a second height relative to the feedshoe;

arranging a printing material hopper to travel along a path comprising the first region and the second region;

moving the printing material hopper onto the discharge opening isolator to block discharge of printing material from the printing material hopper in the first region; and

moving the printing material hopper away from the discharge opening isolator to enable the printing material to be discharged from the printing material hopper in the second region.

15. A 3D printed material blocking device, comprising:

a moveable 3D printer belt comprising a discharge opening isolator in a first region of the 3D printer belt and an exemplary gap in a second region of the 3D printer belt; and

a printing material hopper comprising a discharge opening at a bottom of the printing material hopper,

wherein the 3D printer tape biases the discharge opening isolator into abutment with the discharge opening to block flow of printing material from the discharge opening and positions the gap of the 3D printer tape below the discharge opening to receive printing material from the discharge opening.

Background

The 3D printer includes a movable platform on which successive layers of 3D printing material (e.g., nylon powder, metal powder, etc.) are applied, dispensed, and fused or bonded layer-by-layer to build the product. During powder bed fusion, a 3D material applicator applies a layer of 3D printing material at a predetermined thickness across a working or build region of a movable platform. The 3D printed material bonding apparatus then selectively applies energy to the 3D printed material layer to fuse or bond selected portions of the 3D printed material layer that correspond to a profile of the desired product at a vertical position of the layer. This process continues layer by layer until the entire product is made up of combined layers.

Drawings

Fig. 1A-1D depict top views of an exemplary 3D printer showing stages of movement of a printing material hopper relative to a discharge opening isolator according to the teachings of the present disclosure.

Fig. 2A-2F depict another top view of an exemplary 3D printer showing stages of movement of a printing material hopper relative to a plurality of discharge opening isolators in accordance with the teachings of the present disclosure.

Fig. 3 is a top perspective view of an exemplary printing material hopper relative to an exemplary discharge opening isolator according to the teachings of the present disclosure.

Fig. 4 is a bottom perspective view of an exemplary printing material hopper according to the teachings of the present disclosure.

Fig. 5 is a side cross-sectional view illustrating an exemplary printing material hopper moving relative to an exemplary feeder shoe to discharge a powder layer thereon in accordance with the teachings of the present disclosure.

Fig. 6 is a side cross-sectional view showing the example of fig. 5, where an example printed material hopper has completed discharge of a powder layer on an example feeder shoe and is moving onto an example discharge opening isolator in accordance with teachings of the present disclosure.

Fig. 7 is a front cross-sectional view of the example of fig. 5, wherein an example printing material hopper is shown discharging a powder layer on an example feedshoe in accordance with the teachings of the present disclosure.

Fig. 8A-8B are side cross-sectional views of an exemplary first state and an exemplary second state of an exemplary 3D printing material blocking apparatus having a fixed printing material hopper and a moving discharge opening isolator according to the teachings of the present disclosure.

FIG. 9 is a flow chart representing an exemplary method that may be performed to implement the exemplary vent opening isolator of FIGS. 1A-8 in accordance with the teachings of the present disclosure.

The figures are not drawn to scale. In contrast, the thickness of layers may be exaggerated in the figures for clarity of various layers and regions. Wherever possible, the same reference numbers will be used throughout the drawings and the accompanying written description to refer to the same or like parts. As used in this patent, stating that any part (e.g., a layer, film, region, or plate) is positioned (e.g., located, situated, disposed, or formed on, etc.) in any way on another part means that the referenced part is in contact with the other part, or that the referenced part is on the other part with one or more intermediate parts between them. Stating that any part is in contact with another part means that there is no intermediate part between the two parts.

Detailed Description

Fig. 1A-1D depict top views of an exemplary 3D printer 100 and an exemplary 3D printing material blocking apparatus 102, the exemplary 3D printing material blocking apparatus 102 including an exemplary printing material hopper 105 and an exemplary discharge opening isolator 110. Fig. 1A-1D show top views of stages of movement of an exemplary printing material hopper 105 relative to an exemplary discharge opening isolator 110 during an exemplary iteration of an additive manufacturing process over which exemplary printing material hopper 105 travels over exemplary discharge opening isolator 110.

In fig. 1A, an example discharge opening isolator 110 is disposed in an example first region 112 of an example 3D printer 100. An exemplary printing material hopper 105 is shown moving in the direction of arrow 106 over an exemplary discharge opening isolator 110. The example printing material hopper 105 includes a discharge opening (see fig. 3) at a bottom of the example printing material hopper 105 to discharge printing material from the printing material hopper 105 in an example second region 115 of the example 3D printer 100 adjacent to the example first region 112. When the exemplary printing material hopper 105 is in the exemplary second region 115, the exemplary discharge opening isolator 110 will block the discharge opening of the exemplary printing material hopper 105. In some examples, the example second area is the example feedshoe 120 adjacent to an example printing area 125 of the 3D printer, the example printing area 125 including an example movable platform 130, the workpiece built on the example movable platform 130. In some examples, the example second region 115 on which the printing material is discharged is an example printing region 125 of a 3D printer. In other words, in some examples, the example printing material hopper 105 will discharge printing material directly on the example movable platform 130.

In fig. 1B, the exemplary printing material hopper 105 is shown moving in the direction of arrow 132 along a path that is: the path includes an exemplary first region 112 of the exemplary 3D printer 100 and an exemplary second region 115 of the exemplary 3D printer 100 adjacent to the exemplary first region 112 of the exemplary 3D printer 100. As described above, the exemplary printing material hopper 105 includes a discharge opening at the bottom to discharge the printing material. When the example printing material hopper 105 is engaged with the example discharge opening isolator 110, the discharge opening is blocked and printing material cannot be discharged (see, e.g., fig. 1A). However, when the example printing material hopper 105 is disengaged from the example discharge opening isolator 110, portions of the discharge opening of the example printing material hopper 105 that are not engaged with the example discharge opening isolator 110 are allowed to discharge printing material from the example printing material hopper 105 (see, e.g., fig. 1B). For example, as seen in the example of fig. 1A, no printing material is discharged in the example first region 112, while in the example of fig. 1B, a layer of printing material 140 is shown discharged on the example feedshoe 120 in the example second region 115.

In fig. 1C, the example printing material hopper 105 is shown having completed travel along a path that includes the example first region 112 of the example 3D printer 100 and the example second region 115 of the example 3D printer 100, having discharged a layer of the example printing material layer 140 on the example feedshoe 120 along the example second region 115, and having substantially completed travel along a path that includes the example first region 112 of the example 3D printer 100 and the example second region 115 of the example 3D printer 100 in the direction of arrow 142.

In fig. 1D, the exemplary printing material hopper 105 is shown as having moved back along the path over the exemplary second region 115 and the exemplary feed shoe 120 in the direction of arrow 144. In some examples, when the direction of movement of the example printing material hopper (e.g., 105) is reversed from the position depicted in fig. 1C to move back toward the example discharge opening spacer 110 of the example first region 112, some additional printing material is discharged onto the existing example layer 140 to fill the example layer 140 to the predetermined height H1 (see fig. 5-7), resulting in any printing material deposition that may occur between the first pass (fig. 1B-1C) and the second pass (fig. 1D). In some examples, when the direction of motion of the example printing material hopper (e.g., 105) is reversed from the position depicted in fig. 1C to move back toward the example discharge opening isolator 110 of the example first region 112, the example printing material hopper 105 is depleted of printing material and no additional printing material is discharged in the movement over the existing example layer 140.

In fig. 1D, exemplary printing material hopper 105 is in exemplary first region 112 during engagement of exemplary discharge opening isolator 110 to complete an exemplary movement cycle of exemplary 3D printing material blocking apparatus 102. After forming the exemplary printing material layer 140 on the exemplary feedshoe 120, the exemplary spreader 150 is then advanced to spread the printing material on the exemplary feedshoe 120 evenly over the exemplary movable platform 130 in the exemplary print zone 125, where the printing material is further processed.

Fig. 2A-2F depict top views of another example 3D printer 200 showing an example 3D printing material blocking apparatus 202, the example 3D printing material blocking apparatus 202 including an example printing material hopper 105, an example discharge opening isolator 110 at a proximal end of an example feedshoe 120, and an example discharge opening isolator 210 at a distal end of an example feedshoe 120. Fig. 2A-2F illustrate stages of movement of an exemplary printing material hopper 105 relative to an exemplary discharge opening isolator 110 and an exemplary discharge opening isolator 210 during an exemplary iteration of an additive manufacturing process.

In fig. 2A, similar to fig. 1A, an exemplary printing material hopper 105 is disposed on an exemplary discharge opening isolator 110, the exemplary discharge opening isolator 110 blocking a discharge opening at a bottom of the exemplary printing material hopper 105 to prevent discharge of printing material from the printing material hopper 105 in an exemplary first region 112 of an exemplary 3D printer 200. Fig. 2A shows an exemplary printing material hopper 105 moving in the direction of arrow 212 along a path over an exemplary discharge opening isolator 110 in an exemplary first region 112. In fig. 2B, the exemplary printing material hopper 105 is shown moving in the direction of arrow 214 along a path including the exemplary first region 112 and the exemplary second region 115, and is shown discharging the layer of printing material 140 in the exemplary second region 115.

In fig. 2C, the example printing material hopper 105 is shown having completed traveling along a path that includes the example first region 112 of the example 3D printer 100 and the example second region 115 of the example 3D printer 100, having discharged one layer of the example printing material layer 140 along the example second region 115 on the example feedshoe 120, and having moved along arrow 216 into engagement with the example discharge opening isolator 210 at the distal end of the example feedshoe 120. In fig. 2C, the engagement of the example printing material hopper 105 with the example discharge opening isolator 210 blocks the discharge opening of the example printing material hopper 105 to prevent discharge of printing material.

In fig. 2D, the exemplary printing material hopper 105 is stationary in a position where the exemplary discharge opening isolator 210 blocks the discharge opening of the exemplary printing material hopper 105 to prevent discharge of the printing material. In fig. 2D, the example dispenser 150 is then advanced in the direction of arrow 218 to uniformly dispense the printing material on the example feedshoe 120 on the example movable platform 130 to form a layer 225 in the example print region 125. The exemplary dispenser 150 then returns to the initial position shown in FIGS. 2A-2C. In fig. 2E, the exemplary printing material hopper 105 is then moved back along the path in the direction of arrow 222 over the exemplary second region 115 to lay down a layer of printing material 224 on the exemplary feed shoe 120 for a subsequent iteration of the printing material process. In fig. 2F, the example printing material hopper 105 is again in the example first region 112 during engagement of the example discharge opening isolator 110. The movement of the example printing material hopper 105 onto the example discharge opening isolator 110 completes an example movement cycle of the example 3D printing material blocking apparatus 202.

Fig. 3 is a top perspective view of an exemplary printing material hopper 105 of an exemplary 3D printing material blocking apparatus 302, the exemplary 3D printing material blocking apparatus 302 including an exemplary discharge opening isolator 110 and an exemplary ramp 320 disposed between an exemplary second region 120 and the exemplary discharge opening isolator 110. In the position shown in fig. 3, the exemplary printing material hopper 105 is disposed on the exemplary discharge opening spacer 110, and the upper surface of the exemplary discharge opening spacer 110 blocks the discharge opening at the bottom of the exemplary printing material hopper 105 to prevent printing material from being discharged from the printing material hopper 105 in the exemplary first region 112. The example printing material hopper 105 is shown to include an example fill port cover 330, an example front side 340, an example first lateral side 350, and an example second lateral side 355. After the example fill port cover 330 is removed or displaced, an example printing material, such as 3D printing powder (e.g., nylon powder, Thermoplastic Polyurethane (TPU) powder, metal powder, etc.), is input into the example printing material hopper 105 through an opening in a top of the example printing material hopper 105. An exemplary drive system 360 is shown adjacent to the exemplary first lateral side 350. The example drive system 360 moves the example printing material hopper 105 along a path from the example discharge opening isolator 110 to and over the example second region 115, as shown by way of example in fig. 1C and 2C. In some examples, the drive system is a belt and pulley drive system, wherein the belt extends from a front of the exemplary printing material hopper 105 to a rear of the exemplary printing material hopper 105, and wherein the belt is attached to a carriage that moves along guide rods. The carriage is retained to the exemplary printing material hopper 105 and provides a downward force on the exemplary printing material hopper 105, as well as a translational force exerted by the belt and pulley system. In some examples, the motor used to drive the exemplary printing material hopper 105 includes an A7W93-60611 motor manufactured by Johnson Electric of hong kong. In some examples, the example drive system 360 includes an example DC motor having a pinion on an output shaft of the DC motor that is coupled to a rack adjacent to a path from the example discharge opening isolator 110 to and across the example second region 115 through a gear train that includes one or more gears. The example vent opening isolator 110 includes an example first lateral side 370 and an example second lateral side 375.

Fig. 4 is a bottom rear perspective view of the exemplary printing material hopper 105 of fig. 3. Fig. 4 shows an exemplary front side 340, an exemplary first lateral side 350, and an exemplary second lateral side 355. Additionally, fig. 4 also shows an exemplary back side 400. Collectively, the example front side 340, the example first lateral side 350, the example second lateral side 355, and the example back side 400 define an example interior volume 410 to hold printed material.

Fig. 4 shows an exemplary first fiducial 420 extending along an exemplary first lateral side 350 of an exemplary printing material hopper 105 and an exemplary second fiducial 425 extending along an exemplary second lateral side 355 of the exemplary printing material hopper 105. When disposed in an operational position, such as shown in the example of fig. 1A-3, the example first datum 420 and the example second datum 425 are disposed to contact the example feedshoe 120 when the printing material hopper is moved relative to the example feedshoe 120 of the example second region 115 to respectively define a first lateral boundary and a second lateral boundary for printing material discharged from the discharge opening onto the example feedshoe 120. The first lateral side 350 and the first datum 420 of the example printing material hopper 105 form a first boundary to limit lateral spread of discharged printing material on the first side, and the second lateral side 355 and the second datum 425 of the example printing material hopper 105 form a second boundary to limit lateral spread of discharged printing material on the second side.

In some examples, a width between exemplary first and second lateral sides 370, 375 (fig. 3) of exemplary discharge opening isolator 110 is less than a width between exemplary first and second lateral sides 350, 355 of exemplary printing material hopper 105. During movement of the example printing material hopper 105 along the example discharge opening isolator 110, the example first and second lateral sides 350, 355 of the example printing material hopper 105 slide outside of the example first and second lateral sides 370, 375 of the example discharge opening isolator 110. In some examples, during movement of the example printing material hopper 105 along the example discharge opening isolator 110, the example first and second lateral sides 350, 355 of the example printing material hopper 105 abut the example first and second lateral sides 370, 375 of the example discharge opening isolator 110.

Fig. 4 also shows that the exemplary printing material hopper 105 comprises an exemplary third datum 430 extending along the bottom of the exemplary front side 340 of the exemplary printing material hopper 105 and an exemplary fourth datum 435 extending along the bottom of the exemplary back side 400 of the exemplary printing material hopper 105. Exemplary third fiducial 430 and exemplary fourth fiducial 435 are spaced from exemplary first fiducial 420 and exemplary second fiducial 425 by a first height H1 shown in fig. 5 to define a height H1 of printing material (see, e.g., printing layer 140 in fig. 1C) discharged from exemplary discharge opening 450 defined by exemplary first lateral side 350, exemplary second lateral side 355, and exemplary back side 400. With exemplary first datum 420 and exemplary second datum 425 contacting exemplary feedshoe 120, exemplary discharge opening 450 discharges printing material as exemplary printing material hopper 105 moves along exemplary feedshoe 120.

Fig. 5-6 are side cross-sectional views illustrating an exemplary printing material hopper 105 moving relative to an exemplary feedshoe 120 to discharge an exemplary powder layer 140 on the exemplary feedshoe 120. Fig. 5 is represented by section 5-5 in fig. 2B. Fig. 6 is represented by section 6-6 in fig. 2C. In the exemplary cross-sectional views of FIGS. 5-6, the exemplary first fiducial 420 and the exemplary second fiducial 425 contacting the exemplary feedshoe 120 are not shown. The exemplary third datum 430 of the exemplary front side 340 and the exemplary fourth datum 435 of the exemplary back side 400 are spaced apart from the exemplary feedshoe 120 by a first height H1. In the example of fig. 5-6, gravity acts on the example printed material 500 to draw it through the example discharge opening 450. As gravity pulls exemplary printing material 500 downward, exemplary back side 400 and exemplary fourth datum 435 define printing material layer 140 having height H1 when exemplary printing material hopper 105 moves along exemplary feedshoe 120 in the direction of the arrow, with exemplary first datum 420 and exemplary second datum 425 contacting exemplary feedshoe 120. After dispensing the exemplary layer 140, such as shown in fig. 2E, when the direction of movement of the exemplary printing material hopper (e.g., 105) is reversed, such as shown in fig. 2D, additional printing material is allowed to be discharged onto the exemplary feedshoe 120, wherein the exemplary front side 340 and the exemplary third datum 430 (now lagging) define a next layer of printing material 140 having a height H1 (see fig. 2E-2F) when the exemplary printing material hopper 105 moves along the exemplary feedshoe 120 in the direction of the arrow, with the exemplary first datum 420 and the exemplary second datum 425 contacting the exemplary feedshoe 120.

Fig. 6 presents the movement of the example printing material hopper 105 onto the example discharge opening isolator 210 after the movement shown in the example of fig. 5. Fig. 6 illustrates an example ramp 600 that provides a transition for the example printing material hopper 105 between the example feedshoe 120 and the example discharge opening isolator 210. In some examples, no ramp 600 is provided and the example printing material hopper 105 moves directly onto the example discharge opening isolator 210. In some examples, the example discharge opening isolator 210 and/or the example printing material hopper 105 include chamfered, angled, rounded mating surfaces to facilitate movement of the example printing material hopper 105 onto the example discharge opening isolator 210 upon contact between the example discharge opening isolator 210 and the example printing material hopper 105. In some examples, the example ramp 600 has a length that is less than or equal to the length of the example vent opening isolator 210. In some examples, the example ramp 600 has a length that is greater than a length of the example vent opening isolator 210.

As shown in FIG. 6, the example upper surface 610 of the example vent isolator 210 is disposed a second height H2 from the example upper surface 620 of the example feedshoe 120, the second height H2 being greater than the height H1 of the example third datum 430 and the example fourth datum 435, thereby creating a height differential Δ H (i.e., H2-H1) between the example third datum 430 and the example fourth datum 435 relative to the example vent isolator 210. In some examples, the height H1 of the example vent isolator 110, 210 is between approximately 1.0-4.5mm (e.g., 1.6mm, etc.). In some examples, height H2 of example vent isolator 110, 210 is between about 0.0-1.5mm higher than height H1 (e.g., H2 is 0.1-0.2 mm higher than H1).

In some examples, the example upper surface 610 of the example vent opening isolator 210 is disposed at a height that is lower than a height of the example upper surface 620 of the example feedshoe 120 to place the example upper surface 610 below a height H1 of the example third datum 430 and the example fourth datum 435. While this example will not block the discharge of printing material from exemplary discharge opening 450 to the same extent as the example in which exemplary upper surface 610 of exemplary discharge opening isolator 210 blocks exemplary discharge opening 450, it will nevertheless provide a restriction on the discharge of printing material from exemplary discharge opening 450 and will advantageously reduce friction acting on the exemplary drive system and/or reduce or eliminate wear on exemplary third reference surface 430 and exemplary fourth reference surface 435.

In fig. 6, the exemplary third datum 430 is at a height H1 from the exemplary feeder shoe 120 (e.g., see fig. 1) before the exemplary printing material hopper 105 engages the exemplary ramp 600. Starting from the initial point of contact between the exemplary printing material hopper 105 and the exemplary ramp 600, continued forward movement of the exemplary printing material hopper 105 in the direction of the arrow pushes the exemplary third datum 430 up the elevation difference of ah and onto the exemplary upper surface 610 of the exemplary discharge opening isolator 210. Then, further forward movement of the exemplary printing material hopper 105 in the direction of the arrow pushes the exemplary fourth datum 435 up by the height difference of Δ H, at which point the exemplary printing material hopper 105 will fully engage the exemplary discharge opening spacer 210, which exemplary discharge opening spacer 210 will block the exemplary discharge opening 450 of the exemplary printing material hopper 105 to prevent the exemplary printing material 500 from being discharged therefrom.

In some examples, height H2 of example discharge opening isolator 210 and/or height H1 of example third datum 430 and example fourth datum 435 may be adjusted to a selected height setting from a plurality of available height settings. In this manner, the height difference in Δ H between height H2 of example upper surface 610 of example discharge opening isolator 110, 210 and height H1 of example third datum 430 and example fourth datum 435 may be adjusted. Likewise, a height difference of Δ H between the height H2 of the example upper surface 610 of the example vent opening isolator 110, 210 and the height H1 of the example third datum 430 and the example fourth datum 435 may be maintained, where the value of each of H1 and H2 is increased in proportion to allow the height H1 of the example layer 140 deposited on the example feedshoe 120 to be modified. Selecting different heights H1 for printing material layer 140 enables modification of exemplary printing material hopper 105 to accommodate different printing materials 500 having different characteristics (e.g., particle size, surface coefficient of friction, flowability, etc.). In some examples, rather than modifying height H2 of example vent opening isolator 210 and/or height H1 of example third and fourth datums 430, 435, there are a plurality of different heights H2 (e.g., H2)_n-2、H2_n-1、H2_n、H2_n+1、H2_n+2Etc., where n is an integer), and/or a plurality of different heights H1 (e.g., H1) having an exemplary third datum 430 and an exemplary fourth datum 435 (e.g., H1)_n-2、H1_n-1、H1_n、H1_n+1、H1_n+2Etc., where n is an integer) of a plurality of differently configured exemplary printing material hoppers 105. In such examples, a suitable combination of an example discharge opening isolator 210 and an example printing material hopper 105 may be made from a plurality of different example discharge opening isolators 110, 210 and a plurality of different example printing material hoppers 105 to provide the desired combination of H1, H2. In the example of FIG. 6, the example upper surface 610 of the vent opening isolator 210 has a height (e.g., H2) above the example upper surface 620 of the example feedshoe 120. In some examples, an elevation of the example upper surface 610 of the example vent isolator 110, 210 is different than an elevation of the example upper surface 620 of the example feedshoe 120.

In some examples, with the example ramp 600 disposed between the example discharge opening isolators 110, 210 and the example feed plate 120, some discharge of the printing material 500 will occur before the example discharge opening 450 of the example printing material hopper 105 engages a respective one of the example discharge opening isolators 110, 210. In some examples, residual printed material on the example ramp 600 is pushed to a vacuum collection device for removal. In some examples, in the next discharge iteration of the printing material 500, the residual printing material on the example ramp 600 is driven toward the example feedshoe 120 where it is incorporated into the printing material dispensed in the example print zone 125.

Fig. 7 illustrates an exemplary front view of the exemplary printing material hopper 105 of fig. 5 moving along the exemplary feedshoe 120 and discharging a layer of printing material 140, as shown in section 7-7 in fig. 2B. With respect to the example upper surface 620 of the example feedshoe 120, the height of the layer is H1, and the height of the example third fiducial 430 is also H1. The example first datum 420 and the example second datum 425 contact the example feedshoe 120 during movement of the printing material hopper 105 along the example feedshoe 120 to define a first lateral boundary 700 and a second lateral boundary 710, respectively, for printing material discharged from the discharge opening onto the example feedshoe 120. The first lateral side 350 and the first fiducial 420 form a first boundary to limit lateral spread of discharged printing material on the first side, and the second lateral side 355 and the second fiducial 425 form a second boundary to limit lateral spread of discharged printing material on the second side.

Fig. 8A-8B are side cross-sectional views of an exemplary first state (fig. 8A) and an exemplary second state (fig. 8B) of an exemplary 3D printing material blocking device 800 of an exemplary 3D printer. The example 3D printing material blocking device 800 includes an example discharge opening isolator 805 disposed on an example belt 810 of an example belt and pulley system having an example first pulley 812 and an example second pulley 814.

Exemplary 3D printing material blocking apparatus 800 also includes an exemplary printing material hopper 815 disposed in a fixed position relative to exemplary belt 810. An example gap 840 is formed between a first end 842 of the example vent opening isolator 805 and a second end 844 of the example vent opening isolator 805. As exemplary belt 810 drives exemplary discharge opening isolator 805 in a clockwise direction about exemplary first pulley 812 and exemplary second pulley 814, exemplary gap 840 is intermittently present below exemplary discharge opening 850 of exemplary printing material hopper 815. As the example belt 810 moves (e.g., clockwise), the printing material 500 flows into the example gap 840 under the influence of gravity and fills the example gap 840 to a height (e.g., H1) corresponding to the respective datum of the example printing material hopper 815 and the height H1 of the top surface of the example discharge opening isolator 805.

Fig. 8A shows an exemplary gap 840 of an exemplary tape 810, the exemplary gap 840 being disposed below an exemplary discharge opening 850 to receive printing material 500 from the exemplary discharge opening 850. Fig. 8B illustrates an example band 810 positioned to bias the example discharge opening isolator 805 into abutment with the example discharge opening 850 to block the flow of printing material 500 from the example discharge opening 850.

After the exemplary layer 140 of printing material 500 is formed in the exemplary gap 840 on the exemplary tape 810, the exemplary layer 140 is positioned adjacent to the exemplary spreader and stopped. The example dispenser (e.g., 150; fig. 2A-2F) then dispenses the layer 140 of printing material 500 over an example print area, such as shown in fig. 2D, thereby clearing the example gap 840 to receive the printing material 500.

In some examples, the example printing material hopper 815 includes a front side 860 and a rear side 865 that are inclined in the direction of travel of the example belt 810. In some examples, exemplary front side 860 and exemplary back side 865 of printing material hopper 815 are perpendicular to the direction of travel of exemplary belt 810.

FIG. 9 is a flow chart representing an example method 900, which example method 900 may be performed to implement the example vent opening isolator (e.g., 110) of FIGS. 1A-8. At block 910, the example feedshoe 120 is disposed in the example second region 115 of the example 3D printer 100. At block 920, the example discharge opening isolator 110 is disposed in the example first region 112 of the example 3D printer 100 adjacent to the example second region 115. The example vent opening isolator 110 is disposed at a second height (e.g., H2) relative to the example upper surface (e.g., 620, fig. 6) of the example feedshoe 120. At block 930, the example printing material hopper 105 is disposed to travel along a path that includes the example first region 112 and the example second region 115 of the example 3D printer 100.

At block 940, the example printing material hopper 105 is moved onto the example discharge opening isolator 110 to block discharge of printing material 500 from the example printing material hopper 105 in the example first region 112. At block 950, the example printing material hopper 105 is moved away from the example discharge opening isolator 110 to enable the printing material 500 to be discharged from the example printing material hopper 105 in the example second region 115.

Although certain example methods, apparatus and articles of manufacture have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus, and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.