# US 10,766,197 B2 · Apparatus and method for selective laser sintering an object with a void

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- Number: US 10,766,197 B2
- Document ID: US10766197B2
- Status: Granted
- Kind: B2
- Application number: 15/470,328
- Filed: 2017-03-27
- Published: 2017-10-05
- Granted: 2020-09-08
- Earliest claimed: 2016-03-31
- Assignees: Hexcel Corporation
- Applicants: Hexcel Corporation
- Inventors: Scott DeFelice; Anthony DeCarmine
- Web page: https://patentgrep.com/patent/US10766197B2

## CPC

- B29C 64/393: for controlling or regulating additive manufacturing processes
- B29C 35/0288: {Controlling heating or curing of polymers during moulding, e.g. by measuring temperatures or properties of the polymer and regulating the process (controlling or regulating chemical, physical or physico- chemical processes in general B01J19/0006)}
- B29C 64/153: using layers of powder being selectively joined, e.g. by selective laser sintering or melting
- B33Y 10/00: Processes of additive manufacturing
- B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor
- B33Y 50/00: Data acquisition or data processing for additive manufacturing
- B33Y 50/02: for controlling or regulating additive manufacturing processes
- B33Y 70/00: Materials specially adapted for additive manufacturing
- B29K 2071/00: Use of polyethers {, e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof}, as moulding material
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS

## Abstract

A method of producing an object from a polymer powder using a laser sintering system, whereby the laser sintering system introduces heat energy to solidify select points of a layer of polymer powder according to build data of the object and adjusts the heat energy according to solidification of select points of other layers.

## Claims

### Claim 1

A selective laser sintering method, the method comprising the steps of:
(i) providing build data of an object, the build data comprising a plurality of cross-section patterns according to geometric description data for the object, each of the cross-section patterns comprising data specifying points in the cross-section intended for solidification, and the plurality of cross-section patterns including a cross-section pattern for a layer L0, a cross-section pattern for a layer L−1, and a cross-section pattern for a layer L−2 wherein the layer L−1 is a layer below the layer L0, and the layer L−2 is a layer below the layer L−1;
(ii) applying a polymer powder layer L0 coinciding with the build layer L0 on a bed of a laser sintering system;
(iii) determining an amount of heat energy to introduce by electromagnetic radiation to solidify a point at a first x-y position in the powder layer L0, the point at the first x-y position being intended for solidification according to the cross-section pattern for the build layer L0;
(iv) adjusting the amount of heat energy to introduce at the first x-y position in the powder layer L0 using a controller programmed to make the adjustment based on whether the build data specifies solidification of a point at the first x-y position in the cross-section pattern for the layer L−1 and the cross section pattern for the layer L−2, wherein the adjustment is made to inhibit unwanted fusion between the first x-y position in the powder layer L0 and the first x-y position in the layer L−1; and
(v) solidifying the point at the first x-y position in the polymer powder layer L0 by introducing the adjusted amount of heat energy.

### Claim 2 (depends on 1)

The method of claim 1, wherein the layer L−1 is adjacent to the layer L0.

### Claim 3 (depends on 2)

The method of claim 2, wherein the layer L−2 is adjacent to the layer L−1.

### Claim 4 (depends on 2)

The method of claim 2, wherein the adjusting step further comprises reducing the amount of heat energy to introduce by the electromagnetic radiation to solidify the point at the first x-y position in the powder layer L0 when the build data does not specify solidification of the point at the first x-y position in the layer L−1.

### Claim 5 (depends on 1)

The method of claim 1, wherein the layer L−2 is below and adjacent to the layer L−1.

### Claim 6 (depends on 1)

The method of claim 1, wherein the step of adjusting the amount of heat energy to introduce by electromagnetic radiation to solidify a point at the first x-y position in the powder layer L0 also depends on whether the build data specifies solidification of a point at the first x-y position in one or more powder layers in a heat affected zone that would be impacted by the introduced radiation.

### Claim 7 (depends on 6)

The method of claim 6, wherein the polymer powder comprises one or more of PEK, PEEK, PEKK, PEEKK, and PEKEKK.

### Claim 8 (depends on 7)

The method of claim 7, wherein the polymer powder comprises PEKK.

### Claim 9 (depends on 1)

The method if claim 1, wherein said adjusting is performed such that the amount of heat energy is adjusted so as to inhibit said fusion between the point at the first x-y position in the layer L0 and the point at the first x-y position in the layer L−1 when the build data does not specify solidification of the point at the first x-y position in the layer L−1.

### Claim 10 (depends on 1)

The method of claim 1, wherein step (iv) is performed prior to step (ii).

### Claim 11

A method of solidifying an x-y position in a coating of a polymer powder during a selective laser sintering build process, the method including the steps of:
(i) providing build data for a plurality of layers in a selective laser sintering build, the plurality of layers comprising a current layer, a first layer below the current layer, a second layer below the first layer, and a third layer below the second layer, and the build data specifying a plurality of points for solidification in each of the layers, the plurality of points specified for solidification in the current layer including a point at an x-y position in the current layer;
(ii) applying a coating of a polymer powder coinciding with the current build layer on a bed of the laser sintering system;
(iii) determining an amount of heat energy to introduce by an electromagnetic radiation source to solidify the point at the x-y position in the current powder layer;
(iv) adjusting the amount of heat energy to introduce by the electromagnetic radiation source to solidify the point at the x-y position in the current powder layer using a controller programmed to make the adjustment based on whether the build data specifies solidification of a point at the x-y position in two or more of: the build data for the first layer, the second layer, and the third layer, wherein the adjustment is made to inhibit unwanted fusion between the current layer and the first layer; and
(v) introducing the adjusted amount of heat energy for solidification at the x-y position in the current coating of powder.

### Claim 12 (depends on 11)

The method of claim 11, wherein the first layer is adjacent to the current layer, the second layer is adjacent to the first layer, and the third layer is adjacent to the second layer.

### Claim 13 (depends on 12)

The method of claim 12, wherein among the two or more layers considered for the step of adjusting the point at the x-y position in at least the first layer is considered.

### Claim 14 (depends on 13)

The method of claim 13, wherein the point at the x-y position in at least the second layer is also considered among the two or more layers considered for the step of adjusting.

### Claim 15 (depends on 14)

The method of claim 14, wherein the point at the x-y position in the third layer is also considered for the step of adjusting.

### Claim 16 (depends on 13)

The method of claim 13, wherein said adjusting is performed such that the amount of heat energy for solidification of the point at the x-y position in the current layer is greater when the build data specifies solidification of the point at the x-y position in the first layer than when the build data does not specify solidification of the point at the x-y position in the first layer.

### Claim 17 (depends on 11)

The method if claim 11, wherein the amount of heat energy is adjusted so as to inhibit said fusion between the point at the x-y position in the current layer and the point at the x-y position in the first layer when the build data does not specify solidification of the point at the x-y position in the first layer.

### Claim 18 (depends on 11)

The method of claim 11, wherein step (iv) is performed prior to step (ii).