Method for heating and controlling temperature of composite material during automated placement

• US 6,451,152 B1
• Filed: 05/24/2000
• Issued: 09/17/2002
• Est. Priority Date: 05/24/2000
• Status: Expired due to Term

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Holmes, Scott, Haake, John M., Lawton, Stanley A.
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): Kilkenny, Todd J.
• Application Number:
  US09/578,069
• Time in Patent Office: 846 Days
• Field of Search: 156/272.8, 156/189, 156/173, 156/523, 156/574, 156/273.3, 156/308.2, 219/121.6, 219/121.61, 219/121.62, 219/121.63, 219/121.76, 219/121.78
• US Class Current: 156/272.8
• CPC Class Codes: B23K 26/034 Observing the temperature of the workpiece
• CPC Class Codes: B23K 26/073 Shaping the laser spot
• CPC Class Codes: B23K 26/0846 for moving elongated workpieces longitudinally, e.g. wire or strip material
• CPC Class Codes: B29C 2035/0838 using laser
• CPC Class Codes: 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
• CPC Class Codes: B29C 35/08 by wave energy or particle radiation B29C64/00, B29C71/04 take precedence
• CPC Class Codes: B29C 65/1632 direct heating the surfaces to be joined
• CPC Class Codes: B29C 65/1658 scanning once, e.g. contour laser welding
• CPC Class Codes: B29C 65/1664 making use of several radiators
• CPC Class Codes: B29C 65/1674 making use of laser diodes B29C65/167 takes precedence
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/43 Joining a relatively small portion of the surface of said articles B29C66/45 takes precedence
• CPC Class Codes: B29C 66/472 said single elements being substantially flat
• CPC Class Codes: B29C 66/73113 Thermal conductivity
• CPC Class Codes: B29C 66/83411 Roller, cylinder or drum types B29C66/83431 takes precedence; rollers, cylinders or drums moving relative to and tangentially to the parts to be joined B29C66/8362
• CPC Class Codes: B29C 66/83415 the contact angle between said rollers, cylinders or drums and said parts to be joined being a non-zero angle B29C66/83433 takes precedence
• CPC Class Codes: B29C 66/8362 Rollers, cylinders or drums moving relative to and tangentially to the parts to be joined
• CPC Class Codes: B29C 66/91216 enabling contactless temperature measurements, e.g. using a pyrometer
• CPC Class Codes: B29C 66/91221 of the parts to be joined
• CPC Class Codes: B29C 66/91411 of the parts to be joined, e.g. the joining process taking the temperature of the parts to be joined into account
• CPC Class Codes: B29C 66/91431 : the temperature being kept constant over time
• CPC Class Codes: B29C 66/91641 : the heat or the thermal flux being non-constant over time
• CPC Class Codes: B29C 66/91655 : by controlling or regulating the current intensity
• CPC Class Codes: B29C 66/934 : by controlling or regulating the speed
• CPC Class Codes: B29C 66/961 : involving a feedback loop mechanism, e.g. comparison with a desired value
• CPC Class Codes: B29C 70/30 : Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core
• CPC Class Codes: B29C 70/386 : Automated tape laying [ATL]
• CPC Class Codes: B32B 2309/02 : Temperature
• CPC Class Codes: B32B 2309/72 : For measuring or regulating, e.g. systems with feedback loops
• CPC Class Codes: B32B 2310/0843 : using laser
• CPC Class Codes: B32B 38/0036 : Heat treatment for heating or cooling of layers during lamination B32B37/06, B32B37/08

Abstract

Composite articles are produced by guiding composite tape material through a compaction region where the tape material is pressed onto a substrate, and heating the tape and substrate ahead of the compaction region by irradiating opposing surfaces of the tape and substrate with laser radiation produced by a laser diode array. The laser diode array is divided into independently controllable diode groups, and the diode groups are controlled so as to independently control heating of one area of the tape and substrate relative to another area of the tape and substrate. In one embodiment, the widthwise profile of the light energy is such that a widthwise portion of the tape at an inner radius of a curved path along which the tape is steered at the compaction region is heated to a greater extent than a widthwise portion of the tape at an outer radius of the path. The laser diode array can also be controlled to heat the tape material to a different extent than the substrate to compensate for different rates of heat loss. One or more diode groups of the array can be deactivated when not needed, such as when the tape material is narrower than the full light field generated by the array. Different diode groups of the array can produce light of different wavelengths for achieving different rates of absorption by different areas of the composite materials.

Claims

1. A method of forming a composite article from composite tape, the method comprising:

guiding the composite tape onto a surface of a substrate and pressing the tape against the substrate in a compaction region such that the tape conforms to the contour of the surface of the substrate and is adhered thereto; and

irradiating an area defined by opposing surfaces of the tape and of the substrate proximate the compaction region with a field of light energy generated by a laser diode array to heat the tape and substrate, wherein the laser diode array is controlled so as to irradiate at least one of the opposing surfaces with light energy having a light intensity distribution that is non-uniform in at least one direction.

2. The method of claim 1, wherein the laser diode array is controlled so as to irradiate at least one of the opposing surfaces with light energy having a light intensity distribution that is a function of a curvature of a path along which the tape is guided onto the substrate at the compaction region.

3. The method of claim 1, wherein the tape is guided along a curved path at the compaction region such that an inner widthwise portion of the tape at an inner radius of the path must undergo a greater degree of conformance relative to an outer widthwise portion of the tape at an outer radius of the path, and wherein the laser diode array is controlled such that the inner widthwise portion of the tape receives a greater light intensity relative to the outer widthwise portion of the tape.

4. A method of forming a composite article from composite tape, the method comprising:

guiding the composite tape onto a surface of a substrate and pressing the tape against the substrate in a compaction region such that the tape conforms to the contour of the surface of the substrate and is adhered thereto; and

irradiating an area defined by opposing surfaces of the tape and of the substrate proximate the compaction region with a field of light energy generated by a laser diode array to heat the tape and substrate, wherein the laser diode array is controlled such that a greater amount of heat energy is applied to the opposing surface of the tape relative to the amount of heat energy applied to the opposing surface of the substrate.

5. A method of forming a composite article from composite tape, the method comprising:

guiding the composite tape onto a surface of a substrate and pressing the tape against the substrate in a compaction region such that the tape conforms to the contour of the surface of the substrate and is adhered thereto; and

irradiating an area defined by opposing surfaces of the tape and of the substrate proximate the compaction region with a field of light energy generated by a laser diode array to heat the tape and substrate, wherein at least two tapes are simultaneously fed to the compaction region and placed onto the substrate at different feed rates, and wherein the laser diode array is controlled so as to produce a different amount of heating of one tape relative to the other to compensate for the different feed rates.

6. A method of forming a composite article from composite tape, the method comprising:

guiding the composite tape onto a surface of a substrate and pressing the tape against the substrate in a compaction region such that the tape conforms to the contour of the surface of the substrate and is adhered thereto; and

irradiating an area defined by opposing surfaces of the tape and of the substrate proximate the compaction region with a field of light energy generated by a laser diode array to heat the tape and substrate, wherein the tape is guided and pressed onto the substrate by a tape placement head and the laser diode array is fixed relative to the tape placement head such that when the tape is guided and pressed onto a contoured surface of the substrate having a convex or concave curvature there is a change in orientation of the tape placement head relative to the substrate surface causing the angle of incidence of the light energy striking the substrate to change, and wherein the laser diode array is controlled so as to compensate for the change in incidence angle by varying a profile of the intensity of the light energy in the direction in which the tape placement head travels over the surface.

7. A method for making a composite article from composite tape material, comprising:

guiding composite tape material onto a surface of a substrate and pressing the composite tape material in a compaction region such that the tape material conforms to the contour of the surface of the substrate and is adhered thereto; and

irradiating an area of the tape material and the substrate proximate the compaction region with a field of light energy generated by a laser diode array, the array being divided into at least first and second diode groups which produce at least first and second light zones respectively irradiating first and second regions of the area, and wherein the first diode group is operable to irradiate the first region with light of a first wavelength and the second diode group is operable to irradiate the second region with light of a second wavelength different from the first wavelength, the first region absorbing the light of the first wavelength to a different extent than the second region absorbs the light of the second wavelength.

8. A method for making a composite article from composite tape material, comprising:

guiding composite tape material onto a surface of a substrate and pressing the composite tape material in a compaction region such that the tape material conforms to the contour of the surface of the substrate and is adhered thereto, the tape material having differing widths ranging from a widest tape material to a narrowest tape material;

irradiating the tape material proximate the compaction region with a field of light energy generated by a laser diode array, the array being divided into a plurality of independently operable diode groups producing a like number of light zones located side-by-side along a widthwise direction of the tape material, the array being operable such that the field of light energy irradiates the entire width of the widest tape material when all of the diode groups of the array are activated; and

activating fewer than all of the diode groups of the array when tape material narrower than the widest tape material is being guided and pressed, such that the width of the field of light energy approximately matches that of the tape material.

9. The method of claim 8, wherein guiding the tape material comprises guiding a plurality of individual tapes such that the tapes are side-by-side and collimated as they pass through the compaction region, and wherein the laser diode array is divided such that there is at least one zone extending across the width of each tape.

10. The method of claim 8, wherein the laser diode array is formed by stacking a plurality of laser diode bars atop one another, each bar having a plurality of laser diode groups located side-by-side along a widthwise direction of the bar, the bars being oriented with their widthwise directions generally parallel with the width of the tape material being guided and pressed, and wherein one or more of the laser diode groups of each bar are inactivated when the tape material is narrower than the widest tape material.

11. The method of claim 8, wherein the laser diode array is formed by stacking a plurality of laser diode bars atop one another, each bar having a widthwise direction oriented generally parallel with a lengthwise direction of the tape material being guided and pressed, and wherein one or more of the laser diode bars are inactivated when the tape material is narrower than the widest tape material.

12. A method for making a composite article from composite tape material, comprising:

guiding composite tape material onto a surface of a substrate and pressing the composite tape material in a compaction region such that the tape material conforms to the contour of the surface of the substrate and is adhered thereto;

irradiating an area of the tape material proximate the compaction region with a field of light energy generated by a laser diode array, the array being divided in at least one direction into a plurality of independently activatable diode groups which, when activated, produce a like number of light zones located side-by-side along said direction; and

varying the area of the tape material that is irradiated by the field of light energy by varying the number of the diode groups that are activated.

13. The method of claim 12, wherein the array is oriented such that the light zones are spaced along a widthwise direction of the tape material, and wherein a width of the area irradiated by the field of light energy is varied by deactivating a variable number of the diode groups.

14. The method of claim 12, wherein the array is oriented such that the light zones are spaced along a lengthwise direction of the tape material, and wherein a length of the area irradiated by the field of light energy is varied by deactivating a variable number of the diode groups.

15. The method of claim 12, wherein the array is divided into independently activatable diode groups along each of two orthogonal directions that are oriented parallel to a widthwise and a lengthwise direction of the tape material, and wherein both a width and a length of the area irradiated by the field of light energy are varied by deactivating a variable number of the diode groups in both of the orthogonal directions.