Depositing arced portions of fiber-reinforced thermoplastic filament

Patent metadata

Field	Value
Publication number	US-11292190-B2
Application number	US-201715854676-A
Country	US
Kind code	B2
Filing date	Dec 26, 2017
Priority date	Dec 26, 2017
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

A technique for depositing fiber-reinforced thermoplastic filament in an arc is disclosed that mitigates the centripetal forces that arise in the prior art. In accordance with the illustrative embodiment, the centripetal forces are ameliorated by twisting the filament while depositing it in an arc.

First claim

What is claimed is:

1. A method of depositing a thermoplastic filament that comprises (i) a longitudinal axis L and (ii) a reinforcing fiber that is substantially parallel to the longitudinal axis L, the method comprising:
depositing a first portion of a segment of the thermoplastic filament in a straight line without twisting the thermoplastic filament around the longitudinal axis L and without twisting the reinforcing fiber around the longitudinal axis L, wherein the first straight portion of the segment has a length of S 1 as measured along the longitudinal axis L; and
depositing a second portion of the segment of the thermoplastic filament in a first arc of θ 1 radians and radius R 1 while twisting the second portion and the reinforcing fiber φ 1 radians around the longitudinal axis L, wherein the second portion of the segment has a length of S 2 as measured along the longitudinal axis L; and
depositing a third portion of the segment of the thermoplastic filament in a straight line without twisting the thermoplastic filament around the longitudinal axis L and without twisting the reinforcing fiber around the longitudinal axis L, wherein the third portion of the segment has a length of S 3 as measured along the longitudinal axis L;
wherein the first portion of the segment and the second portion of the segment are contiguous; and
wherein the second portion of the segment and the third portion of the segment are contiguous;
wherein S 1 , S 2 , S 3 , and R 1 are positive real numbers, and wherein θ 1 and φ 1 are real non-zero numbers.

2. The method of claim 1 wherein φ 1 =2πN 1 , where N 1 is a non-zero integer.

3. The method of claim 1 wherein φ 1 =2π.

4. The method of claim 1 wherein the reinforcing fiber in the thermoplastic filament in the second portion of the segment has the form of a helix with a rate of twist of

d
⁢

⁢

φ
1

d
⁢

⁢

S
2

≠
0

such that

d
2

⁢

φ
1

d
⁢

⁢

S
2
2

=
0.

5. A method of depositing a thermoplastic filament that comprises (i) a longitudinal axis L and (ii) a reinforcing fiber that is substantially parallel to the longitudinal axis L, the method comprising:
depositing a first portion of the segment of the thermoplastic filament in a first arc of θ 1 radians and radius R 1 while twisting the first portion and the reinforcing fiber φ 1 radians around the longitudinal axis L, wherein the first portion of the segment has a length of S 1 as measured along the longitudinal axis L;
depositing a second portion of the segment of the thermoplastic filament in a straight line without twisting the thermoplastic filament around the longitudinal axis L and without twisting the reinforcing fiber around the longitudinal axis L, wherein the second portion of the segment has a length of 52 as measured along the longitudinal axis L; and
depositing a third portion of the segment of the thermoplastic filament in a second arc of θ 2 radians and radius R 2 while twisting the third portion and the reinforcing fiber φ 2 radians around the longitudinal axis L, wherein the third portion of the segment has a length of S 3 as measured along the longitudinal axis L;
wherein the first portion of the segment and the second portion of the segment are contiguous;
wherein the second portion of the segment and the third portion of the segment are contiguous; and
wherein S 1 , S 2 , S 3 , R 1 , and R 2 are positive real numbers, and wherein θ 1 , θ 2 , φ 1 , and φ 2 are real non-zero numbers.

6. The method of claim 5 wherein φ 1 =2πN 1 and φ 2 =2πN 2 , and wherein N 1 and N 2 are non-zero integers.

7. The method of claim 6 wherein N 1 =−N 2 .

8. The method of claim 6 wherein N 1 =1 and N 2 =−1.

9. The method of claim 5 wherein θ 1 ≠θ 2 and φ 1 =φ 2 .

10. The method of claim 5 wherein R 1 ≠R 2 and φ 1 =φ 2 .

11. The method of claim 5 wherein R 1 θ 1 ≠R 2 θ 2 and φ 1 =φ 2 .

12. The method of claim 5 wherein the reinforcing fiber in the thermoplastic filament in the second portion of the segment has the form of a helix with a rate of

d
⁢

⁢

φ
1

d
⁢

⁢

S
1

≠
0

such that

d
2

⁢

φ
1

d
⁢

⁢

S
1
2

=
0

;

and
wherein the reinforcing fiber in the thermoplastic filament in the third portion of the segment has the form of a helix with a rate of twist of

d
⁢

⁢

φ
2

d
⁢

⁢

S
3

≠
0

such that

Assignees

• Arevo Inc

Inventors

• Mantha Chandrashekar

Classifications

• B33Y70/10

  Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials · CPC title

• B33Y40/00

  Auxiliary operations or equipment, e.g. for material handling · CPC title

• B29C64/165 Primary

  using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber · CPC title

• D02G3/00

  Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for (for producing crimped or curled yarns D02G1/00) · CPC title

• B29C64/194

  during lay-up · CPC title