Method of filling voids in a filled seal cap

Patent metadata

Field	Value
Publication number	US-10780657-B2
Application number	US-201515535145-A
Country	US
Kind code	B2
Filing date	Dec 22, 2015
Priority date	Dec 24, 2014
Publication date	Sep 22, 2020
Grant date	Sep 22, 2020

Abstract

Methods of using and repairing seal caps as well as constructions comprising seal caps, including in some embodiments seal caps which may be useful in sealing fasteners that protrude into fuel storage cells in aircraft. In some embodiments, methods include the use of optically translucent seal cap and application of a second quantity of sealant to fill voids observed within the interior of the seal cap after cure of a first quantity of sealant.

First claim

We claim:

1. A method of sealing a fastener comprising the steps of:
f) providing an optically translucent seal cap which defines an interior, the seal cap having an average wall thickness of less than 0.5 mm;
g) applying a first quantity of uncured sealant to the interior of the seal cap;
h) applying the seal cap and first quantity of sealant over a fastener;
j) curing the first quantity of sealant to form a first quantity of cured sealant;
k) filling a void within the interior of the seal cap with a second quantity of uncured sealant; and
l) curing the second quantity of sealant to form a second quantity of cured sealant.

2. The method according to claim 1 wherein the step of curing the first quantity of sealant is accomplished by application of actinic radiation to the sealant through the seal cap.

3. The method according to claim 1 wherein the step of curing the second quantity of sealant is accomplished by application of actinic radiation to the sealant through the seal cap.

4. The method according to claim 1 wherein the step of filling a void within the interior of the seal cap with a second quantity of uncured sealant is accomplished by injecting a second quantity of uncured sealant into the void from a syringe.

5. The method according to claim 1 wherein the first quantity of curable sealant is optically translucent.

6. A method of repairing a fastener seal comprising the steps of:
m) providing a protected fastener construction comprising:
i) a fastener;
ii) an optically translucent seal cap which defines an interior;
iii) a first quantity of cured sealant; and

wherein the seal cap is positioned over the fastener such that at least a portion of the fastener resides in the interior of the seal cap;
wherein the interior of the seal cap additionally contains the first quantity of cured sealant which binds the seal cap to the fastener;
wherein the seal cap includes a polyurethane polymer; and
wherein a void is present in a location in the interior of the seal cap;
n) filling the void with a second quantity of uncured sealant; and
o) curing the second quantity of sealant.

7. The method according to claim 6 wherein the step of curing the second quantity of sealant is accomplished by application of actinic radiation to the sealant through the seal cap.

8. The method according to claim 6 wherein the step of filling the void with a second quantity of uncured sealant is accomplished by injecting a second quantity of uncured sealant into the void from a syringe.

9. The method according to claim 6 wherein the first quantity of cured sealant is optically translucent.

Assignees

• 3M Innovative Properties Co

Inventors

• Swan Michael D
• Hebert Larry S
• Ylitalo David A

Classifications

• B29C2035/0833

  using actinic light · CPC title

• B29C73/025 Primary

  fed under pressure · CPC title

• F16B33/004 Primary

  Sealing; Insulation (by means of washers F16B43/001) · CPC title

• B29C2045/0079

  applying a coating or covering · CPC title

• B29C35/0888

  using transparant moulds · CPC title