Non-adhesive thin gel sealants and methods of making and using the same

Abstract

Applicant provides a number of embodiments of a sealant, the sealant comprising a polyurethane gel which, in some embodiments, has a thickness of 12 mil or less (uncompressed). Uses of the sealant are shown, including uses between aircraft parts under compression. Sometimes the sealant may have a very thin skeleton. Sometimes the sealant is in the form of a die cut gasket, a tape or a tacky gel sprayable. Methods for making the sealant are also disclosed. The sealants may be used pre-cured or may be sprayed on to the aircraft parts and form in place.

1 . A device for use on an aircraft assembly, the aircraft assembly having a first part having an inner face portion; a second part having an inner face portion; and a multiplicity of fasteners for joining the two parts, the device comprising:
 a sealant for placement between the two inner face portions, the sealant comprising a tacky, deformable body of polyurethane gel, the body with tacky outer faces wherein the body has a thickness of 12 mil or less uncompressed;   further comprising a skeleton configured with many openings, the skeleton encapsulated in the body and the skeleton having an uncompressed thickness of 12 mil or less.   
     
     
         2 . The device of  claim 1 , wherein the body has a thickness of between about 1-6 mil when compressed between the two parts. 
     
     
         3 . The device of  claim 1 , wherein the polyurethane gel is cured. 
     
     
         4 . The device of  claim 1 , wherein the assembly is a lap joint, a double, a patch, a heat shield or include electronic equipment. 
     
     
         5 . The device of  claim 1 , wherein the tacky body is deposited on one or both of the first or second part by a pneumatic spray gel. 
     
     
         6 . The device of  claim 1 , wherein the body is pre-cured before placement on one of the two inner face portions. 
     
     
         7 . The device of  claim 1 , wherein the body cures after placement on one of the two inner face portions. 
     
     
         8 . The device of  claim 1 , further comprising a release film. 
     
     
         9 . The device of  claim 1 , wherein the skeleton is a woven mesh. 
     
     
         10 . The device of  claim 1 , wherein the skeleton is metallic. 
     
     
         11 . The device of  claim 1 , wherein the skeleton is non-metallic. 
     
     
         12 . The device of  claim 1 , wherein the skeleton is molded or extruded polyamide or polypropylene. 
     
     
         13 . An aircraft having a fuselage, the fuselage comprising:
 multiple panels which overlap partially, the overlaps comprising multiple lap joints;
 wherein the lap joints comprise facing surfaces, the facing surfaces having a thin, tacky, cured, deformable, resilient polyurethane gasket for compression therebetween. 
   
     
     
         14 . The fuselage of  claim 13 , wherein the compressed gasket thickness is less than about 6 mil. 
     
     
         15 . The fuselage of  claim 13 , wherein the gasket includes a skeleton. 
     
     
         16 . A method of joining two adjacent parts on an aircraft, the method comprising the steps of:
 obtaining a thin gasket assembly comprising a cured polyurethane gel body gasket or tape having a first, tacky side and a second tacky side, the gasket assembly comprising a release film on one of the sides;   applying the first side to an inner face of one of the two parts;   positioning an inner face of the other of the two parts adjacent the gasket or tape;   removing the release film from the second side of the gasket before the following step; and, joining the parts with fasteners.   
     
     
         17 . A method of manufacturing a thin gasket having a tacky polyurethane gel body, the method comprising the steps of:
 providing a release film that has been to easily release from a cured tacky polyurethane gel body;   applying an uncured mix of the gel to the adapted release film to a thickness of about 12 mil or less; and   allowing the uncured mix to cure.   
     
     
         18 . The method of  claim 17 , wherein the release film of the providing step has multiple perforations therethrough. 
     
     
         19 . The method of  claim 17 , wherein the release film of the providing step is at least partly coated with release agent. 
     
     
         20 . The method of  claim 17 , wherein the release film of the providing step is meltable. 
     
     
         21 . A sealant for use with an aircraft having a first part and a second part connected with fasteners, the sealant consisting essentially of:
 a sealant for receipt between the parts of the aircraft, the sealant comprising a resilient, cured, deformable, polyurethane body having a tacky polyurethane upper surface and a tacky polyurethane lower surface; and   at least one release film for placement against at least one of the upper or lower surfaces of the body, the release film for removal from the body before placement of the sealant on an aircraft part.   
     
     
         22 . The sealant of  claim 21 , wherein the body has an uncompressed thickness of less than 12 mil. 
     
     
         23 . The sealant of  claim 21 , wherein the body has an uncompressed thickness of between 2 and 12 mil. 
     
     
         24 . The sealant of  claim 21 , wherein the body has a compressed thickness of between about 1-6 mil. 
     
     
         25 . The sealant of  claim 21 , further including a temporary tack decreasing agent on at least one of the upper or lower surface of the body. 
     
     
         26 . The device of  claim 21 , wherein the at least one release film is one release film on one of the upper or lower surface of the sealant and a second release film on the other of the upper or lower surface of the sealant. 
     
     
         27 . The device of  claim 21 , wherein the release film has multiple small perforations. 
     
     
         28 . The device of  claim 21 , wherein the release film is dissolvable in a liquid. 
     
     
         29 . The device of  claim 21 , wherein the release film is heat meltable. 
     
     
         30 . The device of  claim 21 , wherein the release film is an FEP (fluorinated ethylene propylene) sheet. 
     
     
         31 . The device of  claim 21 , wherein the release film is plastic. 
     
     
         32 . The device of  claim 21 , wherein an inert agent is applied to a surface of the release film which engages the sealant. 
     
     
         33 . A method of joining with multiple fasteners, adjacent, inner and outer overlapping panels of an aircraft fuselage, the panels having fastener holes, the method comprising the steps of:
 obtaining a sealant tape comprising a thin, cured, tacky polyurethane gel body having a first, tacky polyurethane surface and a release film on a second cured tacky polyurethane surface;   applying the first, tacky polyurethane surface of the body to an outer edge of one of either the inner panel or the outer panel of the overlapping panels;   positioning the outer edge of the other panel of the overlapping panels adjacent the sealant tape such that an overlap width approximates a sealant tape width;   removing the release film from the second surface of the sealant tape; and   joining the panels with the fasteners so the edges hold the polyurethane gel body under sufficient compression to cause some deformation of the polyurethane gel.   
     
     
         34 . The method of  claim 33 , further comprising the step of:
 applying an uncured mix of polyurethane gel proximate the fasteners.   
     
     
         35 . The method of  claim 33 , wherein the release film of the providing step has multiple perforations therethrough. 
     
     
         36 . The method of  claim 33 , wherein the release film of the providing step is at least partly coated with release agent. 
     
     
         37 . The method of  claim 33 , wherein the release film of the providing step is meltable. 
     
     
         38 . The method of  claim 33 , wherein the release film is plastic. 
     
     
         39 . The method of  claim 33 , wherein the release film is dissolvable. 
     
     
         40 . The method of  claim 33 , further including the step of, prior to the joining step, covering at least partly the first surface with a temporary tack release agent. 
     
     
         41 . The method of  claim 33 , wherein the uncompressed thickness of the sealant tape is about 12 mil or less and the compressed thickness is between about 1-6 mil. 
     
     
         42 . A device for use with an aircraft assembly having a first part and a second part, and fasteners, for applying compression to the two parts, the device comprising:
 a sealant for receipt between the parts of the aircraft, the sealant comprising a resilient, cured, deformable, skeleton-free, polyurethane body having a tacky polyurethane upper surface and a tacky polyurethane lower surface; and   a skeleton between 1-12 mm thick, the skeleton covered and encapsulated in the polyurethane body.