Respirator test accessory
View Patent ↗A head form for testing a variety of respirators. The head form can prevent false leak failures by having a mask registration member upon which the mask under test is mounted, the mask registration member being self lubricating. In one embodiment, the registration member is an inflatable bladder. The bladder can be configured to limit lift away of the inflatable bladder from the recess, thereby mitigating leaks in the head form assembly. The bladder may be configured to limit roll away of portions of the bladder that register against the head form, thereby reducing or eliminating leaks between the inflatable bladder and the mask under test.
1. A head form assembly for testing a respirator, comprising:
a face portion having an outer perimeter;
a base portion that cooperates with at least a portion of said outer perimeter of said face portion to define a recess adjacent said face portion; and
a mask registration member disposed within said recess, said mask registration member being comprised of a base material and presenting a continuous registration surface for seating said respirator, said continuous registration surface being comprised of a lubricious material having greater lubricity than said base material.
2. The head form assembly of claim 1 , wherein said mask registration member is a bladder member.
3. The head form assembly of claim 2 further comprising a structure that restricts outward radial expansion of at least a portion of said bladder member.
4. The head form assembly of claim 1 wherein said lubricious material comprises an additive diffused from said mask registration member.
5. The head form assembly of claim 4 wherein said additive is paraffin wax.
6. The head form assembly of claim 1 wherein said lubricious material comprises a coating.
7. The head form assembly of claim 6 wherein said coating comprises a polytetrafluoroethylene material.
8. The head form assembly of claim 1 wherein said lubricious material is a coating that comprises polytetrafluoroethylene.
9. A method of assembling a head form assembly for a mask fit tester, comprising:
providing a mask registration member comprising a base material and defining a registration surface adapted to interface a respirator, said registration surface having greater lubricity relative to said base material;
providing a face portion of a head form and a base portion of said head form, said face portion and said base portion defining a continuous interface therebetween, said mask registration member being adapted for coupling to said head form between said face portion and said base portion at said interface;
assembling said face portion, said base portion and said mask registration member so that said mask registration member is disposed between said face portion and said base portion at said interface; and
attaching said face portion to said base portion with said mask registration member between said face portion and said base portion at said interface to secure said mask registration member to said head form.
10. The method of claim 9 wherein said greater lubricity of said registration surface provided in the step of providing said mask registration member is provided by an additive that is mixed with said base material prior to formation of said mask registration member.
11. The method of claim 10 wherein said additive diffuses to the surface by a blooming process.
12. The method of claim 11 wherein said blooming process is accelerated by maintaining the temperature of said mask registration member at a temperature of approximately 10° Celsius or lower for a period of approximately 24 hours.
13. The method of claim 12 wherein said additive is selected for the group consisting of paraffin wax, naphthene, polyethylene wax, microcrystalline waxes and normal chain hydrocarbons having from 26 to 29 carbon atoms, and wherein said base material is selected from the group consisting of butyl rubber, buna rubber, and thermoplastic elastomers.
14. The method of claim 9 wherein said mask registration member provided in the step of providing said mask registration member comprises a bladder member.
15. The method of claim 14 wherein said mask registration member provided in the step of providing said mask registration member is configured to restrict outward radial expansion of at least said portion of said bladder member.