Method for drying seal materials for ignition devices
View Patent ↗A method for drying a seal material for use in manufacturing an ignition device, e.g., a spark plug. A free-flowing or loose seal material having a moisture content is provided and brought together with a desiccant for a time sufficient to produce a dry seal material by reducing the moisture content of the loose seal material to a desired level. Thereafter, the dry seal material and the desiccant may be separated from one another so that the dry seal material can be used to form a seal within an internal bore of a spark plug.
1. A method for drying a seal material for use in manufacturing an ignition device, comprising the steps of:
(a) granulating a powdered seal material to form a loose seal material having a moisture content;
(b) providing a desiccant;
(c) bringing the loose seal material and the desiccant together to produce a dry seal material by reducing the moisture content of the loose seal material;
(d) separating the dry seal material and the desiccant;
(e) introducing the dry seal material into an internal bore of an insulator of the ignition device; and
(f) regenerating the desiccant so that it may be used in a drying method, wherein the desiccant is regenerated using waste heat to drive off moisture.
2. The method set forth in claim 1 , wherein said step (a) further comprises providing a loose seal material that includes at least one material selected from the group consisting of: glass, ceramic, metal, or a filler.
3. The method set forth in claim 1 , wherein said step (b) further comprises providing a desiccant that has hygroscopic properties and includes at least one material selected from the group consisting of: activated alumina, activated charcoal, calcium sulfate, calcium chloride, silica gel, clay, or molecular sieves.
4. The method set forth in claim 1 , wherein said step (b) further comprises providing a desiccant in an amount from about 5 wt. % to 50 wt. % of the loose seal material.
5. The method set forth in claim 1 , wherein said step (b) further comprises providing a desiccant in an amount that is calculated to reduce the moisture content of the loose seal material to a target level.
6. The method set forth in claim 1 , wherein said step (c) comprises bringing the loose seal material and the desiccant together in direct contact with one another.
7. The method set forth in claim 1 , wherein said step (c) further comprises bringing the loose seal material and the desiccant together by mixing, stirring, or agitating the loose seal material and the desiccant and promoting a release of moisture from the loose seal material.
8. The method set forth in claim 7 , wherein said step (c) further comprises mixing, stirring, or agitating the loose seal material and the desiccant in a sealed environment.
9. The method set forth in claim 1 , wherein said step (c) further comprises storing the loose seal material and the desiccant together in a sealed environment.
10. The method set forth in claim 1 , wherein the moisture content of the loose seal material provided in said step (a) is in the range of about 3 wt. % to 5 wt. %, based upon the overall weight of the loose seal material, and said step (c) comprises reducing the moisture content of the loose seal material to less than 1 wt. %.
11. The method set forth in claim 1 , wherein step (d) further comprises separating the dry seal material and the desiccant based upon a size difference between the materials.
12. The method set forth in claim 11 , wherein step (d) further comprises separating the dry seal material and the desiccant by sifting or screening out the desiccant from the dry seal material in a manner that relies upon a size difference between the materials.
13. The method set forth in claim 12 , wherein the dry seal material has diameters in the range of about 50 μm to about 850 μm and the desiccant has diameters in the range of about 3 mm to 12 mm.
14. The method set forth in claim 1 , further comprising the step of:
repeating steps (c) to (d) using the regenerated desiccant.
15. The method set forth in claim 1 , further comprising the step of:
after step (e), heating the dry seal material and the insulator to form a seal between the insulator and a metallic component of the ignition device.
16. A method for drying a seal material for use in manufacturing an ignition device, comprising the steps of:
(a) providing a granular seal material having a moisture content in the range of 3-5 wt. %, based upon the overall weight of the granular seal material;
(b) providing a plurality of discrete desiccant components;
(c) bringing the granular seal material and the desiccant components together;
(d) maintaining the granular seal material and the desiccant components in close proximity to one another for a sufficient amount of time to produce a dry seal material by reducing the moisture content of the granular seal material to less than 1 wt. %;
(e) separating the dry seal material from the desiccant components based upon a size difference between the dry seal material and the desiccant components;
(f) forming a seal for the ignition device using the dry seal material; and
(g) regenerating the desiccant so that it may be used in a drying method, wherein the desiccant is regenerated using waste heat to drive off moisture.