Silicone foam symmetrical inversion molding process

• US 5,549,858 A
• Filed: 02/08/1995
• Issued: 08/27/1996
• Est. Priority Date: 02/08/1995
• Status: Expired due to Term

• Current Assignee: Manni-Kit Incorporated
• Original Assignee: Manni-Kit Incorporated
• Inventors: Krotseng, Kathryn G.
• Primary Examiner(s): Kuhns, Allan R.
• Application Number:
  US08/386,108
• Time in Patent Office: 566 Days
• Field of Search: 264/321, 264/139, 264/48, 264/338, 264/259, 264/45.1, 264/46.4, 83/19
• US Class Current: 264/46.4
• CPC Class Codes: B29C 44/1209 by impregnating a preformed part, e.g. a porous lining
• CPC Class Codes: B29C 44/146 Shaping the lining before foaming
• CPC Class Codes: B29C 44/5654 Subdividing foamed articles to obtain particular surface properties, e.g. on multiple modules
• CPC Class Codes: Y10T 83/0429 By compressing

Abstract

A method for molding silicone foam into an article having the features of a designated object. The method includes the steps of introducing a silicone foam mixture into a first mold having a first cavity, wherein the silicone foam mixture forms a first molded object that has a shape which is representative of the first cavity; removing the first molded object from the first mold; pressing the first molded object into a second mold that has a second cavity, which has a basic profile that is representative of the article, the first molded object forming a layer of foam on the top edge of the second mold; cutting the layer to form an opened celled surface on the top surface of the first molded object; and releasing and removing the first molded object from the second cavity. The opened celled surface acquires the configuration that is representative of the second cavity, while the first bottom surface returns to the shape of the first cavity. A detailed layer having the specific attributes of the article can be applied to the first molded object through the use of a third mold.

Claims

1. A method for manufacture of an article of molded silicone foam having the features of a designated object, said method comprising the steps of:

(a) introducing a silicone foam mixture into a first mold having a first cavity, said silicone foam mixture forming a first molded object having a top surface and a first bottom surface that form a shape that is representative of said first cavity;

(b) removing said first molded object from said first mold;

(c) pressing said first molded object into a second mold having a top edge and a second cavity, said second cavity adjacent to said top edge and having a profile that is representative of said article, said first bottom surface of said first molded object being pressed against said second cavity, said top surface of said first molded object forming a layer of foam on said top edge;

(d) cutting said layer to form an opened celled surface on said top surface of said first molded object; and

(e) releasing and removing said first molded object from said second cavity, said opened celled surface having a configuration that is representative of said second cavity, said first bottom surface returning to said shape of said first cavity.

2. The method of claim 1 and including the step of using a serpentine application technique in introducing said silicone foam mixture into said first mold.

3. The method of claim 2 and including the steps of lining a third mold having a third cavity that has specific attributes of said article, introducing a release agent into said third cavity, introducing said silicone foam mixture on said release agent, pressing said first molded object into said third mold with said release agent and said silicone foam, and removing said first molded object from said third mold after said silicone foam mixture has bonded to said first molded object to form a skinned layer, said skinned layer having said specific attributes.

4. The method of claim 2 and including the steps of lining a third mold having a third cavity that has specific attributes of said article, introducing a release agent into said third cavity, introducing said silicone foam mixture on said release agent, pressing said opened celled surface of said first molded object into said third mold with said release agent and said silicone foam mixture, and removing said first molded object from said third mold after said silicone foam mixture has bonded to said opened celled surface to form a skinned layer, said skinned layer having said specific attributes.

5. The method of claim 3 and including the step of allowing said silicone foam mixture to cure in said third cavity for a time range from about three to seven minutes prior to pressing said first molded object into said third mold.

6. The method of claim 2 and including the steps of making a second molded object having a second bottom surface, applying said silicone foam mixture to said first and second bottom surfaces, and pressing said first and second bottom surfaces together to form a first complex shape having a third bottom surface.

7. The method of claim 6 and including the steps of making a second complex shape having a fourth bottom surface, and applying said silicone foam mixture to said third and fourth bottom surfaces to form a first complex article.

8. The method of claim 4 and including the step of allowing said silicone foam mixture to cure in said third cavity for a time range from about three to seven minutes prior to pressing said opened celled surface into said third mold.

9. The method of claim 4 and including the steps of making a second molded object having a second bottom surface, applying said silicone foam mixture to said first and second bottom surfaces, pressing said first and second bottom surfaces together to form a first complex shape having a third bottom surface, making a second complex shape having a fourth bottom surface, and applying said silicone foam mixture to said third and fourth bottom surfaces to form a first complex article.

10. A method for manufacture of an article of molded silicone foam having the features of a designated object, said method comprising the steps of:

(a) introducing a silicone foam mixture in a serpentine manner into a first mold having a first cavity, said silicone foam mixture forming a first molded object having a top surface and a first bottom surface that form a shape that is representative of said first cavity;

(b) removing said first molded object from said first mold;

(c) pressing said first molded object into a second mold having a top edge and a second cavity, said second cavity adjacent to said top edge and having a profile that is representative of said article, said first bottom surface of said first molded object being pressed against said second cavity, said top surface of said first molded object forming a layer of foam on said top edge;

(d) cutting said layer to form an opened celled surface on said top surface of said first molded object;

(e) releasing and removing said first molded object from said second cavity, said opened celled surface having a configuration that is representative of said second cavity, said first bottom surface returning to said shape of said first cavity;

(f) lining a third mold having a third cavity having specific attributes of said article with a release agent;

(g) introducing said silicone foam mixture on said release agent; and

(h) pressing said first molded object into said third mold with said release agent and said silicone foam mixture, and removing said first molded object from said third mold after said silicone foam mixture has bonded to said first molded object to form a skinned layer, said skinned layer having said specific attributes.

11. The method of claim 10 wherein said opened celled surface of said first molded object is pressed into said third cavity.

12. The method of claim 10 and including the step of allowing said first molded object to bond to said silicone foam mixture in said third cavity for a time range of 15 to 25 minutes to form said skinned layer.

13. The method of claim 11 and including the step of allowing said opened celled surface to bond to said silicone foam mixture in said third cavity for a time range of 15 to 25 minutes to form said skinned layer.

14. The method of claim 10 and including the step of allowing said silicone foam mixture to cure in said third cavity for a time range from about three to seven minutes prior to pressing said first molded object into said third mold.

15. The method of claim 11 and including the step of allowing said silicone foam mixture to cure in said third cavity for a time range from about three to seven minutes prior to pressing said opened celled surface into said third mold.

16. The method of claim 10 and including the steps of making a second molded object having a second bottom surface, applying said silicone foam mixture to said first and second bottom surfaces, pressing said first and second bottom surfaces together to form a first complex shape having a third bottom surface, making a second complex shape having a fourth bottom surface, and applying said silicone foam mixture to said third and fourth bottom surfaces to form a complex article.

17. A method for manufacture of an article of molded silicone foam having the features of a designated object, said method comprising the steps of:

(a) introducing a silicone foam mixture in a serpentine manner into a first mold having a first cavity, said silicone foam mixture forming a first molded object having a top surface and a first bottom surface that form a shape that is representative of said first cavity;

(b) removing said first molded object from said first mold;

(c) pressing said first molded object into a second mold having a top edge and a second cavity, said second cavity adjacent to said top edge and having a profile that is representative of said article, said first bottom surface of said first molded object being pressed against said second cavity, said top surface of said first molded object forming a layer of foam on said top edge;

(d) cutting said layer to form an opened celled surface on said top surface of said first molded object;

(e) releasing and removing said first molded object from said second cavity, said opened celled surface having a configuration that is representative of said second cavity, said first bottom surface returning to said shape of said first cavity;

(f) lining a third mold having a third cavity having specific attributes of said article with a release agent;

(g) introducing said silicone foam mixture on said release agent and allowing said silicone foam mixture to cure in said third cavity for a time range from about three to seven minutes; and

(h) pressing said opened celled surface of said first molded object into said third mold with said release agent and said silicone foam mixture, said silicone foam mixture bonding to said open celled surface to form a skinned layer, and removing said first molded object from said third mold, said skinned layer having said specific attributes.

18. The method of claim 17 and including the step of allowing said opened celled surface to bond to said silicone foam mixture in said third cavity for a time range of 15 to 25 minutes to form said skinned layer.

19. The method of claim 18 and including the steps of making a second molded object having a second bottom surface, applying said silicone foam mixture to said first and second bottom surfaces, pressing said first and second bottom surfaces together to form a first complex shape having a third bottom surface, making a second complex shape having a fourth bottom surface, and applying said silicone foam mixture to said third and fourth bottom surfaces to form a complex article.