Multi-shot injection molded method and product
The present invention contemplates a method of forming a member comprising injection molding a first layer into a first tool cavity, overmolding a second layer into a second tool cavity selected from the group consisting of an expandable layer, a sealing layer, an acoustic layer, and adhesive layer, a reinforcement layer, a fastening layer, a second carrier layer, and any combination thereof, overmolding a third layer into the second tool cavity selected from the group consisting of an expandable layer, a sealing layer, an acoustic layer, an adhesive layer, a reinforcement layer, a fastening layer, a second carrier layer, and any combination thereof. The first layer, the second layer, and the third layer may be molded in one injection molding tool and the second and third layer may be segregated from one another prior to any overmolding steps.
1. A reinforcing structure comprising:
(a) an integrally molded carrier having a predetermined shape prior to installation and adapted to fit in a cavity of a vehicle, including a first surface and a second surface;
(b) an injection molded first expandable material capable of being activated to expand under a first activation condition, come into contact with, and adhere to a wall defining the cavity in order to at least partially fill the cavity; wherein the first expandable material is located onto the first surface and is capable of expanding from about 25% to about 400% as compared to its green state and wherein the first expandable material is a structural layer;
(c) an injection molded second expandable material capable of being activated to expand under a second activation condition, to come into contact with, and adhere to a wall defining the cavity in order to at least partially fill the cavity, the second expandable material being located onto the second surface, the second expandable material being capable of expanding from about 200% to about 5000% as compared to its green state and wherein the second expandable material is a sealant material;
wherein the first expandable material, the second expandable material, or a combination thereof, alone, or in combination with the carrier expands to form a complete seal of the cavity following activation and wherein the first expandable material and second expandable material are substantially free of any direct contact with one another when both materials are in their green state.
2. The reinforcing structure of claim 1 , wherein the carrier provides reinforcement following activation.
3. The reinforcing structure of claim 1 , wherein the second expandable material is an acoustic sealing material.
4. The reinforcing structure of claim 2 , wherein the reinforcing structure is free of any separate fasteners or adhesives for attaching the first expandable material or the second expandable material to the carrier or to each other.
5. The reinforcing structure of claim 1 , wherein the carrier comprises a metallic material, polybutylene terephthalate (PBT), Nylon, or a combination thereof.
6. The reinforcing structure of claim 1 , wherein the carrier, the first expandable material, and/or the second expandable material include an integrally formed post.
7. The reinforcing structure of claim 1 , wherein the carrier, the first expandable material, and/or the second expandable material have a parting line and/or a gate vestige.
8. The reinforcing structure of claim 1 , wherein the first expandable material, the second expandable material, or both are each a single continuous piece.
9. The reinforcing structure of claim 8 , wherein the structure is adapted for use in the cavity that is completely or partially enclosed about a periphery.
10. The reinforcing structure of claim 1 , wherein the carrier is insert molded.
11. The reinforcing structure of claim 1 , wherein the carrier is comprised of a first carrier layer and a second carrier layer.
12. The reinforcing structure of claim 11 , wherein the second carrier layer is insert molded.
13. The reinforcing structure of claim 11 , wherein the second carrier layer is a fiber reinforcement.
14. The reinforcing structure of claim 1 , wherein the second expandable material is on a first end, a second end, or both the first end and the second end of the carrier.
15. The reinforcing structure of claim 1 , wherein the first expandable material and the second expandable material contact each other during expansion.
16. The reinforcing structure of claim 1 , wherein the carrier includes an expansion directing feature.
17. The reinforcing structure of claim 16 , wherein the expansion directing feature prevents the second expandable material from interfering with the contact surface of the first expandable material.
18. A method for making the reinforcement structure of claim 1 comprising:
(a) providing the carrier in a mold;
(b) injection molding the first expandable material in the mold; and
(c) injection molding the second expandable material in the mold.
19. The reinforcing structure of claim 1 , wherein the first expandable material and the second expandable material, in combination with the carrier, expand to form a complete seal of the cavity following activation.
20. The reinforcing structure of claim 1 , wherein the second activation condition differs from the first activation condition.