Golf club head comprising microscopic bubble material
A golf club head with at least one cavity including a fill material comprising a polymer and a plurality of microscopic bubbles, and methods of manufacturing such golf club heads, are disclosed herein. In particular, the golf club head comprises an internal cavity that is at least partially filled with the fill material, or a medallion comprising the microscopic bubble fill material. The plurality of microscopic bubbles constitutes at 5-70% of the volume of the fill material, and more preferably approximately 20-30% of the volume of the fill material. The polymer material preferably is a polyurethane having a Poisson's ratio of 0.40-0.50. In some embodiments, the fill material takes the form a medallion affixed to a rear surface of the striking face, while in others, the fill material is injected into the internal cavity.
1. A golf club head comprising:
a body comprising a striking face, sole portion, top portion, rear portion, and cavity; and
a fill material at least partially filling the cavity,
wherein the fill material comprises a first material and a plurality of microscopic bubbles composed of a second material,
wherein the first material is a polymer material and wherein the second material is different from the first material, and
wherein the plurality of microscopic bubbles constitutes 5% to 70% of a volume of the fill material.
2. The golf club head of claim 1 , wherein the polymer material is selected from the group consisting of polyurethane and silicone.
3. The golf club head of claim 1 , wherein the second material is selected from the group consisting of glass, ceramic, and plastic.
4. The golf club head of claim 1 , wherein the plurality of microscopic bubbles constitutes at least 20% of the volume of the fill material.
5. The golf club head of claim 4 , wherein the plurality of microscopic bubbles constitutes 25-30% of the volume of the fill material.
6. The golf club head of claim 1 , wherein the polymer material has a Poisson's ratio of 0.00-0.50.
7. The golf club head of claim 6 , wherein the polymer material has a Poisson's ratio of 0.40-0.50.
8. The golf club head of claim 1 , wherein when a central area of the striking face impacts a golf ball, the golf club head has a pitch of 3000-6000 Hz, an amplitude of 90-100 dB, a duration of 1-2.5 ms, and a ball speed of at least 112.5 mph.
9. The golf club head of claim 1 , wherein the fill material is a medallion affixed to a rear surface of the striking face.
10. A method comprising the steps of:
providing a golf club head comprising a body having at least one cavity;
providing a polymer material;
providing a plurality of microscopic bubbles composed of a low-density material;
combining the plurality of microscopic bubbles with the polymer material to create a fill material; and
injecting the fill material into the at least one cavity of the golf club head,
wherein the plurality of microscopic bubbles constitutes 5-70% of a volume of the fill material.
11. The method of claim 10 , wherein the plurality of microscopic bubbles constitutes approximately 25-30% of the volume of the fill material.
12. The method of claim 10 , wherein the polymer material is selected from the group consisting of polyurethane and silicone, and wherein the low-density material is composed of a material selected from the group consisting of glass, ceramic, and plastic.
13. A method comprising the steps of:
providing a golf club head comprising a body having at least one cavity;
providing a polymer material;
providing an agent material selected from the group consisting of a curative and a catalyst;
providing a plurality of microscopic bubbles composed of a material selected from the group consisting of glass, ceramic, and plastic;
combining the plurality of microscopic bubbles with the agent material to create an intermediary material;
combining the intermediary material with the polymer material to create a fill material; and
injecting the fill material into the at least one cavity of the golf club head,
wherein the plurality of microscopic bubbles constitutes 5-70% of a volume of the intermediary material.
14. The method of claim 13 , wherein the plurality of microscopic bubbles is combined with the agent material at a 5:3 ratio, and wherein the fill material comprises a 1:1 ratio of polymer material and intermediary material.
15. The method of claim 13 , wherein the plurality of microscopic bubbles constitutes approximately 20-30% of the volume of the intermediary material.
16. The method of claim 13 , wherein the polymer material has a Poisson's ratio of 0.40-0.50 and is selected from the group consisting of polyurethane and silicone.
17. The method of claim 13 , wherein the golf club head is an iron-type golf club head comprising a body having a striking face, a sole portion, a top portion, and a rear portion, wherein the at least one cavity is disposed between the striking face and the rear portion, and wherein the fill material completely fills the at least one cavity.
18. The method of claim 13 , further comprising the step of curing the golf club head in an oven after the step of injecting the fill material into the at least one cavity of the golf club head.
19. A method comprising the steps of:
providing a golf club head comprising a body having at least one cavity;
providing a polymer material having a Poisson's ratio of 0.40-0.50;
providing an agent material selected from the group consisting of a curative and a catalyst;
providing a plurality of microscopic bubbles composed of a material selected from the group consisting of glass, ceramic, and plastic;
combining the polymer material with the agent material to form an intermediary material;
combining the plurality of microscopic bubbles with the intermediary material to create a fill material;
injecting the fill material into the at least one cavity of the golf club head; and
curing the fill material within the golf club head,
wherein the plurality of microscopic bubbles constitutes 5-70% of a volume of the fill material.
20. The method of claim 19 , wherein the golf club head is an iron-type golf club head, wherein the plurality of microscopic bubbles constitutes approximately 20-30% of the volume of the fill material, and wherein the polymer material is selected from the group consisting of polyurethane and silicone.