Methods of manufacturing a golf ball

• US 6,793,867 B2
• Filed: 03/09/2001
• Issued: 09/21/2004
• Est. Priority Date: 04/22/1999
• Status: Expired due to Term

• Current Assignee: Callaway Golf Company
• Original Assignee: Callaway Golf Company
• Inventors: Dewanjee, Pijush K.
• Primary Examiner(s): Lee, Edmund H.
• Application Number:
  US09/802,545
• Publication Number:
  US 20010018376A1
• Time in Patent Office: 1,292 Days
• Field of Search: 264/490, 264/255, 264/250, 264/DIG.65, 264/279.1
• US Class Current: 264/490
• CPC Class Codes: A63B 2209/00 Characteristics of used materials
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0064 Diameter
• CPC Class Codes: A63B 37/0065 Deflection or compression
• CPC Class Codes: A63B 37/0067 Weight; Mass
• CPC Class Codes: A63B 37/0073 Solid, i.e. formed of a single piece
• CPC Class Codes: A63B 37/0074 Two piece balls, i.e. cover and core
• CPC Class Codes: A63B 37/0075 Three piece balls, i.e. cover, intermediate layer and core
• CPC Class Codes: A63B 45/00 Apparatus or methods for manufacturing balls working of plastics or substances in a plastic state B29
• CPC Class Codes: B29C 2035/0855 using microwave
• CPC Class Codes: B29C 2045/14877 preheating or precooling the insert for non-deforming purposes
• CPC Class Codes: B29C 35/12 Dielectric heating
• CPC Class Codes: B29C 70/70 Completely encapsulating inserts B29C70/86 takes precedence
• CPC Class Codes: B29L 2031/54 Balls
• CPC Class Codes: Y10S 264/65 Processes of preheating prior to molding

Abstract

A method of manufacturing golf balls is disclosed that prevents the cover from cracking due to thermal expansion of the core during the cover formation process. The method includes the forming a core. One or more optional boundary layers can be applied to the surface of the core. The core and any boundary layers are pre-heated such that the core and any boundary layer undergo volumetric thermal expansion. After the pre-heating, the cover of the ball is formed over the core and any boundary layer. The method of the present invention also decreases cover molding cycle times for golf balls.

Claims

1. A method of manufacturing a golf ball comprising:

forming a core having a diameter ranging from 1.35 inches to 1.64 inches, and applying at least one boundary layer over the core to create a golf ball precursor product, the boundary layer having a thickness of 0.025 inch to 0.075 inch, the core conposed of a polybutadiene material;

heating the golf ball precursor product such that the golf ball precursor product undergoes volumetric thermal expansion of at least 1.2% and

applying a cover over the thermally expanded golf ball precursor product, the cover formed by an exothermic reaction.

2. The method according to claim 1 wherein heating the golf ball precursor product comprises convection heating the golf ball precursor product at a temperature within the range of about 120°

F. to about 180°

F.

3. The method according to claim 2 wherein heating the golf ball precursor product comprises convection heating the golf ball precursor product at a temperature within the range of about 140°

F. to about 160°

F.

4. The method according to claim 1 wherein heating the golf ball precursor product comprises microwave heating the golf ball precursor product for a predetermined time period.

5. The method according to claim 1 wherein the at least one boundary layer comprises a thermoplastic elastomer.

6. The method according to claim 1 wherein the at least one boundary layer comprises an ionomer.

7. The method according to claim 1 wherein the cover comprises a thermoset material with a resin from the group consisting of Allyl Pthalates like Diallyl Pthalates, (DAP) and Diallyl Iso Pthalates, (DAIP);

Aminos;

Cyanates;

Epoxies;

Phenolics;

Bismaleimides;

Silicones;

Liquid Nylon and Polydicyclopentadienes.

8. The method according to claim 2 wherein heating the golf ball precursor product comprises convection heating the golf ball precursor product for about one hour.

9. A method of manufacturing a golf ball comprising:

forming a core, the core composed of a polybutadiene material and having a diameter ranging from 1.35 inches to 1.64 inches;

forming at least one boundary layer surrounding the core, the boundary layer having a thickness ranging from 0.025 inch to 0.075 inch;

heating the core and the at least one boundary layer such that the core and the at least one boundary layer undergo volumetric thermal expansion of at least 1.2%; and

applying a cover over the thermally expanded core and the at least one boundary layer, and the cover formed by an exothermic reaction.

10. The method according to claim 9 wherein heating the core and the at least one boundary layer comprises convection heating the core and the at least one boundary layer to a temperature within the range of about 120°

F. to about 180°

F.

11. The method according to claim 10 wherein heating the core and the at least one boundary layer comprises convection heating the core and the at least one boundary layer at temperature within the range of about 140°

F. to about 160°

F.

12. The method according to claim 10 wherein heating the core and the at least one boundary layer comprises convection heating the core and the at least one boundary layer for about one hour.

13. A method of manufacturing a golf ball comprising:

heating a golf ball precursor product such that the golf ball precursor product undergoes volumetric thermal expansion of at least 1.2%; and

applying a cover over the thermally expanded golf ball precursor product

the cover formed by an exothermic reaction, and

the cover comprised of a thermoset material with a resin from the group consisting of Allyl Pthalates like Diallyl Pthalates, (DAP) and Diallyl Iso Pthalates, (DAIP);

Aminos;

Cyanates;

Epoxies;

Phenolics;

Bismaleimides;

Silicones;

Liquid Nylon and Polydicyclopentadienes.

14. A golf ball having reduced susceptibility of cracking of a cover, the golf ball produced in accordance with the method comprising:

heating a golf ball precursor product at a predetermined temperature and for a predetermined time period to achieve a predetermined volumetric thermal expansion of the golf ball precursor product; and

applying a cover over the thermally expanded golf ball precursor product

the cover comprised of a thermoset material with a resin from the group consisting of Allyl Pthalates like Diallyl Pthalates (DAP) and Diallyl Iso Pthalates (DAIP);

Aminos;

Cyanates;

Epoxies;

Phenolics;

Unsaturated Polyesters;

Bismaleimides;

Polyurethanes;

Silicones;

Urethane Hybrids;

Vinyl Esters;

Liquid Nylon and Polydicyclopentadienes.