Composite articles and methods for making the same

Abstract

The present disclosure pertains to composite articles, and in particular a composite face plate for a golf club-head, and methods for making the same. In certain embodiments, a composite face plate for a club-head comprises a lay-up of multiple, composite prepreg plies. The face plate can be made by first forming an oversized lay-up of multiple prepreg plies having a central portion and a sacrificial portion surrounding the central portion. The lay-up is at least partially cured in a mold under elevated pressure and heat. The lay-up is then removed from the mold and the sacrificial portion is removed from the central portion to form a composite part that is substantially free of defects.

1 . A method for making a composite face plate for a club-head of a golf club, the method comprising:
 forming a lay-up of multiple prepreg plies, each prepreg ply comprising at least one layer of reinforcing fibers impregnated with a resin, the lay-up comprising a central portion and a sacrificial portion surrounding the central portion;   placing the lay-up in a molding tool having an initial tool temperature T i  and initial pressure P 1 , wherein P 1  is at least atmospheric pressure;   at an initial time t 0 , commencing a progressive increase in tool temperature from T i  while maintaining the lay-up at the pressure P 1 , to initiate a progressive increase in lay-up temperature from T i ;   at a time t 1 , later than t 0 , at which the resin exhibits a minimal liquid viscosity, commencing a progressive increase in pressure of the lay-up in the tool from P 1 , and further increasing the tool temperature to cause the lay-up temperature in the tool to continue increasing progressively toward a predetermined temperature T s >T i ;   from the time t 1  to a later time t 2 , allowing the lay-up temperature in the tool to increase further toward T s  while further progressively increasing the pressure of the lay-up in the tool toward a predetermined pressure P 2 >P 1 , during which the resin exhibits a relatively rapid progressive increase in viscosity and reaches the pressure P 2  at the time t 2 ; and   from the time t 2  to a predetermined later time t 3 , allowing the lay-up temperature to increase further toward the temperature T s  while the lay-up remains substantially at the pressure P 2 , thereby allowing the resin to undergo a relatively slow but continued increase in viscosity to a specified pre-cure viscosity level;   at least partially curing the lay-up in a mold so as to form an at least partially cured lay-up having a bulge and roll;   removing the at least partially cured lay-up from the mold; and   after removing the at least partially cured lay-up from the mold, removing the sacrificial portion from the central portion of the at least partially cured lay-up to form a composite part having specified dimensions and shape for use as a face plate or part of a face plate in a club-head.   
     
     
         2 . The method of  claim 1 , wherein the act of at least partially curing the lay-up leaves no more than one void in the central portion of the partially cured lay-up. 
     
     
         3 . The method of  claim 1 , wherein, prior to the act of removing, the fibers of each ply have opposite end portions that extend into the sacrificial portion, and the act of removing the sacrificial portion is effective to separate the end portions of the fibers from the plies forming the composite part. 
     
     
         4 . The method of  claim 1 , wherein, prior to the act of removing, the sacrificial portion completely surrounds the central portion. 
     
     
         5 . The method of  claim 1 , wherein the part, after removing the sacrificial portion, has a void content of about 1.7×10 −6  percent or less by volume. 
     
     
         6 . The method of  claim 1 , wherein the part, after removing the sacrificial portion, does not have any voids. 
     
     
         7 . The method of  claim 1 , wherein the act of removing the sacrificial portion comprises water-jet cutting the sacrificial portion from the central portion. 
     
     
         8 . The method of  claim 1 , further comprising placing an outer layer on the composite part, the outer layer defining a striking surface of the face plate. 
     
     
         9 . The method of  claim 8 , wherein the outer layer comprises a polymeric layer. 
     
     
         10 . The method of  claim 8 , wherein the outer layer comprises a metal layer. 
     
     
         11 . The method of  claim 10 , wherein the metal layer is made of titanium, aluminum, magnesium, steel, or alloys thereof. 
     
     
         12 . The method of  claim 1 , wherein the lay-up has a varying thickness. 
     
     
         13 . The method of  claim 1 , wherein the resin comprises a thermoset resin. 
     
     
         14 . The method of  claim 1 , further comprising mounting the composite part to the club-head. 
     
     
         15 . The method of  claim 1 , wherein the club-head defines a front opening and the method further comprises mounting the composite part to the club-head so as to cover the front opening. 
     
     
         16 . The method of  claim 1 , wherein the central portion of the lay-up has first and second opposing surfaces and a thickness measured from the first surface to the second surface, and the act of removing the sacrificial portion forms an outer peripheral edge of the composite part that extends from the first surface to the second surface. 
     
     
         17 . The method of  claim 1 , wherein the pressure P 1  is within a range 0-100 psig. 
     
     
         18 . The method of  claim 1 , wherein the pressure P 1  is within the range 0-150. 
     
     
         19 . The method of  claim 1 , wherein the pressure P 2  is within a range 200-500 psig.