Abstract: Embodiments of golf club heads, golf clubs, and methods to manufacture golf club heads and golf clubs are described herein. In one example, a golf club head includes a body portion with a front opening and a back opening, a face portion closing the front opening, and a back cover portion that closes the back opening and includes at least 50% of the total area of the back portion, a first port, and a second port. A first mass portion and a second mass portion engage the first port and the second port to close the first port and a second port, respectively. The first mass portion and the second mass portion each includes a material with a greater density than the material of the body portion and the material of the back cover portion. Other examples and embodiments may be described and claimed.

Abstract: Embodiments of golf club heads, golf clubs, and methods to manufacture golf club heads and golf clubs are described herein. In one example, a golf club head includes a body portion having an interior cavity, a back opening portion, a back cover portion covering the back opening portion, a filler material at least partially filling the interior cavity, a first mass portion coupled to the back cover portion, and a second mass portion coupled to the back cover portion. The body portion may be made from a first material having a first density, and the back cover portion may be made from second material having a second density different from the first density. The diameter of the second mass portion may be greater than a diameter of the first mass portion. Other examples and embodiments may be described and claimed.

Abstract: Embodiments of golf club heads, golf clubs, and methods to manufacture golf club heads and golf clubs are described herein. In one example, a golf club head includes a body portion having an interior cavity, a back opening portion, a back cover portion covering the back opening portion, a filler material at least partially filling the interior cavity, a first mass portion coupled to the back cover portion, and a second mass portion coupled to the back cover portion. The body portion may be made from a first material having a first density, and the back cover portion may be made from second material having a second density different from the first density. The diameter of the second mass portion may be greater than a diameter of the first mass portion. Other examples and embodiments may be described and claimed.

Abstract: Embodiments of golf club heads, golf clubs, and methods to manufacture golf club heads and golf clubs are generally described herein. In one example, a golf club head may include a body portion made from a first material with a first density and having an interior cavity, a toe portion with a toe portion edge, a heel portion with a heel portion edge, a front portion, a back portion with a back wall portion including a back opening portion, a top portion with a top portion edge, and a sole portion with a sole portion edge. A back cover portion made from second material with a second density different from the first density is coupled to the body portion to close the back opening portion. The back cover portion includes a port extending through the back cover portion. A filler material is injected into the interior cavity from the port. A mass portion is inserted into the port to close the port. The mass portion made from a third material with a second density greater than the first density.

Abstract: Embodiments of golf club heads, golf clubs, and methods to manufacture golf club heads and golf clubs are generally described herein. In one example, a golf club head may include a body portion made from a first material with a first density and having an interior cavity, a toe portion with a toe portion edge, a heel portion with a heel portion edge, a front portion, a back portion with a back wall portion including a back opening portion, a top portion with a top portion edge, and a sole portion with a sole portion edge. A back cover portion made from second material with a second density different from the first density is coupled to the body portion to close the back opening portion. The back cover portion includes a port extending through the back cover portion. A filler material is injected into the interior cavity from the port. A mass portion is inserted into the port to close the port. The mass portion made from a third material with a second density greater than the first density.

Abstract: A flame-retardant filament-forming copolymer of at least 75 mol % of ethylene-2,6-naphthalene dicarboxylate units and at least 3 mol % up to 25 mol % of randomly copolymerized esters units having bromine or chlorine chemically united with either the diacid residue or both the diacid residue and the diol residue of said ester units. In addition, fibers of the above flame-retardant copolyester resin and flame-retardant cellulosic fibers are blended together to provide flame-retardant yarns and fabrics of excellent physical properties.

Abstract: Method taught for producing a high modulus yarn of filaments of a polyester resin consisting of at least 15 up to 50 mole percent of bibenzoate units and from 85 to 50 mole percent of terephthalate units, said yarn having been uniformly oriented and then heat-set while free-to-relax.

Abstract: A flame-retardant filament-forming copolyester of at least 75 mol % of ethylene-2,6-naphthalene dicarboxylate units and at least 3 mol % up to 25 mol % of randomly copolymerized esters units having bromine or chlorine chemically united with either the diacid residue or both the diacid residue and the diol residue of said ester units. In addition, fibers of the above flame-retardant copolyester resin and flame-retardant cellulosic fibers are blended together to provide flame-retardant yarns and fabrics of excellent physical properties.

Abstract: A flame-retardant filament-forming copolyester resin of at least 75 mol % of ethylene-2,6-naphthalene dicarboxylate units and at least 5 mol % up to 25 mol % of alkylene-2,5-dibromoterephthalate units is disclosed herein. In addition, fibers of the above flame-retardant copolyester resin and flame-retardant cellulosic fibers are blended together to provide flame-retardant yarns and fabrics of excellent physical properties.