Fluid-container and method for controlling crystallinity in blow-molded container

A method for locally controlling crystallinity of a polymeric material in a fluid container, the method comprising:

• injection molding a preform for the fluid container within an injection-mold;
• placing the preform into a blow-mold for blow-molding the fluid container;
• heating and injecting gas into the preform to cause the preform to expand against an inner surface of the blow-mold, thereby forming the fluid container;
• and
• laser heating at least one precise localized portion of the polymeric material of the preform or the fluid container with at least one laser to above a glass transition temperature of the polymeric material but below a melting temperature of the polymeric material to form a first precise localized crystalline region of the polymeric material, wherein the first precise localized crystalline region has a percent crystallinity ranging from 30% to 90%,
• wherein the first precise localized crystalline region of the polymeric material has a size ranging from 0.001 inch to 1.000 inch and has a crystallinity that is greater than a crystallinity in a second region of the preform or the fluid container that is not laser heated, and a transition zone between the first precise localized crystalline region and the second region is sharper than a transition zone between a first infrared heated crystalline region and a second crystalline region that is not infrared heated.

A preform for blow-molding a fluid container, the preform comprising:

• a proximal end;
• a distal end having an open-ended neck;
• and
• a sidewall extending between the proximal end and the distal end along a longitudinal axis,
• wherein a polymeric material of at least a first localized laser-heated crystalline region of the preform has a percent crystallinity ranging from 30% to 90% crystallinity, and wherein a percent crystallinity of an amorphous polymeric material of an adjacent second region of the preform is less than 10% crystallinity.