Container for inhibiting microbial growth in liquid nutrients
View Patent ↗A fluid container and method for inhibiting the growth of microbes in liquid nutrient in a container, the container having an interior surface having a metal-ion sequestering agent for removing a designated metal ion from the liquid nutrient for inhibiting growth of microbes in the liquid nutrient.
1. A method of injection molding a multi-layer plastic preform to be blow molded into a container comprising the steps of:
forming an inner layer of a preform of a first plastic material having an open end, sidewalls, and a closed end, said closed end having a plurality of spaced channels on the exterior surface thereof extending from a central area on the closed end to the sidewalls, said first plastic material includes a sequestering agent for inhibiting the growth of microbes;
providing an overmolding mold cavity defined by sidewalls, an open end for accommodating a core rod, and a closed end with an injection gate there through, and a plurality of channels on the interior surface of the closed end communicating with the gate and extending from the gate to the sidewalls;
inserting a core rod and the inner plastic layer of the preform into said overmolding mold cavity with respective channels of the inner plastic layer of the preform and the overmolding mold cavity substantially aligned; and
overmolding a second layer of a second plastic material on the inner plastic layer of the preform to form an overmolded multi-layer perform in said overmolding mold cavity by flowing the second plastic material from the gate only through the respective channels to the sidewalls of the overmolding mold cavity thereby limiting the second material in the closed end of the multi-layer preform to regions of the channels,
providing internal pressure to said preform so as to form a container wherein the first plastic provides a surface for inhibiting the growth microbes with respect to a liquid placed in said container.
2. The method of claim 1 wherein the first plastic comprises a hydrophilic polymer and said sequestering agent that is immobilized on the inner surface(s) of said container has a stability constant greater than 10 10 with iron (III).
3. The method of claim 1 wherein the first plastic comprises hydrophilic polymer and said sequestering agent that is immobilized on the inner surface(s) of said container has a high-selectivity for biologically important metal ions such as Mn, Zn, Cu and Fe.
4. The method of clam 1 wherein sequestering agent comprises derivatized nanoparticles comprising inorganic nanoparticles having an attached metal-ion sequestrant, wherein said inorganic nanoparticles have an average particle size of less than 200 nm and the derivatized nanoparticles have a stability constant greater than 10 10 with iron (III).
5. The method of claim 1 wherein the first plastic is PET and the second plastic is an injection moldable thermoplastic other than PET.
6. A method of making a bottle having metal-ion sequestering agent, comprising the steps of:
forming an inner layer of a plastic material having an open end, sidewalls, and a closed end, said closed end having a plurality of spaced channels on the exterior surface thereof extending from a central area on the closed end to the sidewalls, said plastic material includes a sequestering agent for inhibiting the growth of microbes;
providing an overmolding mold cavity defined by sidewalls, an open end for accommodating a core rod, and a closed end with an injection gate there through, and a plurality of channels on the interior surface of the closed end communicating with the gate and extending from the gate to the sidewalls;
inserting a core rod and the inner plastic layer of the preform into said overmolding mold cavity with respective channels of the inner plastic layer of the preform and the overmolding mold cavity substantially aligned; and
providing internal pressure to said preform so as to form a container wherein the first plastic provides a surface for inhibiting the growth of microbes with respect to a liquid placed in said container.
7. The method of claim 6 wherein the first plastic material comprises a hydrophilic polymer and said sequestering agent that is immobilized on the surface(s) of said container has a stability constant greater than 10 10 with iron (III).
8. The method of claim 6 wherein the first plastic material comprises a hydrophilic polymer and said sequestering agent that is immobilized on the surface(s) of said container has a high-selectivity for biologically important metal ions such as Mn, Zn, Cu and Fe.
9. The method of claim 6 wherein the sequestering agent comprises derivatized nanoparticles comprising inorganic nanoparticles having an attached metal-ion sequestrant, wherein said inorganic nanoparticles have an average particle size of less than 200 nm and the derivatized nanoparticles have a stability constant greater than 10 10 with iron (III).
10. The method of claim 6 wherein the first plastic material is a hydrophilic polymer and the second plastic is an injection moldable thermoplastic.