A system or method of forming a handle portion of an oral care implement and a handle portion of an oral care implement formed thereby. The method may include providing a first mold that defines a first mold cavity having a shape that corresponds to the handle portion, injecting a first material into the first mold cavity via a first injection orifice with a first hot runner sub-system, and injecting a second material into the first mold cavity via a second injection orifice with a second hot runner sub-system. The second material is injected into the first material thereby forming the handle portion, with the second material forming a core component of the handle portion and the first material forming a shell component of the handle portion that surrounds the core component.

A system or method of forming an oral care implement and an oral care implement formed thereby comprising a base structure having a handle portion and a head portion. The method may comprise providing a first mold that defines a first mold cavity having a first portion that corresponds to the handle portion and a second portion that corresponds to the head portion; injecting a first material into the first portion of the first mold cavity via a first injection orifice with a first hot runner sub-system; and injecting a second material into the first portion of the first mold cavity via a second injection orifice with a second hot runner sub-system, the second material being injected into the first material thereby forming the base structure, the second material forming a core component and the first material forming a shell component of the base structure that surrounds the core component.

The injection moulding of articles formed by plastic materials having different characteristics, for example of different colours, is carried out in a single injection cycle in which the first and the second plastic materials are injected into a first and into a second zone of a mould cavity by first and second injectors controlled according to specific modes so as to define a shape and/or a position of a weld line.

The injection moulding of articles formed by plastic materials having different characteristics, for example of different colours, is carried out in a single injection cycle in which the first and the second plastic materials are injected into a first and into a second zone of a mould cavity by first and second injectors controlled according to specific modes so as to define a shape and/or a position of a weld line.

The injection moulding of articles formed by plastic materials having different characteristics, for example of different colours, is carried out in a single injection cycle in which the first and the second plastic materials are injected into a first and into a second zone of a mould cavity by first and second injectors controlled according to specific modes so as to define a shape and/or a position of a weld line.

A co-injection molding apparatus may mold an injection product that includes a skin layer forming an outer surface by a first material and a core layer surrounded by the skin layer and having an interior formed by a second material. The co-injection molding apparatus may include an injection mold configured to form an injection space to be injection molded by the first material and the second material, a first injector configured to inject the first material, a second injector configured to inject the second material different from the first material and positioned between the first injector and the injection mold, and a runner configured to connect the first injector, the second injector, and the injection mold.

A system or method of forming a handle portion of an oral care implement and a handle portion of an oral care implement formed thereby. The method may include providing a first mold that defines a first mold cavity having a shape that corresponds to the handle portion, injecting a first material into the first mold cavity via a first injection orifice with a first hot runner sub-system, and injecting a second material into the first mold cavity via a second injection orifice with a second hot runner sub-system. The second material is injected into the first material thereby forming the handle portion, with the second material forming a core component of the handle portion and the first material forming a shell component of the handle portion that surrounds the core component.

A system for forming an oral care implement and an oral care implement formed thereby. The system may include a first mold defining a first mold cavity having a first mold cavity axis; first and second injection orifices formed into the first mold and providing passageways directly into the first portion of the first mold cavity, the second injection orifice being spaced apart from the first injection orifice; first and second hot runner sub-systems fluidly coupled to the first and second injection orifices, respectively; wherein the system is configured to dispense the first material into the first portion of the first mold cavity via the first injection orifice, and after passage of a period of time, to subsequently dispense the second material into the first portion of the first mold cavity via the second injection orifice, the second material being injected into the first material to displace the first material.

An injection-molding method is provided in which in a first injection-molding step at least one first material component (17) is injected into a mold cavity (4) of an injection mold (3). The first injection-molding step is terminated when a condition pertaining to a first material volume that has been injected in the first injection-molding step has been met. This condition can be, for example, a minimum filling level which is caused in the mold cavity (4) by a material volume from the at least one first material component (17) that in the first injection-molding step has been injected into the mold cavity (4). When the minimum filling level can be detected or confirmed, for example with the aid of a sensor (10), the first injection-molding step is terminated and a second injection-molding step can optionally be started.

The injection moulding of articles formed by plastic materials having different characteristics, for example of different colours, is carried out in a single injection cycle in which the first and the second plastic materials are injected into a first and into a second zone of a mould cavity by first and second injectors controlled according to specific modes so as to define a shape and/or a position of a weld line.