Method for manufacturing a toothbrush and a bristle head thereof, toothbrush obtained by said method and mould for such method

1. A method for manufacturing a toothbrush of plastic material with a resistant inner core, comprising:

providing a resistant inner core;

introducing said resistant inner core into a mould cavity defined by opposite footprints of a lower half-mould (S 1 ) and of an upper half-mould (S 2 );

after said step of introducing said resistant inner core into the mould cavity, coupling said lower half-mould (S 1 ) with said upper half-mould (S 2 ); and

after said step of coupling said lower half-mould (S 1 ) with said upper half-mould (S 2 ), injecting molten plastic material into said mould cavity to manufacture at least part of a handle of the toothbrush,

wherein said resistant inner core ( 1 ) is arranged in a respective footprint (P) of the lower half-mould (S 1 ) in contact with at least two support platforms (Q, R) for supporting said resistant inner core ( 1 ) in a proximity of a central line of the mould cavity, and

wherein said upper half-mould (S 2 ) is provided with at least one ribbing (L) configured to come in contact with said metal core at least in a position between said at least two support platforms (Q, R) and in an opposite position thereto.

2. The method as claimed in claim 1 , wherein, before the step of introducing said resistant inner core ( 1 ), a transport mask (M), into which a plurality of bristle heads has been introduced, is coupled with said lower half-mould (S 1 ) so that said bristle heads lie in correspondence of respective footprints (P 1 -P 4 ).

3. The method as claimed in claim 1 , wherein at least one of said support platforms (Q) are provided with transversal retaining means (N) for said resistant inner core ( 1 ).

4. The method as claimed in claim 3 , wherein said retaining means are shaped as a pin (N) apt to couple with a corresponding through-hole ( 1 a ) obtained in said resistant inner core.

5. The method as claimed in claim 1 , wherein at least one of said support platforms (Q) is arranged in an area of a centre of gravity of said resistant inner core ( 1 ).

6. The method as claimed in claim 1 , wherein at least one of said platforms (Q) rises from a bottom of the footprint (P) of the lower half-mould (S 1 ) and has a lateral shape with a fluidodynamic profile with respect to a flow of molten material injected into said footprint.

7. The method as claimed in claim 1 , wherein following the step of injecting said plastic material, a thus-obtained semi-finished product is removed from the mould and introduced into a further mould into which a finishing plastic component is injected, apt to fill any recesses ( 2 a - 2 c ) left by said support platforms (Q, R) and ribbing (L).

8. The method as claimed in claim 7 , wherein at least one of said plastic material and said finishing plastic component is injected through a through-hole ( 1 a ) of said metal core.

9. The method as claimed in claim 1 , wherein said resistant inner core ( 1 ) is made of metal.

10. The method as claimed in claim 1 , further comprising:

arranging at least one head component provided with through-holes and tufted with tufts of synthetic single-yarns;

melting the bottom ends of said tufts in shape of heads ( 23 a ) larger than the corresponding holes ( 21 ), the back side ( 20 a ) of said head component being further completed by injecting a completion molten material which is later caused to harden; and

before said injection of said completion molten material, applying a protection membrane ( 30 ) onto said back side ( 20 a ), the membrane having such an extension as to cover said tuft heads ( 23 a ) at least in areas in proximity of high-pressure points of said completion molten material.

11. A mould for manufacturing a toothbrush of plastic material with a resistant inner core, comprising:

a lower half-mould (S 1 ) comprising a first footprint; and

an upper half-mould (S 2 ) comprising a second footprint, the first footprint and the second footprint defining a mould cavity for moulding at least one first plastic component of a toothbrush,

wherein, in the first footprint (P 1 -P 4 ) of said lower half-mould (S 1 ), at least two support platforms (Q, R) are provided which are configured to support a resistant toothbrush core ( 1 ) in a proximity of a central line of the mould cavity, and

wherein the second footprint of said upper half-mould (S 2 ) has a ribbing (L) configured to come in contact with said resistant inner core ( 1 ) at least in a position between said two support platforms (Q, R).

12. The mould as claimed in claim 11 , wherein at least one (Q) of said two support platforms has transversal retaining means (N) for said resistant core ( 1 ).

13. A method for manufacturing a toothbrush of plastic material with a resistant inner core, comprising:

providing a mould for manufacturing a toothbrush of plastic material with a resistant inner core, comprising:

a lower half-mould (S 1 ) comprising a first footprint; and

an upper half-mould (S 2 ) comprising a second footprint, the first footprint and the second footprint defining a mould cavity for moulding at least one first plastic component of a toothbrush,

wherein, in the first footprint (P 1 -P 4 ) of said lower half-mould (S 1 ), at least two support platforms (Q, R) are provided which are configured to support a resistant toothbrush core ( 1 ) in a proximity of a central line of the mould cavity, and

wherein the second footprint of said upper half-mould (S 2 ) has a ribbing (L) configured to come in contact with said resistant inner core ( 1 ) at least in a position between said two support platforms (Q, R).

14. The method as claimed in claim 13 , wherein at least one (Q) of said two support platforms has transversal retaining means (N) for said resistant core ( 1 ).