Oral care implement and filament for the same
A mechanically tapered bristle filament for an oral care implement. The filament is characterized by a long thin tapered end portion. The tapered end portion has a taper length and tip diameter comparable to chemically tapered filaments. The areal surface roughness of the tapered end portion however is greater than chemically tapered filaments thereby producing increased scrubbing action against the surfaces of the teeth. The foregoing taper and roughness characteristics of the present filament enhance inter-dental cleaning effectiveness.
1. A mechanically tapered filament for an oral care implement, the filament comprising:
an elongated shaft terminating in a tip and having a mounting end portion of constant cross section and a tapered end portion;
wherein the tapered end portion has a taper length of 5 mm or more;
wherein the tapered end portion has an areal surface roughness value of at least 0.20; and
wherein the filament has a Nelson Ratio between 0.8 to 1.20.
2. The filament according to claim 1 , wherein the filament has a tip diameter of less than 10 microns measured at 0.05 mm from the tip in the tapered end portion.
3. The filament according to claim 1 , wherein the areal surface roughness value is at least 0.50.
4. The filament according to claim 1 , wherein the filament is formed of nylon.
5. The filament according to claim 1 , wherein the diameter between the tip and 0.05 mm from the tip is less than 10 microns.
6. An oral care implement comprising:
a handle;
a head supported by the handle; and
a plurality of tooth cleaning elements extending from the head, wherein at least one of the tooth cleaning elements is the mechanically tapered filament according to claim 1 .
7. The oral care implement according to claim 6 , wherein all of the tooth cleaning elements comprise the mechanically tapered filament.
8. The oral care implement according to claim 6 , wherein only a portion of the tooth cleaning elements comprise the mechanically tapered filament.
9. The oral care implement according to claim 6 , wherein the mechanically tapered filaments comprise at least some of peripheral bristle tufts on the head.
10. A mechanically tapered filament for an oral care implement, the filament comprising:
an elongated shaft terminating in a tip and having a mounting end portion of constant cross section and a mechanically tapered end portion;
the tapered end portion having a taper length of 5 mm or more;
the tapered end portion having a tip diameter of less than 10 microns measured at 0.05 mm from the tip; and
the tapered end portion having an areal surface roughness value of at least 0.20; and
wherein the filament has a Nelson Ratio between 0.8 to 1.20.
11. The filament according to claim 10 , wherein the areal surface roughness value is at least 0.50.
12. The filament according to claim 10 , wherein the filament is formed of nylon.
13. The filament according to claim 10 , wherein the diameter between the tip and 0.05 mm from the tip is less than 10 microns.
14. A mechanically tapered filament comprising:
an elongated shaft terminating in a tip and having a mechanically tapered end portion, the tapered end portion having a Nelson Ratio between 0.8 to 1.20, wherein the Nelson Ratio is defined by the formula:
Nelson
Ratio
(
Ω
)
=
1
6.458
(
(
λ
R
3
)
+
(
6
θ
R
)
+
(
ϕ
R
8
)
)
wherein
λ
R
=
Taper
Length
Ratio
=
λ
Actual
λ
Target
=
Measured
Taper
Length
Target
Taper
Length
,
measured in millimeters;
wherein
θ
R
=
Tip
Diameter
Ratio
=
θ
Actual
θ
Target
=
Base
Diameter
-
Measured
Tapered
Tip
Diameter
Base
Diameter
-
Target
Tapered
Tip
Diameter
,
wherein the measured and target tapered tip diameters are measured at 0.05 millimeters from the tip; and
wherein
ϕ
R
=
Roughness
Ratio
=
ϕ
Actual
ϕ
Target
=
Sa
tip
actual
-
Sa
base
Sa
tip
target
-
Sa
base
,
wherein Sa is areal surface roughness, wherein Sa tip actual and Sa tip target are measured at 4 millimeters from the tip and is at least 0.2, and wherein Sa base is measured at 7 mm from the tip.
15. The filament according to claim 14 , wherein the tapered end portion has a taper length of 5 mm or more.
16. The filament according to claim 14 , wherein the areal surface roughness value is at least 0.50.
17. The filament according to claim 14 , wherein the target tapered tip diameter is 0.01 mm.
18. The filament according to claim 14 , wherein the filament is formed of nylon.