GB2568031A

GB2568031A - Improvements in or relating to brush filaments

Info

Publication number: GB2568031A
Application number: GB1717507.6A
Authority: GB
Inventors: Page Matthew
Original assignee: Coral Tools Ltd
Current assignee: Coral Tools Ltd
Priority date: 2017-10-25
Filing date: 2017-10-25
Publication date: 2019-05-08
Anticipated expiration: 2037-10-25
Also published as: GB2568031B; GB201717507D0

Abstract

A bristle pack 58 of a brush 50 is typically made up of a plurality of brush filaments 10. A brush filament is disclosed comprising an elongate filament body (12, figure 1) and a ridge profile (14) which extends from the filament body (12) transversely to the length (L) of the filament body (12). The ridge element preferably extends helically along at least part of the length of the filament body to define a plurality of ridge element portions extending at least part way around the filament body. A method of manufacture comprising rotating one or both of an extrusion tool and/or a filament material relative to one another is also disclosed.

Description

IMPROVEMENTS IN OR RELATING TO BRUSH FILAMENTS

This invention relates to a brush filament, a method of manufacturing such a brush filament and a brush including a plurality of such brush filaments.

It is known to use brush filaments to apply a substance, such as a liquid or a powder, to a surface, or to move a substance relative to a surface. An example of such use of brush filaments is a paint brush which is typically dipped in paint to load the brush filaments with the paint and then the paint is applied to a wall by brushing the brush filaments against the wall. Other examples include a toothbrush to apply toothpaste to teeth, a cleaning brush to apply water/cleaning liquid to a dirty surface, a cosmetic brush to apply a cosmetic liquid or powder to skin, and a broom or household brush to direct debris across a surface to a particular area to allow the debris to be collected.

According to a first aspect of the invention there is provided a brush filament comprising an elongate filament body and a ridge profile extending from the filament body transversely to the length of the filament body.

The brush filament having a ridge profile extending from the filament body means that the outward surface of the brush filament is ridged, as opposed to the outward surface being a smooth surface. Such a ridge profile allows the brush filament to have improved substance capture (i.e. substance holding capability) because the ridge profile traps the substance in the space between the protruding ridge profile and the filament body. This applies to situations where the brush filament is being used to apply a substance to a surface or where the brush filament is being used to move a substance relative to a surface since in both cases being able to capture more substance in the ridge profile improves the application or moving of the substance.

Meanwhile, the ridge profile extending from the filament body transversely to the length of the filament body provides controlled substance release from the brush filament. In particular, the transverse arrangement of the ridge profile slows down the release of the substance from the brush filament to the desired surface because the ridge is extending crosswise to the direction of the flow of substance (i.e. crosswise to the direction of the length of the substance). Since the substance must first overcome the ridge profile to flow along the filament body, the substance movement is slowed and thus the substance release is controlled. This prevents the substance from running off the filament body and also provides a more even spread of substance along the length of the filament body.

The dimensions and shape of the ridge profile can be designed to tailor the control of substance release, which may depend on the characteristics of the substance intended to be used with the brush filament.

In an example of the invention wherein the brush filament is used with a paintbrush which is dipped into paint, the transverse ridge profile would not only be able to capture more paint, but it would also prevent the paint from running quickly down and off the end of the brush filament. Moreover, when the paintbrush is being used to apply the paint to a surface, the paint is applied more evenly to the surface because the paint is more evenly distributed along the length of the filament body.

In contrast to the invention, a brush filament that has a filament body and no ridge profile cannot trap more substance between any sort of protrusion and the filament body. Moreover, a brush filament which has a filament body and no ridge profile arranged transversely to the length of the filament body, when dipped in a substance, has no means to control the flow of the substance along the length of the filament body. As such, the substance will tend to run towards one end of the filament body resulting in uneven distribution of the substance on the brush filament and loss of substance from running off the end of the filament body.

Optionally the ridge profile is or includes a ridge element having a ridge element portion which extends part way around the filament body.

Optionally the ridge profile is or includes a ridge element having a ridge element portion which extends fully around the filament body.

The ridge element portion extending part way or fully around the filament body may depend on the characteristics of the substance intended to be used with the filament body and/or manufacturing techniques that are suitable for the brush filament.

Preferably, the ridge profile is or includes a ridge element which extends continuously around and along at least part of the length of the filament body to define a plurality of ridge element portions extending around the filament body.

Such a continuously extending ridge element further helps to provide controlled substance release since the substance is able to flow along the ridge element, while also improving the ease of manufacture of the brush filament. Moreover, the pitch of the ridge element can be chosen to suit the characteristics of the substance intended to be used with the brush filament.

In an embodiment of the invention, the ridge profile is or includes a ridge element which helically extends along at least part of the length of the filament body to define a plurality of ridge element portions extending at least partway around the filament body.

Such a helical arrangement of the ridge element further improves the manufacturability of the brush filament.

The ridge profile may include a plurality of ridge element portions, and the ridge element portions may be spaced from one another along the length of the filament body.

Again, the number of ridge element portions can be chosen to suit the application of the brush filament and/or the substance intended to be used with the brush filament. Moreover, the ridge element portions being spaced from one another along the length of the filament body means that the ridge element portions are stacked along the filament body which helps to provide controlled substance release.

The ridge profile may include a mixture of ridge element portions that are defined by a respective discrete ridge element, and ridge element portions that are defined by a ridge element extending continuously around and along (or helically along) at least a part of the length of the filament body.

Optionally the filament body has an operative end arranged to contact a substance in use, the ridge profile being positioned towards the operative end of the filament body.

The ridge profile being positioned towards the operative end of the filament body means that the improved substance capture and substance release characteristics provided by the ridge profile are efficiently used when the filament body contacts, e.g. is dipped into, a substance in use.

The filament body may be uniform along its length or may instead be tapered along its length.

The filament body may be a solid body or may instead be at least partially hollow.

The filament body may have a cross-sectional shape of one of the following: circular, elliptical, trilobal, quadrilateral, convex, concave or any other irregular polygon variant. .

The design of the filament body can be chosen depending on the intended application of the brush filament and the characteristics of the substance to be used with the brush filament.

For example, the tapered filament body provides a fine operative end which in turn provides a better finish when the filament body is being used to apply paint to a surface. Whereas for other brush filament applications which do not require such finishing benefits, e.g. where the brush filament is being used in a broom to move debris across a surface, the uniform filament body may be sufficient.

The solid filament body provides better bend recovery of the filament body, which in turn improves the longevity of the brush filament, compared to a hollow filament body, but may be more expensive than the hollow filament body because more material is being used.

The different cross-sectional shapes of the filament body can provide different filament characteristics such as stiffness, strength and weight, as well as differing in manufacturing and material cost. The cross-sectional shape of the filament body can therefore be chosen depending on the intended application of the brush filament.

According to second aspect of the invention there is provided a method of manufacturing a brush filament comprising forming a ridge profile that extends from a filament body transversely to the length of the filament body.

The advantages of the brush filament of the first aspect of the invention and its embodiments applies mutatis mutandis to the method of the second aspect of the invention and its embodiments.

Optionally, the method includes rotating one or both of an extrusion tool and/or a filament material relative to one another to form a ridge element which extends continuously around and along at least part of the length of the filament body thus creating the ridge profile.

In this regard, the extrusion tool may be rotated around the filament material which is held fixed in place to form the ridge element, or the filament material may instead be rotated relative to a fixed extrusion tool to form the ridge element. Alternatively, both the filament and the extrusion tool may rotate concurrently or at different times relative to one another to form the ridge element.

The method may include carrying out one or more of the following treatments: filament trimming, filament flagging, filament crimping, chemical dipping.

The treatments may be carried out before, during or after creation of the ridge profile.

Filament trimming allows the brush filament to be cut to a desired length, which may be done at the same time as a plurality of brush filaments to achieve consistent filament length across all brush filaments.

Filament flagging creates split ends at one end of the brush filament, which increases the surface area of the brush filament and thus increases the substance capture capability. It also improves the delivery of the substance onto a surface due to the increase surface area and smaller cross-sectional profile of each split end which leaves fewer brush marks.

Filament crimping puts a wave pattern along the length of the brush filament which reduces bulk density of the brush filament when incorporated into a brush, while at the same time further improving the substance capture capability since the substance can be trapped between the wave pattern. Filament crimping also increases the apparent mass (i.e. “bushiness”) of the brush filament, which can provide a user with the feel of a natural brush filament.

Chemical dipping can be used to either corrode the end of a brush filament to create a textured tip (much like filament flagging), or to apply a coating onto the whole or part of the brush filament. In the latter regard, the coating can be chosen to provide an improved characteristic to the brush filament depending on the intended application of the brush filament. For example, the brush filament may be chemically tipped with silver which improves the application of substances such as latex paint, varnishes and enamels. In another example, the brush filament may be chemically tipped in a non-stick coating to provide the benefit of faster flow characteristics and easier cleaning.

According to a third aspect of the invention there is provided a brush comprising a brush body and a plurality of brush filaments as described hereinabove extending from the brush body.

A preferred embodiment of the invention will now be described, by way of a non-limiting example, with reference to the accompanying drawings in which:

Figure 1 shows a brush filament according to the invention; and

Figure 2 shows a brush incorporating a plurality of brush filaments shown in Figure 1.

A brush filament according to the invention is shown in Figures 1 and 2 and is designated general by reference numeral 10.

The brush filament 10 has an elongate filament body 12 having a length L. The brush filament 10 also has a ridge profile 14 which extends from the filament body 10 transversely to the length L of the filament body 12.

In particular, the length L of the filament body 12 defines a lengthwise direction Xl, and the ridge profile 14 extends in a crosswise direction Yc relative to the lengthwise direction Xl.

In the embodiment shown, the crosswise direction Yc of the ridge profile 14 is at an angle less than 90° to the lengthwise direction Xl (i.e. it intersects the lengthwise direction Xl diagonally). In other embodiments of the invention (not shown), the crosswise direction Yc of the ridge profile 14 may instead be at a right angle to the lengthwise direction XL(i.e. it intersects the lengthwise direction Xl perpendicularly.

In the embodiment shown, the ridge profile 14 is a ridge element 16 which helically extends along the majority of the length L of the filament body 12 to define a plurality of continuous ridge element portions 18 which extend around the filament body. For the purpose of clarity, reference numeral 18 in Figure 1 points to only a select number of ridge element portions 18.

In this way, the ridge element portions 18 are spaced from one another (i.e. stacked) along the length L of the filament body 12.

The ridge element 16 particularly defines two end ridge element portions 18a which extend part way around the filament body 12, and a plurality of intermediate ridge element portions 18b each of which extends fully around the filament body 12. For the purpose of clarity, reference numeral 18b in Figure 1 points to only a select number of intermediate ridge element portions.

In other embodiments of the invention (not shown), the ridge profile 14 may instead include a plurality of ridge elements 16, with each ridge element 16 defining a discrete ridge element portion 18 (i.e. a non-continuous ridge element 16). Moreover, each ridge element portion 18 may extend part way around the filament body 12, or instead fully around the filament body 12. Alternatively, the ridge profile 14 may be made up of a mixture of ridge element portions 18 which extend part way around the filament body 12 and fully around the filament body 12.

In further embodiments (not shown), the ridge profile 14 may include a single ridge element 16 which defines a single ridge element portion 18. The single ridge element portion 18 may extend part way around the filament body 12, or instead fully around the filament body.

In further still embodiments (not shown), the ridge profile 14 may include one or more discrete ridge elements 16 and one or more continuously extending ridge elements 16.

Returning to the embodiment shown, the filament body 12 has a circular cross-sectional shape, i.e. it is round.

The filament body 12 may have another cross-sectional shape, for example circular, elliptical, trilobal, quadrilateral, convex, concave or any other irregular polygon variant. In embodiments where the filament body 12 is not round, the ridge profile 14 may include a ridge element 16 which extends continuously around and along at least part of the length L of the filament body 12 to define a plurality of continuous ridge element portions 18 extending at least part way around the filament body.

The filament body 12 has an operative end 20 which, when the brush filament 12 is incorporated into a brush in use, is arranged to contact a substance (not shown). The ridge profile 14 is positioned towards the operative end 20 of the filament body 12.

The filament body 12 shown has a uniform cross-sectional profile along its length. The filament body 12 may instead taper, and in particular may have a smaller cross-sectional area at the operative end 20 compared to that of the end opposite the operative end 20.

The filament body 12 shown is also a solid body, but may instead be hollow. In the latter regard, the filament body 12 may be hollow via a single hollowed portion or more than one hollowed portion.

The filament body 12 and the ridge profile 14 are made from the same material in the embodiment shown. In particular, the brush filament 10 is manufactured by rotating an extrusion tool (not shown) around a filament material so as to form the helically extending ridge profile 14 and filament body 12.

The brush filament may be made from a synthetic material such as Nylon, polypropylene (PP), polyester, Polytetrafluoroethylene (PTFE) or Polybutylene terephthalate (PBT). The brush filament may instead be made from a metal such as steel (e.g. high-carbon or stainless), brass or phosphorous bronze.

The filament body 12 and the ridge profile 14 may instead be made from different materials, and in embodiments in which the ridge profile 14 includes discrete ridge element portions 18, each ridge element portion may be made from differing materials.

Moreover, the brush filament 10 may be manufactured by any suitable means.

Although not shown in Figure 1, the brush filament 10 may be subjected to post-production manufacturing methods such as filament trimming, filament flagging (i.e. creating split ends), filament crimping (i.e. crimping the brush filament 10 to create a wave) and/or chemical dipping (i.e. either corroding the ends with a chemical or coating the whole or part of the filament with a material).

Figure 2 shows a brush 50 which includes a brush body 52 and a plurality of brush filaments 10 as described hereinabove extending from the brush body 52.

The brush body 52 includes a handle portion 54 and a ferrule 56 which holds the plurality of brush filaments 10 in place. The plurality of brush filaments 10 combine to define a bristle pack 58 secured to the ferrule 56 at a first end 60, and with an operative end 62 lying opposite the first end 60. The operative end 62 is the part of the brush 50 which contacts a substance, e.g. dipped into paint.

The brush 50 may be designed by any suitable means to provide a section for a user to hold and a bristle pack 58 to be used with a substance. For example, the plurality of brush filaments 10 may be punch filled, bar anchor filled, resin-set, pitch set, wire drawn, or any combination thereof so as to form the bristle pack 58.

Claims

1. A brush filament comprising an elongate filament body and a ridge profile extending from the filament body transversely to the length of the filament body.

2. A brush filament according to Claim 1 wherein the ridge profile is or includes a ridge element having a ridge element portion which extends part way around the filament body.

3. A brush filament according to Claim 1 or Claim 2 wherein the ridge profile is or includes a ridge element having a ridge element portion which extends fully around the filament body.

4. A brush filament according to any preceding claim wherein the ridge profile is or includes a ridge element which extends continuously around and along at least part of the length of the filament body to define a plurality of ridge element portions extending at least part way around the filament body.

5. A brush filament according to any preceding claim wherein the ridge profile is or includes a ridge element which helically extends along at least part of the length of the filament body to define a plurality of ridge element portions extending at least part way around the filament body.

6. A brush filament according to any preceding claim wherein the ridge profile includes a plurality of ridge element portions, the ridge element portions being spaced from one another along the length of the filament body.

7. A brush filament according to any preceding claim wherein the filament body has an operative end arranged to contact a substance in use, the ridge profile being positioned towards the operative end of the filament body.

8. A brush filament according to any preceding claim wherein the filament body is either uniform along its length or is tapered along its length.

9. A brush filament according to any preceding claim wherein the filament body is either a solid body or is at least partially hollow.

10. A brush filament according to any preceding claim wherein the filament body has a cross-sectional shape of one of the following: circular, elliptical, trilobal, quadrilateral, convex, concave or any other irregular polygon variant.

11. A method of manufacturing a brush filament comprising forming a ridge profile that extends from a filament body transversely to the length of the filament body.

12. A method of manufacturing a brush filament according to Claim 11 comprising rotating one or both of an extrusion tool and/or a filament material relative to one another to form a ridge element which extends continuously around and along at least part of the length of the filament body thus creating the ridge profile.

13. A method of manufacturing a brush filament according to Claim 11 or Claim 12 comprising carrying out one or more of the following treatments: filament trimming, filament flagging, filament crimping, chemical dipping.

14. A brush comprising a brush body and a plurality of brush filaments according to any one of Claims 1 to 11 extending from the brush body.