GB2173996A

GB2173996A - Production of brushes

Info

Publication number: GB2173996A
Application number: GB08508842A
Authority: GB
Inventors: Brian Mark Ashton
Original assignee: Ashton A E & N Co Ltd
Current assignee: Ashton A E & N Co Ltd
Priority date: 1985-04-04
Filing date: 1985-04-04
Publication date: 1986-10-29
Also published as: EP0196928A2; EP0196928A3; GB2173996B; GB8508842D0

Abstract

A method of making brushes, particularly road-sweeping brushes, by arranging bunches of bristles (2) so that their one ends (2a) extend into a mould (3) for forming the brush base (1), and applying into the mould (3) around the ends (2a) of the bristles a quick-setting liquid plastics material, generally a micro-cellular elastomeric polymer material such as polyurethane foaming by adding water thereto, and allowing the plastics material to set to secure the brush base to the bristles. <IMAGE>

Description

I GB 2 173 996 A 1

SPECIFICATION material, is prefe ra blyca used to foam by adding Production of brushes water thereto, a micro-cellular structure may equally be obtained in other Ways, for example by air

This invention relates to the production of injection or by filling the polymer material with low brushes. More particularly, the invention relates to 70 density articles such as hollow glass spheres. Poly the production of brushes for road-sweeping urethane in which slight foaming is induced by vehicles, although the invention is also applicable to water absorption may suitably have a specific the production of brushes of all types. gravity of about 0.7.

Traditionally, brushes for road-sweeping vehicles In the method of the invention the plastics (hereinafter referred to as road-sweeping brushes) 75 material flows easily and will set and harden around have been manufactured by taking a plywood base the bristles in about 3 minutes, using a polyurethane in which are formed a series of holes for receiving as described above. Thus road-sweeping brushes bunches or tufts of bristles, which are then folded can be produced much more quickly than hitherto, through the holes and secured to the wooden base, and in addition the whole brush base is for example by stapling. 80 manufactured in a single operation, whereby there More recently, a technique has been developed are avoided areas of weakness as occur in the road- for producing road-sweeping brushes having a sweeping brushes of the prior art. The bases of plastics, usually polypropylene, base and also brushes manufactured according to the invention having tufts of plastics bristles, again usually of thus have high impact resistance, leading to low polypropylene. In this technique the tufts of bristles 85 failure rate.

are so arranged that their one ends extend into an The brush bristles may be suitably made of a annular mould into which the polypropylene for plastics material, although of a material different forming the base is melted and applied and allowed from that of the plastics base, for example, to set around the bristles, thus securing the bristles polypropylene or nylon, but other thermoforming to the brush base. However, this method has the 90 extruclable materials could be used. Alternatively, the disadvantage that the polypropylene base material bristles maybe made of horsehair or wires for is only injected over a relatively small segment of example.

the base mould, before being injected into an While the method of the invention is particularly adjacent mould segment, and so on until the base is suitable for the production of brushes for road- completely formed. 95 sweeping vehicles, itwill be apparentthatthe This leads to two drawbacks, the first being that method is equally applicable to the production of the process of forming the brush base around the other brushes, either for industrial or domestic use, bristles takes a long time, perhaps one hourfor or even toothbrushes.

forming a single base; and the second being that When the method of the invention is utilized for because of the batchwise nature of the base 100 producing road-sweeping brushes, the base will be forming, areas of weakness or "cold/hot lines" are usually annular, with bunches of bristles extending formed between the adjacent batches or segments obliquely outwards from the plane of the annular of polypropylene constituting the completed base, base.

as a result of which the brush is likely to crack at In producing roadsweeping brushes there is such areas of weakness. Road-sweeping brushes 105 provided an annular mould above which is arranged produced by this technique therefore have a high a jig for holding bunches of bristles at an oblique failure rate of about 5%. angle with their lower ends disposed within the We have attempted to overcome these mould. A suitable micro-cellular elastomeric polymer disadvantages by selecting a suitable material for material is then filled into the mould and allowed to the brush base which will set in a relatively short 110 set and harden around the bristles, within a few time and which permits the whole brush base to be minutes. The mould is then removed from below the formed in a single operation, and as a result the jig and placed in a drying area, with the bristles present invention has been accomplished. supported by a drying jig which may be simply a Accordingly, the present invention in one aspect circular hole of greater diameterthan the base mould provides a method of making a brush, comprising 115 formed in a plate arranged above the mould. After arranging bunches of bristles so that their one ends drying, the completed bFush is then removed.

extend into a mould for forming the brush base, and The invention will be further described, by way of applying into the- mould around the said one ends of example only, with reference to the accompanying the bristles a quick-setting liquid plastics material, drawings, in which:

and allowing the plastics material to set to secure 120 Figure 1 is a perspective view of a road-sweeping the brush base to the bristles. brush made by the method according to the The plastics material will be one which sets in a invention; relatively short time, and is most suitably any Figure 2 is a plan view of a mould for the base of a elastomeric polymer material having a micro-cellular road-sweeping brush; and structure. A particularly suitable material has been 125 Figure 3 is a schematic sectional view of an found to be polyurethane modified to be marginally apparatus for producing a road-sweeping brush foamed, for example by adding water thereto, but according to the invention.

any other material meeting the requirement of quick Figure 1 shows a roadsweeping brush produced setting may be used in the invention. according to the invention which comprises an While polyurethane, or any other suitable 130 annular base 1 foamed of micro-cellular elastomeric 2 GB 2 173 996 A 2

Claims

polymer material, e.g., polyurethane foamed by 40 CLAIMS adding water

thereto, and bunches 2 of 1. A method of making a brush, comprising polypropylene bristles having their one ends 2a arranging bunches of bristles so that their one ends secured in the base 1 and being disposed so as to extend into a mould for forming the brush base, and extend obliquely outwards from the base. applying into the mould around the said one ends of Such a brush may be suitably produced in the 45 the bristles a quick- setting liquid plastics material, following manner, in which reference will be made and allowing the plastics material to setto secure to Figures 2 and 3. The bristles are arranged in the brush base to the bristles.

bunches and their one ends 2a are applied onto a
2. A method as claimed in claim 1, wherein the hotplate to fuse them together. The bunches 2 of said quick-setting liquid plastics material is a micro bristles are then placed to be held by a jig (Figure 3) 50 cellular elastomeric polymer material.

which comprises an annular plate 5 having therein a
3. A method as claimed in claim 2, wherein the series of holes 5a in which the bristles are placed said micro-cellular elastomeric polymer material is a with their lower ends 2a resting in an annular mould polyurethane foamed by adding water thereto.

3 (better shown in Figure 2). The jig 5 is supported in
4. A method as claimed in any of claims 1 to 3, position by any suitable means 6. As shown in 55 wherein the brush bristles are of a thermo-forming Figure 2, the mould 2 has four equiangularly spaced extrudable material.

recesses 3a formed in its outer periphery, for
5. A method as claimed in claim 4, wherein the forming spaces for receiving bolts when the finished brush bristles are of polypropylene.

brush is installed on a road-sweeping vehicle. The
6. A method as claimed in any of claims 1 to 5, mould 3 also has fourcarrying handles 4. 60 wherein the brush is a road- sweeping brush, and With the bristles thus in position as shown in wherein the brush base is formed in an annular Figure 3, the micro-cellular elastomeric polymer mould.

material is poured into the mould 3 and allowed to
7. A method as claimed in claim 6, wherein the set and harden around the ends 2a of the bunches of brush bristles extend obliquely outwards from the bristles, which procedure takes a few minutes only. 65 plane of the annular base, and wherein during the The polymer material also penetrates to some moulding of the base the bristles are held in a jig extent between the individual bristles of each bunch disposed above the base mould, the said jig having 2. a series of apertures therein for supporting the The mould 3 containing the thus formed brush bristles.

base 1 is then removed to a drying area. During the 70
8. A method according to claim 1 of making a drying, the bristles may be conveniently supported brush, substantially as herein described with by a drying jig (not shown) which may take any form reference to, and as shown in, the accompanying but which is conveniently a plate with a single drawings.

central aperture of greater diameter than the mould
9. A brush produced by a method as claimed in 3, againstwhich aperture the bristles rest. 75 any of claims 1 to 8.

The completed brush, comprising the base 1 and
10. A road-sweeping brush produced by a method bristles 2, is then removed by simply lifting it from as claimed in any of claims 6 to 8.

the mould.

Printed for Her Majesty's Stationery Office by Courier Press, Leamington Spa, 1011986. Demand No. 8817356. Published by the Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.