FI87977B - Method for producing a brush element with a plastic frame - Google Patents

Description

ψ r. The present invention relates to a method of manufacturing a plastic-framed brush element.

In the past, the brush elements have been made in such a way that the brush fibers are fused or glued together at one end, thus forming a comb-like strip 0.5 to 1.5 cm thick. There are several different methods already known for the joining of fibers. The interconnected fiber ribbon is then pressed into a metal base to form a finished product in which the tips of the fibers point directly outward at the metal. base. The brushes are most often in the form of straight strips or round cylindrical brush discs.

However, this current method has involved a great many different steps in the manufacture of the metallic base, whereby the manufacturing time of the product has become unnecessarily long Ά). Even when using brushes, the metal bases have sometimes been able to open and the fibers to come off. In its cylindrical design, the metal base has proved to be unbalanced in structure, with occasional very strong brushing, Or.

lying vibration in the brush machine itself.

Attempts have also been made in the past to make a full plastic brush element, but the parts of the brush made by injection molding did not withstand 30 bristles due to the fact that the fibers of the brush element must be oriented fiber to withstand high wear and injection molding.

The object of the present invention is to provide a method for attaching brush fibers to a plastic base, whereby the method makes it possible to produce brush elements in which the fibers are securely attached to the base and which are also balanced in their cylindrical design. With this method, the base parts are also made very dimensionally accurate compared to the corresponding metal ones, and the weight of the brushing part of the brush machine can be reduced by 15-30%, whereby the transmission devices of the brush machine s are subjected to less stress.

The characteristic features of the production method according to the invention are set out in the appended claims.

] q Injection of the plastic mass into the closed mold by the injection molding technique is not possible in this case »because the molten plastic mass penetrates between the fibers before the mold-based base is completely filled with the plastic mass.

15

In the following, the invention will be explained in detail by way of example with reference to the accompanying drawing, in which

Fig. 1 shows the injection of a plastic mass according to the invention onto a brush fiber strip. Fig. 2 shows a cross-section of a blank pre-injected with molten plastic mass before closing the molds. An example is the manufacture of a cylindrical brush body.

Fig. 3 shows a cross-section with the mold halves closed, whereby the plastic mass is distributed according to the mold, forming the base of the solid plastic brush lamella.

Fig. 4 shows a finished ring brush element ... Figure 1 shows the injection of plastic mass onto the brush fibers. The fibrous strip 1 made of fused or glued fibers at one end is conveyed, for example, between two rotating conveyor belts pressed under a nozzle 2 of a plastic press, which The thickness of the molten plastic strip is 2 - 15 mm tm • h ·

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a 87977 i depending on the volume of the base of the brush body.

A blank of the required length is cut from the blank thus formed and the blank is wound around the lower part 4 of the mold shown in Fig. 2.

The upper mold 5 is pressed against the lower mold 4 according to Fig. 3, whereby the plastic mass is compressed in a mold-like manner () while filling the gaps between the fibers in the base part and thus forming a solid plastic base part 6.

If necessary, e.g. metal support parts or fastening pieces can be placed in the compressible blank before the mold halves are compressed.

It will be apparent to one skilled in the art that the size and shape of the brush elements to be manufactured in accordance with the invention may vary within very wide limits with respect to the fibrous material or its dimensions. Other products can also be manufactured by the same method, e.g. plastic hill elements, street bone, etc. The structure of the devices and molds according to the invention can also vary within the scope of the invention in correspondingly many ways.

25 In the finished brush element, the fibers (8) are firmly attached inside the base part (6), Fig. 4. A tooth (7) is formed to fasten the brush element to its shaft. This can be formed either directly in the mold or as above with a support part to be added to the blank.

30; 3b

Claims (3)

A method of manufacturing a plastic frame brush, wherein the brush element consists of a carrier member (6) made of plastic pulp and brush fibers (8) or brush placed on the inside thereof from one end, and in which way the plastic plastic pulp (3) is sprayed. or extruded on the upper side of a band (1) formed by one end of the associated fiber fibers to form a preform, characterized in that a length of the thus formed preform is placed in an open mold, preferably on a lower mold portion (4). ), after which the mold is closed, preferably by means of the upper mold part (5), whereby the plastic mass (3) is pressed to form a bardcl (G), in which the plastic mass (3) substantially fills the gaps between the fibers (8). 15 Manufacturing method according to claim 1, characterized in that a reinforcing or fastening part is placed in the preform made of the fiber strip (1) and the plastic pulp (3), before the mold is compressed. 20 Manufacturing method according to claim 1 or 2, characterized in that the preform is arranged to form a ring by means of a ring mold (4,5) suitable for this purpose, in which case the finished brush element forms a ring. 25 30