DE19512587C1 - Toothbrush head mfr. by injection moulding formed in one operation - Google Patents

Abstract

Injection moulding is used to mfr. a toothbrush head by a method in which a die is prepared for forming the bristles and forms an injection mould together with a forming die. A plastic or rubber material is pressed into the moulding die so that brush body and bristles are formed from a standard material in one operation. The depressions for forming the bristles are produced by pressing a pin bed die (A) comprising individual pins fixed together into the die (B), which is of a plastic material, which is then converted into a non-plastic state before moulding takes place. Pref. pins are of a metallic material and the tip of the pins are rounded.

Description

The invention relates to a method for producing a Toothbrush head in injection molding technology according to the generic term of claim 1.

A toothbrush made by such a method is known from US 3,691,585, brush bodies and bristles injection molding from the same material in one operation be generated. There is no information on how the recesses for the formation of the bristles are created. DE-PS 9 41 364 also shows and describes a method of the above type. There are the specializations for training the bristles are created as holes in the die.

The object of the invention is to provide the wells for the Forming bristles in the die in a way to create which a variable design of the bristle field with simple means allowed.

This task is characterized by the characterizing features of the claim 1 solved.

The inventive use of a jointly fixed The die can be made from single pins of the existing pin bed stamp plastic mass quickly and easily in the desired manner with the Wells for the formation of the bristles are provided. For different bristle fields only the arrangement of the Single pens to be changed within the pen bed stamp. This can be done by changing or moving the individual pins respectively. With the changed pin bed stamp a new one can then Die are stamped.

Advantageous developments of the invention are in the Unteran sayings.

The invention is described below using an exemplary embodiment the drawing explained.

Show it

Fig. 1 is a side view of the pins,

Fig. 2 is a plan view of the pin bed,

Fig. 3 shows a die during the stamping process by the pin bed stamp and

Fig. 4 shows a finished die together with the form stamp.

The pin bed stamp (A) consists of any number of pins, the shaping part of the shape of the bristles and the non-shaping part has a 4- or 6-sided profile for optimal fixation ( Fig. 1 and 2).

Making metal pins thinner than 0.3 mm is not Problem. The tenon shape of the forming part should be so thin that the casting material easily reach the rounded tip and can be removed without complications after casting. The shorter the pen or the stronger its base, the thinner the later bristle end.

Due to the width of the non-forming part, the density or  set the number of bristles.

The pins can be of different lengths and therefore the Model the brush surface or with the same length different vertical positioning of the brush surface determine.

After the desired arrangement of the pins (preferably metal) and fixation in the pin bed stamp (A) by casting, gluing or bracing, the die (B) filled with a deformable mass (e.g. ceramic) can be embossed by the pin bed stamp (A) ( Fig. 3). After the matrix has hardened, the pin bed stamp (A) is removed and replaced by the form stamp (C) which forms the shape for the brush head base ( FIG. 4).

Plastic, rubber or the like can now be passed through a casting channel Materials are pressed into the mold.

Which materials can be used depends on the Toughness and tear resistance of the material depend on the bristle thickness is the main criterion.

After curing, the complete brush head can be removed. The above Protected claim allows the process Low waste, energy saving and thus ecological production of Matrices for single bristle toothbrushes even for the most complicated Bristle fields, since the pin bed stamp (A) can be used several times can.

The rounded pen tips have rounded bristle ends Follow and save the cumbersome rounding process by grinding or polishing as usual.

Claims (6)

1. Process for the production of a toothbrush head in the injection molding technique, in which

• a matrix with recesses for the formation of the bristles is created,
• - The die forms a casting mold together with a form stamp and
• - A plastic or rubber material is pressed into the mold, the brush body and bristles being cast in one operation from a uniform material, characterized in that the recesses for the formation of the bristles in the die (B) by pressing in a single pin fixed together existing pin bed stamp (A) are produced, the die (B) consisting of a plastic mass which, after being embossed by the pin bed stamp (A), is converted into an unplastic state before the casting process takes place.

2. The method according to claim 1, characterized, that the non-forming lower part of the pins is a 4- or Hexagonal profile for optimal fixation. 3. The method according to claim 1 or 2, characterized, that the pins have a variable length depending on the desired Can have the shape of the bristle field. 4. The method according to any one of claims 1 to 3, characterized, that the connection of the pins in the pin bed stamp (A) through Potting, gluing or bracing took place. 5. The method according to any one of claims 1 to 4, characterized, that the pins are made of a metallic material. 6. The method according to any one of claims 1 to 5, characterized, that the tips of the pins are rounded.