DE2026923A1 - Process for the production of bottles from plastic with a print - Google Patents

Description

E. 9869
1.6,1970 Gl / Kb

Annex to f

Patent registration "

HOBEST BOSCH GMJBif, 7 Stuttgart 1, Breitscheidstrasse Method of making bottles from plastic with

. Imprint

The invention relates to a method for producing Bottles with an imprint »which, from preforms made of thermo plastic plastic in the deformable state can be expanded in a mold by differential pressure.

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109851 / U60

Robert Bosch GmbH "R.'9869 αϊ / Kb

Stuttgart

Bottles made of thermoplastic using the blow molding process Plastic can be printed directly using the screen and dry offset printing process or labeled and decorated by indirect pressure transfer processes. In the latter case it will Print image first applied to an intermediate carrier and transferred to the bottles in a special process. These methods are suitable for printing hollow bodies, whose Walls have a sufficiently high rigidity or in which a core can be inserted to generate a counterpressure. Bottles with very thin, yielding walls and narrowed. Neck can be with the known method because of insufficient rigidity do not print on their wall.

The object of the invention is to provide a method according to which bottles with thin, flexible walls with a Have the imprint made.

This object is achieved according to the invention in that a reduced size is applied to the preforms in their solid state Imprint is applied and the preforms are put in a deformable state thereon in a manner known per se by heating and eventually widened.

With this method, the color for the printed image can be saturated without difficulty using the known printing method the preforms are applied. When the preforms are subsequently heated, they are then firmly bonded to the Plastic surface, so that the final picture is special . is abrasion-resistant and durable »"

In a further embodiment of the invention, for the production of bottles, the shape of which is not similar to that of the preforms is, the imprint is applied to the preforms as a distorted image.

109851 / U60

BATH

Robert Bosch-GmbH R. 9869 Gl / Kb

Stuttgart

For making bottles with a non-circular cross-section the preforms are aligned according to the position of their imprint in the mold. .

The method according to the invention is shown in the drawing using an exemplary embodiment and is described in more detail below described. Show it: ·

Fig. Λ with a preform made of thermoplastic material

an imprint and. f

FIG. 2 shows a bottle produced from a preform according to FIG. 1.

From a thermoplastic material, for example polystyrene, polyethylene, polypropylene, polyvinyl chloride, or the like, a preform 1 (Fig. 1) is first formed in an injection mold in an injection molding process, which has the shape of a hollow truncated cone with a slightly conical shell 2 . The preform 1 is closed at its narrow end, open at its wide end and has at its open end 3 has a radially projecting flange After removal from the mold is allowed to cool the preform 1, wherein said high stiffness ER- λ reached. On the preform 1 solidified in this way, a printed image 4 is applied in the screen printing, offset, gravure printing process, or by means of a printed, heat-sealable film (warm offset printing) for the indication of the contents, designation of origin or advertising.

After printing, the preform 1 is brought to a temperature heated in the plastic or preferably in the thermoelastic Area of the plastic used. The preform is then brought into a blow mold and introduced by introducing it of blown air through its opening as well as by axial stretching

109851/1460

BATH ORIGINAL

Eobert Bosch GmbH 'R. 9869 Gl / Kb

Stuttgart

widened to a bottle 5 with a stamp.

With this enlargement of the surface of the preform 1, the print image is also enlarged, namely to a size which is planned in advance for the finished bottle. Since in the illustrated embodiment, it is assumed in the of a preform 1 with circular cross section and the finished bottle has a square cross section, the stretching of the plastic wall in the circumferential direction is greater than the stretching in the longitudinal direction, the original print image 4 is equal in these two directions enlarged. To therefore. To obtain an image with specific dimensions and specific design on the bottle 5, the print image 4 is printed on the preform 1 in a distorted manner. For example, an oval is selected as the print image if a circle is to appear as an image on the finished bottle. The distortion of the printed image depends on the ratio of the stretching of the wall of the preform 1 in the longitudinal and transverse directions in the individual areas. The various stretching ratios can be determined if a uniform grid is applied to the preform and its distortion is measured on the finished bottle. The print image to be produced can then be predetermined from this.

It is also pointed out that as preforms Tubing sections made of thermoplastic material can be used, depending on the stretching with a printed image provided before heating and expanding.

109851 / U60

Robert Bosch GmTDH. ' . E. 9869

Stuttgart

If the preforms have a round cross-section, on the other hand the bottles made from it a non-circular, but for example a square, oval or the preform becomes a cross-section of another common 3-shape 1 aligned in its circumferential direction when inserted into the blow mold according to its imprint, that the printed image comes to lie on the intended 3-pool determined by the blow mold. "■

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1098.51 / 1460

Claims (3)

HoIjert "Bosch GmbH" H. 9869 Gl / Kb Stuttgart Expectations A method for producing bottles with an imprint, which are expanded from preforms made of thermoplastic material in the deformable state by differential pressure in a mold, characterized in that a reduced imprint is applied to the preforms in their solid state and the preforms themselves on it "as is known, can be transformed into a deformable state by heating and finally expanded" 2. A method for producing bottles according to claim 1, the shape of which is not similar to that of the preforms, characterized in that a tearing pressure is applied to the preforms. 3. Method of making bottles with a cup shaped like a circle Cross section according to claim 1 or 2, characterized in that the preforms according to the position of their imprint in the Shape to be aligned. 109851/1460