DE1012224B - Method and device for scarring or embossing surface structures that contain little or no plasticized thermoplastics - Google Patents

Description

The cold forming of thermoplastics has so far only been possible to a limited extent be performed. This deformation process was only used to produce spatial structures used, the z. B. were produced by the deep-drawing process.

Embossing or graining on flat structures made of thermoplastics, such as. B. foils, with plastic impregnated or coated fibers or artificial leather etc., could so far only 1> at elevated temperature can be carried out, with the embossing in the case of continuous operation or graining when passing the softened foils or the like between corresponding pairs of rollers was achieved.

Either a) the steel embossing roller could run against a rubber roller, with only the front side was grained while the back remained more or less smooth, or b) a steel grain roller against a roller made of paper mache, in which an impression of the contours of the steel roller is impressed is to work.

The latter type of embossing is often used to grain nitrocellulose synthetic leather.

It has now been found, surprisingly, that sheet-like structures made of thermoplastics, such as cellulose derivatives, polymers or copolymers, e.g. B. of vinyl chloride etc., Polycondensates, ζ. Β. Polyamides, polyurethanes, etc., or with these thermoplastics impregnated, coated or laminated fibrous materials, in particular paper, fabric, fleece od. The like. Or Artificial leather taking into account special working methods without softening the surface structure through the action of heat embossed or grained of any kind using the so-called cold-forming process can.

According to the invention, not only flat structures made of plasticizer-free plastics, but also plasticized thermoplastics can be cold embossed or grained if these flat structures are still to be regarded as hard in the sense of the definition of rigid films, the shear modulus of which is thus greater than 5-10 ³ kg / cm ² ( DIN 53 371). In the latter case, the durability of the embossing or graining depends largely on the type and amount of plasticizers added. According to the invention, the limit of permanent embossability is at a content of about 20 parts by weight of plasticizer per 80 parts by weight of plastic, further additions of fillers, pigments and the like are not taken into account.

An addition of certain plasticizers has proven to be particularly advantageous. B. Di method and device for scarring or embossing flat structures,

those that are not or only slightly softened

contain thermoplastics

Applicant:
JH Benecke, Hanover

Dr. Hans Haldenwanger, Hanover -Vinnhorst,
has been named as the inventor

cyclohexyl phthalate, which significantly increase the cold stampability.

To carry out this cold embossing or cold graining are suitable e.g. B. embossing or grain rollers that work against a roller made of paper mache.

The embossing of softened foils can also be assisted by the fact that grain rollers are used or similarly acting embossing devices are used, the raised individual contours (counters) of which an elevated one Have shape.

With the help of these devices, you can emboss the desired shape even in plastic films with a shear modulus greater than 5-10 ³ kg / cm ²

z. B. obtained in the following way without heat supply: The grain should, for example, consist of numerous There are depressions in the form of hollow calf balls. The grain roller for the usual graining when heated should therefore be studded on its surface with hallmarks in the shape of a hemisphere, as shown in Fig. 1 reveals. If these raised hemispheres are replaced by hemellipsoids, the base of which is the same as the of the hemisphere and the height of which corresponds to the major semi-axis of the ellipse (Fig. 2), then with correct

Choice of the major semi-axis of the ellipsoid a scar in the form of hemispherical depressions can be achieved, if the difference between the major semi-axis of the ellipse and the spherical radius of the springback of the material.

The degree of elevation of the forms depends largely on the plasticity and elastic springback of the material from which the fabric is made, and in each individual case is made beforehand determined or determined.

709 587/89

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The following examples are given to explain the invention in more detail.

example 1

Using a grain roller with a pronounced relief against a paper mache roller works, a cellulose acetate film is grained in the cold. ...._.

Example 2 -

A film material made of 80 parts by weight of polyvinyl chloride and 20 parts by weight of dioctyl phthalate, which can also contain other components such as pigments, fillers, dyes and the like cold embossed with a grain roller, the relief of which is exaggerated. The result is an impression that is not exaggerated Relief corresponds.

Example 3

A polyvinyl chloride sheet comprising 72 parts by weight of polyvinyl chloride, 18 parts by weight of dioctyl phthalate and Contains 10 parts by weight of dieyclohexyl phthalate, is embossed in the manner described above and is thereby retained a scar, the contours of which correspond to a rolling relief that is not exaggerated.

In all cases a permanent impression of the foils is achieved.

The new cold embossing process has a softened state compared to the previously usual embossing of the foils a number of advantages. Because the embossing, graining or the like take place at room temperature can, the previously used heatable embossing rollers can be omitted. The additional Steam or electricity costs for heating these rollers are therefore also eliminated.

Another important advantage is that the flat structure during the embossing process not be subjected to any changes. Especially with soft foils, there is hot stamping there is always the risk of uncontrollable and irreparable reversible changes in the event of slight temperature fluctuations Elongations occur. These areas have a grain depth that differs from the surrounding area, which is perceived as annoying by the viewer with suitable visual reflection. | "

In contrast, the invention enables a particularly exact dimensional accuracy, so that the defl; embossed sheet-like structures produced by new processes with particular advantages for the production of voa Photo walls can be used. Such flat structures are also used for metal vapor deposition suitable in a vacuum.

Of course, the cold embossed sheets produced according to the present invention can also find use for all those purposes for which hot embossed hard foils, etc. are used, such as z. B. for book covers, office supplies, as EAO ^ ration, cladding material, etc. '

Claims (3)

Patent claims: 1. Process for scarring or embossing sheet-like structures that are not or only slightly softened Containing thermoplastic plastics, characterized in that the surface finishing carries out their raised individual contours by cold forming with grain or embossing rollers have a shape adapted to the respective plasticity of the thermoplastic material, which is excessive compared to the intended embossing. 2. The method according to claim 1, characterized by the use of sheet-like structures which contain only so much plasticizer that the SchuB module is greater than 5-10 ⁸ kg / cm ² . 3. Device for carrying out the process according to claim 1 and 2, characterized by the use of an embossing or grain roller, the works against a paper mache roller. 1 sheet of drawings . © 709 587/89 7.57 " _Ä [ß