DE3517275A1 - METHOD FOR LABELING PLASTICS - Google Patents

Description

BAYER AKTIENGESELLSCHAFT 5090 Leverkusen. Bayerwerk Group Administration RP ^{13 May 1985}

Patent license Leiluna Kr / Abc

Process for marking plastics

* The invention relates to a method for labeling Plastics by adding a dye using a heat transfer medium is transferred to a plastic.

In measuring, regulating, switching and operating devices are often

to attach easily legible, well-worn labels that in the composition and size of the characters from case to case Case are different. This applies in particular to the keys of input units such as typewriters.

Transfer printing is known, in which a dye is used provided carrier made of paper by means of a hot pressure stamp with light pressure against the plastic is pressed, the dye on the surface

is transmitted.
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The disadvantage of this method is that for Each character requires special stamps, making the process inflexible in terms of fonts and expensive smaller quantities is. With such a stamp, too, it is difficult to maintain the temperature, and this

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Fluctuations in quality degradation with regard to dye intra-sauna and surface of the plastic.

Also known is the labeling of a K _U nststoffteiles with a laser beam, "and this according to the

Lettering is performed.

The disadvantage of this method is that it works through the action of the energy of the laser beam leads to irreversible conversions in the plastic, which is usually with

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significant color changes are associated. The color change Can only be set to a limited extent: that means there is only light text on a dark background or a dark one Writing possible on a light background.

The invention is based on the object of an economical, Find a flexible method for labeling plastics, with the sharp-contoured, abrasion-resistant Characters in any desired color and size on any background only through graphic or electrical

. ". .

Niche specification can be generated, with a destruction of the plastic must not enter.

The object is achieved in that over at least one taxable according to the characters

"-.

The sublimable dye can be used as a heat carrier using a laser beam is diffused via the gaseous phase into the respective point heated surface of the plastic.

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. ι

It was surprisingly found that by means of a short-wave Radiation, especially a laser beam that sublimable dye despite phase change without essential Change of color in the successively heated surface of the according to the desired character Plastic so deep as a result of the partial pressure drop can be diffused in that a sharp contour, abrasion-resistant, easily legible, colored characters are created, The color can be freely selected depending on the meaning (e.g. signal red) and the background. Because of the short, Targeted, even irradiation and the non-contact energy transfer, there is no material damage on. Another advantage of the method according to the invention is the flexibility, since the laser beam over Guidelines (drawings) or computer programs can be controlled.

For colored printing, laser beams with a Focal spot diameter between 0.05-0.1 mm diameter at a repetition frequency of 0.5-10 KHz under a current intensity of 10-25 A and a speed of 5-50 mm / s, in particular of 5-15 mm / s, as particularly advantageous proven. The amount of diffusion depends on the strength of the current times mode number by speed.

In a special implementation of the procedure, the Sublimated dye which has been applied over the entire surface diffuses into it.

By applying a dye to the surface by pouring, spraying, brushing or printing, it is possible to

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each character with the laser beam according to the given To run the course. Which did not diffuse in Residual dye is then removed.

In another implementation of the procedure, the sub-Π ·· ·

Limited dye on a carrier material on the surface of the plastic passed "

With the help of carrier material »that made of paper, fabric or Foil can exist, the sublimed dye is attached to the Position where the laser beam hits. A device with a continuous one is advantageous for this Tape, which is removed from one reel before use and again after signing on the next reel

is wound up.
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In a further implementation of the process, the sublimated dye in gaseous phase to the area, where the laser beam hits, at high speed

passed with simultaneous compaction. 25th

By supplying dye in gaseous phase with high Speed and compression through the funnel-shaped design of the gas channel can achieve an intense effect be, with the excess dye always

again immediately sucked off to be added to the circuit again to become.

In one implementation of the method, the sublimable Dye in thermoplastically processable,

Flowable or pressable plastics diffused.

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The process can be advantageous for materials such as acrylonitrile 1 -butadiene-styrene (Novodur IHl) Cellulose acetate (Cellidor If) - polyamides (Durethan Hl) Polycarbonate (Makroion ®). Polyester and polybutylene terephthalate (Pocan Hl) or a mixture of the above Polymers and preferably (PC / ABS blend (Bayblend | R |) PC / PBTP blend (macro blend §) and polyurethane as well Silicone rubbers are used. In particular are ThermoDlastic materials can be processed.

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ORIGINAL INSPECTED

example 1

A transfer printing paper printed on the surface with Resiren T. blue is positioned on a typewriter key made of Novodur PH-AT (ABS) and under the laser optics of a Nd-YAG solid-state laser. It will be a Focused laser beam generated (1 = 1.06 u) and guided in a circle over the paper. After removing the The dye in the irradiated zone is in the paper

Penetrated plastic.
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Example 2

A polyester film printed flat with Resiren T. red (Hostaphan RE 0.050 mm) is placed on a switch cover

made of Pocan B 1505 (PBTP) and positioned under the laser optics of a Nd-YAG solid-state laser. A focused laser beam is generated (1 = 1.06 Ii) and in Circular shape passed over the film. After removing the film, the dye in the irradiated zone is in the art

^ substance penetrated.

Example 3

A polyester film printed flat with Resiren T. black (Hostaphan RE 0.050 Tt) is positioned on a plastic housing made of Durethan BKV 30 and under the Laser optics of a Nd-YAG solid-state laser arranged. It a focused laser beam is generated (1 = 1.06 u) and guided in a circle over the film. After removing the film, the dye is in the irradiated zone in the Plastic einaedrunaen.

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Claims (5)

Claims 1. Process for marking plastics by a dye is transferred to a plastic by means of a heat transfer medium * indicated by this. * "that about at least one according to the characters controllable laser beam as a heat carrier of the sublimable dye over the gaseous phase in each point heated surface of the Plastic is diffused. 15th 2. The method according to claim 1 »characterized in that that the applied directly on the surface suhlimierbe dye is diffused. 3. The method according to claim 2, characterized in that that the sublimed dye is carried past the surface of the plastic on a carrier material will. 4. The method according to claim 3, characterized. that the sublimable dye is in the gaseous phase at the area where the laser beam hits the surface of the plastic at high speed passed with simultaneous compaction will. 5. Process according to Claims 1-4, characterized in that the sublimable dye is thermoplastic Processable, pourable or pressable synthetic · substances is diffused. Le A 23 828