Materials for the production of holographic self-adhesive pasters
I. Top layer of self-adhesive paster – material and thickness
Holographic self-adhesive stickers are produced by pressing to a plastic electroplated or transparent film. Acrylate gule is then put on the basal layer (metallic layer) of the sticker. Holographic etiquette therefore has 3 layers, and characteristics of these layers can be chosen according to your needs and intended application of this self-adhesive sticker.
Top layer of holographic etiquette is made of a plastic film which is very thin and translucent. This film for printing of self-adhesive sticker can be made of OPP, PVC or PET materials. The most used material for holographic stickers is PET (polyethylene terephthalate) in almost amorphic form, which guarantees high transparency. All holographic etiquettes are normally produced on the basis of a PET film because this material fulfils all required characteristics almost perfectly. One of the fancied characteristics is high resistance against wide variety of chemicals, mechanical strength, extremely high impenetrability of liquids and gases, low thermal dilatation and resistance against high temperatures which allows the lamination of holographic seals and also impress in laser printer (the melting point of PET is around 267 °C). Its alternative can be an oriented polypropylene which is used mostly as a wrapping material for its better pull strength. Therefore it is no used for a production of self-adhesive stickers but it is rolled to rolls as feature-length wrapping materials.Of course there are customer’s holographic motives all over the sheet which are repeating in cycles. There is no gluing at holographic OPP wrapping films. PVC joined with holographic printing can be used for special applications like a wrapping material for groceries (instant contact with the groceries). PVC film is known for its high mechanical expansion and therefore has to be combined with layers of other materials like OPP or PET to be suitable for a production of the holographic film.This kind of film can then be also used for a production of holographic periodical patterns used for wrapping.
Another optional parameter of a load-bearing film of holograms is thickness of the film. This information is not important for standard applications of the self-adhesive stickers and holograms are printed to PET film with the thickness of 67 microns. For your special applications of etiquettes or wrapping materials you have an option of choosing the thickness of 20 microns. The price will be calculated individually if a customer chooses his own thickness. All prices listed at our website are calculated with the thickness of 67 microns of a PET film.
II. Middle metallic layer for holographic impression
The middle layer out of all 3 layers of the holographic self-adhesive sticker “sandwich” is a very thin metallic layer into which a holographic impression alone is transacted. Exactly this layer is a load-bearing medium for rainbowlike passages creating pictures that are in your pre design. Top layer in a form of a plastic film gives mechanical strength to the sticker and protects the metallic layer from damaging.
Most commonly used is an aluminium layer which gives holograms a typical appearance of silver reflecting areas with rainbow like tones. Silver colour of the base offers the most plastic, the most colourful and the most outstanding effects even when the light is very bad. The most perfect effects are achievable at the full daylight.
Apart from the most famous silver colour of holograms you can also choose from other colours just so it suits your purposes. The colour of a load-bearing film stays unchanged and a colour-bearing part according to your choice will be borne by a layer of metal into which the hologram is printed. Apart from silver, amid commonly used colours belongs also golden, and for these most commonly used colours we have prices calculated here at our websites. You also have an option of a blue, green, yellow, red colour... A price for these colours of medias will be calculated individually with a concrete order.
Demonstration of possible types of colored films for the production of holographic self-adhesive etiquettes and also wrapping materials.
Another possible look of self-adhesive sticker is translucent hologram on a transparent film. Sticking transparent hologram over a picture or a text does not affect its readability and does not look disturbing even though it is greatly recognizable and visible from other angles. More information about this type is written in section “your design-transparent”.
A technique of translucent holograms on a transparent film can be used for production of self-adhesive stickers and wrapping film.
III. Method of demetallizing of load-bearing metallic layer
After physical production of holographic self-adhesive sticker – pressing of graphical items to load-bearing metallic film- the hologram itself is almost finished. It will contain as many layers as the method of its production allows. In this phase of production can, however, be used another method which gives your predesign another layer or can be used as a very effective creative item. In another layer it is possible to define the transparencies. From a digital processing of a picture we deal with one bite alpha channel. At a completed load-bearing metallic film with holographic relief, a photosensitive layer is applied. This layer is lighten through a template produced on a base of graphical layout of demetallizing layer, the photosensitive surface is then chemically initiated to wash away the coping film from unlighted areas. After that, the holographic layer is oiled in an acid which outlines the uncovered areas of load-bearing layer. Holographic impression which should be visible are not influenced by this process, however, other areas are outlined and therefore stay transparent.
This method is usable no matter of previous preparation of hologram (single layered, two layered, with master...) and can also be used for numbering or text describing. This layer is always greatly visible and readable. By this method it is also possible to create translucent windows e.g. for visualizing of series numbers at which will the securing self-adhesive sticker be stick on. Demetallization is also used for a production of transparent holograms which should not cover the pictures at which they are stick on. Last but not least it is a method which allows to create a self-adhesive sticker with arbitrarily shaped edges – e.g. in a shape of a seal or a leaf with burnt edges. Samples of this method are shown in this section demetallized safety self-adhesive stickers made in advance.
IV. Self-adhesive basal layer
After hologram is pressed into metallic film on a load-bearing plastic film, the etiquette is finished. But to make a self-adhesive sticker, another layer has to be put on – a glue. On a basal metallic layer a very thin layer of a permanent transparent acrylic glue is applied.
An option of choice when designing your own self-adhesive stickers is in this layer represented by Tamper-evident or Void-evident technology. In these types of self-adhesive stickers, the glue is not applied on a whole area of hologram, but through the template with a specific pattern. When the sticker is removed, in those areas which were not under-glued, the metallic film does not divide from a plastic film and the graphics that was used for a production of the template will not get visible. Stickers produced this way show increased probability of unauthorized unsticking and react by a specific damaging of load-bearing metallic layer – exposing the words “VOID”, “ORIGINAL”, “Cancelled” or a regular graphical emblem (depending on a type of chosen pattern medium). It is clear right away that the hologram was unsticked even if just a little bit. Attempts to stick it on again will not change anything about the visibility of exposed words. This technology highly increases security value of a seal because even if the seal was unsticked from a badly ungreased or a rough surface by potential violators, it will be changed by exposing the greatly visible words for good.
When ordering tamper evident self-adhesive stickers you can choose from above stated words or you can create your own graphics made of words or emblems. The choice of user’s pattern will, of course be financially more demanding than general usage of patterns from our menu.
|A1 - security self-adhesive sticker with VOID pattern||B1 - classic sticker with a destructive pattern|
|A2 - a remnant of the pattern after unsticking VOID sticker||B2 - a remnant of a pattern after unsticking a classic self-adhesive sticker|
|A3 - a remnant of a ripped VOID sticker||B3 - a remnant of a ripped classic self-adhesive sticker|
|C1 - colored paster with a destructive pattern||D1 - security sticker with a square VOID pattern|
|C2 - a remnant of a pattern after unsticking the colored self-adhesive sticker||D2 - a remnant of a pattern after unsticking VOID sticker|
|C3 - a remnant of a ripped colored self-adhesive sticker||D3 - a remnant of a ripped VOID sticker|
V. Hot stamping
Another alternative of gluing is so called hot-stamp technology – hot impressing of holographic etiquettes. Instead of a permanent glue, a hot melt glue is applied on the metallic side. Impressing of a hologram on a pattern happens in heat, that is how the glue gets active. By hot impressing it is possible to put holograms on paper and also plastics, there is an extremely strong connection with the surface. In addition, an impressed hologram does not stand out of the surface and becomes its very naturally looking part. Hot impressing is normally done by the machines and that is the reason why the stickers are not organized in a raster but rather in a thin endless chain and this way the machine can unwind it itself.
Holographic etiquettes for hot stamp impressing on a stripe that is put into the machine.
VI. Adherence of self-adhesive holographic films
We have tried a strengthened layer of glue for holographic etiquettes intended for more problematic (rough) surfaces. You can now use this option even in your predesigns of self-adhesive sticker. You can try the paster with a higher gluing layer yourself, directly for your application. You can find it in in-store stickers - Flip-flop multi layered holographic seal. More information about adherence of the sticker is written in the next article.
Normally, holographic stickers are made on a very thin PVC film, its thickness is about 30 micrometers. It is intended to produce a self-adhesive sticker that would be as thin as possible and therefore would not disrupt the surface on which it is stick on. This way it will not create a disruptive relief and its edges will not be too high. As the PVC film is thinner, the sticker is more resistible against intended and unintended unsticking – with this extremely low thickness it is not possible to unstuck the sticker with the nail or a razor and it gets instantly and visibly damaged. With regard to determining holographic self-adhesive materials is impossibility of unsticking of the sticker a very important and watched parameter. An important role here plays the layer of glue which is applied on the basal side.
A layer of glue that is used as a basal part of holographic self-adhesive materials cannot increase a profile of the paster because of the reasons stated above and therefore this layer is extremely thin. For these applications ahigh quality hydro gel glue is used.
To get an expected adherence to the surface after sticking on the sticker, to keep all these production methods is not enough. A phase of application – actual sticking of the sticker to an intended place - is as important as these methods. This procedure is done usually by you. Because of that, please, keep these two important things in mind:
VII. Cleanliness of the surface
Not even the best glue will keep the sticker sticked on a greasy surface. The hologram will act the same way on a greasy surface as it acts on a greasy sheet from which you unstick it before sticking it to the surface. In a case of paper or enamel ceramics you don’t have to ungreased the surface, but many industrial products come into contact with oils or lubricants during the production. This does not involve just industry, where a need of ungreasing the surface is evident. Even a simple thumbing of the surface before sticking the sticker can result in a decreaseits adherence with the surface, because our fingers tend to be unexpectedly greasy. Before application of the sticker on surfaces like these, we recommend using chemical agent for ungreasing – thus a suitable dissolvent. It is inevitable to choose it the way that the surface of an object will not get damaged. As a completely universal and effective can be considered a pure alcohol or isopropyl alcohol – which does not have to be suitable for cleaning pure glassy surfaces because it could leave white marks after drying, just as roughly denaturised alcohol. Before applying the sticker on very greasy surfaces, especially industrial parts, we recommend using benzin. As completely unusable isconsidered diesel or classic petrol for combustion engines , applying of these substances is counterproductive. For metallic segments which came into direct contact with lubricants during the production is possible to use the most effective product for ungreasing – tetrachlor. It is necessary to be careful about your health while using it (mostly ventilating) and secure that there will be no eventual contact with plastic parts of cleansed product – those would be immediately and irrecoverably damaged.
VIII. Structure of the surface
Apart from cleanliness of the surface, its very structure is important. It does not really matter whether the surface is absorbent or not. Critical is whether the surface is smooth or rough. Glazed metallic surfaces chrome and glazed parts, smooth plastic or glassy surfaces create absolutely ideal place for sticking on the hologram because here it will be stick by its whole area. From places like these it is sure that it cannot be taken off without damaging. In case of rough surfaces the constant of adherence will, unfortunately decrease. That, however, does not mean holograms cannot be stick on these surfaces because thanks to quality glue there is great back-up. As the surface is rougher, demands for ungreasing it increase. From microscopic point of view rough surface represents some kind of a hilly land and distinctly decreases the area which will be used to stick the sticker on with a glue. For the layer of glue is very thin, the area used for sticking the stickers is only tops of those “hills”. If it is possible, we commend to glue an object or a product in a place that will be structurally most suitable for the best adherence (in a part of the most suitable material). A big problem could be an unlacquered wooden surface – here it is necessary to do practical testing by sticking the sticker for the surface of wood can be scapppled many ways with different degrees of smoothness. Another option of resolving this is using increased layer of glue. You can use this option when pre designing and ordering the self-adhesive sticker according to Your design.
If you are planning to stick the sticker on a product that could have a problematic surface (according to what is written above), we recommend you to order samples first and try their sticking to the surface. Do not forget to order order a Flip-flop holographic seal along with the samples.This seal has a much higher layer of glue so its adherence to rough surfaces is much better. You can ask for a strengthened layer of glue while ordering the self-adhesive stickers according to Your design.
IX. Holographic master
Holographic master is a name for original pressing forms for reproduction of holograms it is a deck into which an exact mathematically generated picture according to graphical pre designs of hologram is burnt by laser. If you need to seal a lot of copies, also copies of the master have to be made. For sealing is normally used nickel stamping die – a nickel deck with a “printed” picture of a hologram. There are many types of holograms and in connection with that also multiple ways of pressing die production. The master can be produced by burnout with help of a coherent collimated laser light radiation directly on a glazed metallic deck. By this process a positive pressing die is directly produced. A more used method of using laser radiants with much smaller capacities and therefore cheaper appliance with using of the photo path – a glassy deck with a layer of photosensitive material, which is brought up by lighted/unlighted (positive/negative photo material) and this deck is lightened instead of a metallic deck. A master produced like this cannot be used for impression of holograms on cylinder presses and therefore a metallic copy of it has to be made. A glassy deck with holographic pattern is silvered by silver vapours. Consequently produced conductive layers are then used either for direct galvanizing by a nickel or for production of copies, with a help of so called electronic forming which results in a nickel deck for impression. As many dies can be created as its needed for a precise production according to desires of a customer.
X. Safety self-adhesive pasters with guilloche graphic item
Guilloche item is another graphic security appliance which you can use in your predesign of a hologram. It consists of thin corrugated lines which create ornamental patterns (rosaces) for many known from their childhood game Inspiro. Complicated geometrical formations of guilloches are suitable for securing and decorating too. Typical usage is securing most of the state documents of high importance nad mainly for preventing bank notes from falsifying. Guilloche strings can be found in ID cards, driving licences, arms licencs, passports, technical cards, highway stamps, reports, trade licences and of course, on every paper means of payment. Specially paper money and bankable papers have been guilloched by many applications. Long time ago it was necessary to use resourceful mechanical machines using a similar principle to above mentioned Inspiro to create a guilloche. They carved thin corrugated lines into a metallic deck, creating compliacted, multiple times crossing and immutable cyclic geometrical formation according to a mechanical setting of the machine. This stamping die is then used as a printing deck for primer printing of documents and papers that want to be secured. The higher safety level the thinner line, thicker line printing and more crossing used in the pattern.
Guilloche presents a good prevention against falsification by scanning, printing or copying. Individual lines of the geometrical pattern are damaged while scanning and followed-up reproducting and therefore consist of many disjointed points thanks to deficient discernment of scanning and also printing. Todays numerical processing allows fluent and fast predesign of guilloche ornamentts thanks to exact mathematically described curves and preparation for printing in unlimited discernment. The same way of imitation of security picture could be used when falsifying and that is the reason why a software for generating guilloche patterns offers a function of making random mistakes in the structure of the curves. In som e places of the line it turns aside from the matemathically calculated position on purpose and a falsificate will differ in these abnormalities under the microscope. Apart from the function preventing from falsification and copying, a guilloche can have only a decorative function and gives respectability and authenticity to the documents. Above that, graphically unused areas get filled. Decorative patterns are used as a predesign or e.g. frames of graphical items – rosaces.
design of a hologram or a vinyl self-adhesive sticker with guilloche
If your vectoral graphical appliance allows to create a guilloche pattern, simply blend it into one layer of the predesign. If you want to use guilloche predesign at your order, we offer you our own guilloche ornament as a pattern. The same way we are capable to create ornaments of this type, like a rosace rounded by graphical items added by you. All you need to do is contact us and describe your idea.
Example of a motive with a guilloche and demonstration of a graphical item-guilloche