Adhesive / Glue Guide

Adhesives are essential in bookbinding as they are used to join different materials. Choosing the right adhesive can contribute significantly to the quality and longevity of the final product. In this guide, we will detail the different types of adhesives used in bookbinding.

Basics of adhesive selection

There are several factors that influence the selection of the right adhesive for bookbinding. Here are some of the most important:

• Material: Different materials require different types of adhesives. For example, gluing paper and cardboard usually requires a different adhesive than gluing leather or metal. Materials can be printed or unprinted, coated, smooth and this can influence the choice of adhesive.
• Type of use: The way the adhesive is applied can also influence the choice. Some adhesives are better suited for machine applications, others for manual ones. In addition, there are adhesives that are applied at high temperatures (hot glue) or at room temperature (cold glue).
• Environmental variables: Temperature, humidity and pressure can greatly affect the performance of an adhesive. An adhesive that performs well in dry conditions may not be the best choice in a humid environment. Similarly, adhesives that work well at high temperatures may lose their adhesive properties at low temperatures.
• Open Time: Open time refers to the amount of time an adhesive can process before it begins to set. Some projects require an adhesive with a long open time to allow sufficient time for adjustments, while others require an adhesive with a short open time to set quickly.
• Individual preferences: Finally, personal preferences can also play a role. For example, some people prefer natural adhesives such as starch or animal glue, while others prefer synthetic adhesives such as PVA or polyurethane glue.

Choosing the right adhesive can make the difference between a book that lasts a long time and one that falls apart quickly. Therefore, it is important to carefully choose the right adhesive for each bookbinding project.

What different types of glue are there?

Adhesives are needed in all areas of bookbinding and as a result there are very many different types of adhesive on the market. It is not easy to get an overview of all types of adhesives. Different adhesives have different specific properties and processing methods. Here are the main types of adhesives for bookbinding:

Dispersion glue (white glue, cold glue)

Dispersion adhesive, also called white glue, is a water-based adhesive whose components are finely dispersed (dispersed) in water, often based on polyvinyl acetate (PVAc). It solidifies through the evaporation of the water. Therefore, as a rule, both of the components to be bonded must be absorbent (e.g. paper, cardboard, leather, textile, etc.). To set well, the adhesive must be fixed (pressed). Advantages of dispersions are the easy application and the good final strength. There are dispersion adhesives that can be reactivated by moistening and some that cannot be reactivated or dissolved. A significant advantage of dispersion glue in the adhesive bonding process is its sensitivity to heat. It can be made more flexible by heating and thus shaped into a curve. A disadvantage is that this type of adhesive has longer drying times than other adhesives.

Application: bookbinding processing

All the adhesives in this category

Hot melt jelly (protein glue)

Hot melt jelly is a protein adhesive and is melted in the solid state (block), applied to the adhesive surface when hot and forms a solid bond when cooled. It is characterised by the fact that it has a high initial strength even before final drying. Jelly is usually used for lamination work as well as for the production of book covers. The adhesive is usually fast setting, suitable even for difficult products, elastic and dries without tension. Particularly noteworthy is that papers deform less than when dispersions are used and that Jelly Adhesive is a biodegradable natural product.

Application: machine book cover production

All hot melt jellies

EVA hot melt (hot melt adhesive)

Hot melt adhesives are melted in a solid state (e.g. granules), applied to the bonding surface when hot and form a strong bond when cooled. Strength is achieved very quickly, immediately after the melt has cooled and solidified. Hot melt adhesives consist of 100 % solids. Hotmelt adhesives based on ethylene vinyl acetate (EVA) are used for a wide range of standard applications due to their attractive price-performance ratio. They are characterised in particular by short open and setting times, have a solid adhesion, even on difficult surfaces. Ideal for high production volumes or low idle times.

Application: machine perfect binding

To our hotmelts

PO hot melt (hot melt adhesive)

Polyolefin (PO)-based hot melts are used where EVA hot melts reach durability limits but PUR is not required. Compared to conventional EVA hot melts, they offer a greater overall performance spectrum, such as higher thermal stability, an improved adhesion spectrum or good low-temperature flexibility. The group of PO-based hotmelts is also the most frequently used type for bonding in nozzle and roll application. They are universally applicable, can also cope with difficult papers and are suitable for all types of binding work. They are isocyanate-free and easily recyclable. Due to the low application quantity and savings in maintenance and cleaning of the machines, a high economic efficiency is given. We distribute Planatol's PO hotmelts under the Planamelt brand.

Application area: machine perfect binding, also for difficult-to-process papers and grammages up to 250 g/m²

All Planamelt adhesives

PUR adhesive (PUR hot melt)

PUR adhesives are reactive polyurethane (PU) hot melt adhesives. They are melted in a solid state (candles, granules) and applied to the bonding surface while hot. PUR adhesives are still soft after processing, then harden via a chemical reaction with the paper fibres and with moisture from the environment. The result is a product that is flexible in hot and cold conditions and extremely strong. PUR is mainly used in industrial operations and requires special equipment and techniques for application.

Application: Machine perfect binding of difficult products, such as. highly coated papers over 130 g/m², for foiled papers, digitally printed papers, production of photo books

All PUR adhesives

Animal glue (glutin glue)

Glutin glues are water-soluble natural adhesives obtained from animal waste by boiling. This produces a jelly, which is called glue. The main ingredient, glutin, is a mixture of substances similar to gelatine. Depending on the material from which they are produced, glutin glues are distinguished as bone glue, hide glue, rabbit glue, fish glue and hen bladder glue. Particularly purified glutin glue is known under the collective term gelatine and is used, among other things, in restoration.

Application: traditional bookbinding techniques and restoration

All adhesives for restoration

Vegetable glue

Classics here are starches (usually in powder form) from cereals for making starch paste. This is an important adhesive for paper and cardboard in restoration and conservation. In addition to the classic rice and wheat starch, algae glue also belongs to the genus of vegetable glues, which is particularly suitable for gluing fibres in the production of very tear-resistant paper, e.g. also tears in the restoration of paintings.

Application: Restoration

All starches & pastes

All adhesives for restoration

Cellulose-based glue

Cellulose-based adhesives are also commonly found in restoration. They are extremely difficult for microorganisms to attack, are physiologically harmless and water-soluble. They are often used for reversible, flexible bonding and for gluing paper, as well as for bonding and fixing water-sensitive products.

Application: Restoration

All adhesives for restoration

Which adhesive is best suited for which application?

Most of the adhesives presented here are either from the Planatol brand or our own brands PräTack / PräMelt. Planatol is a leading manufacturer of adhesives in the graphic arts industry and, with its extensive product portfolio, offers a suitable adhesive for almost all types of application. With our own brands, we have focused on creating an affordable alternative, especially in connection with the use of our machines.

It is important to note that these are general recommendations and that the specific requirements of a project may depend on many factors. It is always a good idea to test the adhesive before applying it to your entire project.

Crafts / DIY

For craft work / DIY projects, we recommend four adhesives: our recommendation for general work here are the universal bookbinding adhesives Planatol BB, Planatol BB Superior and PräTack B66, because all three can be used for all kinds of manual work. The only requirement here is to work with absorbent materials such as paper or cardboard. Planatol BB Superior (Sup) and PräTack B66 are also suitable for more difficult materials for which the regular Planatol BB does not work. And when the job gets really tough, Planatol AD 94/5B comes into play. Its wide range of applications also makes it a convincing choice for painted, lacquered, foiled and calendered surfaces.

Backlining

For good stability and long life of a book, a good backer adhesive is needed. Planatol 152 and Planatol 37 are suitable for this purpose. Both adhesives are dispersion adhesives. Planatol 152 has a viscoplastic film, whereas Planatol 37 has an extremely hard film.

Spine-binding

Planatol 152 and Planatol AD 94/5B are ideally suited for spine-binding. For uncoated papers, Planatol 152 is the perfect spine-binding adhesive. For coated or foiled surfaces, Planatol AD 94/5B is suitable.

Case-making, laminating (manual)

There are several adhesives that can be used for manual book cover production and for laminating: PräTack K11 and PräTack K22, SKG glue, Planatol Elasta N, Planatol EM70 & Planatol AD 94/5B. PräTack K11 is a dispersion adhesive for bonding materials with untreated surfaces such as paper, cardboard, board, binding materials, etc. The same applies to PräTack K22. In addition, this adhesive is also suitable for bonding materials with treated surfaces as well as for bonding coated surfaces against each other (e.g. English buckram).

SKG is also a dispersion adhesive, which contains plasticizers and is solvent-free. This is suitable for bonding paper, cardboard, binding materials and other unpainted materials. SKG can also be used for DIY projects.

Planatol Elasta N can be used for restoration and lamination work. The consistency is pasty when used. EM70 can be used to laminate and bond untreated paper, cardboard, linen, paper- or fabric-coated foils to absorbent substrates. Planatol AD 94/5B is suitable for lacquered, coated or foiled surfaces, e.g. efalin, elephant hide paper, PVC and similar coating materials, as well as leather.

Case-making, laminating (machine)

For machine book cover production, 6 adhesive options are presented.

If hot glue is not to be used (i.e. the gluing machine does not have a heating function), our clear recommendation here is the dispersion adhesive PräTack K22, which is, however, mainly suitable for uncoated surfaces (such as uncoated paper, cloth and leather). For more difficult surfaces and easier cleaning, we recommend using a gluing machine for hot melt (jelly).

If a gluing machine with heating function is available, we recommend using hot melt jelly. Depending on the material and machine configuration, PräMelt OT24 Digital, PräMelt OT30 Universal, Plakal 371 (only for fully automatic ceiling machines such as Kolbus DA260, DA270), Plakal Covertack 535 and Plakal Covertack 531 are suitable here. A detailed overview of the hot melt jellies can be found at the bottom of the product pages.

Casing-in (machine)

For optimal bonding during machine casing-in of materials with untreated surfaces with themselves or with other materials with treated surfaces, PräTack E40 should be emphasized. This is because it has been specially developed for casing-in books. Planatol AD 94/5B can be used for machine casing-in of book covers made of PVC, as it is highly viscous and post-adhesive.

Headband application

For applying headbands, use Planatol 152, Planatol 37 or Planatol AD 94/5B. Planatol 152 has a viscoplastic film and Planatol 37 an extremely hard film. If you need a fast-setting adhesive, Planatol AD 94/5B is the one to use.

Bookmark / Page-marking ribbon application

In addition to classic bookbinding glues such as Planatol BB and PräTack B66, our PräTack E40 casing-in glue can also be used for manual processing. This is particularly recommended for machine processing in the PräziRibbon bookmark ribbon insertion machine.

Restoration

Starch glue, cellulose glue or hot melt (bone glue) is used for restoration work. Common brand-name products are Planatol RH8 and Planatol Elasta N. Planatol RH8 is particularly easy to apply with its water-soluble and paste-like consistency. Planatol Elasta N is well suited for restoring and laminating with paper and cloth overlays. The special feature of hotmelt (bone glue) is that it is prepared on the basis of animal glutin. It thus ensures neutral, distortion-free bonding of untreated materials in manual binding and restoration.

Binding (manual): Book block production

Manual perfect binding with small equipment can be performed with PräTack B66, Planatol BB and Planatol DK B 3040. PräTack B66 is designed for fan perfect binding of coated and uncoated papers. Planatol BB is ideal for uncoated papers. Planatol DK B 3040 is suitable for difficult, heavily coated papers.

Perfect binding (machine): Book Block Production

For machine perfect binding to make book blocks, the adhesive used depends on the machine used in each case. For small devices and machines that allow fan glue binding (or work according to the Lumbeck method), dispersion adhesives that are also used in manual perfect binding are suitable: PräTack B66, Planatol BB and Planatol DK B 3040. Our recommendation for optimal perfect binding in book block production is PräTack B66. This dispersion adhesive is perfect for fan-fold perfect bindings of coated and uncoated papers, also for art print and digital print papers. Planatol BB can also be used for perfect bindings on small fan-fold perfect binders for uncoated papers. Planatol DK B 3040 can be used to achieve perfect bindings on small fan-type perfect binders, even with difficult, heavily coated papers.

Automated perfect binders differ mainly between the range of hotmelts that can be processed and the application method (usually nozzle or roller). In general, a distinction is made here between EVA hotmelts, PO hotmelts and PUR hotmelts. As a rule, adhesive binders that process EVA hotmelts can also process PO hotmelts without any problems. When changing over, extensive cleaning is important; if you have any questions in this regard, please do not hesitate to contact us. PUR hotmelts can only be processed on specially designed adhesive binders/equipment.

EVA hotmelts are suitable for simple applications without special requirements in terms of temperature, number of sides or layflat characteristics. They are less suitable than PO hotmelts or PUR adhesives when it comes to processing difficult paper types. They are mainly convincing due to their lower price. However, if you look not only at the number of kilograms, but also at the consumption, PO hotmelt is often the better choice.

All Hotmelts

PO hotmelts are universally applicable, can also process difficult materials and result in very good impact behavior. Significantly less adhesive is required than with EVA hotmelts and machine cleaning is less time-consuming, so PO hotmelts often also bring a cost advantage. In addition, PUR hotmelts are more resistant to heat and cold than EVA hotmelts (nearly as good as PUR hotmelts). PO hotmelts from Planatol are grouped under the "Planamelt" product range. Here Planamelt R is the adhesive we usually recommend for the majority of applications and materials. Planamelt R has excellent sheet edge adhesion even with difficult materials such as papers > 200 g/m² and can be used for both spine gluing and side gluing. In addition, the hotmelt adhesive has a medium to long open time and a medium setting time. Planamelt W has almost the same properties, except that it sets slightly faster than Planamelt R and is pigmented white. Planamelt S has been specially developed for side gluing and is particularly suitable for difficult materials. Planamelt Pro has been specially developed for side gluing of thread-stitched brochures, has a strong adhesive strength even on lacquered surfaces and an even shorter open time than Planamelt W. In addition, Planamelt Pro is easy to round. Planamelt HSP has been developed for small perfect binders and for very fast finishing.

All Planamelt hotmelts

PUR adhesive can only be used on special PUR adhesive binders because the adhesive reacts immediately when it comes into contact with atmospheric moisture. However, when used correctly, PUR adhesive has very high adhesive strength and excellent adhesion, even on difficult surfaces. If a PUR adhesive binder is used, we recommend Planatol PUR 2880 as a true adhesive all-rounder that is equally suitable for roller and nozzle application. This adhesive is also suitable for difficult papers, as it sets relatively quickly and has only a short open time. In addition, S-PUR 2022 can also be used, which has a short open time, sets quickly and still has good tear-off properties.

All PUR glues

Side glues for perfect binders

For side gluing of books, brochures, etc., Planatol AD 165 and Planamelt S can be used. This is a cold glue (dispersion adhesive) on one side and a PO hotmelt on the other. The Planatol AD 165 is post-adhesive and very fast tightening. Planamelt S has excellent adhesion to various substrates, even difficult ones. Ideal for side gluing on all common perfect binding machines or for gluing endsheets.

Block gluing of tear-off blocks

The Planatol Blockleim is suitable for block gluing of tear-off blocks. Planatol Blockleim is a dispersion adhesive for block gluing with a brush, whereby it has a viscoplastic film. This property is excellent for the production of note (tear-off) blocks. If the adhesive strength on, for example, tear-off blocks should or must be higher, then we recommend Planatol BB.

Manual gluing of form sets is possible with Planatol FF, Planatol DK B 2100 as well as Planatol FF 60. Planatol FF is suitable for form sets made of normal papers. Planatol DK B 2100 is suitable for normal and carbonless papers and is also suitable for block gluing of mechanically and chemically reacting carbonless papers. Planatol FF 60 adhesive has been specially developed for the production of form sets from chemically reacting carbonless papers (color reaction papers), e.g. with first sheet SM paper (typewriter paper) or CB (Coated Black). The addition of center sheets CFB (Coated Front and Back) to the sets is possible at will.

Labeling

Labels can be applied to cardboard or paperboard using Planatol Elasta N. While Planatol HW 730 is designed for labels on painted sheet metal, varnished or foiled surfaces, for paper or cardboard on polyethylene or polypropylene, and for carbonized labels.

Banding

For banding, the Planatol 152 is ideal for uncoated paper and board grades. Various surfaces can be processed with the Planatol AD 94/5B.

What do the following terms mean in connection with adhesives?

There are some important technical terms that are used in connection with the subject of adhesives. You should definitely know some of these terms in order to be able to better evaluate possible areas of application and adhesive behavior.

Bonding

In adhesive technology, bonding means the transition from the liquid to the solid state. Drying by evaporation of solvent or water, solidification by cooling of a melt or by a chemical reaction. It is only through bonding that the adhesive achieves its internal strength.

Adhesion

Describes the adhesion between two different materials.

Initial adhesion (tack)

In technical terms, the term initial tack, also known as tack, refers to the adhesive strength that an adhesive has immediately after application. The adhesive strength is thus not yet designed for a final load, as in the case of final tack.

Wetting

Wetting is the ability of liquids to spread evenly on solid materials.

Film

The term film refers to the layer of adhesive applied to an adhesive surface. This can have various properties, e.g., elastic, transparent, opaque, post-adhesive, waterproof, or even thermoplastic (roundable).

Cohesion

Describes the internal strength of the bonded adhesive.

Open time

Open time is the time period within which the materials to be bonded must be joined (calculated from the time of adhesive application). Also called "wet bonding time" for dispersion adhesives.

Pasty

Pasty means as much as mushy, thick.

Viscosity

The term viscosity is a measure of the viscosity of liquids and melts. The greater the viscosity, the thicker (less flowable) the fluid; the lower the viscosity, the thinner (more flowable) it is, so it can flow faster under the same conditions. When using hot melt jelly, for example, the optimum viscosity is regulated by adding water. To illustrate this, imagine a glass with oil and a glass with water. As the liquids are poured out, one notices that the water flows quickly and in all directions, while the oil flows slowly out of the glass and initially piles up before flowing in all directions.

Softener

Using plasticizers, which are additives, adhesives can be made softer and more elastic.