There is an adhesive for every application
General adhesive products
A classroom staple throughout the world, glue sticks have a number of advantages. They are non-toxic and non-acidic, which means they can be safely used by children and do not yellow over time. They are considered a low bonding adhesive, and are used on various types of paper, such as cardboard, foam board and poster board. The adhesive in a glue stick dries clear, and is used for applications like labelling, art projects and scrapbooking. Glue sticks are generally made from a range of similar ingredients, although the exact proportions are particular to the manufacturer. This results in the varying quality of each brand. Most ingredients found in glue sticks are fairly safe and act as thickeners, binders and smoothers.
Acrylic polymer is the ingredient which helps the glue stick to dry quickly. It gives the adhesive strength. It is non-toxic and non-explosive, and remains colourless.
Polyethylene glycol is a binder. It aids lubrication and prevents the adhesive from drying out.
Sodium stearate is one of the primary ingredients in glue sticks and is responsible for the opaque white colour.
Super glue, also known as cyanoacrylate adhesive, is able to bond very quickly to a range of substrates. This very strong bond dries clear. This type of adhesive is available in different viscosities, but can be fussy about the types of surfaces to which it bonds and the amount of glue used. Super glue works best on surfaces that fit together closely.
In general, super glues are ideal for fixing wood, metal, ceramics, leather, glass, and some types of plastic, but it is not good for foamed plastic, unless specified on the bottle.
This type of adhesive works best in tensile applications that have low impact strength requirements. Superglue sets and cures in a matter of minutes. In its uncured state, acetone can be used to clean up spillage. Once the glue has set this no longer works.
Did you know?
The earliest use of adhesives was discovered in central Italy, dating back 200 000 years. Stone flakes were partially covered with birch-bark tar – a simple, one component adhesive.
This is the most common kind of adhesive for crafting, and allows users to glue porous, lightweight materials such as paper, cardboard and cloth together. White craft glue is easy to clean up and has a very low toxicity level, making it ideal for use in classrooms and homes. The glue is water-based, which makes it liquid and easy to apply. However, craft glue is soluble in water and therefore not recommended for applications in a damp or wet environment.
Keep in mind that the glue must dry before it sets completely. Clamping is usually required to hold the items in place until the glue has dried. It takes approximately one hour to set firmly, and 24 hours to cure. White craft glue dries clear and is somewhat flexible. It can be mixed with fillers such as glitter or paint powder to enhance its decorative effects.
Mod podge was developed over 40 years ago and is an essential adhesive in a crafter’s tool box – especially when it comes to decoupage. It is ideal for gluing, sealing and finishing. It is water-based, which means it is easy to use and easy to clean. It is also non-toxic. Mod podge dries quickly, allowing for multiple coat applications in quick succession. It dries clear, and any spills can be cleaned with soap and water. Classic Mod Podge comes in gloss and matte finishes. The difference between these two is the finish that results when it’s dry; gloss is shiny while matte is not. Classic Mod Podge is great for all types of projects and most surfaces. Originally a brand of adhesive, “mod podge” has now come to denote any of this type of glue.
Wood glue comes in two forms: “white glue” or polyvinyl acetate (PVA), which is a general hobby and craft glue and dries clear; and “yellow glue” or aliphatic resin emulsion, which is commonly referred to as “carpenter’s glue”. PVAs exhibit more slip during assembly. Yellow wood glue is water-based and designed to work with all types of wood. It is immediately tacky, for better hold in the uncured state. It is also generally more rigid which makes it easier to sand. PVAs are non-toxic and very easy to use, but hard to repair since most glues (including PVA itself) do not adhere well to hardened PVA glue. White wood glue tends to creep under a constant load. Generally, wood glues set in less than an hour. However, it is better to leave them to cure for 24 hours in order to reach full strength. Wood glues vary in their waterproof properties. Some wood glues exhibit waterproof properties, while others are completely unsuitable for exterior use.
Several wood glues have poor “gap-filling” ability. This means they either soak into the wood and leave the gap empty, or remain to fill the gap but have little structural integrity.
Hot glue is essentially melted polymers (plastic). The melting and cooling of these polymers provides an adhesive property. Hot glue is most commonly applied using a glue gun. These machines can be wired or battery operated (cordless), and different types will take different diameters (weights) of the polymer glue stick. The guns are available in low (120°C) and high (193°C) melting options. The types of hot glue available vary according to the polymer type. It can be used on porous and non-porous surfaces. Because of the high viscosity of hot glue, it can bond uneven surfaces together and is ideal for filling gaps. Hot glue provides a quick-setting option for a variety of crafts and substrates, and is the perfect all-purpose craft glue for quick set-up and execution. However, it is not used in high-strength applications and does not do well in temperature extremes. It is also not suitable for children.
A spray adhesive is a contact adhesive based in a solvent that is applied by means of an aerosol spray. This type of adhesive can be used with paper, foam board, fabrics, photograph paper and felt. Specialty contact adhesives are also available in a can to roll or brush on for larger, more demanding projects that involve wood, plastic or metal.
Apply spray adhesives in a well-ventilated area, and allow the solvent to evaporate completely before bonding with the substrate. This is a permanent bond which cannot be repositioned.
Fabric adhesives can be liquid white glues like the polyvinyl acetate (PVA) types mentioned above.
A wide range of products cover light- to heavyweight fabric bonding. Choose the right type of adhesive for the fabric you want to glue. Some versions are safe for washing and dry cleaning. Fabric adhesives are ideal for fixing hems, or for adhering items in DIY projects like making headbands.
There are a range of adhesive tapes on the market, including duct tape, packaging tape, sticky tape, masking tape and washi tape.
Tapes are generally made of two layers. The first layer is cellulose, plastic or even paper, while the second is a rubber-based, pressure-sensitive adhesive.
Pressure-sensitive adhesives (PSAs) or self-stick adhesive forms a bond when pressure is applied between the item with the glue on it and the substrate. It does not require any solvent, water or heat to become sticky. They hold properly at room temperature, but tend to lose their tackiness in extremely low or high temperatures. The amount of pressure exerted on the adhesive determines the degree of bond. Factors such as smoothness and cleanliness of the surface are key to proper bonding.
Pressure-sensitive adhesives are available in two forms: permanent and removable. Removable adhesives are designed to form a temporary bond, and ideally can be removed after months or years without leaving residue on the substrate. They are available in sheets and dots, and can be used in a multitude of craft projects. They stick to substrates such as lightweight paper, plastic, metal and glass. Removable PSAs are found on tapes, labels, decals and post-it notes. They have low adhesion and generally cannot support much weight.
Permanent applications of PSAs are only moveable after they are initially applied. Thereafter they cure and tend to leave residue behind when peeled offed.
An example of permanent application includes safety labels. Some high-performance permanent PSAs exhibit high adhesion values and can support kilograms of weight per square centimetre.
Also known as mounting putting, Prestik, Blu-tack and Patafix, adhesive putty is a re-usable pressure-sensitive adhesive made of a synthetic rubber compound that is non-toxic, non-hazardous and non-carcinogenic. It doesn’t shrink or dry out, which makes it ideal for use in the classroom and the office.
Prestik is commonly used to attach lightweight objects such as posters or sheets of paper to walls or other dry surfaces. It is often packaged in separate strips for convenience, and can be re-used.
Epoxies are generally very hard, durable adhesives that bond to multiple substrates successfully, even in the most extreme environments. They are two-part systems – meaning that two substances need to be mixed together – designed for high-performance bonding. Epoxy resins are a class of reactive polymers. These co-reactants are often called “hardeners” or “curatives”. The reaction between these resins forms a thermosetting polymer which has a strong bond and high temperature- and chemical resistance. Epoxies have excellent gap filling properties due to their high cohesive strength.
Polyurethane adhesive is a multi-purpose glue that is flexible, resilient and bonds to a variety of surfaces, including textile fibres, metals, plastics, glass, sand, ceramics, rubber and wood. It is ideal for wood with a high water or oil content, where other adhesives would fail to bond.
Often, items bonded with polyurethane are clamped together for a few hours to ensure they cure. Optimal curing time is between six to eight hours. Mineral spirits or acetone can be used as a solvent before the adhesive has cured properly, while dried glue can be sanded away.
As an adhesive, polyurethane resists moisture and heat, so it is ideal for use in the sun or underwater.
Did you know?
Polyurethane can be found in just about every room of your house. The material became popular during World War II, and since then this polymer has protected, re-invented, joined or transported countless items. It seals surfaces such as wood, metal and paint to protect them from rot, corrosion or fading. It also insulates walls, temperature-controlled vehicles and consumer coolers. It is found in upholstery, packaging crates and plastic wheels such as those on a dolly. It is considered an elastomer, which means it has elastic properties while maintaining rigidity – otherwise known as structural memory. It is used in the creation of thermoplastics, which are rigid, smooth and durable. These are difficult to recycle but can be re-used.