The use of polyurethane adhesives, their properties and the best brands

Polyurethane adhesives’ robust bonding power and versatility have made them a mainstay in the paint and paintwork materials industry. These adhesives are a popular option for both DIY and industrial applications because of their reputation for creating strong bonds with a wide range of surfaces. Polyurethane adhesives are a dependable solution for a wide range of bonding applications, handling materials such as wood, metal, plastic, and ceramics.

The remarkable strength and flexibility of polyurethane adhesives is one of their most notable features. Polyurethane, in contrast to certain other adhesives, is able to tolerate a great deal of strain and movement without degrading. Because of this, it’s perfect for applications where the bonded materials may be subjected to impacts, vibrations, or variations in humidity and temperature. Moreover, polyurethane adhesives resist UV rays, chemicals, and water, guaranteeing that bonds hold even in harsh conditions.

It’s crucial to take your project’s particular needs into account when choosing a polyurethane adhesive. Variations in formulation between brands can affect things like viscosity, temperature resistance, and curing time. Gorilla Glue, 3M, and Loctite are a few of the top brands available, having a solid reputation for dependability and quality. You can find the ideal adhesive for your needs from a variety of products offered by these brands, each of which is designed for a specific purpose.

In conclusion, polyurethane adhesives are an effective tool in the paint and paintwork supply industry. Their exceptional blend of robustness, pliability, and resilience to challenging circumstances renders them a superb option for numerous undertakings. You can make well-informed decisions and attain optimal outcomes for your bonding requirements by comprehending their properties and perusing the products offered by leading brands.

Features and advantages of polyurethane glue

An adhesive based on solid synthetic resins is called polyurethane glue. The primary distinction between this glue and its counterparts is the amount of these components—up to 95% in this case, compared to significantly less in other adhesives. The unique curing principle of polyurethane glue involves a chemical reaction that starts when the composition comes into contact with water vapor. Carbon dioxide bubbles are consequently released, and the glue layer solidifies into a thick layer.

Such is how the glue appears and behaves in the mounting foam. A thin layer of glue is applied, and as it slowly expands, the excess comes out of the seam. With a knife or chisel, it can be carefully cut off as it has completely solidified. This composition offers numerous benefits.

1. Strong gluing of homogeneous and heterogeneous materials. Thanks to the rigid and reliable relations, the polyurethane -based remedies tightly fasten wood, plastic, metal and many other materials. It is possible to use it on a raw wood or treated with an antiseptic – this will only accelerate curing.
2. Water resistance. Polyurethane compounds are indispensable with high humidity, as well as when contacting products with water. They do not deteriorate from such conditions, because the adhesive seam will be moisture resistant and can serve as a sealant.
3. Enough open exposure time. Even a beginner can work with a polyurethane. The glue does not freeze for 20 minutes, and during this period you can safely fit the details, install the fixers. For a reliable connection, you need to fix the product for 1 hour, although it is allowed to fully use it only after a day.
4. Simplicity of work. Thanks to convenient application, easily slipping of the composition, it is easy to use it.
5. Lack of harm to materials. Glue does not overshadow the porous bases of moisture, does not cause the risk of their warping. Thanks to this, you can use it even for laying parquet without the danger of swelling of the dies.

Adhesives made of polyurethane are immune to freezing, heating, and temperature fluctuations. They are resistant to aggressive compounds, oils, and gasoline chemically. Polyurethane can only be used to glue silicone, polyethylene, and polypropylene because the adhesion quality will be poor.

The scope of adhesives

Adhesives based on polyurethane are used in a wide range of applications because of their versatility. Both natural and synthetic materials can be used with them, including fabrics, plastic, rubber, glass, polystyrene, ceramics, and they won’t even damage cardboard and paper. Adhesives work well for exterior projects because they don’t scare off frost or precipitation. The following are the applications for polyurethane:

• gluing the finish – ceramic and stone tiles, marble, mosaics, porcelain tiles;
• sealing defects in inflatable products – boats, pools, children"s toys;
• fixing window profiles, edges of PVC on furniture, panels;
• gluing the base with stone crumbs in the production of flexible stone;
• attachment of artificial lawns, rubber mats in stadiums and sites, in gyms;
• release of sandwich panels;
• joining cornices, baguits, skirting boards, stucco moldings, wooden beams and plastic elements;
• repair of glass products, porcelain, ceramics, plexiglass in everyday life;
• restoration of furniture and interior items;
• shoe repair – gluing heels, soles, spars;
• laying the floor, panels, blocks, filling the cracks, arranging thermal insulation systems and warm floors;
• use as a car sealant to protect parts from corrosion.

Composition and properties

Urethane rubber, which varies in quality and manufacture, is the fundamental component of polyurethane adhesives.

• properties that appear after final polymerization;
• the structure of the adhesive layer that can be linear or mesh;
• the degree of solubility in organic solvents.

Only 10% of the raw materials are produced domestically; the majority are produced by foreign manufacturers. The final characteristics and quality of the product are determined by the inclusion of additional components (more than 10–15 items) in the composition of polyurethane adhesives. Viscosity, glue adhesion, solidification speed, indicator dependence on temperature and humidity, and shelf life all depend on the particular combination and quantity of these materials. You should list the following as additions to polyurethane:

• zinc oxide, Titan"s dioxide, soot, Portland cement;
• hydroxiles and isocyanates;
• acetone, alcohols and organic solvents;
• artificial and aromatic resins, Pava;
• aqueous emulsions, alkaline solutions of salts, acids;
• Crystallization stabilizers and accelerators.

Dyes and pigments, which are typically based on metal oxides, give the final mixture a variety of shades. Adhesives are purchased in amber or brown for woodworking and in gray or black for metalworking. In addition, compositions in white, yellow, and other colors are for sale. They are liquid, pasty, or gel in consistency.

Adhesives’ properties differ greatly from one another because of their varied composition. For instance, the consumption can range from 500–1000 g/sq. m for uniform continuous application to 150–200 g for point application.

The completed coating can be used at temperatures between -40 and +120 degrees. Smooth materials can also glue, but the optimal clutch is seen when the rough, porous surfaces are joined.

Some characteristics of polyurethane compounds are:

• It is allowed to work with adhesives only at plus temperatures – from +15 degrees, otherwise their curing will slow down, and the properties of the finished seam may change;
• glue has thixotropic (increases viscosity at rest, lures with mechanical exposure), therefore, before the start of operation, you need to wait for the moment of complete curing;
• Polyurethane prevents the spread of fungus and mold due to antiseptic properties.

Types of polyurethane adhesives

One-component and two-component adhesive compositions are possible, depending on the quantity of polyurethane-based components used.

One -component compositions

One-component glue is most frequently used in daily life to glue wood, repair shoes, and fix equipment. He is prepared for use because the hardener and main composition are contained in a single bottle. Moisture, either in the air or in the material itself, is necessary for the product to polymerize. Light moisturizing the base is advised if the relative humidity is less than 60%. The glue seam’s volume increases after foaming begins, so this must be considered when determining how thick to make it.

Two -component adhesives

Two packs, which need to be opened before work and their contents combined, stand in for the two-component composition. These steps are taken immediately before the products are glued; otherwise, the glue will degrade more quickly. When joining the components, it’s critical to closely follow the proportions; otherwise, the chemical reaction won’t start. These adhesives don’t react well to humidity; instead, a second bottle’s hardener drives the polymerization process, which is why they’re used to glue surfaces that are resistant to moisture (like metal and glass). Adhesive seams can be heated to temperatures between +100 and +110 degrees to speed up the drying process.

Application and safety rules

When working with wood that has less than 8% moisture content, both surfaces are sprayed with water, liquids are allowed to absorb, and glue is only applied after this. Other necessary preparations must first be made, such as cleaning up dirt, trash, dust, fats, and other pollutants. Additionally, clean the paint, plaster, and cement bases. Alcohol or a solvent wipe is used for degreasing.

A thin layer of glue is spread across the whole surface. This is particularly practical if the glue has an aerosol form. Using a spatula, thick pastes and viscous solutions are applied and distributed. Adhesives consisting of two components are first mixed as directed by the manufacturer, followed by comparable procedures. The following guidelines apply when handling polyurethane:

• The amount of glue should be small, otherwise the expanded layer will turn out to be too thick;
• Complex bases are covered from both glued sides, others – only from one;
• Porous surfaces are treated with glue in 2 layers, the second is applied 2-3 minutes after the first;
• Aerosol adhesives are sprayed with uniform stripes every 10 cm, retreating 8 cm from the edge;
• After application, the product is allowed to dry for 5-10 minutes and only then the parts with strong pressure on them are fixed (if possible, they roll the product with a roller);
• The elements of the product after tight fitting are fixed with clamp, leave it for 1.5 hours;
• After the polyurethane dries, the crawled foam residues are neatly scraped off with a chisel;
• You can use the product in a day.

Squeeze the bottle to release the air, then twist the lid right away to prevent the remaining glue from degrading. The adhesive layer can be treated with hot air from a hair dryer to expedite the drying process, and only then can the details be connected.

Polyurethane adhesives are toxic to the body because they contain organic solvents in their composition. Wearing a respirator and providing adequate ventilation are necessities when working. When glitter gets on the skin, it must be immediately cleaned with soapy water to prevent irritation. Rubber gloves are the only item that are worth covering.

How to dilute and wash the glue – means

Alcohol can be used to slightly dilute the glue if it gets thicker. A tiny amount of solvent must be added; otherwise, the product will become spoiled. Additionally, there are unique solvents for polyurethane known as "viscosity optimizers," which work with methylence, acetone, and ethyl acetate. You can also use toluol, but the adhesive seam will become much larger. It is acceptable to add Desmodur activator up to 7% of the total mass in order to increase adhesion and heat resistance.

Rather than removing the dried-on glue from the instruments? Until the material is frozen, the spatula and other tools need to be cleaned right away. If not, all dried drops are wiped with liquid using a rag dampened with acetone. Gummy glue is extracted mechanically.

Hardening time

The type of glue, its composition, and a few more ingredients all affect how long a glue takes to cure exactly. Primary curing usually takes 20 to 60 minutes, during which time the parts must be firmly fixed. It’s crucial to press the surfaces firmly and evenly next to one another. The compositions fully solidify in a day, though for certain adhesives it takes two days. After four hours, polymerization stops when exposed to hot air.

Storage features

The product should be stored in a closed container between 12 and 24 months at a temperature between +10 and +30 degrees; the packaging will specify the exact expiration date. The container needs to be placed away from heat sources, flames, and direct sunlight. It is advised to use the polyurethane glue as soon as possible after opening the bottle and to store it for no longer than six months. The glue hardens or thickens with air, which is why the cork is twisted as tightly as it can. Tubes, banks, and bottles should all always be upright.

Polyurethane adhesives have shown to be a dependable and adaptable option for a range of uses. They are appropriate for both home and industrial applications due to their superior bonding strength and flexibility. Because they ensure long-lasting results and are resistant to environmental factors like moisture and temperature changes, these adhesives are particularly valued for their durability.

The exceptional ability of polyurethane adhesives to adhere to a variety of materials, such as glass, metal, plastic, and wood, is one of their best qualities. They are therefore the preferred choice for a wide range of tasks, from straightforward home repairs to intricate manufacturing procedures. Their practicality and efficiency are increased by their speedy curing time and ease of use.

A polyurethane adhesive selection should take your project’s particular requirements into account. Several well-known brands with a reputation for dependability and quality are Gorilla, Loctite, and 3M. These companies make sure you can find the ideal adhesive for your specific needs by providing a variety of products designed for various uses.

In conclusion, few adhesives can match the strength, adaptability, and durability that polyurethane adhesives provide. These adhesives offer a dependable solution, whether you’re assembling components in a workshop or mending a broken item at home. You can guarantee the best performance and longevity for your adhesive needs by choosing a reliable brand.

Because of their outstanding strength and adaptability, polyurethane adhesives are widely used in a variety of industries, including the building and automotive sectors. They can bond a variety of materials, such as wood, metal, and plastics, and have outstanding durability and resistance to environmental factors. Several well-known companies that manufacture superior polyurethane adhesives are Gorilla, Loctite, and 3M, each of which has a range of products to meet various requirements. Knowing the characteristics and ideal applications of these adhesives will help you achieve successful and long-lasting results whether you’re working on a professional repair or a do-it-yourself project.

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