4 Advice to Choose a PUR for Profile Wrapping

Usually, people think that buying the best adhesive or the best system available on the market is 99% of the final successful outcome. Thanks to our many years of experience we realised that, as fundamental the quality of the chosen products and technologies may be, quality alone is not enough to reach the final goal. There are many factors that can influence the final outcome, in particular when using a special process such as surface finishing.

View Details

BELOW IS A BRIEF LIST OF ESSENTIAL POINTS TO TICK OFF FOR A SUCCESSFUL APPLICATION:

1. Knowledge of supports and treatments to be performed in the presence of materials with low surface energy, such as PVC, WPC, etc. (by developing low carbon footprint adhesives such as the LOW VOC WPN 3 and WPN10-0% VOC- primers)

2. Knowledge of wrapping foils: each foil needs special application techniques; for instance: CPL melamine foils require a specific pre-heating treatment – at above 90°C – in order to be modelled without breaking and be applied to profiles with difficult geometries, such as door jambs. It is by combining application knowledge with the best product, in this case, TK .25PV, an adhesive with a very high initial grip at high temperatures, that ultimate success is attained.

3. Knowledge of systems: The importance of knowing how to choose a high-precision hot melt application head that allows for homogeneity of coating over the entire width of the foil even on extremely wide surfaces of over > mm. Homogeneity of coating is fundamental, for example, with thin foils or glossy foils, where the quantity of glue used can create visible surface waves.

4. Knowledge of adhesives: The choice of adhesive, as mentioned above, is essential. Often, customers use a different adhesive for each type of foil or profile. It is our experience that, in some cases, the same adhesive can be used with different materials, adjusting the application parameters or the tooling, and by using specific machine accessories to heat or cool the surfaces according to need.

5. Knowledge of guaranteed product performance: For instance, in the case of profiles to be used outdoors, it is important to know where the final product shall be installed and choose the right combination of adhesive and wrapping foils, one that can withstand specific climate stresses.

6. Knowledge of the application process, in order to guarantee improved performance: for instance, ncreasing the machine speed by 1m/min makes it possible to produce 480m of profiles more in an 8-hour shift.

THE WPR-TAKA EXPERT TEAM SHALL BE AT YOUR SIDE FROM START TO END, FOR GUARANTEED PERFECT RESULTS!

Hot melt adhesives are a versatile and widely used solution in different industries ranging from edge banding and furnitures, bookbinding and graphics, packaging to endless DIY applications. Their ability to bond quickly and effectively, cost-effectiveness, and being eco-friendly, made them popular for industrial applications.

In this article, we'll explore and compare EVA (Ethylene Vinyl Acetate)and PUR (Polyurethane)hot melt adhesives. By understanding the differences, you can better decide which type to choose for your projects.

EVA Hot Melt Adhesives (Ethylene Vinyl Acetate):

EVA hot melt glue is the most common and widely used type in various industries. They are popular because they offer a good balance of cost performance. EVA adhesives are typically used in edge-banding and furnitures, packaging, bookbinding, and as glue sticks for DIY applications.

Characteristics of EVA Hot Melt Adhesives:

• Temperature Range: EVA adhesives are applied at moderate to high temperatures, usually between 120°C and 220°C, allowing them to bond quickly as they cool.

• Adhesion: They provide good adhesion to porous surfaces like wood, paper, non-wovens, and plastics, makes it ideal for furnitures, books, paper packaging products.

• Flexibility: EVA adhesives can tolerate some movement and bending in the materials they bond, which is helpful in applications with slight flexibility.

• Cost: EVA hot melts are among the most affordable types of adhesives, making them a cost-effective option for large-scale industrial use.

  Jiwei Product Page

Applications for EVA Hot Melt Adhesives:

1. Edge-banding & furnitures: EVA hot melts are commonly used in furniture assembly and edge banding due to their strong adhesion and ease of application.

2. Bookbinding and graphics: The ability to bond paper quickly makes EVA adhesives a go-to for bookbinding textbooks, magazines, and commercial printings.

3. Packaging: EVA hot melts are an ideal choice for sealing carton, trays and folding boxes as well for various paper packaging, providing strong, fast-setting bonds.

Limitations:

While EVA adhesives are versatile, they have temperature and durability limitations. As a thermoplastic material, EVA will soften above 80°C so the bond can be weaken. As well, for difficult-to-bond and non-polar materials, it can perform poorly in bonding.

PUR (Polyurethane) Hot Melt Adhesives:

PUR adhesives are highly durable and form incredibly strong bonds, making them suitable for demanding industrial applications. Unlike EVA adhesives, which form bonds primarily through cooling, PUR adhesives undergo a chemical curing process that strengthens the bond over time. This makes them a much more permanent adhesive solution compared to EVA.

Characteristics of PUR Hot Melt Adhesives:

• Curing Process: PUR adhesives absorb moisture from the air or materials after being applied and cooled, triggering a curing process that forms a strong and permanent bond. Initial strength is achieved after 24 hours, with full cure typically within 48 to 72 hours.

• Temperature & Chemical Resistance: PUR adhesives are highly resistant to heat, chemicals, and environmental conditions, making them ideal for outdoor applications and products exposed to harsh environments.

• Adhesion: They bond well to a wide range of materials, including plastics, metals, glass, and wood, offering much stronger adhesion than EVA adhesives.

Applications for PUR Hot Melt Adhesives in furnitures:

1. Edge banding:PUR adhesives are becoming more popular for high-end furnitures, where "zero" bond-line and environmental factors are critical.

2. Profile wrapping:PUR adhesives are taking the place of EVA adhesives for wrapping window and door frames, where strong bonds and resistance to heat and chemicals are important.

3. Lamination:PUR adhesives are becoming the go-to choice for lamination due to their excellent bonding strength, smooth surface finishes and environmental resistance.

Limitations:

While PUR adhesives are highly durable and form incredibly strong bonds, they can be costly and are very strict about conditions (i.e. temperature and humidity), not to say that it requires additional gluing equipment and regular maintenance.

Conclusion:

EVA hot melt adhesives is ideal for most-diverse bonding tasks where cost performance and streamline production are among the priorities. Whereas, PUR adhesives offer superior strength and temperature resistance, but requires additional equipment setup, maintenance and training.

By understanding the strengths and limitations of EVA and PUR Hot Melt Adhesives, you can ensure that you're using the right one for your project.

Not sure what the best solution is for your needs? We are here to help.

For more information, please visit PUR for Profile Wrapping.