Adhesive manufacturing involves formulating, mixing/blending, and processing raw materials to create a range of adhesives with specific properties and characteristics. Do you want an adhesive that will spread thinly to accommodate a smooth or thin decorative layer, or do you want a thicker adhesive that won’t get lost in the nooks and crannies of a rough surface? In the past, this optimization process often included using an adhesive blend, a combination of two or more bonding agents. The resulting mixture improved the product performance by being tailored according to the project’s needs. Recently, single component adhesives, such as BreezeBondTM, have also become available that can be specifically formulated for a range of forest product applications.
Each application has specific requirements, such as unique substrate materials, environmental conditions, and required bond strength. Failing to consider these factors can result in inadequate bonding, compromising the final product’s reliability. In addition, the wrong blend can lead to costly rework, impacting production schedules and increasing expenses. Conveniently, since BreezeBondTM can be offered as a single component from the adhesive factory, it can reduce the chance of these types of issues with forest products.
Some customers, however, may feel uncomfortable switching their adhesive completely over to BreezeBondTM alone, and would like to retain some of the properties of their existing adhesive, commonly polyvinyl acetate (PVAc), at least initially. In these instances, BreezeBondTM can be blended with PVA. This can help customers reduce their exposure to the volatile petroleum markets, while making safer products in the process!
Here is a closer look at the key considerations when selecting the right adhesive formulation to ensure that you get the best possible bonding results:
1. Surface Type and Cleanliness
Different surfaces can require specific types of adhesives to achieve effective bonding. For example, smooth surfaces like sanded wood or paper may benefit from a lower viscosity adhesive than rough or porous surfaces. Such coarse surfaces may need a thicker, or higher viscosity adhesive mix to ensure adequate material is retained between the layers to be bonded.
Another important consideration is the cleanliness of the surface. Adhesives usually work best when starting with a clean, dry surface. If the surface is contaminated with dust, grease, or other debris, it can prevent the product from forming a strong bond. In such cases, surface preparation may be necessary, which can include abrasive surface preparation or even a primer for some types of adhesive. Selecting an adhesive blend designed to bond with compromised surfaces may be necessary.
2. Temperature Range
It is necessary to understand the adhesive’s operating temperature range and the application’s intended environment. This will allow selection of a blend or formulation specifically designed to maintain its properties and bonding strength within the required limits. Otherwise, a product in a high-temperature environment beyond its recommended range may result in softened or lost adhesion.
3. Dry and Wet Strength
Dry strength pertains to the adhesive’s bond strength in dry conditions, while wet strength refers to its bonding capability in humid or wet conditions. Different types of bonds have varying levels of dry and wet strength. In some cases, a moisture barrier such as a sealant is also used.
Packaging is one of the most prominent examples of an industry where blends with high wet strength are required. For example, disposable preformed fiber crates, cartons, or other containers must maintain their bonding strength even in humid or damp environments. Otherwise, moisture can weaken the bond and cause the structural integrity of the packaging to break down, resulting in product damage or loss during shipping and handling.
4. Hot Press Temperature
Hot press temperature refers to the temperature at which the adhesive is activated and the bonding process begins. Different architectures have different temperature requirements; some bonds require high temperatures to activate, while others require lower temperatures. If the hot press temperature is too high, it can cause the adhesive to break down or become over-cured. This can result in weak bonding or even adhesive failure. High temperatures can also adversely affect the materials being bonded, causing discoloration, cracking, wrinkling, or even burning. In these instances, it may be necessary to extend the duration of the press at a lower temperature.
5. Press Duration
The press duration is the amount of time the adhesive and substrate are held together under pressure and temperature during bonding. As is the case with temperature, the duration depends on the adhesive type, substrate material, and total thickness. If the press duration is too short, the adhesive may not crosslink adequately. Conversely, it may break down if the duration period is too long. Sometimes, as mentioned earlier, it is possible to extend the press duration at a lower temperature to achieve bonding if the product materials are sensitive to elevated temperatures.
6. Tack
Tack refers to the adhesive’s ability to adhere to a substrate quickly and form an instant bond under light pressure. The tack level required for a particular application depends on several factors, such as the substrate material, the application method, and the desired bond strength. It can also be adjusted by changing the formulation or modifying the processing conditions during adhesive manufacturing. Oftentimes, a cold press step is implemented prior to hot press to ensure sufficient wetting onto the surface of the substrate.
Choose Specialty Organics To Find the Formulation Right for Your Product
Specialty Organics is an established, eco-friendly adhesive manufacturer offering a range of products and services, including BreezeBondTM. We offer BreezeBondTM in a variety of formulations, including from low viscosity to high, to tailor its characteristics to meet the needs of your specific application. Specialty Organics also offers toll manufacturing, pilot plant proof of concept, scale-up, and custom synthesis services to meet your adhesive and coating-related needs. We also offer contract manufacturing for businesses looking to outsource their adhesive production.
We understand the importance of timely delivery and offer flexible production scheduling to cater to your needs! Contact us today to learn more about our products and services.