In the past, commonly used hot-press adhesives carried substances hazardous to humans and the environment. Fortunately, environmentally friendly, petroleum-free adhesive options are now available. This guide will cover all the basics you need about non-toxic, ultra-low VOC, hot press adhesives.
Non-toxic adhesives are an excellent option for companies who wish to limit not only their exposure to the liabilities resulting from hazardous substances contained in their existing petrochemical-based adhesives, but also the higher costs involved with sourcing from scarce and ever dwindling resources. These new sustainably sourced adhesives are ideally free of petroleum-based products and safe for both people and the environment. Also, they are frequently water-based and odorless, making them essential for individuals sensitive to fragrances.
Water-based adhesives, (natural binders fall under this category), are produced from plant or animal extracts or materials that mimic ingredients found in nature which are water soluble. They are thus less likely to include hazardous compounds in their composition. As a result, they are a popular option for a wide variety of industries, including paper, plywood, paint, and cardboard manufacturing.
Here are the common types of non-toxic adhesives, described in further details:
Natural plant-based components, such as cornstarch or soy, produce adhesives that are often water-based and biodegradable, making them a viable option for individuals interested in lessening their influence on the environment, both during use and after it is disposed of and sent to a landfill. One example is Specialty Organics’ BreezeBond™, an innovative soy protein-based sustainable adhesive. Moreover, once bonded, these products have virtually no lingering odor.
Casein and gelatin are two natural components used to produce animal adhesives. These adhesives are frequently utilized for woodworking. Although they are biodegradable, they are not considered as sustainable as plant-based adhesives, as animals require large swaths of land and have significantly higher water and energy requirements than plants, not to mention the ethics involved with the treatment and living conditions of animals raised in high-throughput settings.
Ultra Low VOC Adhesives
Many existing adhesives contain volatile organic compounds (VOCs), but ultra low VOC adhesives are made without these harmful chemicals. As a result, these adhesives emit far fewer toxic chemicals into the air, improving indoor air quality and promoting a healthier working or living environment.
There are several types of ultra low VOC adhesives available in the market. Here are some of the most popular ones:
Epoxy adhesives are popular for many applications, including construction and woodworking. They are known for their high strength and excellent resistance to water and chemicals. Once cured, they do not emit significant VOCs. They do, however, require a hardener to cure, which may use toxic chemicals. The manufacturing process to make epoxy also uses hazardous precursors. They are also somewhat expensive.
Acrylic adhesives are also known to have low to ultra-low VOCs and are often used in the automotive industry. They are also a popular choice for bonding plastics. Modern water-based acrylic paints have also replaced older high VOC oil-based paints. Acrylics are, however, made of polymers that are currently derived from fossil fuels, and may contain a number of additives that may not be biodegradable.
Polyurethane adhesives are another ultra low VOC adhesive commonly used in the construction and automotive industries. They offer excellent resistance to impact and weathering. Polyurethanes are, however, made by reacting diisocyanates with polyols. Diisocyanates are generally expensive to produce, using toxic ingredients such as phosgene during their manufacture.
Silicone adhesives are known for their excellent heat and weather resistance, making them suitable for high-temperature applications. They are also commonly used in electronics and medical devices to prevent short circuits due to their insulative properties. Although they are known for being flexible which can be desirable in some applications, they are not known for imparting a durable, rigid bond.
It is important to note that while some silicones are biodegradable, most silicones have prolonged residence times in the environment. Many are pervasive and bioaccumulative with known negative health effects.
Cyanoacrylate adhesives, or “super glue,” are fast-drying adhesives commonly used in electronics and woodworking. Once cured, they do not emit significant VOCs and offer superior bonding strength, although the bonds can be thin and brittle due to their low viscosity. They are also known for being relatively expensive per unit volume, and manufacturing them uses precursors like cyanide and petroleum-based solvents.
Common Existing Hot Press Adhesives
Hot press or hot melt adhesives are thermoplastic adhesives applied in a molten or suspended state and then solidified upon crosslinking and cooling. They offer a fast and efficient bonding solution commonly used in manufacturing and woodworking applications.
Here are some of the most common types of hot press adhesives:
Polyvinyl alcohol (PVA)
PVA thermoset adhesives are frequently utilized in the packaging and paper industries. This is because they adhere well to a range of materials, have a desirable consistency/tack, and can have a quick application time. However, the precursor (polyvinyl acetate, or PVAc) is currently sourced from fossil fuels and PVA is slow to biodegrade. In addition, the price of PVA has been trending upward, and unless its source of feedstocks change, they will remain a net contributor to unwanted carbon emissions.
Polyolefin hot melt adhesives, such as ethylene vinyl acetate (EVA), are commonly used in the automotive and construction industries. They offer excellent bonding strength and resistance to heat, moisture, and chemicals. These are currently derived from crude oil.
Polyamide (UF resin)
Polyamide hot melt adhesives are known for their excellent heat resistance and are used in applications ranging from textile and forest products to automobile tires. In addition, they offer a strong and durable bond to various substrates. These are currently the largest class of thermosetting resins, with urea-formaldehyde (UF) resins comprising up to 80% produced worldwide. Another type of polyamide, melamine-formaldehyde resins, are often used in laminates such as flooring. Although formaldehyde is more tightly bound in melamine-formaldehyde resins than in urea-formaldehyde, efforts are underway to find alternatives to formaldehyde-containing resins due to ever-tightening regulations.
Polyester hot melt adhesives are widely utilized in the woodworking and furniture industries. They have high strength and may bind with various materials, including wood, metal, and polymers. While they are non-volatile and bio-based polyesters have been demonstrated and may realistically have a sustainable future, most are currently derived from crude oil and natural gas.
Factors To Consider When Selecting an Adhesive for Your Application
Choosing the right adhesive for your application ensures a strong and reliable bond. Here are some key considerations when selecting an adhesive:
- Substrate: Different adhesives work better with certain substrates than others, so choosing a compatible adhesive and/or sealant is important.
- Environmental Conditions: Will they be exposed to heat, moisture, or chemicals? Some adhesives offer better resistance to these factors than others, so it is important to consider the operating conditions when selecting an adhesive.
- Application Method: The application method can affect the efficiency of the bonding process. For instance, some adhesives are applied in a liquid form, while others are applied in a more of a paste form or even a solid powder in some cases.
- Strength: Different adhesives offer different levels of bonding strength, so do your research to determine the right adhesive that can retain the necessary strength for your application.
- Safety and Sustainability: Look for glues that are low VOC and non-toxic, and choose sustainable options when possible. They are likely to have a lower carbon footprint as well.
The Importance of Choosing Safe and Sustainable Adhesives
When manufacturing products that come into contact with people or the environment, it’s crucial to prioritize safety and sustainability. The following are the benefits of choosing safe and sustainable adhesives:
Adhesives are used in a multitude of products, including furniture, toys, and food packaging. If these adhesives contain harmful chemicals, they can pose health risks to consumers. The most common consumer exposure to adhesives is inhalation of VOCs emitted from urea-formaldehyde resins.
Reducing Environmental Impact
Manufacturers can reduce their environmental impact by choosing sustainable adhesives that contribute to a healthier planet. Many adhesives are made from non-renewable resources and have a significant environmental impact. Specifically, as alluded to above, adhesives that emit VOCs contribute to air pollution and can adversely affect human health. Additionally, using renewable resources, such as plant-based materials, can help reduce the reliance on scarce resources like crude oil.
Ensuring Biodegradability and Recyclability
Using biodegradable adhesives can help reduce waste and limit the impact of landfills and the water table. At the same time, recyclable adhesives can be easily separated from other materials and recycled at the end of their useful life. By considering the complete life cycle of your products, you can help reduce waste and conserve resources.
Meeting Regulatory Requirements
Many countries have regulations requiring manufacturers to use safe and sustainable adhesives in their products. By choosing these types of adhesives, manufacturers can ensure that their products meet regulatory requirements and avoid any potential legal issues, while protecting their customers and the environment. Project leads can also help ensure a higher Leadership in Energy and Environmental Design (LEED) rating on construction projects, which can help companies save time and money through tax credits, zoning allowances, reduced fees, and expedited permitting. By using products that are made of sustainable materials, designers and architects can also help their project meet Environmental Social Governance (ESG) goals.
Choosing safe and sustainable adhesives doesn’t mean sacrificing performance. On the contrary, many sustainable adhesives offer comparable or superior performance to traditional adhesives.
BreezeBondTM by Specialty Organics, Inc.
After investing years into extensive research and development, experts successfully fine-tuned a proprietary hardwood and plywood hot press adhesive free from petroleum and formaldehyde additives. BreezeBondTM, a product by Specialty Organics, Inc., is a pioneering adhesive family of products that harnesses the potential of protein modification and cross-linking in soy adhesive manufacturing.
Designed specifically for hot press applications, this adhesive attaches phosphorus to the amino acid groups in proteins found in soy flour. Then, optionally, oxidizing agents can be added to fortify bonds, further enhancing the adhesive’s overall performance.
This novel product provides a safer alternative to petroleum-based adhesives, which often contain petrochemicals and formaldehyde compounds that can impact human and environmental health.
The benefits of BreezeBondTM include the following:
- Single-component adhesive
- Cost-effective option with minimal investment requirements
- Plant-based adhesive free from harmful petrochemicals and formaldehyde additives
- Months of shelf life and a spreadable consistency
- Eco-friendly adhesive from sustainable and renewable materials
- Virtually odorless once cured, with a pleasant, mild scent prior to cure
- Abundant raw materials
- Sequesters carbon, helping manufacturers achieve their net zero carbon goals
Secure Your Projects With Safe and Sustainable Adhesives From Specialty Organics, Inc.
Specialty Organics, Inc. manufactures adhesives for a range of hot-press applications while adhering to its mission of making products that are less harmful to the environment. Aside from BreezeBond™, we also offer toll manufacturing services, custom synthesis, proof of concept, and product scale-up in our pilot plant.
We are eager to provide a formulation that meets your product’s specifications! Contact us now to get the high-quality supplies you require for durable bonding.