GLUE

Is Glue Sustainable?

Glue is a sticky topic for the eco-minded. Is it vegan? Biodegradable? The answer depends on the glue type.

Generally, adhesives fall into two main camps: natural and synthetic. Humans have been using natural adhesives for millennia, but in the 20th century, synthetic glues were developed and have over time largely replaced natural adhesives. Much of this was thanks to the aircraft and aerospace industries, which required adhesives with high structural strength and resistance to fatigue and extreme conditions. These high-tech, synthetic adhesives eventually trickled down into more mundane industrial and domestic applications.

Here, delve deep into the contents of glue—both natural and synthetic—to decipher which options have the lowest environmental impact, plus learn how to make your own adhesive at home.

• Ingredients in Synthetic Glues

Synthetic adhesives like Gorilla Glue and Elmer's belong in two categories: thermoplastics and thermosets. The resins used in thermoplastic adhesives include nitrocellulose, polyvinyl acetate, vinyl acetate-ethylene copolymer, polyethylene, polypropylene, polyamides, polyesters, acrylics, and cyanoacrylics. Resins used in thermosets include phenol formaldehyde, urea formaldehyde, unsaturated polyesters, epoxies, and polyurethanes.

Many ingredients used to make synthetic glue are plastic polymers, petroleum-derived and -dependent. The petroleum industry is notoriously destructive, and these products do not break down readily after discarded.

• Is Elmer’s Glue Sustainable?

Ever notice that the logo of Elmer's is a cow? That's because the glue brand was a spin-off from the Borden Condensed Milk Company; Elmer the bull was the husband of the Elsie the cow, Borden's uber-popular spokesbovine of lore.

In the late 1920s, Borden acquired the Casein Company of America, the leading manufacturer of milk-derived casein adhesive. In need of a marketing boost, the company gave Elmer the cow the job of representing the company's new glue.

In 1968, the company created Elmer's School Glue and Glue-All, both using top-secret concoctions of fossil-fuel derivatives. In 2013, it launched Elmer's School Glue Naturals, whose pourable and stick versions are comprised of 99% and 88% "natural" ingredients, respectively. Besides soybeans and American-grown corn, their primary ingredient, it's unclear what those natural ingredients are.

• Ingredients in Natural Glues

Natural glues are mostly of animal or vegetable origin. You've heard of horse parts in glue, right? It's true, people have been using animals—horses included—to make glue for thousands of years; in the 18th century, the first commercial glue factory, based in Holland, used animal hides. Animal glues were traditionally used for wood joining, book binding, crafting musical instruments, producing heavy gummed tapes, and other specific applications.

Though they are used much less frequently nowadays, they are still preferred for corrugated board, envelopes, bottle labels, book bindings, laminated film, and foils, for example. Today's natural glues are made of everything from animal parts—including rabbit skins, gelatin, milk proteins, and serum albumin from animal blood—to vegetable starches, natural gums like agar and gum arabic, and natural rubber latex.

• Which Is Better, Natural or Synthetic?

In terms of performance, synthetic adhesives are significantly more versatile. They can be manufactured with more consistency, too. Both are factors in why synthetic glue is the current standard.

Though not all have the sticking power of synthetic options, natural glues tend to be cleaner to manufacture and less toxic when degrading. The problem you run into with natural glues, besides subpar performance, is animal welfare concerns. Both synthetic and vegan glues can be cruel in their testing methods, but nonvegan natural glues also contain animal products in their formulas.

The most sustainable type of glue is plant-based, though this type is perhaps least effective. Can't find a plant-based glue near you? Consider whipping one up yourself.

• How to Make Your Own Glue

The easiest homemade glue is a simple flour and water paste. It doesn't have the most amazing adhesive quality, but it's perfect for things like simple crafts and papier-mâché. Start with a half cup of flour and add a little water at a time, stirring until you have a paste consistency. That's it.

There are a lot of DIY glue formulas out there that use milk, but if you want a vegan option, here's a good slightly-more-complex recipe.

Ingredients

• 1.5 cups flour
• 4.5 cups room-temperature water
• 1.5 cups white sugar
• 3 tablespoons vinegar
• 2 tablespoons baking soda

Steps

• Mix flour and water in a pot over medium-low heat, stirring continuously.
• Once the mixture is warm and blended thoroughly, add sugar and continue stirring.
• After the sugar is mixed in, add vinegar and mix.
• Add baking soda, then mix.
• Continue mixing until the liquid thickens and begins to bubble.
• Remove from heat and use immediately to bind paper, cardboard, or fabric.