Q&A: What is Protein Glue?

by L.D. Davis Industries
Soft gel netting is what’s left over from the production of vitamin E and nutrition gel capsules.

Protein glues, also called jelly or cake glues, are used in many everyday applications like bookbinding, game board manufacturing, packaging, woodworking and more. The main ingredient in protein glue is recycled scrap gelatin from pharmaceutical netting. Gelatin is derived from collagen, hence the name “protein” glue.

Pharmaceutical and nutritional encapsulating companies normally dispose of their excess netting. Instead of this material going to waste, L.D. Davis is able to utilize it by recycling the gelatin for use in its adhesive products.

There are a number of high-quality sources of recycled pharmaceutical and nutritional gelatin, which can come in the form of soft gel netting or ground hard cap. Soft gel netting is what’s left from the production of vitamin E and nutrition gel capsules. Ground hard cap comes from excess pharmaceutical capsules.

Besides gelatin, other raw materials used in the manufacturing process of protein glue are sugars, Epsom salt, water and glycerin. Since all raw materials are 100 percent natural, protein glues are biodegradable.

What bookbinding equipment commonly is used with protein glues?

  • Crathern and S&S
  • Horauf Universal
  • Perfect Binder Machines
  • Pot Devin Machines
  • Sheridan Roll Feed Case Maker
  • Stahl Case Maker
  • Kolbus Case Maker

What are the benefits of using protein glues in bookbinding?

  • Open time, tack level and viscosity easily adjusted to different running parameters
  • Easy cleanup with water
  • Eco-friendly, biodegradable, recyclable and repulpable
  • Water-soluble
  • Forms a strong, long-lasting bond
  • Useful in “green” applications
  • Application issues can be corrected by operators with temperature, dilution and application levels
Ground hard cap is from excess pharmaceutical capsules.

Protein glue is one of the most effective adhesive solution for casemaking, however it is not feasible to use a hot glue system in a very low volume operation. In short-run casemaking applications, PVA (Polyvinyl acetates) glues work very well. PVA glues are water-based and are applied at room temperature.

For 90 years, L.D. Davis Industries has been manufacturing industrial and commercial adhesive solutions. They specialize in protein, hide and liquid glues. All adhesives manufactured by L.D. Davis Industries are eco-friendly and biodegradable. L.D. Davis Industries also is an established distributor for hot melt and PUR adhesives. For more information, visit www.lddavis.com.