The Scoop on Envelope Adhesives

If you’ve ever sealed an envelope with a lick and a prayer, congrats, you have experienced envelope adhesive in action. (And if you had a whole stack to get through, maybe a little dry mouth too.)

But what most people don’t think about while sealing and sending is the serious adhesive science happening behind the scenes, er, under the flap.

At Chicago Glue & Machine, we geek out about that kind of stuff. And since you’re here, we’re guessing you might too. So, let’s talk about envelope glue.

Not All Envelope Adhesives Are Created Equal

Whether you’re mailing invoices, wedding invites, or a secret pen pal letter, the adhesive holding that envelope shut better do its job. H. B. Fuller understands that and offers a full line of envelope adhesives designed to work across machines, paper grades, and even those weird plastic windows

Here’s a few standouts in their envelope adhesive lineup:

PWE4000 Front Seal Gum

This gum doesn’t mess around. It’s consistent, dependable, and basically the overachiever of the adhesive world.

• Works on all envelope machines
• Re-moistening performance that stands up to even the highest speed inserting equipment
• Laughs in the face of humidity (which helps prevent that dreaded flap tabbing or envelope blocking during storage)

EG3464 Extrusion Gum

Do you have the need for speed? Great because this gum thrives at speeds up to 1600 envelopes per minute. That’s basically Formula 1 for adhesives.

• Manufactured with proprietary polymer tailored for clean cut-off
• Designed to reduce messy tailing and nozzle build-up during manufacturing process
• Gets the job done on a variety of OEM systems
• And yes, it gives you that clean, accurate gum line that makes everything look sharp

WB2338 MXRB-001 Rotary Back Gum

For rotary gumming applications, this one’s the go-to.

• Cuts down on slinging and blocking
• Sticks well on a variety of envelope grade papers
• Drying time is optimized for best overall performance (another overachiever)
• Great gum box adn viscosity stability

EG3361W Window Patch Gum

This is your perfect match for those envelopes with a peek-a-boo window.

• One gum fits all, simplifying your inventory
• Cuts back on SKUs that need to be stocked
• Sticks to tricy window films like polystyrene and polypropylene
• Bonus: clean machining = less downtime = happier operators

Peel. Stick. And Done.

Let’s not forget our peel-and-stick envelope pals. These water-based solutions can be used inline or on a stand-alone gumming machine and they promote clean machining. Don’t let their simple “peel, stick, done” look fool you, they pack an aggressive bond. For self-seal applications, meet:

• W3320 Gum – A pressure-sensitive adhesive (PSA) that brings strong bonds and clean machining to peel-and-stick envelopes
• Hydrogrip 20985 – The behind-the-scenes hero of self-seal latex envelope

Why We Care (and Why You Should Too)

We’re amongst friends so we’ll be honest, adhesives are not always the flashiest part of envelope production. But when they don’t work? Everyone notices. Clean machining, fast application, strong bonds, and low maintenance are the kind of things that keep your line moving and your team happy. That’s where we come in!

At CGM, we’re here to do more than just sling glue, we’re helping you find solutions to your stickiest situations, like which adhesive is best for your application type. If you want to talk envelope adhesive (or geek out with us), give us a call at (800) 419-GLUE or visit our website.