November Glue Talk

At Glue Machinery Corporation, we understand the world of industrial adhesives can seem daunting, prompting our customers to send us questions about problems they’d like answers to. These problems range from requests for product overviews to seeking industry best practices. Rather than keep all this information to ourselves, we thought, “Let’s do our Glue Diligence®” and share it with you through our monthly content series, Glue Talk: Answers to Your Questions About All Things Adhesive.

Q: When should I consider moving from Glue Dots to Glue Drops in applying adhesive directly to substrates?

Consider moving from Glue Dots to applying hot melt glue directly to your materials when you need to accelerate production, improve product quality and/or reduce costs.

Glue Dots are small, circular sticky glue wafers that are sandwiched between release liner. They offer convenience to end users who remove these pressure sensitive adhesive dots from the liner and place them between two materials. With the correct hot melt machines to include handguns, benchtop metering systems or high speed automatic machines, pressure sensitive dots of hot melt are applied directly to the substrates they want to bond. The manual, semi- automatic and automatic application speeds of hot melt equipment can be much faster than possible with Glue Dots. Glue Dots are hot melt adhesives and hot melt adhesives are most effective when melted and applied directly to the substrates and the bonds are made quickly.

Glue Dots offer a range of bond strengths. The choice of bond strengths becomes far less important with hot melt as dot size, temperature and compression can be adjusted to achieve the best possible bond required. The average cost for Glue Dots is 1 cent each. The average cost for a dot of hot melt applied from a handgun, bench top metering machine or automatic machine is somewhere between 1/10th and 1/20th of one cent each.

Q: What happened to many of the cold glue machinery companies?

Many of the cold glue machinery companies to have decided to reduce their focus on cold glue equipment. Some have decided to get out of this business altogether leaving their customer base without support. This is occurring in part because the markets that require cold glue extrusion systems are considered mature with limited growth potential.

One such market is the business forms industry where as many as 36 extrusion guns with complex pattern controllers are used to bond many layers of paper together. The “Paperless” society has dramatically reduced the need for multiple copies of every business transaction.

Another reason for the reduction in companies supporting precise cold glue systems is that there can be very little residual sales of cold glue components over the lifetime of the equipment. We have seen high speed glue machines in corrugated plants that have operated for 10+ years with barely a part purchased to support the gluer.

Many of the cold glue machinery companies are have morphed into hot melt machinery companies as in many applications hot melt gluing is much faster than cold gluing. Some German cold glue machine manufacturers who have relationships with big European OEMs producing printing and folding machines have managed to continue to sell smaller volumes of their cold glue machines.

Cold glue extrusion equipment applies water-based glues with accuracy and speed. Water-based glues are very good at bonding paper substrates but compression and time are required to achieve bonds.

We at Glue Machinery Corporation will continue to offer high-speed cold glue equipment and peripherals to support the many industries that use water-based adhesives in their manufacturing processes. We will also continue to strive to offer the best possible products and insure that the correct water-based glues are used to manufacture bags, cartons, boxes, folders, business forms, envelopes, print finishing, tissue and woodworking.

Q: What is Glue Diligence?

The standard description of Glue Diligence is “Free technical service offered by Glue Machinery Corporation™ to help manufacturers determine the correct adhesive and application method to efficiently produce high quality product at the lowest price.”

We have come to realize that Glue Diligence is much, much more. It is a valued service offered only by Glue Machinery Corporation to manufacturing companies that want real answers regarding adhesive equipment and adhesives. While other companies do “testing,” very few take it to the next level as with Glue Machinery Corporation.

Here is a typical Glue Diligence interaction:

  • Customer calls with questions and speaks to the President of the company about their application
  • Information and ideas are immediately exchanged and all the right questions are asked
  • All conversations are strictly confidential
  • Basic recommendations regarding machinery, adhesive and assembly process are made
  • Recommendations are documented to the customer to insure clarity
  • Quotations and information are sent to the customer where possible
  • Customer is invited to send samples of substrates for evaluation and recommendation
  • Glue Machinery Corporation will work with any adhesive manufacturers glue that the customer suggest
  • Glue Machinery Corporation contacts the customer to insure that any testing will meet the requirements of the customer
  • Substrates are glued with lab equipment and video of the process are sent to the customer for review
  • Video demonstrating bond strengths are sent to the customer
  • Samples are sent to the customer with a tracking number, copy of quote and short report
  • Glue Machinery follows up with customer within one day of receiving samples

Service is free and can usually occur within one week of the initial discussion.

Q: Why are so many customers reluctant to invest in the correct gluing equipment for “Duplexing/ Laminating” paperboard materials to produce quality business cards and invitations?

Most customers tell me that they just cannot justify the expense. The return on investment is not easily realized. What most customers who use the correct glue coatings system and adhesive have come to realize is that they can easily produce super high quality business cards and invitations and can quickly expand their product offerings.

Most printing companies consider duplexing to be a kind of niche product when many customers with the correct gluing machinery and glue have turned the duplexing business into a real profit center. With the correct glue machine and glue they can produce high quality materials quickly at a very low price. The correct gluing equipment, including the Glue Machinery Corporation R Gluer used with GIA1086 repositionable paper to paper glue, is easy to set up, maintain and clean up. It can be set up for any job in 10 minutes and run for minutes to many hours without stopping, and the clean up takes about 10 minutes. The glue cost to duplex is typically 1-2 cents per sheet.

Q: What is the difference between PUR hot melt and standard hot melt?

PUR hot melts are moisture curing reactive polyurethane hot melt adhesives. Hot melt adhesives bond with temperature loss and do not actually cure. Both offer the benefit of fast bonding between substrates, but PUR takes it to another level as it actually cures.

PUR’s offer fast bonding but also offer higher temperature resistance than standard hot melts; they can offer incredible flexibility and elongation characteristics not available with hot melts. PUR’s are also only available in sealed containers that keep moisture from reaching the adhesive, require special equipment to process them, cost more than standard hot melts and bond a much wider range of materials and over a wider range of temperatures.

Standard hot melt adhesives are available in a range of non-sealed container forms that include sticks, chips, pillows and blocks. Likewise, they only require standard hot melt equipment and are widely used where the glue is stronger than the substrates, notably in packaging applications.


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