Fugitive glue provides temporary attachment and is selected around both holding and removal requirements. Hot melt grades are one route to assess for automated card and insert attachment.
A card must stay on its carrier through packing and delivery, then come away without an unacceptable mark. Those are two separate approval requirements. A sample that peels easily on the production bench may still fail after storage, while a stronger bond may damage the printed carrier.
This guide covers temporary spot attachment for cards, inserts and direct-mail pieces, with a practical test plan for buyers comparing bulk adhesive and ready-made glue dots.
What fugitive glue means
In printing and packaging, fugitive glue usually means an adhesive selected to create a removable, temporary bond. Suppliers also use the term fugitive adhesive, along with descriptions such as removable glue, gummy glue and credit card glue.
The name describes the intended bond behavior. It does not specify one chemistry, application temperature or level of tack. Supplier terminology varies, so confirm that the proposed grade is designed for your removal requirement.
How the temporary bond works
The adhesive makes contact with both surfaces and holds the attached item through the required handling period. When someone removes the item, the bond must release within the agreed force and appearance limits.
Depending on the grade and surface pair, the glue may stay mainly on one side or lift away as a cohesive piece. Specify which result you need. A card that comes away clean while leaving a visible glue deposit on the letter may be acceptable for one project and unacceptable for another.
Hot melt fugitive adhesive is heated for dispensing and develops its usable bond as it cools. A pressure-sensitive hot melt grade retains tack after cooling. Liquid fugitive grades also exist and require their own application and bond-development checks.
Hot melt describes the processing route; fugitive describes the intended release behavior. A hot melt can therefore be formulated for temporary attachment.
Removable and repositionable requirements
A removable grade may be intended for a single attachment and removal. Repositioning adds another requirement: the item must attach again and still meet the holding target.
If the customer will peel and reattach a card, include repeated attachment cycles in the trial. Initial tack alone cannot establish that capability.
When reviewing PSA hot melt adhesive options, ask specifically about temporary attachment and the intended surface pair. The PSA category includes grades with different adhesion targets.
Bulk adhesive versus ready-made glue dots
Bulk fugitive glue and ready-made removable glue dots offer different ways to place adhesive at the attachment point. Choose the format around the existing equipment, required pattern and production workload.
A dispensed dot of bulk glue is not necessarily the same product as a preformed adhesive dot supplied on a release liner.
| Selection point | Bulk hot melt fugitive adhesive | Ready-made removable glue dots |
|---|---|---|
| Supply format | Bulk adhesive in the supplier’s specified form | Preformed adhesive dots on a release liner |
| Application | Compatible heated dispensing system | Manual, assisted or compatible automated transfer system |
| Pattern control | Equipment settings control deposit amount and placement | Supplied dot dimensions and spacing constrain the pattern |
| Heat at application | Adhesive is heated before dispensing | Preformed dots generally transfer without melting on the line |
| Main process checks | Temperature, viscosity, shot consistency, stringing and shutdown behavior | Liner release, complete transfer, registration and application pressure |
| Purchase comparison | Adhesive consumption plus equipment operation and maintenance | Cost per applied dot plus applicator operation and liner waste |
| Removal approval | Test the selected grade on finished substrates | Test the selected removable dot on finished substrates |
Ready-made glue dots are available in removable and permanent formulations. Specify the bond type when requesting samples.
Bulk hot melt is worth assessing when an existing line can dispense a controlled pattern and place the attachment consistently. Preformed dots are worth assessing when avoiding a heated application step or using a fixed deposit size suits the job. Either format can support automation with appropriate equipment.
Compare cost per acceptable finished piece. Include adhesive use, rejected pieces, application labor, maintenance and changeover losses. A lower adhesive purchase price does not establish a lower production cost.
Card, insert and direct-mail bond tasks
Define the attachment task before choosing the tack level. The weight, stiffness and contact surface of the attached item affect what the bond must withstand.
| Bond task | What the attachment must survive | What to inspect after removal |
|---|---|---|
| Plastic card on a printed carrier | Placement, conveying, envelope insertion and delivery | Glue on the card, lifted ink and damage to the carrier |
| Paper coupon or return envelope | Folding, stacking and handling without detachment | Fiber tear, wrinkles and loss of printed information |
| Sample sachet in a brochure | Movement of the filled sachet and pressure in packed stacks | Film damage, print transfer and remaining adhesive |
| Folded insert on packaging | Spring-back of the fold and movement during packing | Torn panels, coating lift and readable instructions |
Use production materials for approval. An unprinted paper sheet cannot represent a varnished mailer, and an uncoated plastic coupon cannot represent the finished card surface.
Provide the supplier with the paper grade, ink or toner process, varnish, lamination and any surface treatment. Include material from different production batches if those batches vary in normal use.
For cards, mark the allowed glue zone on a drawing. Keep the deposit clear of any area that must remain accessible or undamaged, such as a chip, magnetic stripe, barcode or scratch panel.
A continuous protective-film coating needs a different trial because the adhesive covers a much larger area and must release across that surface. Use the separate hot melt PSA for protective films guide for that application.
Hold, peel, staining and surface damage
Approve holding performance and removal appearance separately. Record both results for every sample condition.
The following is a suggested trial framework. Set acceptance limits with the customer and adhesive supplier before testing; these are not universal fugitive glue specifications.
| Check | Suggested trial | Define the acceptance requirement |
|---|---|---|
| Initial hold | Run the assembly through the next production steps after placement | Allowed movement and detachment rate |
| Hold during storage and transport | Condition packed assemblies under the expected load and environment | Position tolerance and retained attachments |
| Removal force | Remove the item using a fixed direction, speed and fixture where practical | Acceptable force range and ease of removal |
| Adhesive residue | Inspect both surfaces immediately after separation | Which side may retain glue and how much |
| Staining | Compare bonded areas with unbonded controls after storage | Acceptable halo, discoloration or translucent mark |
| Surface damage | Inspect paper, print, varnish and film after removal | Limits for fiber tear, ink lift, coating loss or distortion |
| Blocking | Open assemblies stored in representative stacks | No unintended bonding to adjacent pieces |
Make peel results comparable
Record the substrate pair, deposit size, number of glue spots, placement pressure, conditioning time and removal temperature.
For flexible test strips, a defined peel geometry can support comparison. A rigid card may need an application-specific pull or removal fixture. Report the method with the result, and avoid directly comparing a card pull-off force with a tape peel value expressed per unit width.
The peel, tack and shear testing guide explains the different properties these tests measure. Use that background to design the test, then verify the actual card or insert assembly.
Separate residue from staining
Residue is adhesive left on a surface. Staining is a visible change to the substrate, which may remain even after the adhesive deposit has been removed.
Photograph both sides under consistent lighting. Keep an unbonded control from the same material batch beside each tested sample. Check the back of thin paper as well as the bonding face.
Descriptions such as “low stain” or “clean removal” should be confirmed on the finished material after the required storage period.
Treat difficult removal as a compatibility result
If peeling lifts the print or tears the carrier, record the failure before attempting cleanup. Review the grade, deposit amount, bonding location and surface construction.
Any proposed removal or cleanup procedure needs a separate compatibility trial on a spare finished sample. Agree on the procedure with the adhesive and substrate suppliers, then check for color change, loss of gloss, softening and remaining tack. An unvalidated cleanup step should not turn a failed removal test into a pass.
Dispensing and dwell-time checks
A laboratory sample can approve the surface pair, but the production trial must also show that the line applies the adhesive consistently.
For bulk hot melt, begin within the supplier’s recommended processing range. Confirm compatibility with the melter, pump, hose and applicator. A grade supplied for bulk equipment may not suit a handheld glue gun.
Record:
- Tank, hose and nozzle temperature settings, with actual readings where available.
- Adhesive viscosity at the stated test temperature.
- Deposit mass or dimensions, spot count and position.
- Line speed and the delay between dispensing and attachment.
- Placement pressure and contact duration.
- Stringing, nozzle drips, missed deposits and squeeze-out.
- Performance after pauses, restarts and the expected heated residence time.
Inspect samples from the start, middle and end of the run. Include normal speed changes and a planned pause. Stable performance during uninterrupted running alone does not establish restart performance.
For preformed glue dots, check liner release and complete transfer at the intended speed. Inspect for skipped dots, double application and positional errors.
Keep the different time intervals separate
“Dwell time” is too vague unless the trial record states which interval it means.
| Time interval | What to record | What the trial should establish |
|---|---|---|
| Dispensing to placement | Delay between adhesive application and contact | The assembly bonds throughout normal line timing variation |
| Time under pressure | Duration and pressure of the placement step | The deposit makes sufficient contact without unacceptable spreading |
| Bonded storage time | Time between assembly and removal | Hold and removal remain acceptable when the recipient opens the item |
| Heated residence time | Time adhesive spends hot in the equipment | Dispensing remains acceptable through the planned operating cycle |
For a preliminary screen, buyers might compare immediate removal, 24-hour removal and seven-day removal. These are example checkpoints, not a standard approval schedule. Extend testing to cover the actual interval between production and customer use.
If mailers may spend several weeks in storage, test that interval. Include relevant warm, cold or humid conditions and representative stack pressure. Accelerated conditioning can help screen candidates, but it needs correlation before it can represent a stated real-time storage period.
Once the substrate pair is fixed, change one main variable at a time. For example, compare deposit amounts before changing both the adhesive grade and applicator temperature.
Sample approval inputs
A useful sample request describes the finished attachment and its acceptance limits. “We need fugitive glue for cards” leaves too many variables unresolved.
Send the following information with your inquiry:
| Input | Details to provide |
|---|---|
| Application | Card affixing, coupon attachment, insert placement or sample attachment |
| Substrates | Exact materials, thicknesses, coatings, printing and surface treatments |
| Attached item | Dimensions, weight, stiffness and a photo or physical sample |
| Bond pattern | Allowed glue zone, spot count and target deposit size or mass |
| Equipment | Bulk hot melt system, liquid dispensing system or preformed-dot applicator |
| Production conditions | Line speed, application-to-placement delay and contact pressure |
| Storage and delivery | Expected duration, temperature, humidity and stacking conditions |
| Holding target | Permitted movement, handling steps and acceptable detachment rate |
| Removal target | Which surface must be clean, allowed residue and surface-damage limits |
| Reattachment | Whether a single removal or repeated attachment is required |
| Purchasing requirements | Trial quantity, forecast volume, packaging and required documentation |
Ask for the proposed grade’s technical data sheet, safety data sheet, processing guidance and storage instructions. Confirm which performance statements come from tests on your materials.
After the trial, retain approved assemblies and an approval record covering the grade, material batches, equipment settings, deposit pattern, conditioning schedule and results. Agree on sample quantities and acceptance rules before the production run. Changes to print, varnish, card finish or adhesive grade should trigger a review of the affected tests.
Contact KAISUN to discuss sample evaluation with your finished substrates, equipment details and holding and removal requirements. Ask the team to assess whether a suitable hot melt PSA grade is available for your temporary attachment task.
