Solvent-Free Laminating Adhesives
Laminators converting flexible packaging structures use a solvent free adhesive for flexible packaging when they need bond strength without the drying ovens and solvent handling of solvent-borne systems. chemlinkai supplies solvent-free adhesives matched to your film combination, coating station and curing schedule, with bond and cure behavior verified on your structure before supply.
How the system works
Solvent-free lamination replaces solvent-borne adhesive with a 100 % solids reactive system applied warm at low coat weight, then cured over time. The physics are different: there is no solvent to flash off, so bond builds by chemical reaction and by wetting of the two film surfaces at the nip.
The system has to be right in three places: at the applicator, where the adhesive must spread evenly at low coat weight; at the nip, where it must wet both webs before reaction advances; and in the curing store, where time and temperature must match your schedule. We specify the working temperature, coat weight window and cure profile for your machine, then verify bond development on your film combination over time.
- Coat weight and nip conditions matched to your laminator type
- Cure profile aligned with your storage schedule and temperature
- Bond aging checked on your actual film and foil combination
- Adhesive, ink and varnish interfaces coordinated within one system
Why do laminates fail bond tests after curing — and how is the cause found?
Solvent-free lamination failures usually appear after curing, not at the nip, and they follow three patterns. First, low initial bond that never builds: the mix ratio or nip temperature was off, so the reaction did not advance. Second, a strong initial bond that drops after aging: one film surface is contaminated or over-treated, and the adhesive-to-surface bond degrades over time. Third, tunneling or channeling: coat weight is too high, or the adhesive was applied onto a film with poor flatness.
Because a solvent free adhesive for flexible packaging has no solvent to forgive process error, the diagnosis starts at the machine log, not the adhesive drum. We correlate your mix ratio, pan temperature, nip load and curing record with the bond curve, isolate the variable, and correct the process window or the formulation — whichever the data points to.
Representative system parameters
Guidance ranges for solvent-free laminating adhesives before a trial. Final values are set against your laminator and structure.
| Parameter | Representative range | Remark |
|---|---|---|
| Solids content | 100 % | No solvent to flash off in the drying tunnel |
| Application temperature | 30 – 50 °C (grade-dependent) | Set by viscosity and nip wetting needs |
| Coat weight | 1.0 – 2.5 g/m² | Structure- and film-dependent |
| Mix ratio | Per grade — set at supply | Dispensed by your metering unit |
| Curing time to convert | Method-specific — set by trial | Depends on structure, temperature and humidity |
| Pot life | Method-specific — set by trial | Window for your applicator system |
| Bond after aging | Method-specific — set by trial | Tested on your films at agreed intervals |
Representative ranges for system selection — typical values — batch TDS on request.
Where the adhesive sits in the structure
The adhesive layer joins the printed outer film to the sealant web; bond strength and cure behavior are properties of this three-layer stack, including both film surfaces.
Verified data on bond development, cure behavior and aged peel strength is published after customer and company approval. Request current test results via the form.
Solvent-free lamination — common questions
Direct answers for laminators, converters and purchasers.
Can we run your adhesive on our existing solvent-free laminator?
Almost any modern solvent-free line can run it, but we qualify the applicator type, metering unit and heating capacity first. The trial confirms the working window on your machine before volume supply.
What happens to bond strength at high humidity or in winter temperatures?
Cure kinetics respond to temperature and, for some grades, humidity. We set the cure profile with your seasonal conditions in mind and test aging under the conditions your plant actually sees.
Do you supply adhesives for food-contact structures?
Application scope — including food-contact claims — is confirmed in writing for your structure and destination market before supply. Compliance documentation is released after verification.
What is the drum life and storage requirement?
Storage life is stated per grade with the temperature range. Drums must be kept sealed and used within the stated window; we provide handling instructions with every delivery.
Why does our laminate tunnel even at correct coat weight?
Tunneling is usually a film flatness or nip-tension issue rather than an adhesive fault. We check web tension, nip load and film roll quality with you before changing chemistry.
Documentation
Documents are released per application and destination after final verification.
Documents marked “pending” are released after final verification — request the current version through the form and we will send it with the applicable scope.
Set up a lamination trial on your films.
Send your film combination, laminator details and the bond criteria from your customer specification. We match the adhesive and cure profile, then verify bond development on your structure.