In industrial manufacturing, forming a film by applying adhesive uniformly is a common process for achieving efficient and precise bonding. This technique is particularly suitable for applications such as large-area compositing and the bonding of multi-layer materials. So, which types of adhesives are appropriate for such applications?
I. Hot Melt Adhesive
Hot-melt adhesive is one of the most widely used types of adhesive films. At room temperature, it exists in a solid state; when heated to a specific temperature, it melts into a liquid, which is then applied to a substrate to form an adhesive film. Upon cooling, the film rapidly cures, developing initial tack.
Features: 100% solid content, solvent-free, environmentally friendly, and features rapid curing speed—making it ideal for automated production lines.
Common types include EVA (ethylene-vinyl acetate copolymer), PUR (moisture-curing polyurethane), PA (polyamide), etc.
Applications: Widely used in book binding, packaging, sanitary products (e.g., diapers), automotive interiors, and other related fields.
II. Solvent-based Adhesives
This type of adhesive is prepared by dissolving a polymer in an organic solvent. After application, the solvent is evaporated by passing the material through a heating oven, leaving behind a uniform solid adhesive film.
Features: strong initial tack, excellent wetting performance on a wide range of materials, and a broad adjustable range of adhesive film properties.
Note: During production and use, volatile organic compounds (VOCs) must be handled, and strict environmental and safety requirements must be met.
Applications: Widely used in the production of flexible packaging laminates (e.g., food packaging bags), labels, and adhesive tapes.
III. Water-based Adhesive
Similar to solvent-based adhesives, water-based adhesives involve dispersing polymers in the form of fine particles within water. After application, heating causes the water to evaporate, allowing the polymer particles to coalesce and form a continuous adhesive film.
Features: Uses water as the dispersion medium, making it safe and environmentally friendly.
Note: The drying rate is typically slower than that of solvent-based adhesives, and the energy consumption is relatively higher.
Applications: Widely used in fields with stringent environmental requirements, such as woodworking, paper processing, and textile compositing.
IV. UV-curing Adhesive
This is a specialized adhesive that, once applied as a film, can transition from a liquid to a solid state within seconds when exposed to ultraviolet (UV) light of a specific wavelength.
Key features: extremely fast curing speed, low energy consumption, and precise control capability.
Note: Dedicated UV curing equipment is required, and at least one of the surfaces to be bonded must be capable of transmitting ultraviolet light.
Applications: Primarily used in electronic product assembly, optical lens bonding, and glass product processing, among other applications.
product recommendation
Product Name: JOMP1518K Hot-Melt Adhesive
Product Introduction: A solvent-based modified hot-melt adhesive synthesized from specialized resins, which can be applied to substrates such as PET, PVC, PU, TPU, and PEI to form a uniform adhesive film. The adhesive film exhibits initial tack at room temperature, and upon activation under high temperature and pressure, it achieves strong adhesion.
Product characteristics: The coating forms a uniform and stable film with strong adhesion; once fully crystallized, it exhibits excellent thermal performance, capable of withstanding high-temperature soldering at 300 °C for 45 seconds.
Application Areas: Coating, hot-press bonding of various materials—including PET, PVC, PU, and TPU—making this solution ideal for electronic composite film applications requiring high-temperature resistance.
Forming a Film: Match the Coating and Joining Sequence
Choosing adhesives suitable for forming a film starts with the surface that the wet coating must cover. A smooth plastic film, a porous fabric and a metal foil do not present the same coating conditions. Identify the substrate finish, any release treatment and the possibility of contamination before judging the adhesive by appearance in a container. A liquid that spreads easily may still retreat from a contaminated area as it dries. Conversely, a coating that appears thick during application may level before the film becomes stable. The useful question is whether the selected material can produce continuous coverage using the intended coating equipment. Roller application, spraying and screen printing impose different demands on flow and recovery after application. Review those demands with the material supplier rather than assuming that a workable hand-coated sample proves production suitability. Film formation also needs a clear place in the assembly sequence. For a carrier-based coating, the carrier must leave through an available drying path; closing the laminate too early can trap it between surfaces. For a thermoplastic coating, the film must be formed and later activated without damaging the substrate. A light-curing coating needs access for the required light throughout the area intended to cure. What use is a uniform-looking film if the buried interface never develops a dependable bond? Treat coating continuity, drying or curing, and final joining as separate checks. It’s easier to identify the cause of a defect when these stages are observed individually. Inspect for pinholes, edge retreat, ridges and trapped bubbles before lamination hides them. Also consider how the film will be stored or handled between coating and bonding: dust, unintended blocking and changes in surface tack can interfere with joining. The JOME industrial adhesive product catalogue is a starting point for discussing the required material family; the coating method, substrate pair and joining sequence should accompany that discussion. Keep a record of the coating face and handling route so that a promising trial can be reproduced on the same surfaces.
Qualify the finished film through the actual laminate
For qualification, adhesives suitable for forming a film need evaluation after the intended joining process. An isolated dried film can reveal flexibility or obvious surface defects, but it cannot establish adhesion to both faces of a laminate. Prepare representative specimens with the same surface treatments, coating method and assembly order planned for production. Examine the edges as well as the center. An edge that receives less coating, remains exposed during drying or experiences greater bending can behave differently from the interior. Check whether the film transfers consistently and whether local wrinkles prevent intimate contact. In heat-activated bonding, pressure helps establish contact, while the thermal history influences flow and solidification. Neither step should be adjusted without considering the temperature sensitivity and dimensional stability of the substrates. A flexible film can still damage a thin laminate if the joining process causes the supporting layers to distort. After bonding, inspect the failure surfaces from a suitable peel or separation test. Adhesive left mainly on one face points toward an interface that deserves investigation; adhesive divided between both faces suggests a different failure path. Record tearing of the substrate separately so that material damage is not mistaken for an adhesive problem. Compare freshly assembled specimens with specimens conditioned for the actual service environment. Moisture, cleaning agents, repeated folding and temperature changes may affect either the adhesive or the surrounding layers. Select the exposures that represent the application instead of subjecting every film to an unrelated test sequence. If the finished laminate must remain optically clear, include haze, bubbles and changes in appearance in the evaluation. If it must remain flexible, inspect the bond after bending, including the transitions near rigid parts. Recheck film continuity when the coating process is transferred to production equipment; a change in web tension or drying path can create defects absent from a laboratory drawdown. Send the substrate identification, observed failure location and process notes through JOME adhesive application enquiries when requesting material guidance. These details make the selection question more useful than simply asking which adhesive can make a film.
Selection of the right grade from the full JOME product catalogue usually starts with drawings and service conditions. The companion piece on Can powdered fillers be added to adhesives sits alongside this guide, the the JOME adhesive manufacturer profile lists every family, and the contact JOME for project review handles enquiries.