In composite manufacturing, the bond line can be just as important as the materials being joined. Its thickness, the loads it must withstand, and the stage at which components are assembled all influence the adhesive formulation required. These considerations become particularly relevant as manufacturers work with complex composite structures, layered carbon-fiber laminates, and assembly processes that demand precise handling.
Recent developments in composite adhesives address several of these needs, with solutions spanning structural fabrication, laminate performance, and component assembly.
Interplastic Expands Its Composite Bonding Portfolio
On September 18, 2026, Interplastic Corporation announced an expansion of its COR-Grip Pro bonding compounds and adhesives portfolio for composite manufacturing.
The expanded product family covers structural bonding, core bedding, radius and fillet formation, fairing, transom construction, and sprayable composite applications. It also includes solutions for specialized fire-retardant and corrosion-resistant requirements.
These products serve different stages of composite fabrication. Structural bonding and hull-to-deck assembly require materials suited to the demands of the joint, while core bedding and fillet formation call for compounds compatible with the component's construction. Interplastic also highlights compatibility with its resin and gel-coat technologies, allowing manufacturers to select bonding materials alongside other products in its composite systems.
Rather than introducing a single new adhesive, the announcement broadens an existing product family, giving manufacturers more bonding and fabrication options across composite production.
L&L Products Introduces a Thermoplastic Adhesive for Carbon-Fiber Laminates
Impact damage can reduce a composite laminate's residual strength, making its ability to retain mechanical performance after impact an important consideration in structural applications.
On September 23, 2026, L&L Products introduced Toughened T-Link, a thermoplastic adhesive developed for layered epoxy carbon-fiber composites. It is intended for applications requiring greater ductility, flexural performance, and energy absorption while retaining the processing advantages of thermoplastic adhesives.
In internal testing conducted by L&L Products, composite panels made with Toughened T-Link film and epoxy prepreg layers demonstrated a 66% increase in compressive strength after impact compared with panels made using epoxy prepreg layers alone. The tests followed ASTM D7137, a standard test method for measuring the compressive strength of polymer matrix composite laminates after impact.
The improvement was specific to the panel configurations tested and should not be generalized to other composite structures, where results may vary with the materials, lay-up, and test conditions. The company also reported improved short-beam shear performance under ASTM D2344, although it did not quantify that increase in its announcement.
The product's processing characteristics are another part of its intended value. It is engineered to conform to deep-drawn and irregularly shaped parts and is available in film, pellet, and micropellet formats. L&L Products also identifies dry-to-the-touch handling, room-temperature storage, and fast consolidation as product features. The company notes that thinner films and monofilaments may allow adhesive to be placed only where needed, potentially reducing material use and weight.
These features offer manufacturers additional options for incorporating thermoplastic adhesive into layered composite structures, subject to application-specific process validation.
Sicomin Introduces Epoxy Adhesives for Specific Assembly Requirements
Joint geometry and assembly sequence can influence adhesive selection. Thick bond lines require suitable gap-filling and non-sag properties, while rapid component positioning depends on how quickly an adhesive develops sufficient handling strength.
On October 15, 2026, Sicomin announced two cartridge-based epoxy adhesives, SR 740 and SR 790, extending its portfolio of products marketed as CMR-free.
SR 740 is a non-sag structural adhesive designed for large bonding areas and applications requiring substantial gap filling. It accommodates bond-line thicknesses of up to 25 mm and is intended to provide high bond strength, toughness, and fatigue resistance. Potential applications include hull-to-deck joints, structural fillets, and other primary and secondary bonding operations in marine, industrial, and construction settings.
SR 790 is formulated for rapid component positioning before secondary lamination or final structural bonding. At 20°C, its approximate gel time is 10 minutes, with a clamp time of around 20 minutes. By developing handling strength quickly, it can reduce the time components need to remain clamped during assembly. Actual cycle-time savings will depend on joint design, operating conditions, and subsequent manufacturing steps. The adhesive is intended for bonding composite materials, metals, and timber.
The CMR-free designation refers to substances classified as carcinogenic, mutagenic, or toxic to reproduction. Sicomin presents both products as additions to its CMR-free epoxy range. This designation should not be interpreted as evidence that the adhesives are free from all health or environmental hazards.
Selecting Adhesives for Composite Manufacturing
Adhesive selection depends on the demands of the finished component and the manufacturing process. A formulation suited to a thick structural joint serves a different purpose from an adhesive intended to improve post-impact laminate performance or speed up component positioning.
Substrate compatibility, joint geometry, mechanical loads, service conditions, and curing requirements all influence whether a product is suitable. For structural and safety-critical components, validation under representative operating conditions remains essential before an adhesive is adopted for production.