Laser-Assisted Thermoplastic AFP In Situ Consolidation at Industrial Speed

Thermoplastic automated fiber placement (AFP) has existed as a validated manufacturing technology for more than two decades. The process can produce some very high-performance structural composite parts with fiber volume fractions above 55%, interlaminar shear strengths exceeding 60 megapascals and the weldability and recyclability that thermoset laminates cannot offer, all without an autoclave. 

Yet its industrial footprint remains narrow. Entry-level research AFP systems have routinely exceeded $1 million and unidirectional (UD) thermoplastic tapes historically cost thousands of dollars per kilogram, while the process knowledge required to operate these systems has, for the most part, sat inside a small number of aerospace primes and well-funded European research programs. 

This has all resulted in a technology that the composites industry understands well in principle but rarely uses in practice. In a bid to change that ratio, composites researcher Dr. Fedor Antonov is building accessible laser-assisted thermoplastic AFP systems through his latest company, Layway (Suzhou, China). 

Antonov holds a Ph.D. in the mechanics of deformable solids from Moscow State University and spent several years at the Skolkovo Institute of Science and Technology (Skoltech) researching continuous fiber composite design optimization. In 2014, he founded Anisoprint (Esch-sur-Alzette, Luxembourg), a company built around continuous fiber co-extrusion 3D printing using a thermoset-thermoplastic bi-matrix composite filament. Layway, his second company, applies laser-assisted thermoplastic automated fiber placement (LATP-AFP) to structural composites manufacturing. 

Layway currently has two main products. LabAFP is a single-tow, 2-kilowatt (kW) LATP-AFP system built on a KUKA (Augsburg, Germany) KR16 robot with a 600 × 600-millimeter working envelope which targets research, process development and education. The AFP1 is a turnkey LATP-AFP system designed for direct part production. Compatible with welding, overmolding and overprinting workflows, it is designed for industrial production. 

I spoke with Antonov about how his experience has shaped the direction and challenge he looks to solve with Layway, the engineering rationale behind both of the company’s systems, the physics governing in situ consolidation and what thermoplastic AFP still has to resolve.

CW: Your background is in computational mechanics and composite design optimization. Most AFP system developers come from machine-building or aerospace backgrounds. How has your starting point changed what Layway prioritizes?

Fedor Antonov (FA): I tend to start from the application rather than the machine to understand where continuous fiber thermoplastic composites [TPC] create value, how structures should be designed for these materials and how the manufacturing process must adapt to specific applications, including the economics. 

One major lesson I learned from years in additive manufacturing is that the machine is not the product. The value created for a particular customer application is the product. That perspective helps identify opportunities that a purely technology-driven approach overlooks. My role is to connect materials, mechanics, applications and system design into a coherent industrial solution. So, that’s what I do. 

CW: TPC have been described as “a few years from mainstream adoption” for a while. What has finally shifted that timeline, and what was still missing when you started Layway?

FA: The technology was not the limiting factor. TPC were technically ready years ago. The real constraints were scale and economics. Before founding Anisoprint, I worked on thermoplastic AFP research at Skoltech with Professor Zafer Gürdal. At that time, UD tape materials could cost hundreds of dollars per kilogram, and entry-level AFP research systems could exceed $1 million. Broader industrial adoption was unrealistic under those conditions. 

What has changed is convergence. Material availability improved dramatically as the number of tape suppliers grew and prices dropped significantly compared to even the early 2010s. Robotics, laser hardware and industrial automation became more accessible. But machine accessibility remains one of the largest missing pieces. Many AFP systems are still too expensive and too complex for broad industrial use. That was the central motivation behind Layway.

CW: At Anisoprint you developed a thermoset-thermoplastic co-extrusion system for continuous fiber deposition. What did that work reveal about the structural limits of extrusion-based processing, and how did those limits inform Layway's AFP approach?

FA: The most important lesson was the fundamental tradeoff between geometric freedom and structural performance. Extrusion-based composite printing can produce highly complex geometries with relatively simple hardware, which is valuable for prototyping, tooling and customized low-volume parts. For large-scale structural applications, it has fundamental limitations. 

Throughput is one. High-performance composite structures require large material volumes, and extrusion is slow because material must be heated conductively, melted, transported through a nozzle and deposited layer by layer. Laser-assisted tape placement operates at much higher energy throughput. Lasers provide fast, localized heating with precise temporal control, making multi-kilogram-per-hour deposition rates realistic and cycle times below 10 minutes achievable for many structural parts. 

The second limitation is consolidation. In extrusion-based printing, material is deposited without compaction pressure, which limits fiber volume fraction and mechanical properties. AFP changes this through pressure-assisted consolidation at the nip point. The compaction roller applies pressure while heat is applied and is then immediately removed. That combination solves the central contradiction in TPC deposition, which is that the interface must be hot enough to bond during placement, but solidify immediately afterward to maintain dimensional stability.

Laser heating and thermal control

CW: The LabAFP uses a 2-kW near-infrared laser at a wavelength of 1,080 nanometers with a 15 × 40-millimeter (mm) spot elongated in the direction of tape travel. What drove that specific geometry?

FA: The spot geometry was designed around the thermal requirements of nominal 0.5-inch-wide thermoplastic UD tape. After compaction, this tape typically reaches 14- to 14.5-millimeters (mm) in width. The 15-mm spot width closely matches the final consolidated tape geometry and provides tolerance for alignment variation across different material systems. 

The 40-mm length is related to thermal exposure time. In a standard configuration, the spot is roughly split across the nip point with approximately 20 mm heating the incoming tape and 20 mm heating the substrate. This ratio is adjustable because the AFP1 head allows the laser angle to change. As laminate thickness increases, substrate heating becomes more important because more thermal mass must reach bonding temperature. With polyetheretherketone [PEEK], this configuration consistently reaches processing temperatures up to approximately 450°C at layup speeds around 300 millimeters/second (mm/s). The rest of the laser specifications are to achieve the desired processing temperature characteristics.

CW: Carbon fiber composites absorb near-infrared radiation mainly through the fibers, not the matrix. Heat then conducts into the polymer before melt temperature is reached. What practical constraint does this mechanism place on the process at 300 mm/s?

FA: At 1,080 nanometers, thermoplastic matrices are relatively transparent while carbon fibers absorb the overwhelming majority of laser energy. The fibers act as localized heat generators at the bonding interface, with thermal energy concentrated at roughly the depth of the first exposed fiber layer, typically on the order of 10-15 microns, and conducting into the surrounding polymer from there. 

In AFP, only the interfacial polymer layers need to reach melting temperature to achieve bonding. Because UD tape is thin, often around 0.14 mm thick, temperature distribution through the tape becomes fairly uniform even at speeds up to 300 mm/s. The transient regimes of acceleration, deceleration, cuts and restarts are the most demanding part of the process. The absorbed power density is very high, and even a brief slowdown can create local overheating if laser power is not dynamically synchronized with robot motion. At around 200 mm/s, a typical process may require roughly 800 watts (W) for carbon fiber-reinforced polyamide (e.g., nylon) (CF/PA) and around 1,200 W for CF/PEEK, depending on optics configuration, fiber volume fraction and tape thermal properties.

CW: What is the compaction roller doing thermally at the nip point, and how is the cooling system designed around that function?

FA: The true nip-point temperature is difficult to measure directly because the roller blocks optical access. What the system measures is the temperature in the observable region immediately before the nip point. The actual interface temperature inside the contact zone is lower because heat loss begins once material leaves the laser exposure area. 

The dominant function of the roller is compaction and pressure-assisted consolidation, not heat extraction. The cooling effect is relatively moderate because it occurs mainly through conductive heat transfer at the top surface of the tape rather than at the heated bonding interface. The roller geometry and cooling system are designed around process stability, pressure uniformity and roller durability. Internal cooling is primarily necessary to prevent overheating and degradation of the roller material itself, especially when using compliant rollers operating continuously at high process temperatures.

Consolidation mechanics

CW: Published studies on LATP-AFP of carbon fiber-reinforced polyphenylene sulfide (CF/PPS) show in situ consolidated laminates achieving around 21-22% crystallinity versus 35%+ for hot-press consolidation, with interlaminar shear strength penalties of up to ~35%. How should that gap be interpreted, and what does Layway prioritize as a result?

FA: Crystallinity is scientifically interesting and relatively easy to study, which is why there is a large body of research on it. From an industrial processing perspective, porosity, interfacial bonding quality and consolidation consistency have a much stronger influence on mechanical properties. Porosity levels above 5% can reduce interlaminar shear strength several times over. Differences in crystallinity within typical AFP processing ranges often produce much smaller changes on the order of 10-20% in interlaminar shear strength. 

Our process priorities follow that hierarchy: achieve proper interfacial melting and bonding, minimize voids and porosity, maintain stable consolidation and then optimize crystallinity within the remaining process window. There is also a strategic manufacturing question. If secondary consolidation using methods such as hot pressing or vacuum bag-only [VBO] in an oven follows AFP, crystallinity can be adjusted in that cycle, and AFP functions as a high-rate preforming process. In that route, the crystallization problem becomes much more manageable.

CW: What void content does your system achieve in practice at the stated layup speeds around 300 mm/s, and at what level does post-consolidation become necessary?

FA: At 300 mm/s, the effective consolidation dwell time under the roller is on the order of tens to roughly 100 milliseconds. Our best experimental results for true in situ consolidation at that speed reached approximately 2.5% porosity under carefully optimized conditions using high-quality source material. 

Industrial in situ consolidated AFP more commonly operates in the range of 3-5% porosity. There is no universal threshold above which post-consolidation automatically becomes mandatory. The more relevant questions are how consistent the porosity distribution is, how much mechanical-property scatter it creates, and whether the designer can confidently characterize and apply the resulting properties. 

In regulated aerospace applications, certification frameworks may effectively require void contents below 1% regardless of structural performance. If the process cannot consistently meet that specification in situ, secondary consolidation becomes necessary by requirement rather than by engineering judgment.

CW: The LabAFP uses an open-architecture, closed-loop temperature control system. What are the most consequential nonlinear interactions in the system, and what misunderstandings appear most often?

FA: The most important interacting variables are laser power, deposition speed, temperature at the bonding region and compaction behavior. Temperature is a dependent variable as it is mainly the result of the interaction between laser power and layup speed, together with geometry-dependent effects. 

Most people initially assume the process is linear, where higher power and/or lower speed gives higher temperature. The process becomes nonlinear once motion and geometry are introduced. Robot acceleration and deceleration change thermal exposure time. Changes in curvature alter laser incidence angle and spot geometry. Changes in focal distance modify power density. Even if commanded laser power and speed remain nominally constant, actual thermal and consolidation conditions change significantly during real deposition. 

The most common misunderstanding is treating measured surface temperature as equivalent to interface temperature. The actual bonding conditions at the nip point depend on heat transfer, pressure, material rheology and timing simultaneously. Practical AFP process development remains empirical even where the underlying physics are well understood.

Accessibility and the aerospace trap

CW: You describe the relationship between aerospace and AFP development as an "aerospace trap." What does that mean for the broader composites industry?

FA: Aerospace has been the primary driver of AFP and TPC because it funded much of the early development and validated the technology. But aerospace is a very unusual market. Customers are technically sophisticated and willing to pay large premiums for performance. That environment allowed AFP to mature technically, but it also insulated the technology from broader industrial realities. 

Industrial scale does not come from market size in dollars, it comes from market size in tons. Aerospace remains small in production volume, highly regulated and slow-moving. Thus, AFP systems evolved into expensive, specialized platforms optimized for a small number of advanced users. When access to LATP-AFP is limited to large corporations and well-funded research centers, the ecosystem learns more slowly. Material suppliers receive less application feedback. Process knowledge accumulates in isolated pockets instead of spreading across the industry. New applications emerge slowly because the number of people capable of testing ideas remains small.

Layway’s systems are designed to operate at a fraction of the cost of conventional industrial AFP platforms, with modular architectures and accessible process control that place thermoplastic AFP within reach of startups, university programs and manufacturers outside the traditional aerospace supply chain. It achieves this by building its systems around mature industrial robotics platforms and Asian manufacturing supply chains, reducing hardware costs without compromising process capability, and by offering open-architecture software that exposes process parameters directly to the user rather than locking them behind proprietary control systems.

CW: Where does single-tow AFP remain competitive for production applications, and what production volumes are achievable at Layway’s current throughput?

FA: Single-tow systems are particularly valuable when parts contain relatively small features, require local reinforcement, need steering flexibility or when overall part size is small. A large multi-tow head can become inefficient or geometrically limited because minimum steering radius, tow-drop logic and local feature resolution become restrictive. 

There are many industrial use cases where total material volume per part is small even if production volume is high: motor rotor sleeves, composite sliding bearings, shafts, tubes, pipes, pressure sleeves and near-net shape thermoplastic preforms for drones, robots and lightweight mobility structures. Using 0.5-inch-wide tape, with a 300 mm/s laydown rate, a cylinder 250 mm long, 50 mm in diameter and with a 2-mm wall thickness can be made in less than 5 minutes.

One single-tow AFP machine that achieves near-net shape preforms in 5 minutes can produce ~100,000 parts/year. That is a better fit than large aerospace AFP systems, not a scaled-down version.

If a near-net shape preforming process achieves a 5-minute cycle time, a single machine can theoretically produce on the order of 100,000 parts per year depending on uptime assumptions. Single-tow AFP is a better fit for a different class of applications than the traditional large aerospace market. It is not a scaled-down version of those systems.

CW: What is the largest unsolved physics problem in LATP-AFP, and what is Layway doing to address it?

FA: The goal is true in situ consolidation. As a practical benchmark, producing laminates below 1% porosity directly during placement represents an ultimate target for high-performance applications. The challenge is that consolidation is not one physical phenomenon. 

Porosity is the outcome we measure, but the mechanisms behind it are coupled: heat transfer, melt viscosity, intimate contact formation, polymer-chain diffusion, compaction pressure, air evacuation, tape quality, crystallization behavior, cooling rate and motion dynamics. Good in situ consolidation is demonstrable in controlled laboratory conditions, especially at lower speeds or in winding processes. 

Achieving the same quality consistently at industrial AFP speeds, on real geometries, with robust process windows, is still difficult. The answer is most likely a combination of incremental improvements: better thermal control, better pressure control, better trajectory planning, better tape quality and better understanding of the actual consolidation time window. 

One direction is increasing effective consolidation time without sacrificing deposition speed through using multiple rollers, post-deposition reheating, multi-pass roller consolidation or localized secondary consolidation immediately after placement. We are working on that together with simulation partner OTOMComposite (Enschede, Netherlands), with the goal that physics-based process planning will eventually allow the trajectory planning software to predict thermal fields before deposition and generate numerical control code that already includes local process adjustments based on geometry, curvature, material and expected heat transfer. The central challenge is giving the material enough thermal and mechanical time to consolidate properly while keeping the process fast enough to remain industrially meaningful. That is the problem Layway is built around solving.