Loop
Lace
MaterialsAFP vs hand lay-up: repeatability, scrap, lead time
Updated 15 October 2026
Hand lay-up is flexible and cheap to start with, but repeatability and scrap depend on the operator. AFP (automated fibre placement) lays fibre with a machine along a programmed path: repeatable parts, low scrap and a process that is easier to qualify. LOOP is the evolution of AFP for small and medium complex parts that large AFP cells do not handle.
By Valerio Di Pompeo, co-founder and CEO of Spherecube
Hand lay-up: flexible, but tied to the operator
In hand lay-up an operator cuts plies of fabric or prepreg, lays them one at a time in the mould, orients them and compacts them by hand. The part then goes into an autoclave, an oven under vacuum bag or a press. The process is flexible, needs a low initial investment and suits almost any shape.
The price of this flexibility is variability. Fibre angles, overlaps and compaction depend on the experience of the person laying up; ply offcuts end up as scrap; every layer takes labour time. Across a batch, two nominally identical parts can differ.
AFP: a machine lays the fibre
In automated fibre placement a robotic head lays pre-impregnated tows along a programmed path, compacts them with a roller and cuts them where needed. The angles are those of the program, fibre goes only where it is planned and offcuts almost disappear. Traditional AFP cells, however, are designed for large surfaces, with a very high investment and a minimum steering radius that limits tight curves.
Side-by-side comparison
| Hand lay-up | Traditional AFP | LOOP | |
|---|---|---|---|
| Repeatability | Low, operator-dependent | High | High, ±0.2 mm positioning |
| Scrap | High, ply offcuts | Low | Low, fibre only where needed |
| Lead time | Labour for every ply | Fast on large surfaces | Automated deposition on small and medium parts |
| Qualification | Tied to the operator and inspection | On the programmed process | On the process and the LACE program |
| Fibre angles | Operator-dependent | With minimum steering radius | 0°, 90°, ±θ, steered |
| Parts | Any | Large (wings, fuselages) | Small–medium, complex |
| Cell investment | Low | Very high | Modest |
LOOP: the evolution of AFP for small and medium parts
LOOP keeps the principle of AFP, continuous fibre laid by a machine along a programmed path, but brings it down to the scale of a single part. It works on up to 6 axes on a tilting table or a rotary mandrel, steers the tow at constant width through fibre steering and interrupts it only where needed. The paths are created in LACE, which generates the program for LOOP, so the same file produces the same part every time.
The environmental impact changes too. According to Andreozzi et al., The International Journal of Advanced Manufacturing Technology (2025), the Spherecube process has −30.5% CO₂ emissions vs prepreg lay-up with autoclave curing.
When to choose which
Choose hand lay-up for one-off parts, very irregular prototypes or small volumes where investment must stay minimal and part-to-part variability is acceptable.
Choose traditional AFP for large aerostructures, panels and wide surfaces with gentle curvature, where the investment is justified by size and volume.
Choose LOOP when the part is small or medium, structural and complex, with tight curves, closed shapes or inserts, and you need the repeatability of an automated process without the cost of a large AFP cell.
Frequently asked questions
Does AFP completely replace hand lay-up?
No. Hand lay-up remains the right choice for one-off parts, very irregular shapes and small volumes with minimal investment. AFP pays off when repeatability, low scrap and a process documented part after part are required.
Why isn't traditional AFP used on small parts?
Traditional AFP cells are built for large aerostructures such as wings and fuselages: the investment is very high and the minimum steering radius limits tight curves. On small and medium complex parts they are not cost-effective. LOOP brings automated deposition to this scale.
Is an automated process easier to qualify?
Generally yes, because you qualify the process rather than the hand of an individual operator: the same program produces the same fibre path on every part. Qualification still remains specific to the part, material and industry.
Have a part and not sure which process fits? A feasibility study takes 10 working days.
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