Today we are giving the floor to Franck Knockaert, Industry and Quality Manager worldwide at Ciel & Terre, one of the key figures behind Ciel & Terre’s global industrial operations. Before diving into the Ciel & Terre’s manufacturing process and technical expertise, let’s first get to know Franck a bit better.
At the heart of the floating solar manufacturing expertise of Ciel & Terre
Franck is a French industrial engineer who has been living in Japan for over 10 years. With a degree in production and logistics, he brings eight years of experience in the automotive industry. As a result, he has developed a solid background in process optimization and quality assurance. He joined Ciel & Terre 4.5 years ago and, since January 2023, he has taken on the role of Head of Industry for Ciel & Terre as a global industrial manager. His job entails a versatile role. In addition, he supports industrial and quality teams across the group by helping them implement efficient, cost-effective processes. He also ensures that high standards of quality are consistently met throughout the production chain. Moreover, he directly supports the R&D team with industrial-related topics and new product development. His responsibilities also include creating quality control documentation and KPI analysis tools for both existing and newly developed products.
Ciel & Terre, a precise manufacturing process to guaranty FPV quality
The link between manufacturing and research and development processes
Generally, industrial manufacturing should be involved in the R&D process as early as possible. While the R&D team focuses on generating innovative ideas, the industrial team contributes essential knowledge on manufacturing feasibility and cost control. Consequently, designs can be validated faster. Therefore, industrial investment is optimized from the beginning. In short, the collaboration between R&D and industrial operations fosters efficiency and innovation.
What are the different steps in the manufacturing of the floats?
In simple terms, manufacturers use a combination of HDPE (High-density polyethylene) and MB (Masterbatch) to create floats through a blow molding process. To put it simply, the process operrates like a recipe, following several well-defined steps in sequence:
1- Mixing the materials: First of all, operators load a mixer with the right proportions of high-density-polyethylene (HDPE), masterbatch (MB) and regring (recycled plastic).
2- Feeding the machine: Next, the blended material moves into a hopper. This step allows for direct feeding into an extrusion screw.
3- Melting the plastic: As the process continues, the screw gradually heats the mixture across three zones: feed, transition and melting. The temperature reaches about 200°C, thus turning the plastic into a molten state.
4- Accumulating the molten plastic: Once fully melted, the plastic moves into the accumulation head of the blow molding machine.
- This accumulator acts as a storage chamber, holding the molten plastic under pressure before extraction.
- Depending on the machine, its size varies, with the largest models storing up to 50 litres—enough for about two floats or nearly twice the volume required for one.
5- Forming the parison: After that, the molten plastic is extracted through a die, forming a vertical tube called a parison, which hangs between the open mold halves. Importantly, its diameter varies depending on the machine and product size.
6- Mold closing and blowing:
Once the bottom of the parison reaches the blow pin (a device that injects cold air), the two halves of the mold close and pinch the parison, much like a waffle iron closing around churros.
7- Cooling the mold: Then, old air blows inside the parison to inflate it, causing it to conform to the mold shape. Meanwhile, cold water circulates through the mold to cool and solidify the plastic. Moreover, the cooling time is carefully controlled to ensure the float maintains its proper shape and durability.
8- Releasing the produc: After cooling, the mold opens and ejects the float, which still carries flashes—excess plastic around its edges. Meanwhile, the machine prepares for the next cycle to maintain continuous production.
9- Trimming the float: Finally, the operator trims any excess plastic (flashes) from around the edges and cuts the necessary holes to meet final specifications.
What are the main challenges involved in taking a float from prototyping to final production?
Nevertheless, taking a float from prototyping to final production presents seven major challenges:
- Designing the product specifically for the blow molding process. This includes controlling wall thickness, avoiding sharp angles, and placing parting lines correctly.
- Selecting the right materials to guarantee consistency, buoyancy, strength, and environmental resistance. (All materials are tested and validated by our R&D team.)
- Managing tooling, such as mold design and leak testers, is critical. Blow molding molds are costly and time-consuming to produce, especially when considering target cycle times and cooling efficiency.
- Considering the gap between prototype and mass production, while a prototype may perform well in testing, it can fail under full-scale manufacturing stress.
- Ensuring strict quality control by verifying that each float meets specifications, is waterproof, and passes durability testing.
- Optimizing manufacturing processes to reduce material waste and limit regrind usage without compromising product integrity.
- Finally, securing a reliable supply chain for raw materials is essential. The selected supplier must scale up efficiently, delivering consistent volume, lead time, and supporting post-processing steps such as trimming, leak testing, and assembly
How does Ciel & Terre select its row materials? and what is key for the company to ensure row material quality?
When it comes to raw materials, the procurement team handles sourcing. Once materials like HDPE and MB are approved by the R&D team, we ensure quality by requiring suppliers to provide certifications such as COA, TDS, and mill sheets indicating chemical composition and mechanical properties for each new batch.
What is product commissioning?
Commissioning involves the necessary controls to validate new tools (e.g., molds) or new materials (e.g., masterbatch, HDPE), ensuring we can produce within part drawing tolerances.
For instance, key checks include:
- Firstly, shrinkage analysis to anticipate dimensional behavior and assess the need for cooling jigs.
- Then, full dimensional analysis using control charts and CP/CPK analysis.
- Additionally, thickness analysis to identify critical points for mass production control.
- Moreover, ear filling quality checks guarantee mechanical strength.
- Finally, visual inspections cover the bung area, parting lines, logos, and markings.
Ensuring Quality Throughout the Production Process
How does Ciel & Terre ensure the quality of floaters during production process?
Quality is ensured thanks to the following documents:
- MSR sheet (Management Shift Record): records weight, rejects, defects, yield and NG rate.
- AFC sheet, records dimensional quality control.
- TFC, records thickness quality control.
Each document has corresponding analysis tools to detect deviations early and enable timely process adjustments.
What tests are performed in the factory to ensure the reliability of the products?
Before production, all operators are trained to properly handle and inspect products. We use work instructions, method statements and defect checklist (defaultech) to guide them. During production, we perform:
- Visual checks (shape, date, logo, etc.)
- Leak tests
- Poka-yoke systems to ensure the float is watertight and the cap is correctly installed.
What types of defects are you most vigilant about, and how do you detect them early?
We are vigilant about many types of defects such as holes, deformation, incomplete blowing (miss blow), burn marks, and contamination. At Ciel & Terre, we pay particular attention to less visible issues like leaks, underweight floats, scratches, excessive flashes, bung circularity, ear bubbles or channels, and correct marking (date/logo).
Each float undergoes a leak test, and operators inspect surface quality before weighing. After long production stops (e.g., over one hour, weekends, holidays, or new batch launches), we require 5 OK floats in a row, including ear cutting checks, to validate the restart. All things considered, these quality checks are non-negotiable.
How do you manage and document traceability of the materials throughout production?
Each quality document related to raw materials and finished products is carefully checked upon reception from the supplier. The frequency of these document submissions is predefined with the supplier and stored in a dedicated SharePoint folder.The same applies to quality analysis reports, ensuring traceability across all stages of production.
Continuous improvement and efficiency in production
Each quality document related to raw materials and finished products is carefully checked upon reception from the supplier. The frequency of these document submissions is predefined with the supplier and stored in a dedicated SharePoint folder.The same applies to quality analysis reports, ensuring traceability across all stages of production.
How do you optimise the production?
Several actions help us improve efficiency:
- Implementing 5S to optimize the workspace
- Reduce cycle time and using cooling jigs to increase output
- Lowering cooling water temperature and increasing cooling pipe diameter to stabilize product dimensions faster.
- Placing the mold as close as possible to the die head to minimize unnecessary parison and reduce regrind/waste.
- Adjusting parison thickness according to TCF/ACF files to stay within target dimensions and reduce wall thickness variability.
- Introducing automation where viable (e.g., trimming, leak testing).
- And more, depending on machine setup and production goals.
What is the role of automation and robotics in your current and future production lines?
Currently, most partners are equipped with basic automation like volumetric or gravimetric blenders/feeders, conveyors for flash regrind, and upper pinchers to extract the float from the mold.
- Some high-volume production sites have invested in:
- Automatic flash cutting
- Automatic leak testing
- Automated cooling jigs
These solutions help increase productivity and consistency.
What recent process have been set to improve the efficiency of the production?
In our Indian factory, we successfully implemented the 5S method, including zoning, visual standards, labelling, and regular cleaning audits to maintain an organized and efficient workspace.
We also discussed OMMF design optimizations with the local Industrial Manager to reduce raw material use and improve cycle time performance.
What is the manufacturing timeline for a floating solar system?
It depends on multiple factors. A 1 MW project using a single float type may take less than a week or up to 2–3 weeks to manufacture.
Key influencing factors include:
- Blow molding machine throughput
- Accumulator head capacity
- Cooling pipe and blow pin efficiency
- Water and air temperature
- Use of external cooling jigs
- Availability of multiple molds or suppliers for simultaneous production
For a full-scale project with various float types and on-site installation, timelines should be reviewed with a Project Manager, typically using a Gantt chart.
What logistical challenges are encountered when transporting and installing floating solar equipment?
The main challenges include:
- Transport regulations, such as float quantity per pallet, vary by country.
- Truck size limitations
- Safe and efficient packing procedures
- On-site storage space, especially in compact areas like small ponds (e.g., in Japan)
As for installation, we recommend contacting the Operations & Maintenance (O&M) team, as they manage on-site assembly under EPC contracts.
OUR GLOBAL AND CERTIFIED MANUFACTURING APPROACH
Where are Ciel & Terre’s floating solar solutions produced?
Our floats are currently produced in six countries: France, Japan, Taiwan, the United States, India, and Brazil.
We collaborate with one or more blow molding partners in each location, and we operate our own factory in India.
How does Ciel & Terre select its manufacturing partners?
Through a two-step audit process:
- A self-audit completed by the supplier.
- A site audit carried out by Ciel & Terre team members.
The audit covers:
- Quality management
- Raw material traceability
- Continuous improvement
- Production performance
- Mold and tooling capability
- Maintenance systems
And requires documentation as evidence.
Based on the results, we assess if the supplier is eligible, and whether they may require technical support before collaboration.
How does the company anticipate and adapt to regulatory or certification changes in its manufacturing processes?
To date, we have not faced any major changes of this kind. Most of the processes we use, especially for blow molding are standard and well-established across industries, so regulatory shifts have not yet impacted our manufacturing methods significantly.
From raw material to final float, Ciel & Terre’s manufacturing process is built on precision, quality, and continuous improvement. Thanks to the expertise of teams like Franck Knockaert’s, the company ensures reliable and durable floating solar solutions — ready to meet today’s energy challenges.
BY FRANCK , INDUSTRY MANAGER OF CIEL & TERRE JAPAN
& LILOUANN, MARKETING
