Global Gypsum recently visited the Alkmaar, Netherlands, headquarters of the gypsum forming belt manufacturer Derco Gypsum, speaking to key staff and touring the site’s production facilities...
Global Gypsum (GG): Please could you introduce Derco Gypsum to our readers?
Joëlla de Ruijter, (JdR): Derco started making thermoplastic process and conveyor belts in 1984, so it is celebrating its 40th Anniversary in 2024. It was founded in Alkmaar, the Netherlands, by my grandfather Quirinus de Ruijter, the founder of the modern plastic conveyor belt. The company passed to my father, Claus de Ruijter in the early 2000s and I joined in February 2024, with a focus on marketing.
GG: What is the company structure in 2024?
JdR: The company remains in Alkmaar on its original site, with around 65 employees. Around 50 of these work in belt production. There are two divisions: Light-weight, which mainly produces belts for agriculture and food, and: Heavy-weight, which is entirely dedicated to gypsum wallboard forming belts. This sector represents around 25% of our sales in a typical year. All belts are made in Alkmaar and are shipped internationally for installation, either by our in-house expert teams or by the client itself.
GG: When did Derco first become involved in the wallboard sector?
Neil Woolliscroft (NW): In 2007 British Plasterboard (BPB), now part of Saint-Gobain, approached Derco. It wanted to explore alternatives to the traditional rubber belts that it had been using, as rubber was becoming more scarce. It thought that thermoplastic belts were worth pursuing from the perspective of quality, as more and more boards were being used without wallpaper. The quality of the belt is reflected in the quality of the board, of course... Belts need to be flat across their entire width, without imperfections of any kind.
Ton Brüsche (TB): I led the discussions with BPB for Derco, working to identify the fabrics, plasticisers and construction techniques that would be required. BPB supplied a list of requirements, including thickness, abrasion resistance, elongation factor and more. We were convinced that PVC could meet BPB’s needs. As we developed the PVC forming belt, it became clear we were working on something fairly innovative, a step up from previous approaches.
GG: What were the biggest challenges to overcome?
TB: The joint was a major issue and required a new approach for BPB and for Derco. The received wisdom was that ‘step joints,’ most often used with rubber belts, would be the best option. These require a length of around 1m for the joint, but were found to not be suitable. Instead, we adapted our PVC belt splicing technique for the forming belt. Today, this covers a length of just 170mm at 93% of the breaking strength of the belt, and it is completely smooth. The flexibility is also superior to rubber belts. This means that they can fit around smaller pulleys, which enables users to reduce the power of the drives, reducing the energy needed to run the wallboard line.
GG: I take it BPB was convinced...?
NW: Of course, otherwise we wouldn’t be speaking! The first PVC forming belt was supplied to a BPB plant in Termoli, Italy, in 2008 in a Number 1 position. It was only removed in 2023 after 15 years of successful service and is now being used in a Number 2 position at Saint-Gobain’s Cassola plant, also in Italy. The second belt was installed in a CertainTeed plant in the US and is still going strong too. Indeed, after 15 years since we entered this sector, we have sold more than 500 belts to wallboard plants around the world.
GG: What kinds of belts are made today?
NW: For the first decade Derco made a standard belt 14.7mm thick. Although it is now in its fifth generation, this belt is now known as the Original, as it was joined by some other products in 2021. For markets that use glass mat fibre facers, mainly North America and Türkiye, we produce the Premium belt. This has greater abrasion resistance to combat the greater abrasion of the glass fibres used in this kind of wallboard. The Premium is constructed of a PVC core with an outer layer based on a polyurethane blend. It lasts around six times longer than competitors’ belts and is available in 10mm and 14.7mm thicknesses. There is also an Economy range of the Original, which is 10mm-thick, for companies with smaller budgets. The Premium has an abrasion resistance of 40mm3 compared with rubber at 250mm3 and PVC at 150mm3, so it is significantly harder wearing. All of these are made to measure, but are sometimes also available from stock.
GG: How was 2023 for Derco?
NW: 2023 was a wonderful year for Derco. We made 60 PVC forming belts, around 20% more than in 2022 and three times as many as our nearest competitor. Notable markets that supported this increase were South America, Europe and the US. Indeed, the Global Gypsum Conference in Chicago, US, was particularly productive in this regard. We had an extremely productive event promoting the Premium belt, to North American producers in particular, and made fantastic connections with clients old and new. The exhibition stand was very busy, even as we were trying to leave!
GG: What drove the increase in sales?
NW: The year was notable for an increase in the number of endless belts being sold, particularly to clients in Asia and South America. These are manufactured entirely in Alkmaar, rather than spliced on site. Derco can install them, or the client can do it themselves. We also supplied several endless belts to Turkish original equipment manufacturers, which are well established in the Middle East.
GG: How is a typical forming belt made?
TB: The process starts with the mixing department, where sieved PVC powder is mixed with additives, dyes and plasticisers to generate PVC paste. There are around 400 different PVC paste blends across all applications. We use high-end non-toxic PVC for gypsum forming belts, as this prevents the plasticiser from reaching the surface over time. This leads to the longest possible belt lifetime.
All forming belts are made from three separate sections, each 750m long and 3200mm wide. A core is built up and then further coated with additional PVC up to the required thickness, either 10mm for the Economy or 14.7mm for the Original. The Premium differs in that it is coated with a polyurethane-based blend, which has no plasticiser at all. This ensures that no plasticiser can migrate to the surface at all.
To make a joint we use a special ply-separator, which I developed in the 2000s. It cuts in between the fabrics so it doesn’t damage them. This is used in the manufacturing facility to produce endless belts and to splice belts at clients’ sites.
Each production run can make a section 750m long and up to 3200mm wide. A forming belt is typically 200m x 1400mm, so we can produce six forming belts from
each run.
GG: How are belts installed and what support do you provide?
NW: All belts, both endless and non-endless come in transport frames, which can also be used for installation. A 200m belt weighs 6t. It is possible to install belts using special equipment. We support customers with videos, which include ways to repair our thermoplastic belts with our specially-developed repair kits. If there is a scratch we can also show users how to drag grind the belt without risk.
TB: As well as this, we have improved the splicing process for joining belts on-site so the process is now much more streamlined than in the past, requiring less equipment and time. It is straighter, shorter and flatter than ever before. This is important when belts are running on the fastest wallboard lines in the world at up to 250m/min. When you are running at this kind of speed, the belt straightness is crucial.
NW: We have also increased the speed of installation. A one day turn-around for turn-key project is completely possible, but clients often wish to clean the line once the old belt has been removed.
GG: What are the company’s targets for 2024?
JdR: We aim to further expand our supply of forming belts to the global gypsum sector in 2024. On top of this, we have some major new plant projects and closer and closer ties with OEMs, which is the best endorsement we can have. Derco is growing step by step.
GG: How will Derco change in the future?
JdR: The current manufacturing facility has evolved over the past 40 years, based on the units that were available at the time. This is why the company plans to move into a new purpose-built site in 2026. This will enable us to streamline the production process, to make more efficient use of space and to increase our sustainability credentials even further by the use of solar panels on the roof. We have already used 100% renewable energy for the past 20 years. The designs are coming along well on this exciting project.
We will also increase the sustainability of our raw materials and ask more of our suppliers. We already recycle old belts into new refurbished conveyor belts and try not to waste anything, but are now taking this even further, with a significant PVC recycling research project already underway.
NW: There may also be changes to the products that ‘wallboard producers’ manufacture in the coming years. We anticipate a shift towards making products for the entire building envelope, possibly incorporating gypsum, insulation products and roofing membranes. The requirements placed on forming belts, or perhaps even other kinds of belts, will change. Derco looks forward to tackling the challenges this presents alongside its current and future clients.
JdR: We will expand our local support network and continue to align with market trends flexibly. For example we are currently developing partnerships with local engineering companies in the US to improve our responsiveness in this very important market. We need to be ready to adjust to the demands of the market, always looking to improve. We want to recruit the best, energetic personnel and harness that energy for the good of the company and the global gypsum sector. The future is pretty bright!
GG: Thank you very much for your insights today.
ALL: You are welcome!
