RIS & TBS-SVA: rubber in the maintenance hole

Ever looked at a maintenance hole cover? There is a good chance it bears the letters TBS and was rubber-coated by us. This collaboration stretches back over 70 years. In fact, TBS was our very first customer.

RIS stands for Rubber Industrie Soest, as Soest is where we set up business in the 1950s. We subsequently relocated to Lelystad due to the growth of the business and the need for more space, but we have always retained the name RIS; no longer as an abbreviation but rather as a nod to our origins. Our first order came from TBS Soest, for whom we fitted maintenance hole frames, outlets and maintenance hole covers with rubber seals. Now, more than 70 years later, TBS remains a valued customer, and our collaboration has expanded into a wide range of products.

a brief history

FROM THEN TO NOW

The Technical Bureau for cast iron products Soest (TBS) was founded in the early 1930s and originally only produced cast iron pavement gullies and maintenance hole covers. Just before the war, iron became scarce and expensive. This led TBS to experiment with combining cast iron and concrete – a successful formula due to its high quality and low costs. In the years that followed, TBS continued to grow and ultimately became the market leader in pavement gullies, maintenance hole covers, sluice gates and penstocks. In 2017, TBS was acquired by Triacta, and in 2020 it merged with SVA. Both companies now operate as brands under the TBS-SVA Group B.V., headquartered in Nederweert.

leveraging the benefits of rubber

CAST IRON, RUBBER & CONCRETE IN ONE PRODUCT

The rubber-coating of TBS cast iron takes place in our Lelystad factory, where we fit maintenance hole frames, outlets and maintenance hole covers with a rubber seal. This seal prevents noise when traffic passes over the maintenance holes. Additionally, rubber absorbs vibrations, reducing wear and extending the product’s lifespan.

Why is rubber able to absorb vibrations?

rubber in the street

THE PRODUCTION PROCESS:
BONDING RUBBER & CAST IRON

Metal and rubber are not compatible by nature. To bond these materials, a specialised production process has been developed. The naturally rough surface of cast iron from the sand mould eliminates the need for additional roughening, allowing maintenance hole frames, outlets and maintenance hole covers to be coated directly with an adhesion primer to ensure a strong bond with the rubber. After priming, non-vulcanised rubber is applied to the cast iron, and the moulds are carefully positioned on top. The cast iron and mould are then placed in the hot press, where the vulcanisation process begins. During this process, the rubber takes its final shape and develops its specific properties. Once the rubber coating is complete, any excess rubber flash is removed, and the product is coated with a layer of black paint. At the concrete factory in Nederweert, the cast iron is integrated into the concrete housing, completing the final product after which it is ready for use. This remarkable process brings together cast iron, rubber and concrete, creating products that are seamlessly integrated into the streets.

Effective drainage is becoming ever more important, and we are therefore proud to be able to make a contribution by collaborating with TBS-SVA.