Resin manufacturer Resinnovation benefited from its experience in the development of special adhesives when developing RabbitResin for Polypipe in Siegen, North Rhine-Westphalia. The orange-coloured resin for the internal pipe coating is the heart of the Polypipe Coating System, and another company was also involved in its success: Resinnovation and Polypipe brought Innoquip on board, a machine manufacturer from the Taunus region of Rhineland-Palatinate that has been working closely with Resinnovation for many years.
January
The two managing directors of Polypipe, Jens Becker and Oliver Seemann, were looking for a suitable resin for internal pipe coating using the spray process - and at the same time for the right equipment for the application: from mixing the resin to conveying it to the damaged area to the application itself. ‘With the existing systems, the components are first mixed in the spray head. But then the mixing ratio is randomised. We wanted to be sure that the resin always enters the spray head correctly mixed,’ says Seemann.
Jens Becker describes the challenge: ‘We had customer pressure: the longer the curing time of the synthetic resin for the internal pipe coating, the greater the customer's problems. This functional repair involves in-house work. When the residents are on site, they want to go to the toilet. But during the work, you forbid them to do just that. So we're driven by the customer to minimise the curing time as much as possible.’
February
The challenge: developing a fast-curing resin. ‘We approached Resinnovation with the requirement to develop a new, fast resin for internal pipe coating - which also remains open long enough to be conveyed to the rehabilitation site,’ explains Becker, emphasising: ’We want products developed and produced in Germany so that the contact persons are always available. We want prompt results that we can influence ourselves. And we want a resin that works - and is permanently available!’
March
Fastness was the order of the day - which is why an epoxy solution had to make way for a polyurethane resin in the laboratory, according to a chemist from Resinnovation: ‘The big challenge came from the desire for a very short open time. The resin had to be tack-free after a very short time so that the equipment could be withdrawn for the next application layer without sticking to the first layer applied.’ This is because with internal pipe coating, the spraying equipment is retracted again after each spraying process in order to apply the next layer in the following pass. Two to three layers of 1 to 1.5 mm each are built up to achieve the required layer thickness of 3 mm. Another criterion was viscosity: the resin must be able to be transported up to 20 metres, so it must not be too viscous - at the same time, it must be thixotropic enough not to drip off the pipe wall.
Chemical resistance is also crucial. For coatings in the wastewater sector, the material must be able to withstand chemical attacks such as ten per cent sulphuric acid, even if it is ‘only’ domestic wastewater.
While the laboratory was working on the project, the designers at Innoquip were also developing a machine that mixes the resin and hardener in the correct ratio and, in the next step, delivers them directly to the area to be repaired and applies them there. The third team developed an app for the process with which the dosing technology and conveyor technology can be optimally controlled, which creates a report on the rehabilitation measure to accompany the rehabilitation and thus ensures paperless documentation.
April
The chemist emphasises the great advantage of all teams working in parallel and closely networked with a lively exchange on the various components of the system is that they can exchange information and adapt to each other at any time: ‘The fact that the machine was developed in parallel with the resin helped us a lot with resin development and on-site testing. This meant that we were always able to test the current resin in the application promptly.’
May
From theory to practice: with a prototype of the machine, the concept could be turned into reality. ‘We were given the task of producing a ‘small’ quantity in the laboratory,’ smiles the chemist and explains: ’In this case, 20 to 30 kg were required for one machine filling. That's quite a challenge for the laboratory, which usually produces around two kilos at a time, to produce ten times that amount.
July
In summer, it's time to give the child a name - it should emphasise the speed of the system, stand out and be memorable: The RabbitCoater (mixing and dosing technology), the RabbitMover (controls the retraction of the tube packet), the RabbitControl control app and RabbitResin, the resin for the inner tube coating, are launched.
After the laboratory phase comes the production phase: the RabbitResin had to be produced in larger batches. Now, instead of 10 x 2 kg, half a tonne of material is produced at once.
October
But in autumn, there's a splash of colour - RabbitResin shines in bright orange! Polypipe's corporate colour - and a colour that fits in well with the times, says Becker: ‘Orange was the trend colour in 2020. And this also sets us apart visually from other processes in the field of internal pipe coating.’ Standing out is now the order of the day, as Polypipe is launching its system on the market. More and more customers are being convinced by what the RabbitCoater, RabbitMover, RabbitResin team and the RabbitControl app can do.
November
Now it's time to scale up - after eleven eventful months, the test series becomes series production. The number of enquiries from rehabilitation companies increases, as do the quantities of resin produced and dispatched from Rülzheim in the southern Palatinate. The RabbitControl app is added to the AppStore. And RabbitCoater and RabbitMover go into series production in the Taunus region.
Things get serious again the following spring: numerous tests in test laboratories are scheduled for approval by the German Institute for Building Technology. Complex tests for tensile strength, chemical resistance, abrasion resistance and high-pressure flushing resistance will be carried out by independent laboratories. It will be a few more months before Polypipe holds the certificate in its hands. Then a letter will arrive: the DIBt approval has been granted - under the approval number Z-42.3-601, the ‘Rehabilitation of damaged wastewater pipes inside buildings with nominal diameters from DN 40 to DN 200 with the coating system labelled “RabbitCoating” is on its way.
Source: Resinnovation, Author: Katja Nicklaus
You can find the article at: https://bi-medien.de/fachzeitschriften/umweltbau/kanalsanierung/ein-kunstharz-entsteht-in-11-monaten-von-der-idee-bis-zur-serienreife-u18601
