Shenggen who worked in the construction related sectors for 30 years said: “I can see a rising standards for insulation. Polyurethane has better than performance than PVC. Glass fibre reinforced PU has better mechanical and wind resistance for high buildings. The stiffness of window frames is a key point.”
Shenggen started working directly with polyurethane in 2001. At that time he was investigating the material as an insulation for buildings. The polyurethane side took off with a dedicated PU project in 2004. This was “agreed with the Shanghai Government which attached high importance to the project,” he said.
Eventually, Shenggen spun off a separate business from the Shanghai Real Estate Scientific Research Institute. “We founded the company Collodin while I was working at the Institute as a hobby at first” he said adding that “This was encouraged by government.” He left Institute in 2009 to devote his energies to the new project. That was the time that cooperation with Huntsman started.
Huntsman Polyurethanes now supplies the resin system for the pultruded products based on a Rimline polyol blend and Suprace MDI isocyanate. The firm says that this wets the glass reinforcement well, and can allow high line speeds at low pull forces.
China’s construction standards started to rise from about 2001, Shenggen said. Then, “polyurethane was mostly used in paints or floors or coatings. I could see that rising standards might offer an opportunity for polyurethane,” he said.
Glassfibre PU composite have advantages combining some of the benefits of PVC and aluminium including better K factor, better mechanical properties also glass filled polyurethane has better fire performance than PVC or aluminium,” he said.
Collodin designed frames which have “passed a 30 minute fire test. Polyurethane can do this, PVC and aluminium find it impossible,” Shenggen said.
The window system has already won accolades in China. In January 2016 the company’s TICO PUR Energy-Efficient Window and Door System was named among the top 40 innovation practices in Shanghai.
Despite using fairly exotic window frame technology, Shenggen said that his frames are as cheap to make as metal reinforced PVC which he said. “Polyurethane gives a high level of insulation, so the overall cost is not expensive when compared with other solutions that would require insulation,” he added.
Collodin makes its own pultrusion dies, he said: “at the start we bought our own dies from a die maker, but now we have our own capacity.”
Collodin’s process has several parts, he explained. ”There’s injection box where the PU impregnates the glass this is typically 35 cm long. After passing through the resin bath the composite passes through a three stage die where the temperature rises from 170 °C to 200 °C and then back down to 90 °C before emerging.”
Shenggen said that Huntsman supplied injection box design but Collodin has built expertise in this area. Polyurethane is supplied to injection box by a domestic mixing and metering machine supplied byHuafan and Jinhua Paike.
The machine runs at between 0.6 and 1 m/min “this compares favourably with epoxy which runs at around 0.2 m/min. Using polyurethane is therefore 2 to 3 times faster than using unsaturated resins,” Shenggen said.
After the profiles are extruded, they are cut to length and sprayed off-line. The spraying process is around 10 times faster than the pultrusion process, he said.
Collodin currently has 12 machines producing the glass fibre reinforced polyurethane window material, but it plans to operate another three factories, Shenggen said.
He added his firm will then be producing 70-80kT/year polyurethane composites and will produce an area of something like 10,000,000 m² of frames.
Two phase expansion
We have scheduled the first phase to be complete in the first half of 2017. This will see the firm increasing capacity from its current 12 mahines to 60 machines,” he said.
“There is a second phase scheduled to start in the second half of 2017 with a similar 60 machines. I will start the marketing process and we will start trialling product,” he explained.
Shenggen said the expansions are being funded by an investment company, which he declined to name and it is possible that Collodin may go public with a flotation in a few years’ time,” he added. However, before that happens the company would have to be restructured, he said.