Following PU China and the KPUS meetings in Guangzhou and Jeju Island, Korea in August and September, Urethanes Technology visited a number of companies across the Korean peninsula.
Located in the city of Busan in the south-east of Korea, DUT Korea was founded in 1992 by Yong Chai Jung, an ex-military mechanical engineer. The company works closely with a number of local universities in the bustling town.
In addition to making and developing mix heads for polyurethane foam, the company has recently diversified into the bedding sector. This gives it a second revenue stream and helps capture value downstream from the foamer. ‘The most comfortable bed is the one I want to make,’ Jung said.
The light engineering business has devised a continuous foaming process that enables foam with six or seven different densities across a block to be produced. Typically, the foam will be denser where the greater pressure is put on the mattress, at the shoulders and hips.
He said that the idea is that the foam can then be cut from cured blocks in the same way as conventional mattresses, but without assembly and gluing as this can increase costs and lead to quality issues.
Near the sea
DUT employs about 60 people in Busan, South Korea. The company owns the freehold of two purpose-built factories which occupy 5610 m2. The workflow is designed so that parts are produced, either from scratch or semi-finished castings, at the first plant and finished at the second.
He said DUT wants to merge the two factories onto one large site as this will reduce its costs. Additionally, the port of Busan in which DUT is located is surrounded by residential areas. The local authority is interested in developing it for residential development.
DUT claims to be one of two companies, the other being Krauss Maffei, which make both the pumps and the mixing heads for its machines. ‘Korean steel is used here,’ Jung said with pride.
Before setting up the company, he worked as an army military technician at a military machinery complex near Busan. While he was employed there he wrote a high school textbook about mechanical engineering. He became only the 59th person to be designated a Korean master technician, that was 11 years ago, now there are 125.
Jung likes to do his work in the old-fashioned way, using a set square and drafting board I’m ‘only analogue!’ He said. He likes to produce his own drawings when designing the firm’s pumps.
DUT, which stands for Dual Use Technology, started trading in 1992 and got into the polyurethane business in 1997 when it started to make parts for polyurethane production.
It was an accidental process, Jung says. Initially, the company was built to make bearing for military equipment bearings, when a friend at a large Korean company explained that they were trying to devise a machine to make polyurethane parts.
Working for the big boys
The large firm had a solution, he said, but the mix heads it had developed needed to be replaced every two or three years and it was expensive to import them, Jung added.
Another large Korean company had tried for seven years to build its own mix head, but was unsuccessful, he said. This was when Jung designed his fist successful mix head, which was then adopted by the large firm.
‘I used my experience in working for the army to understand the problem and bring the solutions to build my new machine. This relationship still pays off,’ he said. For example, when the large Korean tech business builds plants overseas that need polyurethane machinery, his company is often the preferred supplier.
DUT exports between 50 and 70% of output each year because of this, he said.
After its start with mix heads, the company started looking at polyurethane machinery, as imports of high pressure machinery were expensive, he said. Korea had the ability to make low pressure machines, but the industry needed high pressure machines. ‘These were hard to build in Korea,’ he said. But DUT can supply them into Korea, he added.
DUT’s business is good, and the firm exports most of its production. ‘It depends on the world position,’ Jung said. ‘About 20-30% share is sold on the world market.’ He added that this can be up to 50-70%, with clients such as Samsung and LG using the same models of DUT machinery in their overseas bases as they do in Korea.
‘They want to keep the quality without changing mix heads and pumps,’ he said.
Jung said that the most recent mix head offering, DTRC, which was launched at K 2015, is a patented system. DUT had developed mix heads in the past, but failed to protect the designs sufficiently well, he said.
Tilt for better mixing
The DTRC model is a dual tilt direct impingement model, which has angled impingement of the isocyanate and polyol in the mix chamber. The jets point towards the back of the chamber. ‘This,’ Jung said, ‘improves mixing, laminar output flow and efficiency.’ Because the mix is better, he claimed, then quality is better and there is less scrap than can occur with other designs where the diisoycanate and polyols directly impinge at 180˚.
Jung claims that there could be between five or 6% raw material savings. ‘Energy use is lower and machine life is better,’ he said.
The idea for the design came from looking at existing 180˚ impingement mix heads. ‘They have the most flow, but if the flows were angled then it is much better,’ Jung said.
Take-up would be better if it were not for the fact that there is established business using existing mix heads which are good and give good service. ‘The market needs to be developed,’ he said.
Also at K2015, the firm launched a nucleation system. DUT is not aggressive about supplying the part. There are other producers in the market with similar systems and they have not been successful, he said. Nippon Steel is using the DUT nucleation system for a rigid foam system.
DUT’s business is split about 50-50 between flexible and rigid, with the automotive sector taking up a large part of the flexible business. In the rigid business, DUT ‘supplies machinery all the way from the coil to the cutting on the line and builds conveyors and converters,’ he said.
Looking around the workshops
We do that because some parts do hard service. The conveyor is the most important of these. We track parts; each part has a serial number,’ Jung explained.
DUT has supplied lines to Nippon Steel which is making rigid foam insulation at its plant in Nagoya, using a DUT mix head and a 30m long conveyor line. This is hydraulically operated, machines DUT supplies to India, for example, have a manually screwed down haul-off line.
Such a manually-adjusted screw-down haul off line has been supplied by DUT to Sintex in India, Jung said.
The company’s client base includes firms such as Inoac and Toyota, he added.
The firm has two production and assembly plants separated by short distance by road from each other. Looking around the assembly lines we saw mould carriers and rotating tables under construction at one site, at the other site we saw how the technically demanding mix heads are constructed. Jung said that around five people assemble each mix head in a production-cell environment.
Jung has also been turning his mind to something different to the standard range of machinery. He is interested in the mattress market. And on a pilot plant makes foam for pillows and mattresses. The mattresses are made in a box foam plant and can feature up to seven layers which change across the bed with different hardness’s from head to foot. These can be supplied on a motorised frame so that the masses can be infinitely adjusted.
