Roger Bakowski, Head of TPU Marketing in Europe, the Middle East, Africa and Latin America (EMEA/LA) in the Polyurethanes Business Unit of Bayer MaterialScience AG With Christmas fast approaching, this is the perfect time to look back on 2011. We have made great strides this year. Our constant drive to innovate is paying dividends. This is reflected in the topics we have presented to you in our Newsletter this year. Highlights have included our new, sustainable ether- and ester-based TPU grades with a high proportion of renewable raw materials, our new Desmopan® 98 range as a cost-effective alternative to polyamide 11 and 12, and the new TPU grades for drive belts. In keeping with the Christmas spirit, this Newsletter contains some rather pleasant surprises. For example, we have developed a high-speed TPU that enables very fast production. What's more, we have also raised the bar once again in terms of the consistent quality of our Desmopan® 400 series, showing that we are always working on improving our production processes. Our success would not be possible without the trust of our customers! On behalf of the whole team, I would like to thank you for placing your trust in us. You can be sure that we will do everything in our power to remain your preferred partner for TPU products in the future. Finally, may I wish you a very happy Christmas and a successful start to the New Year. Sincerely,

Ihr Roger Bakowski

Incredibly fast – new TPU for extremely short cycle times

We have expanded our product range to include Desmopan® DP 3055D DPS 066, a high-speed ester-based TPU. Its melt hardens significantly faster than any other comparable TPU grades that we produce. We anticipate that this TPU will greatly reduce cycle times – by as much as ten percent depending on the wall thickness. This offers tremendous potential for cutting production costs.

Using this high speed TPU will pay dividends for components with thicker walls – such as castors or the heel taps of ladies shoes – as well as thin-walled applications, such as ID tags for pigs and sheep. In the latter case, initial production trials have shown that the injection molding cycle requires practically no cooling time and thus allows extremely fast tag production. With thick-wall components, there is the additional benefit that the rapid hardening process prevents the formation of vacuoles – hollow spaces that can form as the melt cools and contracts.

Improved mold removal, higher abrasion resistance

The fast hardening of the melt does not come at the cost of the mechanical properties. These remain at their normal high level and are comparable with those of standard TPU Desmopan® DP 3055D. The abrasion and wear resistance have been further improved. Raising the mold temperature slightly to 45 - 55°C makes it possible to use the standard flow paths and eases the mold removal process. This process is optimized greatly through the skilled use of additives to ensure minimum cycle times. To ensure that this new material is also suitable for use outdoors and that it can handle tasks in wet environments reliably, as with all other products in the Desmopan® 300 range, effective hydrolysis protection is incorporated as an additive.

Outlook

In the medium term, we are also planning to develop “high speed grades” for other candidates in the 300 series, such as Desmopan® DP 3059D, DP 3065D and DP 3072D. We are aiming to achieve considerable cost savings for users with our series that are most frequently used for the production of construction components subject to high stresses.

Fig. 1 Hardening kinetics DP 3055D und DP 3055D DPS066

In demand – the original color of Desmopan® DP 3690AU

In South America, the original color of our Desmopan® DP 3690AU used in the production of shoe components is currently all the rage and is fast becoming a design USP and reference standard. Many manufacturers are therefore striving to match the shade of our transparent ester-based TPU. And customers are requesting “color 3690.” A leading Brazilian producer of parts for tennis and sports shoes uses this material and believes that the original color gives the company's products a real competitive edge. Desmopan® DP 3690AU stands out from the crowd thanks to its white shade with slightly fluorescent bluish shimmer that underlines the material's transparency.

Fig. 2

Desmopan® 400 series – even more consistent product quality

We are constantly working to optimize our production processes. With this goal in mind, we have further improved the consistency of our Desmopan® 400 series. This is possible thanks to improved dosing of the special chain extender, which is primarily responsible for the property profile of each of the individual ester-based material grades. Overall, this significantly reduces fluctuations in the mechanical properties and melt viscosities, for example. The 400 series has a long and successful track record in the production of high-tech functional parts in automotive, mechanical and apparatus engineering.

Desmopan® DP 85085A – increased purity, more effective additive

We have also improved the production of our aliphatic, light-stable Desmopan® DP 85085A series and its two grades DPS 055 and DPS 063. We no longer incorporate an additive essential for this series' properties during the chemical reaction of the TPU basic components. Instead, we process it into a masterbatch that is only added once the finished TPU has been pelletized. This new process for incorporating the additive has no impact on the product's formulation and offers users two benefits. First, the additive is subject to lower thermal loading, which increases the purity of the material. And second, the additive is more effective overall. Both these features pay dividends when using the TPU.

The masterbatch can be identified in the product by its granule proportions ranging from opaque to translucent. The color and properties of the components made from the TPU remain unchanged. Changing the way in which we incorporate this additive also benefits us by improving the occupational safety during the production of this TPU. Thanks to its high rebound resilience, “snappiness,” low-temperature flexibility and hydrolysis resistance, it is ideal for brightly colored applications in automobile interiors.

No need for microbe protection with silver additives for Desmopan®

Time and again, customers ask whether an additive containing silver ions would afford Desmopan® better protection against microbiological decay and microorganisms. We therefore used test sheets and customer samples to test a representative selection of our ether- and ester-based TPUs in soil burial tests to DIN EN ISO 846 (method D). For the vast majority of applications, this test best reflects the natural biological load created by the climate, mold and bacteria. The results of the test series clearly show that there is no need to incorporate an additive containing silver ions, because the chemical composition of ether-based TPUs offers protection against microbes. In the case of ester-based TPUs, the addition neither prevents nor noticeably slows the degradation. These findings do not rule out the possibility of proven growth inhibition under clinical laboratory conditions for particular strains of bacteria through the use of silver ions.

Fig. 3 Microbes

Nostalgia pure and simple – TPU wheel trim rings

One of the past issues of our Newsletter already featured the wheel trim rings of Gronau-based company Ravus (www.ravus.de) that are designed to give modern tires an authentic nostalgic look. Made of light-stable, aliphatic Desmopan® grades, they can be pigmented in white and fixed to the steel rim of modern tires as quickly and easily as hubcaps. Ravus has now significantly expanded its product range to meet the rising demand. This success is also testament to the effectiveness of our aliphatic TPUs. They give the rings – which are now available for 12”, 13”, 14”, 15” and 16” tires – their abrasion resistance and secure fit. The portfolio also includes a variant with narrow black and white stripes that is produced using in-mold technology from a foil based on our Desmopan®. The wheel trim rings may set the hearts of vintage car fans racing, but they have also been discovered by tuning experts who use them to give new vehicles a retro look. The latest additions to the portfolio are rings for red and black-and-red wall tires.

Fig. 4a 2CV

Fig. 4b Isabella

Fig. 4c Mercedes 190

Correction

In the previous newsletter, the top story on drive belts inadvertently missed out the ® sign for the brand name Kevlar®. Therefore, we would like to point out here that Kevlar® is a registered trade name of DuPont.