October, 23, 2019 - Wacker, the Munich-based chemical group, showcased numerous silicone-based innovations at K 2019, the International Trade Fair for Plastics and Rubber. Key new products included fire-resistant silicone elastomers, self-adhesive silicone rubber grades with extremely low-friction surfaces and ultrathin silicone laminates for electroactive applications. The focus was also on liquid silicone rubber grades that, thanks to their greatly reduced volatiles content, do not necessarily require post-curing and thus unlock various advantages. A new silicone-based additive also made its debut, allowing compounders of thermoplastic elastomers to produce softer and more dirt-repellent plastics. With multimaterial printing, novel auto-control and several technical enhancements in terms of both freedom of design and precision, the latest printer generation, ACEO®’s new 3D silicone printer, is setting new standards. The K 2019 trade fair took place in Düsseldorf, Germany, from October 16 to 23.
At the world’s largest tradeshow for plastics and rubber, the Munich-based chemical group showcased its innovations under the motto “Thinking Beyond”. On an area of 300 square meters, a multitude of novel products ranged from thermally conductive Silicones for battery cooling in electric vehicles, flame-retardant silicone rubber for rolling stock and self-adhesive Silicones with low-friction surfaces to electroactive silicone laminates for actuators and sensors.
“Silicones are extremely versatile and effective. They are essential for novel product solutions and belong to the innovation drivers in key industry sectors such as automotive, medical, and electronics,” says Robert Gnann, head of the Wacker Silicones business division. “Silicones are therefore more and more sought after in many industries. Future technologies such as e-mobility and digitalization, global efforts to increase the standards of living and health and realizing the sustainability goals of the European Union and the United Nations will hardly be feasible without high-performance materials such as Silicones.”
The rise in product and industry specifications also presents a major challenge to manufacturers. “Some standard materials can no longer keep pace with this development,” said Christian Gimber, Vice President Engineering Silicones at Wacker Silicones. “That is why more and more companies are counting on silicone elastomers. Thanks to their outstanding mechanical and chemical properties, silicones have become indispensable for solving demanding technical problems and developing and implementing innovative technologies.”
Wacker Booth Covered Eight Topics
At this year’s trade show, Wacker’s booth was covering eight topics. One of these focused on the advantages of liquid silicone rubber that contains very few volatile components. Since early 2019, this applies to Elastosil LR 3xxx, Elastosil LR 6xxx and Silpuran 6xxx Silicones manufactured in Europe. Thanks to ultra-modern process technologies, Wacker says it has managed to slash the content of volatile Dx siloxanes in its liquid silicone rubber by at least 90 percent. By upgrading the LSR portfolio in this way, the company says it is enabling manufacturers of silicone parts to meet regulatory requirements and industry as well as customer needs more readily and reliably than ever before. According to the company, Wacker’s initiative is setting new industrial standards worldwide.
According to Wacker, the Elastosil LR 5040 product line cures to form elastomers that possess the same mechanical properties without thermal treatment as a product that has been post-cured. Users can skip the lengthy and costly process step of post-curing altogether, Wacker says. Due to their high purity, parts made of Elastosil LR 5040 are suitable for food-contact applications and can be used in line with the recommendations of the German Federal Institute for Risk Assessment (BfR) and the US Food and Drug Administration (FDA), the company assures. They also meet the criteria of selected biocompatibility tests in ISO 10993 and US Pharmacopeia (Class VI).
Elastosil LR 5040 was also at the center of this year’s injection-molding demonstration at the Wacker booth. Here, food-contact parts were produced out of the liquid silicone rubber.
Solid Silicone Rubber for New Fire-Safety Standard
Fire safety in rolling stock has long been governed by national standards. With the EN 45545-2 standard in effect across Europe, the safety requirements that manufacturers of rolling-stock components must meet have become stricter. Wacker says its existing product portfolio includes solid and liquid silicone rubber solutions already certified for a large portion of the applications mentioned in EN 45545-2 – especially those subject to the standard’s R22 and R23 requirement sets.
Now, to allow manufacturers to produce large-format bellows and profiles in compliance with the new fire-safety codes, the Munich-based chemical group has added a new grade of flame-retardant solid silicone rubber to the product portfolio. According to Wacker, Elastosil R 771 meets today’s fire-safety codes and enables the manufacture of rolling-stock components in accordance with the R1 and R7 requirement set. This makes Wacker one of the first silicone producers worldwide able to offer a certified silicone rubber compound approved for the new standard.
Self-Adhesive Liquid Silicones with Less Friction
Wacker has expanded its portfolio of self-adhesive liquid silicone rubber with two further product lines: Elastosil LR 3671 for food technology applications and Elastosil LR 3675 for the automotive industry. The company has combined in these products two technologies that are firmly established in the silicone compounding industry, with a track record in numerous applications: Silicones with self-adhesive properties and grades featuring intrinsically low-friction surfaces.
Wacker says that the new liquid silicone rubber grades adhere to metals and selected thermoplastics and cure to form elastomers with dry, low-friction surfaces. They thus enable cost-effective large-scale production of injection-molded hard/soft composites, the company claims.
Silicone Laminate for Sensors and Actuators
Nexipal is a novel silicone laminate with electroactive properties. According to Wacker, it consists of several ultrathin precision silicone films that are coated with electrically conductive material prior to lamination. The result is an actuator that creates movement, as soon as electrical voltage is applied.
The laminates can furthermore be used to measure mechanical deformation electrically. Thus, Nexipal can also serve as a sensor. Wacker sayts that the product is wear-free, compact and energy saving, and ideal for use in innovative applications. Tablet displays equipped with Nexipal are able to create vibrations and haptic feedback which simulate the shape of keys or control panels that can be operated blindly by touch, the company claims. Such a feature can be especially useful in automotive applications.
Genioplast Pellet 345
Genioplast Pellet 345 complements Wacker’s portfolio of silicone-based additives for the compounding of thermoplastic polymers. The product has been specifically developed with thermoplastic polyurethanes (TPUs) in mind, but can be used for modifying other thermoplastic elastomers as well. For example, the product, which is supplied in pellet form, can markedly boost the properties of thermoplastic polyamide and copolyester elastomers, Wacker claims.
Genioplast Pellet 345 is a silicone copolymer and is processed like a thermoplastic. The manufacturer says that organic polymer segments contained within Genioplast Pellet 345 make it so compatible with thermoplastic polyurethanes that, unlike conventional Silicones, it disperses very finely and homogeneously throughout the polyurethane matrix. In so doing, it becomes physically bound to the matrix and is therefore unable to migrate.
According to Wacker, the addition of Genioplast Pellet 345 boosts the surface smoothness of thermoplastic polyurethanes, thereby enhancing their scratch and abrasion resistance. Moreover, the surfaces become more resistant to contamination by foodstuffs and cosmetics, the manufacturer explains. In Europe, the product is authorized for food-contact applications as well.
3D Printing with Silicone
At this year’s K, Wacker presented its latest innovation in the field of 3D printing with real silicone: the ACEO® Imagine Series K2. With its multiple printing nozzles, the new printer can print up to four different silicone materials simultaneously, allowing entirely novel designs to be realized, Wacker says. 3D objects can now be printed in different colors and with different degrees of hardness. The new technology also benefits the printing of objects, which require support material. For such cases, up to three different materials or colors are available.
Another highlight is ACEO’s new auto-control technology. It measures the silicone layer applied with each printing operation and compares it with the target value specified in the CAD model. If the program detects any discrepancies, they are automatically corrected with the next layers. In this way, the new printer produces precise and detailed 3D prints, which are even suitable for difficult industrial applications, Wacker guarantees.