Modern technologies are continuously creating new demands on the surface finish of moulded plastic parts. For high-gloss surface demands, mould tool designers should aim to use a steel grade with good ‘polishability’.

Tyrax ESR is a new high-hardness, corrosion-resistant tool steel from Uddeholm, developed for applications with extreme demands on surface finish.
The surface finish of a mould is dependent on the polisher’s technique, in combination with the microstructure and cleanliness of the tool steel. Uneven hardness across the surface means an uneven removal of material during the polishing process, where harder areas will resist abrasion better than softer areas. Uneven hardness may be the result of impurities in the steel and segregations.
Two of the most common polishing defects are pitting and orange peel. Pitting looks like scattered pinholes dispersed over the surface, and is usually due to pull-outs of hard particles, such as carbides or oxides. The best way to avoid such problems is to choose a very clean steel, such as an ESR grade, with fine and evenly distributed carbides. Pitting can also arise if the mould is stored in a humid environment, where localised corrosion attacks may cause pits at the mould surface. In such cases, a corrosion resistant tool steel is required.
Orange peel means that the surface morphology looks similar to an orange peel, as caused by plastic deformation at the mould surface. The best way to reduce the risk of orange peel is to choose a tool steel with a homogeneous microstructure, such as an ESR grade, in combination with high hardness.
The chemical analysis of Uddeholm Tyrax ESR enables the polisher to reach a high gloss surface finish in three polishing steps, compared with five steps for AISI 420 ESR, reducing the polishing time by 40-50%.
For further information www.uddenholm.com

A new universal cylindrical grinding machine from Swiss specialist Kellenberger majors on providing high value at the entry level, while offering reliability, precision and high productivity via its state-of-the-art intuitive programming function.

Available in the UK from Jones & Shipman Hardinge, the Kellenberger 10 (K10) combines proven technology using many Kellenberger components and sub-assemblies from the established K100 machine, coupled with the latest programming technology. For instance, Kellenberger Blue teach/programming software enables semi-skilled operators to use the machine, thereby optimising use of the work team. Kellenberger Blue solution software is accessed through a FANUC 0i-TFP CNC control with a 19” touch screen.
In standard format, the machine can accommodate workpieces up to 1000 x 400 mm in size with a top table weight capacity of 100 kg. The table profile is also a proven Kellenberger design with the full length wheel dressing interface located on its rear to reduce re-tooling work and extend wheel dressing possibilities.
K10 models feature generous X and Z-axis strokes (365 mm in X, 1150 mm in Z), collision-free operation and dressing ratios. The low-maintenance, high-precision linear guide on the X axis and the flat sliding V guides on the Z axis are equipped with optical absolute linear position measuring systems. Furthermore, the B axis is designed as an automatic indexing axis (1° Hirth gearing) with high positioning accuracy and a +30°/-210° swivel range.
The K10 also offers the ability for users to expand or customise its capability by adding a range of optional equipment such as a second external grinding wheel, larger grinding wheels, a tailstock, gap control and balance sensors, and measurement control via probing.
For further information www.hardinge.com

The two-machine X series of two- and three-axis surface grinders from Taiwan-based Perfect has long been a part of RK International Machine Tools’ portfolio of precision grinding machines. Now, thanks to the addition of full CNC in the form of the Siemens 828D control, these machines have gained even greater versatility, with the three-axis versions now able to perform full contour grinding as standard.

The X25 with its 250 x 500 mm table – and the larger X36 with 300 x 600 table – feature 550 mm and 600 mm clearance between table and spindle centreline respectively. Both variants are based on a construction that was developed through FEA for added stiffness and support. Spindles are also high-performance P4 units with precision angular contact bearings delivering runout of <2 μm. The spindle itself features an inverter giving users a choice of spindle speed to suit specific materials. Craig Digweed, RK International’s product manager - grinding products, says: “With the addition of full CNC control from Siemens, the X series provides, as standard, cycles to cover surface, crisscross, plunge and pitch [same pitch and same depth] grinding. However, customers can now specify optional cycles such as stair, side, profile and contour grinding, giving them much greater control over their operations.” Table speed ranges from 1 to 25 m/min, dependant on machine specification, with a cross feed of 1100 mm/min on all machines. A table mounted, three-piece dressing diamond is standard and, to accommodate the variety of additional grinding cycles, rotary and roller dressing devices can be offered for wheel forming options. For further information www.rk-int.com

IMTS 2020, which is set to take place in Chicago on 14-19 September, has launched a dedicated educational resource on its website to help rebuild the manufacturing supply chain post-COVID.

The new mini site provides a repository of information to help manufacturers, OEMs and job shops increase resiliency when faced with future disruptions. Content includes stories, videos, webinars and podcasts that provides the manufacturing industrial base with guidance on how to rethink, re-engage and re-establish its supply chain.
For further information www.IMTS.com/supplychain

In Europe, Telsonic is adding vibration friction welders from Korean manufacturer Daeyoung to its portfolio of plastic bonding technologies.

The business relationship already enjoyed by the two companies in the North American market (US, Canada, Mexico) will now be extended to Europe, Russia and North Africa. To this end, the Telsonic GmbH centre of excellence in Germany has been expanded to assist users on-site with support and technical service, from design to tool manufacturing.
For further information www.telsonic.com