DLC-coated components from HASCO boost productivity
Today, moving parts in tool and mould making are increasingly being coated in order to prevent premature wear, extend maintenance intervals and thus reduce costs. Particularly in the case of highly-stressed moving parts, insufficient tribological properties can lead not only to wear phenomena but also to mould breakage, frictional corrosion and the seizure of moving parts inside the mould.
HASCO, as a pioneer in this field, has relied on DLC coating for many years. This "Diamond-Like Carbon" coating is a metal-free hard coating. It gives the coated components a very long service life due to its structure and very good tribological properties, such as optimum dry running, while offering a high wear resistance at the same time. DLC is generally applied in a layer 1 µm thick in a PACVD (Plasma-Assisted Chemical Vapour Deposition) process at temperatures below 180 °C. This prevents any warpage or loss of hardness in the coated part. With a temperature resistance of around 350 °C, the DLC coating has sufficient thermal stability for tool and mould making. The application of the coating does not affect the quality of the part surface and hence surface structures are reproduced 1:1.
With these properties, DLC coatings offer significant productivity advantages for moving mould components, such as cores, slides, ejectors, guide and centring elements and a great deal more. The high coating hardness and low friction values result in considerably longer service lives compared with uncoated or differently treated surfaces. This boosts productivity enormously, even without lubrication, permitting a greater number of shots – which is of major importance for a large number of applications. Even during genuine dry running, any seizure (cold welding) of the mould components is effectively avoided. Since no lubrication is required, DLC-coated parts are ideal for use in cleanroom environments and the food industry.
HASCO recognised these advantages many years ago and successively extended its comprehensive range of more than 100,000 standard parts by a large number of standardised DLC-coated components.
New flat locating unit
In cases where particularly stringent requirements are placed on the precision of injection moulded parts, the new HASCO flat locating unit Z 086/… is an ideal addition to the standard use of pilot pins and locating guide bushes. The tight-fitting tolerance ensures reliable and highly precise centring of injection and die-casting moulds, especially for flat injection moulding applications with short opening strokes.
The DLC coating gives the flat locating unit excellent slip characteristics which minimise friction and wear and consequently reduce the outlay on maintenance too. The space-saving lateral mounting makes the flat locating unit easy to install from the side of the mould.
Stack mould components
Stack moulds offer twice the number of cavities and hence double the output for the same clamping force, thus ensuring more effective machine utilisation. Alternatively, the number of cavities can be kept the same and the clamping force halved, thus reducing the necessary investment and the space required. The HASCO gear housing Z1545/... and rack unit Z1547/..., available in 2.5 and 5.0 modules, permit the simple and reproducible installation of stack moulds of this type. The DLC coating on all the slideways reduces the friction values and considerably extends service life and maintenance intervals without need for separate lubrication.
Two-stage ejectors are used primarily to achieve precise, subdivided ejector movements. Contrary to the case for latch locking units (see below), which reliably control the movements of the mould plates by opening the mould, two-stage ejectors control the ejection sequence by dividing the ejection movement over two strokes. In so doing, automatic and precise holding and opening mechanisms permit the dependent movement of two plates. All HASCO two-stage ejectors basically have DLC-coated functional surfaces as standard. The lubricant-free functional surfaces permit longer maintenance intervals. Applications in the medical and food technology sectors are thus feasible, as are parts that require subsequent painting.
Latch locking units
Latch locks are used primarily on moulds with multi-stage parting planes. They can be subject to particularly high loads as a function of the part dimensions and the size of the mould.
The HASCO latch locking units with DLC-coated functional surfaces keep friction and wear down to a minimum while offering maximum protection against corrosion. They are especially suited to use in the food and medical sectors, since production can be run without lubricants, thus making it cleanroom-compatible.
Further examples of DLC-coated standard components from the HASCO range are ejection and demoulding elements, such as ejector pins and sleeves and also guide elements, including guide pillars, square guide bars, locating units, and many more.
HASCO offers a whole series of standard components with DLC coating which combine high wear resistance and excellent friction properties. DLC is an ideal form of surface protection for highly stressed standard parts in tool and mould making.
The coating combines a very high hardness with optimum tribological properties in respect of friction, wear and lubrication, which are becoming increasingly important for lubricant-free production, such as in cleanrooms. The good biocompatibility of the coating means it is suitable for use in the food industry and for medical devices. Lubricant-free production permits longer maintenance intervals for users, together with longer service lives for the components used, and hence considerably boosts productivity.
Alongside all these technical advantages, customers also appreciate the fact that they can order HASCO standard components from stock. This ultimately also saves time and money.
Author: Dr. Michael Thielen, freelance editor
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