A new high-density media combines the advantages of plastic and ceramic media in one product.
With the newly developed fast cutting plastic media "trowalplast HDC", Walther Trowal offers a product that is ideal for grinding and surface smoothing of metal work pieces, especially die-castings. The high density and sharp edges of the embedded abrasive material contribute to a drastic shortening of process times. But they also produce excellent surface finishes at a surprisingly low wear rate.
Walther Trowal has pioneered the development of the new HDC media (High Density Cut) and is now introducing it in the German market. This media consists of a plastic carrier filled with zirconium silicate, thus combining the advantages of lightweight plastic media with the extremely high density of the abrasive filler material. This combination yields metal removal rates that are comparable to ceramic media with, at the same time, a surprisingly low wear rate and excellent surface finishes.
Angelika Helten, head of the chemical lab at Walther Trowal, comments on the reasons for developing this new media type: "Many of our customers would love to work with ceramic media, because their finishing tasks require a high grinding performance. But ceramic media tends to chip and frequently wears relatively fast. That is why they are using plastic media, which produces the required finishing results, but at much longer processing times. Our new HDC media combines the advantages of plastic and ceramic and is, therefore, the ideal solution."
An excellent application for the new HDC product is the finishing of die-castings, for which until now plastic media – for example the type "ET" from Walther Trowal – has been used.
The HDC is equally effective in all types of mass finishing equipment. This applies to high-energy centrifugal disk finishing machines, which generally cause a very high wear rate of ceramic media, as well as to linear continuous feed vibratory systems, which only allow a relatively narrow band of processing times. Especially in these machines the HDC is particularly effective, because it produces significantly better finishing results at the prescribed cycle times.
Christoph Cruse, general sales manager at Walther Trowal, wants to make it easy and simple for the customers to test the new high density media: "Those customers who are already using our equipment can simply order a machine load of the new media and test it in their machine. For new customers, who consider investing in a mass finishing machine, we offer processing trials in our test lab free of charge."
Improved grinding performance
Because of its relatively high bulk density and the sharp edges of the abrasive material the HDC offers grinding characteristics similar to ceramic media.
Besides the actual material content the media shape plays a significant role. While ceramic media are only available in relatively few shapes, the HDC can be produced in all the known shapes and sizes for plastic media. This allows Walther Trowal to offer media that are perfectly adapted to the different work piece shapes and sizes. Initially, the company will offer the HDC as 8 mm (0.3") cones. This is the smallest size available on the market. And it is ideal for finishing work pieces with many internal corners and passages.
For the daily mass finishing operations the media color is also an advantage: Contrary to the mostly grey ceramic media the HDC with its pink color can be easily recognized in case of media lodging in the work pieces.
Lower wear rate
To date a high grinding performance automatically meant a high wear rate. With the HDC media this is different: Despite its high metal removal rate, in comparison to other fast cutting media in the Walther Trowal product range the high-density media is wearing relatively slowly.
No silica and alumina
The HDC media is filled with zirconium silicate. Besides the fact that the abrasive grains have exceptionally sharp edges, this abrasive has the added advantage that it does not contain any aluminum oxide or silicon dioxide. Therefore, it can be used for work pieces, which must not be in contact with these two materials. With the HDC Walther Trowal can now offer a range of fine grinding and fast cutting media that does not contain aluminum oxide.
For further information: www.walther-trowal.de