Milling elastomers – high surface quality and burr-free results
Elastomers are special plastics that are characterized by their high elasticity and dimensional stability. Glass transition point is below the operating temperature, which allows them to retain their shape while deforming elastically under load and then returning to their original shape. These properties make elastomers a sought-after material in numerous industrial applications, from automotive and medical technology to the construction and packaging industries.
To ensure that elastomers are produced efficiently and with high Surface finish milled, special requirements for tools and machining strategies must be taken into account. The tools of the Hufschmied Sharp line were specially developed for these challenges and enable burr-free cutting edges, high dimensional accuracy and a long service life even with difficult materials such as rubber, latex or caoutchouc.
What are elastomers?
Elastomers are plastics that can deform significantly under load without permanently changing their structure. Once the load is removed, they immediately return to their original shape. This property distinguishes them from Thermoplasticswhich can be deformed when heated, as well as Thermosetting plasticswhich are rigid and no longer deformable after curing.
The most well-known elastomers include:
- Rubber – versatile in seals, vibration elements and tires
- Latex – frequently used in medical devices and special coatings
- rubber – proven in industry, e.g. for conveyor belts or seals
Challenges in machining elastomers
The Machining of elastomers is considered particularly challenging because material properties such as elasticity and springback make processing difficult. Particularly important is:
- as well as a high surface qualityto be able to use components without rework
- that Avoiding burr formation, which often occurs at the cutting edges
- that Stability of the tools, as elastomers can place heavy strain on the cutting edges
Hufschmied relies on specially developed geometries: The Sharp-Line tools are equipped with sharp cutting edges that ensure low cutting pressure. This reduces material deformation, while polished guide chamfers and generous back clearance prevent the material from smearing onto the back of the tool.
Milling of elastomers with Hufschmied Tools
The following basic rule applies to the processing of elastomers: preferably use left-handed (pushing) toolsThis tool geometry prevents burrs from forming on the upper edges of the cutting surfaces.
Recommended tool lines:
- Sharp line → for elastomers with a focus on surface quality and cutting edge retention
- Universal Line → ideal for machining hard rubber and solid materials
In addition, offers Hufschmied A wide range of sliding geometries in Z1, Z2 and Z3 end mills, so that the right solution can be found for every application. The sharp cutting edges of the Sharp-Line tools ensure low cutting pressure and thus minimal material deformation. Polished guide chamfers and the special clearance angle design prevent the elastomer from smearing on the tool back. The result: smooth, clean cutting surfaces, burr-free top edges and significantly reduced post-processing.
Layered structures made of thermoplastics and thermosets
In many industrial applications Material combinations of elastomers, thermoplastics and thermosets A typical example is the construction of Instrument panels in automotive interiors:
- Duroplast support with glass fiber reinforcement (for stability)
- Soft foam to improve the feel
- Thermoplastic film (e.g. TPO or TPO2) for optics and surface
For such Multilayer materials Tool geometries are required that combine stability with cutting edge retention. In addition to the Universal-Line and Sharp-Line tool lines, Mixed geometries such as NC or "PerPlex" geometries are used. These combine main cutting edges made of Universal Line geometry with trailing cutting edges made of Sharp Line or PerPlex. Hufschmied calls these innovative hybrid tools “TWISTER tools” – ideal for burr-free milling of complex components with layered structures.
Advice and products
Do you want to mill elastomers reliably, precisely, and with the highest surface quality? Then benefit from the experience and innovative tool solutions of HufschmiedOur team will advise you on the selection of the appropriate geometry, provide you with information, and support you in implementing it in your production.
FAQ – Frequently Asked Questions
Why is machining elastomers so challenging?
Elastomers deform significantly under load and tend to smear. Only special tool geometries with sharp cutting edges and large back clearance prevent these problems.
Which tools are suitable for milling rubber?
For soft and elastic materials such as rubber or latex, tools from the Sharp Line are recommended, while for harder elastomers such as hard rubber, the Universal Line is ideal.
How can burrs on elastomers be avoided?
Through the use of left-hand twisted (pushing) tools the cutting force is optimally dissipated so that no burrs form on the upper edges.
Which strategies are important for CNC milling of elastomers?
In addition to the choice of tools, CNC path machining plays a major role: short chip formation, low heat input and precise cutting paths ensure high surface quality.
What are TWISTER tools and what are they used for?
TWISTER tools combine cutting edges of various geometries in a single tool. They are particularly suitable for layered structures made of thermoplastics, thermosets, and elastomers, which are frequently found in automotive interiors.
