Drill holes up to 400 mm deep - and in high-strength tool steel: the tool manufacturer Polar-Form from Lahr in the Black Forest used to rely on single-lip drills for this purpose. Until they met Mathias Scherer from precision tool manufacturer Walter a good three years ago. The trial run with a Walter DC170 Supreme as a pilot drill and the X treme D40 and D50 as deep-hole drills convinced the injection mold specialists to use the tool in the future. Specifically, this means for Polar-Form: The machining time for cooling channel drilling has been more than halved - with a correspondingly positive effect on machine running times.

Polar-Form Werkzeugbau in Lahr has earned a reputation in the market as a specialist for complex injection molds and rotary tables. It primarily supplies suppliers to the automotive industry as well as customers in the electrical and medical technology sectors. Founded in 1993, a total of 70 employees now work in the modern production building in Lahr. Polar-Form develops and builds complex, customized turntables and tools for companies worldwide - from Mexico to China. With over 800 turntables manufactured to date, the company is one of the market leaders. Contract manufacturing is another mainstay of the tool manufacturer: Polar-Form takes on challenging metalworking jobs for metal and tool manufacturers. In addition to milling, die-sinking and wire-cutting, this primarily includes deep-hole drilling.

Increasingly important in the industry: plastic parts

Polar-Form has been deep drilling since 2003 - and the proportion of the company's orders accounted for by this demanding form of metalworking is growing continuously. This development is driven by various factors. On the one hand, there is the trend towards lightweight construction methods. In addition to lightweight materials such as aluminum, plastic parts are taking on more and more functions in vehicles, machines and electrical appliances. Gearshifts and buttons, keyboards, sockets and sealing rings are just the most obvious examples. The shapes are also becoming increasingly complex. The know-how and process reliability of proven experts in the design and production of complex injection molds and turntables, such as Polar-Form, are therefore in demand. At the same time, efficiency and cost pressures in production are increasing: production cycles are becoming ever shorter and the number of injection-molded parts per tool is rising. Today, 48 to 64 parts are standard for the injection molding of smaller parts - in three to four seconds. This places particularly high demands on the cooling of the mold and rotary plate during the injection process.

Deep hole drilling is one of the operations involved in the production of injection molds and especially for rotary plates on which the multi-component molds are clamped. In particular, channels and feeds for cooling, hydraulics or other materials are created in this way.

Deep boreholes are required for ducts and supply lines for cooling, hydraulics and other materials. © Walter

From fearful machining to a success factor

"For many metalworkers, deep-hole drilling is something of a fearful machining process. During machining, the worker cannot see the machining area, and if something goes wrong, in extreme cases the drill and the component are damaged," says Raphael Weber, work preparation and programmer at Polar-Form.

Polar-Form has made deep hole drilling one of its core competencies. For the company, this also means regularly investing in new machines, software and the further development of its own expertise. The acquisition of a new machining center in 2014 was the reason for Mathias Scherer, sales representative at Walter, to contact Michael Gür, team leader for rough machining at Polar-Form. Scherer recalls: "When companies invest in a new machining center, the established processes are always put to the test. At Walter, we attach great importance to very close cooperation with our customers and optimize all relevant processes. On site in the production hall on the machines on which the order will later be executed. If the customer agrees."

Michael Gür and his team went for it: Together, they identified in test runs with different parameters where the use of the DC170 Supreme and the Walter X treme D40 and D50 deep hole drills would actually pay off and optimized the process sequences with the support of Walter technicians.
"Cooling channel drilling takes up a lot of time and machine capacity. The drilling alone takes many hours per turntable. We analyzed this complex process and were then able to reduce the machining time by more than half," says Mathias Scherer, describing the procedure. "Even though a Walter drill is more expensive to purchase than a single-lip drill, very significant increases in efficiency quickly become apparent as soon as you take a holistic view of the machine costs."