Close dovetailing of injection moulding and toolmaking for greater flexibility

The specialists in delicate products

“Small, but with maximum precision” is how manager Philipp Türk describes HT Tooling’s products. The medium-sized company in Bergisch Gladbach specialises in the production of small injection-moulded parts measuring between one and 60 millimetres. These delicate components weigh only a few grams and require the highest precision throughout the production chain. At HT Tooling, this starts right at the toolmaking stage. With its latest investment in a Mitsubishi Electric MP2400 Connect, the company is underlining its quality aspirations.

Interior of the MP2400 Connect with mounted vice. Even tiny 5 x 5 mm sheets are machined at HT Tooling with a tolerance of 5 micrometres.

As a medium-sized company, it is good to have two mainstays. HT Tooling GmbH from Bergisch Gladbach has made a name for itself in the fields of injection moulding and toolmaking. As a spin-off of the hearing aid manufacturer Interton, the specialists have been producing tiny components with high precision for some 60 years: injection-moulded parts between one and 60 millimetres and weighing between 0.4 milligrams and 50 grams.

Plastic parts for hearing aids are, as ever, part of the product range.

“After spinning off our injection moulding and toolmaking operations at the beginning of 2000 and converting them into a company in its own right, our initial focus was on the production of injection-moulded parts for hearing aids,” Türk explains. “We quickly expanded our customer base and acquired new orders for small and tiny injection mouldings.”

Tiny, but with maximum precision.

HT Tooling is broadly positioned and serves the global market with its products. Although the latter are not always visible, they perform important tasks. Most of them are small products that require specialised expertise or are made of unconventional materials. These include cable grommets and pushbutton rockers, for which metal plates are inserted during the injection moulding process.

Toolmaking and injection moulding operate hand-in-glove

For HT Tooling’s customers, the combination of injection moulding production with competent toolmaking is very important. “There are two points I’d like to stress here that our customers bring up again and again,” says manager Hans-Herbert Türk. “It is our expertise in toolmaking and injection moulding that is combined on a single site and that customers can always rely on.” In addition, the close dovetailing of injection moulding and toolmaking offers the advantage of rapid access to all in-house resources. This means they can meet delivery deadlines even if there is damage to the moulds during production.

The production of high-precision and tiny shapes.

Bending dies with the highest surface quality – advanced machines lend shape to customers’ ideas.

At HT Tooling, injection moulding and toolmaking are located in the same building. The distances are short, communication between the departments is efficient and the teams in both areas are highly flexible. Repairs to and modifications of the moulds can thus be carried out quickly. “We produce many small and very small series as well as prototypes,” explains Philipp Türk. “In these areas, adjustments and changes are an everyday occurrence. By dovetailing toolmaking and injection moulding, we can respond very quickly to customer requests and implement changes.”

Moulds for in-house production and for customers

In the toolshop, the specialists make all the tools and moulds for in-house production activities, while also supplying customers with high-precision tooling. “As yet we haven’t actively advertised our toolmaking services,” says Hans-Herbert Türk. “Our customers come to us thanks to word-of-mouth recommendation.”

MP2400 Connect

In addition to their wire-cutting and die-sinking EDM machines, the specialists have high-precision CNC milling and turning machines at their disposal. Specifically for rapid repairs and reworking a laser welder is installed, which can be used for smoothing out minor irregularities.

Advanced software tools and expertise

Customers come to HT Tooling with definite ideas and finished 3D design solutions. “Together with our customers, we analyse the data and check them with our advanced software tools. Often we then find solutions that can significantly improve the workpiece.”

By using a rotary axis, forming tool tips with a diameter of 0.3 mm can be fabricated.

Rotary EDM

A new project the company started two years ago is rotary EDM or erosive cylindrical grinding. “After slight initial hitches, we are very satisfied with the results we have now achieved,” says Philipp Türk, describing the current situation. “We have now built a reputation and established a market that makes us optimistic about the future.” The basic principle of rotary EDM is simple. The workpiece is clamped onto a rotary spindle for machining and shaped with the EDM system.

Plastic parts for the textile industry

HT Tooling currently machines workpieces with diameters from 0.15 millimetres upwards. In doing so, the company is able to machine a wide variety of materials, including cemented carbide. It is very difficult to machine such products with the desired precision using conventional methods such as grinding or turning.

Better surface finish and faster cycle times

High surface quality is required in the production of small injection-moulded parts and tools. “For this reason, when we purchased a new EDM system, we opted for a Mitsubishi MP2400 Connect,” says Türk, “as it delivers top-quality surfaces. The EDM systems of comparable manufacturers and the existing machines achieve similarly good values, but have significantly slower cycle times.” The Mitsubishi Electric MP2400 Connect has been running in HT Tooling’s toolshop for a good year now. “So far we’ve been very happy with our Mitsubishi system’s performance,” says a delighted Türk. “Our customers are happier with the quality of the machining.”

Managers Hans-Herbert and Philipp Türk (from left to right)

In Mitsubishi I can say we’ve found the right one. Philipp Türk, manager at HT Tooling

HT Tooling’s management knows that a change of manufacturer is always associated with extra work and expense. That’s why they thought long and hard before taking the plunge. The decisive factor in the end was the after-sales service. “In the event of failures, which always happen once in a while, we expect a service that is quickly on hand with advice and spare parts,” Türk explains. The maker of the old EDM machines was not always up to the mark. “We were looking for a manufacturer who, firstly, has outstanding machines in its range and, second, provides outstanding service,” says Türk, summing up the requirements. “In Mitsubishi I can say we’ve found the right one.”