A global partnership between Huf Tools and Synventive

With a market share in lock sets of over 20 per cent, Huf is one of the leading suppliers in this segment worldwide. The company is still privately owned and employs around 7,000 people at sites in 14 countries across the globe. Over 300 designers work in offices in Germany, the US and China. Huf was the first company to develop components for the cutting-edge Passive Entry and Keyless Go vehicle access and driver authorisation systems.

Huf Tools – a global specialist in mould production

Huf Tools is a wholly owned subsidiary that emerged from the former equipment manufacturing segment of its parent Huf Hülsbeck & Fürst. Since 1999, the company has been developing and producing high-quality injection moulds, as well as automated assembly systems for the products made in the Huf Group, but also for customers from both the automotive and non-automotive industries.

In Velbert, Germany, Huf Tools produces complex injection-moulded parts for multi-component, overmoulding and internal-gas-pressure applications and applies exceptional process expertise to put these into operation. It manufactures equally complex technical parts in its Yantai China plant. As a result they can achieve greater capacities and more cost efficiency when handling large tooling projects.

Plastics used include glass-fibre reinforced polyamides and polypropylenes, PBT, ABS/PC, TBEs/TPS and SEBS. Final weights are between 0.1 g and 180 g. This places extreme demands on the hot-runner systems used. The systems have to align perfectly with the final weight/combination of materials to ensure good process management.

A global partnership to maintain consistently high quality

In the past, the various international companies in the Huf Group chose different hot-runner suppliers to make their injection moulds. At Huf Tools this increased the level of technical complexity when injection moulds had to be made for a component produced across the world in various companies.

Andreas Hill, Divisional Manager of Mould Engineering at Huf Tools explains: “This was always a complex issue because we didn’t just have different people to contact at the various hot-runner suppliers, but we also had to take into account a number of different specifications resulting in a complicated technical coordination processes. These sorts of issues can have an impact on process stability in the subsequent injection-moulding process and make achieving consistent quality difficult. It would have been beneficial to standardise the hot-runner technology used from the very beginning”.  

In 2011, the first contact was made between Huf Tools and the hot-runner manufacturer Synventive. Synventive’s hot-runner technology was investigated in detail and its after-sales capabilities thoroughly reviewed.

Andreas Hill adds: “As an automotive supplier we can’t afford any extended periods of downtime. If worst comes to worst, we need a local maintenance specialist. One of Synventive’s advantages is that it’s based near our global production facilities, so we always have a Synventive specialist close by”.

After Huf Tools had carried out its analysis, an initial order for a hot-half concept was given to Synventive for four two-component tools. Each tool includes a 4+4 hot runner system for the hard and soft plastic components.

fig. 1: Mold for a hybrid part of Mercedes “Keyless Go"access and driver authorization system	fig. 2: Typical Synventive Plug’n Play Hot Runner System

A door-lock component for the Mercedes S class was to be injection moulded. This door-lock component is part of the innovative Mercedes Keyless Go access and driver authorisation system.

Designed as a hybrid part, the hard component consists of PBT with a moulded-part weight of 12 g, a magnetic part and an SEBS soft-plastic component with a moulded-part weight of 2 g.

This Keyless-Go function allows the driver to open or close and start or stop the vehicle without inserting or pressing a key. If the key is close to the vehicle and the user takes hold of one of the door handles, the vehicle’s electronics talk to the key via the induction antennae. If the authorisation is correct the vehicle is unlocked. 

After the first order, Andreas Hill was enthusiastic: “Synventive’s hot-runner technology has impressed us. Its reliable technology, global presence and fast direct communications, have made Synventive an important strategic partner for us. With very few exceptions, we only use Synventive’s plug ‘n play technology instead of the traditional hot-half method today”.  

The plug ‘n play technology involves hot runner systems with threaded nozzles mounted according to the tool design specification and are pre-wired and pre-plumbed according to customer requirements. They are factory tested to ensure perfect performance and are inserted into the injection mould as a complete plug 'n play module. As a result, tool makers no longer have to apply time consuming adjustments to the tool when fitting different hot-runner components and they realize a closed, leak-free unit within the tool.

fig. 3: Mercedes Keyless Go hybrid component

Because there is little contact to the tool and with heating conditions to match, ideal temperature management to the connection point is achieved. As a result, the requirements for a failure-free, reproducible injection moulding process with a high degree of product quality are achieved.

Michael Böther, Design Manager at Huf Tools adds that: “Synventive’s plug 'n play technology is a superb option for us. We now have a number of plug ‘n play systems in operation, mainly with nozzle flow channel diameters of 6 mm, all of which function without any problems. This technology means a clear separation of responsibilities. Synventive is in charge of the hot-runner technology and we’re responsible for the tool technology. Should servicing be required, the plug ‘n play module is easily removed from the tool for quick access. Synventive guarantees its service capabilities and the availability of spare parts”. And Andreas Hill adds: “The quality of our tools guarantees consistent and reliable production. This includes hot-runner technology which complies with our high demands”.

www.synventive.com