Herzog shut-off nozzles boost productivity

With Swiss precision engineering combined with over 35 years’ experience, Herzog exhibited at CHINAPLAS 2016 its excellent shut-off nozzles, which are used exclusively in plastic injection molding processing and are often an essential component of the machine. “Installed at the crucial interface between heated injection unit and cooled mold, the nozzle is the gateway which regulates the melt flow while bearing the entire contact force of the machine.” Mr. Paul Coffey, President of Herzog explained.

Shut-off nozzles were originally developed in the 1960’s to prevent melt drooling from the nozzle orifice once the injection unit pulled back from the cold mold after injection. This not only prevented loss of material but also reduced process breakdowns.

Even today shut-off nozzles can still be used for this purpose but of course the advantages of using them have increased considerably since those times. Nowadays the primary functions of the shut-off nozzle include: 1) Reducing cycle times by dosing the next shot regardless of whether the mold is open or if the injection unit is retracted; 2) Improving part consistency by enabling accurate and repeatable shot loading; 3) Facilitating advanced molding techniques such as physical and chemical foaming, melt pre-compression and multi component injection molding.

To cover today’s spectrum of applications Herzog continuously develops and expands its selection of shut-off nozzles. The product profile ranges from custom-engineering solutions for specific demands, through pneumatic and hydraulic needle and bolt style nozzles, to economical spring loaded systems.

For over 40 years, Herzog has built its reputation on developing exceptional shut-off nozzles for injection molding machines. As a technology leader, each innovative solution is meticulously engineered at its Swiss facility and since 1996 the company is certified in accordance with ISO 9001:2008. Mr. Coffey says: “By following a customer intimacy philosophy we work closely together with injection molding machine manufacturers and processors worldwide and this feedback loop helps us to realise our customer’s exact needs. This is achieved and supported by having our own companies on three different continents - Europe, USA and of course, in China,” Mr. Coffey stressed.

Mr. Paul Coffey, President of Herzog

Customization was always an essential target for Herzog, to allow its products to be flexible enough to fit with different applications and to operate under different circumstances. Herzog designs the core product in a certain way which allows various options to be included such as mixers, filters and different heating systems. Each nozzle can also be manufactured with specific material selections which allow for abrasion and corrosion protection. This ensures that they can be applied to suit the broadest range of applications. Added to this are different sizing options as well as flexible tip and adapter geometries which for example allow a user to use the same core product together with different molds or even machines. All of these are options which the customer can choose as he requires.

In injection molding, it is clear that both increasing machine cycle speed and automation are two developments which have to be followed closely. When it comes to faster running machines, this naturally places increased demands on every component in the machine. “For us we have to ensure that our product performance matches the machine’s profile. We are finding different and faster ways of actuating our nozzles. Also in terms of wear we have to be careful in both material selection and how each mechanical component is designed to ensure longevity of parts. In terms of automation, obligations such as industry 4.0 demand that everything in the production chain is seamlessly integrated. We have to ensure that our components enhance the process as opposed to burdening it. This applies too in terms of the supply chain where we are currently evaluating systems. Our target here is to allow our customers, to have full access to all relevant information to their specific product which allows for spare part ordering, stock information and accompanying documentation and so on. We aim to allow for full integration into our customers own systems which improves productivity enormously while at the same time reducing the workload considerably for our customers,” Mr. Coffey added.