IMA January-February 2013 Feature - Hot Runners

Injection Moulding Asia Hot Runners

Choosing the right side-gating solution

by Martin Baumann, Husky Business Manager, Hot Runners

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by direct gating with a side-gate hot runner is also superior to parts manufactured with a cold runner.

Other advantages include faster cycle times, easier maintenance, design flexibility and performance across a wider temperature range.

With more and more hot runner manufacturers offering side-gate hot runners, it is becoming increasingly important for mould makers to look at the various products on the market, the benefits each offers, and to compare them against the customer’s needs. By carefully evaluating each and integrating the side-gate hot runner that best suits your customer, you’ll help in positioning yourself as a valuable partner to their business.

s a mould maker, being able to deliver maximum value to your moulding customers is critical to differentiating yourself and gaining a competitive advantage in the market. One of the best ways to do this is to offer customers a more complete solution that saves them time and money, along with the convenience of dealing with only one supplier.

Supplying a more complete solution, however, requires not only designing and manufacturing high-quality, high-performance moulds, but also selecting a hot runner that performs at the same high level and meets the customer’s needs.

Hot runners are one of the most important components in a mould and have a dramatic impact on speed, quality and uptime. As a mould maker, if you’re looking to provide an optimal solution to customers, it’s imperative to give careful consideration to the hot runner used in the mould.

Ensuring part quality art quality is always a priority for moulders, and is particularly important in an industry such as medical where side-gate hot runners are often used.

Quality is so critical here primarily because safety is such a huge concern. With medical parts, sharp edges or pronounced gate vestiges can potentially tear latex gloves or even skin. In the medical industry, even seemingly small improvements in quality can make a significant difference in everyday applications and their safety.

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Side-gate hot runners he hot runner market is constantly evolving, with suppliers always looking to develop innovative solutions to address market demands. Side-gate hot runners are one of the more recent developments in injection moulding, being perfectly suited for deep draw parts such as pipettes, syringe barrels and other smaller parts that don’t have the flat surface needed for optimal gating performance with traditional hot runners.

Side-gate hot runners provide numerous benefits for these types of applications such as the ability to direct gate parts that would traditionally require a cold runner. This saves both resin and time by eliminating the need for additional downstream processing.

The quality achieved

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Since the nozzles on sidegate hot runners are mounted on the sides of the housing as opposed to the end with traditional hot runners, multiple nozzle tips per housing are possible, resulting in more cavities

Gate quality is one of the areas where parts are scrutinised and carefully evaluated, since this is where excess plastic and sharp edges are most common.

With the hot runner having the largest impact on gate quality, it is important for mould makers to carefully evaluate which side-gate hot runners can deliver the quality that customers require. There can be a significant difference in gate quality between various side-gate hot runners. Some side-gate solutions are better suited to producing high quality parts than others, with certain models able to offer minimal vestige.

Side-gate hot runners are one of the more recent developments in injection moulding, for deep draw parts such as pipettes, syringe barrels and other smaller parts

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Hot Runners In terms of overall part quality, a side-gate hot runner that allows for the use of a single-piece mould is usually preferred. A single-piece mould allows for better quality parts because it eliminates the possibility of misalignment of the two halves of the mould. With a split cavity design, if the two parts of the cavity are misaligned, it can result in “parting lines” or excess plastic on finished parts where the cavities meet. A single-piece cavity design also provides better cooling to further improve part quality and productivity.

Factors to consider ide-gate hot runners such as Husky’s Ultra SideGate were designed with part quality as a top priority. Ultra SideGate was designed for precision and repeatability, offering almost zero vestige (~0.05 mm) and allowing for a single-piece mould to aid in producing better quality parts.

When selecting a side-gate hot runner, there are things to consider other than simply the performance and part quality. It’s also important to consider things like the ease in which maintenance can be performed.

Uptime is an incredibly important measure for moulders and any time an injection moulding machine isn’t running means lost production and revenue.

Reliability and the ability to perform maintenance easily, whether scheduled or not, is a huge advantage for moulders as it allows them to get their machine and mould back up and running more quickly. With most moulds, accessing the hot runner nozzle tips requires the mould to be removed from the injection moulding machine before it can be serviced.

Side-gate hot runners such as Husky’s Ultra SideGate, however, allow access to the individual tips while the mould is still in the machine – a huge advantage and time saver for moulders. By allowing access to the individual tips while still in the mould, maintenance can be performed quickly and easily, allowing the machine and mould to be up and running again more quickly.

Just as time is money when we talk about machine uptime, it can also be said that space is money. Every mould only has a finite amount of space, with the goal being to use that space as efficiently as possible. The more compact you can make injection moulding tooling while still retaining the same level of productivity, the more parts you can make in that same amount of space.

Because the nozzles on side-gate hot runners are mounted on the sides of the housing as opposed to the end with traditional hot runners, side-gate hot runners allow for multiple nozzle tips per housing, resulting in more cavities within the same size mould footprint. This is a huge benefit for moulders, particularly for those where space is at a premium. In addition to allowing for more nozzles per housing, a nozzle like Husky’s Ultra SideGate that offers tip-to-tip spacing as small as 55 mm

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By allowing access to the individual tips while still in the mould, maintenance can be performed quickly and easily

further maximises the use of space and can fit more cavitations in a small mould base.

Often, new technology brings with it different or specific operating procedures. Such is the case with many of the side-gate hot runners currently on the market. Having to learn and run a different set of operating procedures presents additional challenges for moulders and also adds start-up time and expense by way of employee training. By choosing a side-gate hot runner that operates in the same manner as traditional hot runners, you’re able to make the integration of a new mould easier and more seamless for customers.

Certain side-gate hot runners also require separate specific temperature controllers to manage start-up and shut down of the tool – another added expense for customers. Integrating a side gating solution that is compatible with any existing temperature controller system your customers may already have in place, will save them both time and money and offer production flexibility.

When considering suppliers for a new mould, moulders evaluate mould makers and their moulds on a number of things – cost, quality, flexibility and ease-of-use among others. In order to stand out, secure business and sustain those relationships over the long run, it is important to always consider how you can deliver additional value to your moulding customers.

Ultimately , it comes down to who can provide them with the easiest way to make the highest quality parts at the lowest cost.

For mould makers with customers in need of a side-gating solution, it is important to understand the differences between the various side-gate hot runners on the market and the benefits that each delivers. While most side-gate hot runners have a similar purpose, the quality, size, convenience and flexibility each offers can vary considerably. Taking the time to understand your customer’s needs and integrating a side-gate hot runner that best meets those needs will go a long way in positioning yourself as one of the preferred mould makers in your industry.

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