Label converters are switching to new ink sets and formulations, in response to rising operating costs, supply shortages and safety regulations. But some ink types need careful viscosity or temperature control – meaning changes in the ink kitchen. Modular dispensing systems allow easy changeover of equipment, colours and settings – for a seamless transition.
If there’s one certainty in these turbulent times, it’s that the ink kitchen is a place of great change for converters. Some are lessening the impact of rising operating costs by switching to new ink sets – like UV-LED, with its lower energy consumption. Others are forced to use adapted ink formulations to get the same colours, because raw materials are scarce. Additionally, suppliers to food and pharmaceutical markets are adopting safer ‘low migration’ inks.
But new inks mean changes to handling procedures: inks have special flow characteristics and drying conditions that vary according to their chemistries. Depending on the application, the ink dispensing system may need to include special conditioning equipment, agitators or filters. As we shall see, with a modular ink dispensing system, you can switch to new inks and keep operating smoothly – without disrupting your processes.
The challenges of handling new inks
First, though, let’s look the developments and trends in label inks:
Mono-pigments for a higher colour gamut
The Pantone Matching System (PMS) is the most widely applied colour-mixing system among label printers. The printer can reproduce spot colours by mixing two or more standard basic colours. These basic colours include different pigments.
In addition to PMS, several ink suppliers are offering a system with mono-pigmented base colour inks. This system includes high pigment concentrations plus additives for specific applications, so ink suppliers can offer a higher colour gamut and increased flexibility.
Separating technical varnishes from pigments: achieve more with less!
Some ink manufacturers are taking a modular approach to supplying inks. They are selling pigment colour concentrates independently from the varnish and chemicals that give ink its flow, adhesion and drying or curing characteristics. Their rationale is that supplying ink ingredients directly brings cost advantages. It can also save base components and space around the ink dispenser: if a different ink set is required, then an extra technical varnish barrel will suffice, instead of several identical colours with different technical characteristics. The same variety of colours can therefore be blended from a reduced number of base components, with much less complexity – a golden rule of ‘lean’.
LED-UV Inks: temperature control
There has been a growing adoption of LED-UV inks. Avoiding mercury use and producing no ozone, these offer lower energy costs, sustainability benefits, and sometimes faster printing speeds. Some of these inks require a temperature-control unit to optimize flow. Furthermore, the temperature and viscosity must be kept constant throughout the container.
Low-migration Inks: adapted pumps or valves
‘Low-migration’ inks are increasingly required for food and pharmaceutical packaging. These inks are formulated with higher molecular weight raw materials and chemistries that do not bleed or migrate. These ink ingredients may require adapted pumps or valves to ensure proper functioning of the dispenser.
The disruption to supply chains globally has hit ink manufacturing hard, with certain chemicals difficult to source. Suppliers mitigate for this by adapting ink formulations, which may result in a change of ink characteristics, like viscosity. In this scenario, therefore, the converter must adapt pumping conditions even when handling the same base colours.
Managing change: modularity is the way
In summary therefore, it is highly likely that label converters must contend with change in the ink supply, whether it’s a one-off move to a new set, or regular reformulations. A modular ink dispensing system design is essential, to help converters adapt to these changes smoothly, without causing disruption.
A modular machine or piece of equipment is formed out of separate modules or ‘subsystems’, that are both independent and interdependent. This offers important benefits:
- Customization: a system can be built for the specific application. For example, a dispenser can be built up with different configurations of base components, like container sizes, pump sizes, agitators and heaters.
- Upgradability: parts can be exchanged, and new equipment added to the system’s configuration, as requirements change. There should be space for adding new containers for colours and varnishes, or new conditioning equipment.
- Ease of installation and use: the system can usually be assembled faster, at lower cost. Easy to use barrel connections simplifies the exchange of base inks.
- For manufacturers of dispensing equipment, building a complex machine is simpler: customers can expect relatively shorter lead times and better value for money.
Essential features of the modular dispenser
Here are the key features of a modular ink dispenser – and equipment needed for making a smooth switch to new inks or flow settings:
Backbone frame provides flexibility
A slim, lightweight steel ‘backbone’ frame provides a compact, centralized casing for the connections that feed ink from the base components to the dispenser. It also provides a base to station each component’s pump. The components – buckets, barrels, or IBCs – may be arranged in a line or wall-formation around the frame.
This configuration allows more flexibility in positioning buckets, as well as conditioning equipment. There is also easy access to each connection for fast component exchange.
To keep inks or technical varnishes on a constant temperature, a barrel heater can be applied. Temperatures can be controlled by an adjustable thermostat, which is positioned in the machine console and integrated with the machine emergency stop circuit.
Agitators for consistent viscosity and temperature
Agitators maintain the homogeneity of the base inks, at the required viscosity or temperature (when a heater is applied). They keep the inks moving about, so there are no differences within the container. They are inserted into the container via the lid, and their mixing cycles are programmable in the ink management software.
Pumps – positioning and sizes
The pump for each container feeding the dispenser is situated on a dedicated pump stand, instead of the container lid. This frees up space for insertion of an agitator, and allows larger pumps than the standard ¼” size. Larger pumps, like a ½” size are usually needed for handling high-viscosity inks or larger ink volumes.
In summary therefore, with a modular dispensing design converters can stay agile in times of change and uncertainty – adapting or expanding the configuration with minimal disruption and less financial outlay.