Our customer came to us with a problem; as recycling and environmentally friendly products become more popular in today’s market, they were under increasing pressure to develop a range of products that were biodegradable. They were originally using High Impact Polystyrene (HIPS), and wanted an alternative that would keep the original quality of their products while allowing them to rebrand as biodegradable.
Our team worked hard to develop the correct process for creating biodegradable injection moulded products. They assessed and adjusted the processing parameters for this material work in moulds that were designed for HIPS. The paper-based compound that we decided on for eco friendly injection moulding was not suitable for the moulds as they were; the melt temperature gave great concern, as there was a greater risk of ignition, and the colour of the raw material posed issues with colouring the product brown as requested by our client.
A small number of trials were conducted on several moulds in the early stages of this progress, so that we could see how the material flowed within them, and how it reacted when injected. These first indications went well, so we progressed the trials.
When we started processing these products on a larger scale, we began to encounter issues with the processing of the material. Many hours of perseverance and further trials went into getting the process just right. We made modifications to the moulds so that we could change the material flow design in the runner system and the cavities. Flow leaders were added to the cores and the runner system was increased to allow a larger volume of material to flow to the injection gates, allowing the material to fill the cavities effectively.
While the results of these trials were perfect, the pigment was not mixing well with the raw material, creating a marble effect. This was something we wanted to communicate to the client.
Our client was sent a sample, as we wanted to show them this marble effect, and discuss with them different possibilities for pigment that might work better, but they loved it. They decided that this marble effect was the perfect way to distinguish them from competitors, and a good way to market their biodegradability.
