The dishwasher is undoubtedly practical, but it is a real challenge for many materials, especially plastics and bioplastics. Just because two materials look similar does not mean they can withstand the same stresses. It is a bit like apples and pears: both are fruit, both come from the same tree - but they are not the same. The world of plastics is no different. Dishwasher resistance in particular shows how different the properties of different plastics can be - and why it is important to choose the right material for the right application.
Temperature stability
One of the biggest challenges is temperature resistance. It is a familiar phenomenon: you accidentally put a plastic bowl in the dishwasher and the next time you open it, you have a deformed piece of plastic in your hand. This is due to the high temperatures in the dishwasher cycle, which can reach around 65-75°C. Even conventional plastics are not all temperature resistant enough to withstand these conditions without damage. The challenge is often even greater for bioplastics, which are often more thermally unstable. To counteract this, we have developed a bio-PBS-based material without sunflower seed hulls and instead with mineral fillers: GC green 71 MI T30. This is an innovative, biodegradable material without sunflower seed hulls that is dishwasher safe and food safe. So there is nothing to stop it being a sustainable, easy-care product for the home.
Chemical resistance and hydrolytic degradability
Another barrier to dishwasher suitability is the chemical resistance of materials. Dishwasher detergents often contain aggressive substances that are harmful to both conventional and bio-based plastics. These chemicals can cause cracks, discolouration or surface changes and shorten the life of the material. Rougher, corroded surfaces also have hygienic disadvantages, as dirt and bacteria can adhere more easily. In addition, regular contact with hot water accelerates hydrolytic degradation. During hydrolytic degradation, the molecular chains of the (bio)plastic are attacked by water molecules, causing the material to weaken and become brittle. While synthetic plastics gradually lose their strength, biodegradable plastics are often particularly susceptible to the effects of hydrolytic degradation.
Bioplastics are often more sensitive to these chemical influences. One example is our GC green with sunflower seed hullsdesigned for outdoor use, not dishwasher safe. Discolouration and wear will show after the first wash. Our GC pro range, on the other hand, is not designed for dishwasher cycles and will only show visual and structural weaknesses over time.
Our solution: The right material for the right application
Each of our materials is customised for a specific application. Our GC greenline has a natural look and is ideal for disposable applications or packaging. These biocomposites are ideal for use with dry foods as they are robust but sensitive to moisture and dishwasher cycles. The material mix of sunflower seed hulls and bio-PBS provides a unique look, but also has a tendency to migrate, making it unsuitable for moist foods. Similarly, our GC pro-line, which is not biodegradable, but offers durability and stability.
For food applications where dishwasher suitability and durability are important, we have developed the GC green 71 MI T30 This material meets the highest dishwasher and food safety standards and combines the benefits of biocomposites with the everyday practicality required for dishwasher use.
Conclusion: the right material is crucial
Each material has its strengths and weaknesses. Not every (bio)plastic is dishwasher safe - and that's a good thing. Thanks to our wide range of materials, we can ensure that the right material is available for every application. Our customers should always make sure that they choose the right product for their specific needs and not 'compare apples to pears'. Just as the dishwasher suitability of glass and plastic should not be equated, bioplastics should always be considered in the context of their intended application.
With our development such as the GC green 71 MI T30 we offer a sustainable solution that sets new standards in terms of dishwasher safety and suitability for everyday use.
