Nic bread bin - BPO, we know how

For over 100 years now Brabantia is making all efforts to design household products that are durable, convenient and well made. In cooperation with Brabantia BPO developed a new bread bin. The lid of the bin can be used as a serving tray, very practical and multifunctional. But of course, as a consumer you also just want a bread bin that can be closed tightly so your bread stays fresh. With this idea BPO went to work.

For a successful design the lid and bin have to fit on top of each other very well. The bread bin has a rectangular design with high sidewalls. Brabantia wanted to make the bread bin using injection moulding, with the injection point in the centre of the bottom. Similar plastic products are known to be sensitive to warping (shape distortion due to unequal shrinking of the plastic) because of the injection moulding process. Especially the long side walls of a design are susceptible to unwanted deformations. This gives the risk that the lid may not fit correctly on the bin. Brabantia was aware of this risk and contacted BPO, as experts in the field of injection moulding, to be one step ahead of potential problems. A Moldflow simulation was conducted, with an emphasis on warpage. As expected, the first simulations showed the long side wall to bend inwards approximately 2 millimeters. The design was adjusted based on these results: Brabantia gave the long wall a bit more curvature and the fitment of the lid was changed.

Another potential risk with injection moulding is the deformation of the middle of the bottom. The bin has a standing rim, but if the deformation of the bottom exceeds the height of this rim, the bread bin may ‘spin’ around if placed on a flat surface. This possible effect was also judged in the Moldflow simulation. The bottom deforms approximately 1 millimeter upwards, which is a good result.

The actual product showed very similar results as the simulations. In these Moldflow simulations for the bread bin BPO was focused on the warpage effect. But at the same time as the Moldflow simulations, filling pattern, filling pressure, required clamp force, cooling time, weld lines and air traps are analysed. All these variables were found to be in order for this skillfully designed bread bin. The result is really something to behold: a fine product with a lid that fits perfectly!