Production – different methods
Learn more about processing natural polymers
To process natural polymer into a desired shape, there are different methods that are ideal for each area of application. Each procedure starts with fusing of the compound in a machine that works similarly to a meat grinder, but hot. NaKu mostly works with the following procedures:
The liquefied natural polymer is formable and is injected into the required tool shape under high pressure. During the cooling phase, the biopolymer solidifies again and remains in the mould. We use this procedure to manufacture the preforms for the NaKu bottles of PLA. This is the most used procedure in the plastics industry and most plastic or biopolymer products are manufactured with this process.
The molten mass is pressed through a tubular nozzle. The emerging hot tube is pulled up and is inflated from inside like a balloon. The material cools down during this process. A thin foil is created that we use as a raw material for our fresh-storage bags, freezer bags, snack bags, and bags that fit standard European transport box sizes. Different thicknesses can be achieved with this method, ranging from thick construction foil to very thin fresh-storage bags (ranging from 100 to 10 µm).
Viscous compound is pressed at high pressures through an opening that has the shape of the finished product, producing a natural polymer product with a constant cross-section.
Deep Drawing (thermoforming):
As a raw material for deep drawing we use flat plates or foils of natural polymer. These are then heated until they become viscous and formable, but not fluid. The formable foil is then sucked into a mold under negative pressure to give it its shape. Consequently, the edges are stamped off. This is how yogurt pots or blister packs are produced, for example.