The raw materials for cookware
- 分类： FAQ
- 发布时间： 2020-07-27 09:53:12
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概要: Over the ages, humankind has used many different materials for cookware. Each material has different requirements and properties. Apart from clay vessels, copper kettles or uncoated aluminium cookware, above all cast steel pots and pans have been used in more recent human history.
Over the ages, humankind has used many different materials for cookware. Each material has different requirements and properties. Apart from clay vessels, copper kettles or uncoated aluminium cookware, above all cast steel pots and pans have been used in more recent human history. Ever higher requirements relating to cooking and cleaning triggered the development of stainless steel, aluminium and cast aluminium cookware as well as non-stick coatings. Today, BERNDES focuses on cookware made of stainless steel, aluminium and cast aluminium.
The starting point for stainless steel products is a stainless steel blank (flat disc). This is greased, placed in a hydraulic drawing press and shaped over a so-called deep-drawing die. Next, the edge of the raw body is punched so that the finished cookware has a clean pouring edge. For better heat conduction, stainless steel bodies are fitted with a capsule base. Aluminium is integrated in the capsule base to optimise the absorption and transfer of heat.
A circular aluminium disc (blank) is used for the pan or frying pan. BERNDES uses discs between 3 and 5 mm thick. We use two different production methods and exclusively process aluminium alloys approved for contact with food.
Similar to stainless steel processing, the aluminium blank is greased and placed into a hydraulic drawing press where it is shaped over a deep-drawing die. Depending on the product size and blank thickness, a weight of up to 200 tons is applied for this forming process. The advantage of deep-drawn parts is an even thickness of base and walls. This ensures good heat conductivity.
Impressing die forging (also called closed-die forging)
Again, this involves forming an aluminium disc. The press works with two dies (top and bottom tools) which it slams together, applying pressing forces of up to 4,000 tons. The finished cookware produced in this way has an almost identical appearance to cast parts (see Cast aluminium), however, the two types differ in heat conductivity and heat retention.
Aluminium has only been used for about 200 years. That may seem a long time, but compared to the above materials it is a very young addition! What makes cast aluminium ideal for cookware is its optimal heat conductivity und heat retention as well as its light weight. The casting process involves injecting liquid aluminium into a pre-shaped casting mould under vacuum. This ensures there are no air bubbles. The advantage of this process is that even complex shapes are possible which can not be made from aluminium blanks, e.g. frying pans with grilling ridges, rectangular shapes or deep casseroles with cast-on handles. The result is perfect material distribution for every product.