Stainless steel containers

Corrosion-resistant stainless steel containers, corrosion protection for metal containers

Weld removal

  • Fibre discs with ceramic abrasive grain offer high stock removal, while velour discs are a good choice for defined surfaces: our abrasives remove weld seams in no time at all

Defined surface quality

  • For the food industry in particular, compliance with predefined Ra and Rz values is not optional
  • By using VSM abrasives, you guarantee a reliable and consistent finish that always maintains the surface quality
  • Our abrasives also let you keep any corrosion issues under control

A defined finish

  • VSM non-woven abrasives give the final touch to any surface: For a matt or satin finish

Stainless steel containers: functional and attractive

Many industries use stainless steel containers, tanks and silos for the manufacture, transport and store their products. There are good reasons for this, because stainless steel is not only extremely versatile and easy to machine compared to titanium or Inconel, but depending on the treatment and maintenance,also corrosion-resistant, acid-resistant or chemically resistant, hygienic and food-friendly. It also looks good: High-gloss surfaces appear hygienic and attractive to customers and consumers. This stainless steel container is a real all-rounder – the right grinding plays a decisive role in its manufacture and application-specific modification.

Materials, areas of application and industries

By far the most commonly used material in tank and container construction is stainless steel. Containers made of non-ferrous metals such as aluminium are also used in some industries, for example for simple transport (e.g. granules) or when manufacturing compressed air containers. But stainless steel is clearly the most popular material. Three industries in particular use stainless steel containers: The food industry, chemical companies and the medical and pharmaceutical industries. The range extends from pressurised containers and process containers to mixing containers, storage and fermentation tanks, vacuum and mobile containers and many more.

Strict requirements in the food industry

If you think of food and its sale and transport, you immediately imagine shiny stainless steel containers. For example, the milk tanker, probably the obvious symbol for hygienic food logistics. Stainless steel offers the food industry a lot of advantages over traditional materials used in the past, such as wood, glass, copper, brass and plastics. This is mainly due to its protective chromium oxide layer, which guarantees outstanding protection against corrosion. Fine surfaces make stainless steel easy to clean. Other alloying components not only make the steel acid-resistant, but also protect it from other aggressive substances such as cleaning agents, bacteria or germs. Thanks to this very high hygiene standard, stainless steel is perfectly suited to the food industry.

However, this is linked to compliance with defined surface roughness depths, the surface quality is critical. For example, if scratches or score marks occur during loading, unloading or cleaning the container (here we are concerned with surface roughness in the micrometre range), they may only be extremely slight. The deeper the score marks, the harder it is to clean the container and the greater the risk of bacterial growth, germ formation or similar. Other problems include residues that cannot be removed by cleaning, or corrosion. In order to achieve the smoothest possible hygienic surfaces, they can be reground and polished as required.

Fine surfaces with very low surface roughness values are prescribed for use in the food industry. The smoother and more reflective the surface, the lower the surface roughness. This is why high-gloss, polished stainless steel containers are particularly suitable for food. The exact requirements for materials that may come into contact with food are set out in EU Regulation 1935/2004/EC.

Use in the chemical and pharmaceutical industries

Similarly with regard to surface finish, stainless steel or pressure tanks are used in the chemical and pharmaceutical industries. Here, too, low surface roughness is required, but sterility and aseptic properties (pharmaceuticals) as well as high resistance to highly acidic substances (chemicals) are required.

Achievement of defined surface finish values

Since certain, precisely defined surface roughnesses (Rz) and average roughness values (Ra) must be complied with in container construction, the focus is on achieving or restoring a desired surface quality. VSM offers the full range of abrasives to achieve this: the ceramic grain series from VSM Ceramics to Actirox for coarse and efficient removal tasks, VSM Compactgrain for the defined, fine surfaces with uniform roughness. VSM non-woven abrasives are the final step in achieving the perfect finish, from matt to satin.

Grinding by hand or with special container grinding machines

Ideally, the sheets arrive at the container construction company pre-ground to the required surface by the steel service centre with wide belt or coil grinding machines. The surfaces of the cylindrical tank jackets, bases and cones have therefore already been processed internally and externally for consistent, premium quality and guaranteed surface roughness.

During manufacturing of stainless steel containers, grinding is often done by hand. Here, the sheets are welded together and the weld seams are then machined: Specifically, this involves grinding out the weld seam roots and grinding the weld seam elevations of the longitudinal and circumferential welds, inside and outside, as well as welding beads on flat sheets. Everything is finely ground so the required surface roughness is achieved for the respective purpose. This is mainly done with hand grinders, i.e. angle grinders or belt grinders.

However, in some tank manufacturing firms, all surfaces, both inside and out, are also produced with coated abrasives. After the form production of cylindrical components and formed, usually curved bottoms, machining continues from coarse descaling to the achievement of the fine surface. Special container grinding machines of different dimensions are used for this purpose.