Why To Use stainless steels in hygienic liquid and food applications?

Why To Use stainless steels in hygienic liquid and food applications?

Cleanability and being CIPable is the key to hygiene. The smooth, bright surfaces of stainless steel are eminently cleanable and can remain so over time. It withstands wear, impact and fluctuations in temperatures while inhibiting dirt and scale accumulation and avoiding bacterial growth within surface

And the naturally forming self-healing passive layer provides the corrosion protection rather than an applied coating, which may be damaged and degenerate. The ability to easily wash and sanitise stainless steel allows for bacteria to be removed effectively and simply. Tests have demonstrated that stainless steel has a low bacterial retention capacity. Corrosion resistance of stainless steel means it is inert and does not alter the taste or smell of food or drink products, resisting the lactic acids formed by fermenting milk or acidic foods like tomatoes.

Smooth Surface

Stainless steel has a smooth, non-porous surface that's easy to clean. There are no holes for dirt, bacteria, and other contaminants to accumulate in, reducing the risk of bacterial growth and making it easier to maintain cleanliness.

Formation of a protective layer

When stainless steel is exposed to air, it reacts with oxygen to form a thin layer of chromium oxide on the surface. This layer, known as passivation, protects the steel from further chemical reactions.

 Corrosion Resistance

The chromium oxide layer prevents corrosion and rust formation, which is essential for maintaining a clean and hygienic surface.

Because of this corrosion resistance, stainless steel can handle exposure to moisture, chemicals, and different cleaning agents without deteriorating.

Chemical Resistance

Stainless steel doesn't react with most chemicals. This is mainly due to the protective oxide layer. This property ensures that the material won't introduce contaminants into the environment.

Heat Resistance

Stainless steel can withstand extremely high temperatures without warping or degrading. It has a melting point of around 1,400°C. This heat resistance comes in useful in situations where sterilisation or high-temperature processes are needed to maintain hygiene and sterilization

Durability

Stainless steel is a strong, durable material that can withstand frequent cleaning and harsh environmental conditions without losing its structural integrity.

Non-Toxic

Stainless steel is non-toxic and doesn't leach harmful substances into the products or processes it comes into contact with.

Hygienic Handling and Welding

Stainless steel can be welded hygienically by inert gas welding and robotic welding and also severeal surface treatments like passivation, pickling and itching to increase its corrosian resistance.

Our skilled stainless steel welders are certified accoriding the norms; ASME Section IX), EN ISO 9606, EN ISO14732 and similar and they are renewed periodically.

 Type AISI 304  and Type 316 stainless steels are major grades of stainless steel used in hygienic applications. L – Low Carbon versions of AISI 304 and AISI 316 are also avaliable

In practice however, hygiene, together with the demands of strength, corrosion resistance, formability and weldability, etc. will frequently indicate stainless steels of the austenitic 18%Cr/10%Ni AISI 304 (X5CrNi18-10;1.4301) type as these will, in the majority of environments likely to be encountered in food processing plant(and particularly in wet areas), meet all these requirements very well.

 Where greater corrosion resistance isrequired, one of the 17%Cr/12%Ni/2·5%Mo AISI 316 types (four of which are listed below) may be specified. The resistance to pitting corrosion of stainless steels improves as the molybdenum content (and, with it, the cost) increases and it is therefore important to specify the appropriate level of molybdenum for the intended application.

As Gemak we use certified AISI 304L (1.4307)  and AISI316L(1.4404)  Low carbon verisons of stainless steel 

Stainless steel materials have 2 major parameters; Surface Roughness and Surface Finish.

Generally in hygienic food application surface roughness is required to be Ra<0.8.

Surface finish is the visual appearance of the metal and is created through various processing methods, including rolling, polishing, and blasting. These finishes range from dull to bright and include special textures that may be mechanically applied for highly specialized applications.

In General Gemak uses 2B finish with Surface Roughness Ra<0.8. where other productions are avaliable upon request like, 2N, Mirror Polish and Surface Roughness Ra<0,6 mainly required for pharma process and Ra<0,4 which can be maintained  by electropolishing

Standart

SURFACE CODE

SURFACE PROCESS

EN

AISI

1D

1

No1

Hot rolled, annealed, matte finish

2B

2B

2B

Cold rolled, annealed, matte finish

2R

BA

BA

Cold rolled, annealed, glossy finish

2J

6

SB

Cold rolled, brushed

2K

3

3N

Cold rolled, satin finish (coarse)

3

4N

Cold rolled, satin finish (fine)

2M

 

BA 21

Cold rolled, glossy, square pattern

BA 22

Cold rolled, glossy, diamond pattern

BA 25

Cold rolled, glossy, cross pattern

BA 42

Cold rolled, glossy, leather pattern

 

 

No1-100

Hot rolled, teardrop pattern finish