Packaging steels are thin gauge flat carbon steels coated with tin or chrome on both sides. They are very important raw materials for the production of steel packaging, which allow food to be stored safely and with an extended shelf life. The publication focuses on the production process of ETP and ECCS steel, as well as the problem of corrosion of steel packaging.

The topic of legislative changes that require the elimination of chromium (VI) compounds from the steel passivation process was also discussed. The packaging steel industry is currently facing the need to develop a new passivation technology. Leading packaging steel manufacturers in cooperation with varnish and paint suppliers have developed chromium (VI) free technologies by implementing chromium (III) compounds and titanium oxide technology.

Authors focus also on new trends and potential development directions for the packaging steel industry.

This paper demonstrates a low-profile, wide-band, two-element, frequency-reconfigurable MIMO antenna that is suitable for diverse wireless applications of 4G and 5G such as WLAN/Bluetooth (2.4–2.5 GHz), WLAN (2.4–2.484 GHz, 5.15– 5.35 GHz, and 5.725–5.825 GHz), WiMAX (3.3–3.69 GHz and 5.25–5.85 GHz), Sub6GHz band proposed for 5G (3.4–3.6 GHz, 3.6-3.8GHz and 4.4–4.99 GHz), INSAT and satellite X-band(6 to 9.6 GHz). Proposed MIMO favour effortless switching between multiple bands ranging from 2.2 to 9.4 GHz without causing any interference. Both antenna elements in a MIMO array are made up of a single module comprised of a slot-loaded patch and a defective structured ground. Two PIN diodes are placed in the preset position of the ground defect to achieve frequencyreconfigurable qualities. The suggested MIMO antenna has a size of 62 ×25 ×1.5 mm3. Previous reconfigurable MIMO designs improved isolation using a meander line resonator, faulty ground structures, or self-isolation approaches. To attain the isolation requirements of modern devices, stub approach is introduced in proposed design. Without use of stub, simulated isolation is 15dB. The addition of a stub improved isolation even more. At six resonances, measured isolation is greater than 18 dB, the computed correlation coefficient is below 0.0065, and diversity gain is over 9.8 dB.