HMI Interface for the Textile Industry

The application required achieving an IP67 rating for the front frame to ensure safe use in installation environments.
This feature can be obtained by addressing key factors of the aluminum frame to ensure bonding with the front display glass.

• Flatness of the frame
• Adequate roughness of bonded surfaces
• Distribution of fixing points

Correct flatness is achieved by avoiding excessive deformation of the front bezel. The factors contributing to deformation include material selection, milling approach, and specific adjustments to the application of PEM press inserts. 

The use of gaskets requires special attention to ensure uniform pressure on the perimeter. A study of the HMI panel’s fastening system to the supporting structure was necessary, with holes distributed at the high-load points in proportion to the dimensions of the rear casing, ensuring proper sealing of the gasket. 

Finally, to protect against external falling elements, a top cover was created to shield the rear box containing the electronics.

The project had to consider existing constraints:

• Predefined external dimensions
• Predefined internal electronics dimensions

We designed a structure that acts as a “tailored suit” for the device. 

Particularly, to maintain a fixed depth, the box was designed with deformations on the sheet metal via stamping to house and protect the bulkier components without affecting the overall volume. 

This solution, creating a custom fit for the internal electronics, required the development of dedicated stamps for the necessary deformations with the aid of 3D laser cutting technology, allowing processing at every surface level.

Additionally, the design of these stamps was also studied for future 7” and 15” HMI systems to optimize the solution across product versions. 

Another important solution to accommodate the electronics while maintaining dimensional constraints was the creation of custom spacers for the board support, overcoming the limits of traditional standard systems available on the market. 

The press-fit sheet metal spacers were made of stainless steel 303 and brass to ensure proper holding on different laminated supports.

The choice of the most suitable material for creating a mechanical system is made by considering multiple aspects:

• Product usage conditions
• Compatibility with technologies used for processing
• Aesthetic parameters of the finished product
• Costs

The true goal lies in finding the right balance between the various needs. 

The rear box, being recessed, was made of pre-galvanized steel, the best compromise between functionality, electrical conductivity, resistance to corrosion over time, and cost-effectiveness. 

For the front frame, we opted for aluminum alloy 5005, with milling and subsequent natural oxidation treatment, ensuring lightness and a good aesthetic finish resistant to operator use.

This system consists of five different materials (aluminum, pre-oxidized aluminum, pre-galvanized iron, stainless steel, and brass). 

The result was achieved using 13 different technologies (punching, milling, stamping from mold, assembly and application of press inserts, bending, satin finishing, turning, silk-screening, welding, industrial washing, laser cutting, 3D laser cutting, and mold construction), 5 of which were sourced from our trusted network (oxidation, silk-screening, 3D laser cutting, turning, and dedicated mold construction).

1. 5 Materials

2. 13 Technologies

3. 7 Core processes