What determines the quality of a welded mesh panel?

Introduction

Welded mesh panels are a popular choice for a variety of fencing solutions.? These panels are a strong, versatile option that can offer varying levels of protection depending on the raw material, coating and weld strength. At first glance, these panels can all look very similar but there are a number of crucial factors that determine the quality and performance of a panel, and therefore the overall fencing solution.

At Siddall & Hilton, we pride ourselves on rigorous quality measures to ensure our panels perform under the most extreme of circumstances to ensure you get the performance you demand, every time.? Here are some of the factors we look at:

Core wire diameter & aperture size

The consistent core wire diameter or gauge, along with well-defined aperture sizes, forms the fundamental framework of a robust welded mesh panel. These two factors work in harmony to determine the overall strength, load-bearing capacity, and structural integrity of the panel. The core wire diameter or gauge ensures uniformity and predictability in the wire's tensile strength, minimising weak points that could compromise the panel's performance.

Furthermore, the aperture sizes are crucial in defining the mesh's purpose and functionality. Smaller apertures provide higher security by preventing unauthorised access, while larger apertures offer visibility and are usually lighter in weight and cost-effective, making them suitable for various applications, from perimeter fencing to industrial enclosures.

Weld quality and strength

The welding process is a technical one, with the subsequent quality of a welded mesh panel highly dependent on ensuring every step is completed correctly in line with the given specification.? The welding machine must be set up correctly based on the qualities of the base material, and have the appropriate power relative to wire diameter to ensure the correct weld finish.

The torque setting for testing the weld strength is based on the diameter and tensile of the base wire.? A setting of 70% of wire tensile is important to achieve optimal performance of the resulting panel. ?Any damage to the welding part can be expensive and may cause permanent structural damage to the final product.

Coating Quality

There are a number of different coating options available for welded mesh panels, each with a slightly different result.? These include:

Pre-galvanise:

A process used before the final product is assembled, the wire is immersed or dipped in a “galvanizing bath” of molten zinc for a short period of time. Once the steel is removed from the bath, excess zinc is removed using a mechanical wiper, air knife, or steam. This leaves a relatively thin galvanized coating of zinc, 30 - 80 g/m2. Performing this process before welding the wire prevents distortion during the coating process and ensures a smooth finish. Using pre-galvanised wire does mean that the cut ends of the wire and weld areas are not protected from corrosion, meaning subsequent polyester powder coating is essential. Pre-galvanised products must adhere to the quality standard BS EN 10244-2:2012 as a minimum.

Galfan coating:

Galfan is a zinc-aluminium alloy coating applied before the final product is assembled, the wire is immersed or dipped in a "galvanising bath" of molten zinc (95%) and aluminium (5%) resulting in a coating thickness of 275 - 300 g/m2, this combination provides excellent corrosion protection compared to traditional zinc coating and is often used to extend the service life of a product, achieving 40+ years. Coating the wire before welding prevents panel distortion during the coating process and ensures a smooth finish. Using Galfan wire has the added benefit of providing corrosion protection to the cut ends of the wire and weld areas are protected from corrosion, meaning subsequent polyester powder coating is not required. Galfan-coated products must adhere to the quality standard BS EN 10244-2:2012 as a minimum.

Polyester Powder Coating:

Also known as electrostatic spraying, this process is completed after the welding and manufacturing process and is popular as it creates a thick and durable layer of protection for metal surfaces which is ideal for fencing solutions. Once treated, surfaces are almost impervious to scratches, chips and other surface imperfections, delivering a long-lasting result. PPC products must adhere to the quality standard BS EN 13438:2013 as a minimum.

Hot dip galvanising:

This is a chemical treatment for steel, applied after the manufacturing process, it creates a toughened, long-lasting and corrosion-resistant coating with a service life of 40+ years. Steel is put through a chemical wash to remove all rust, oil and mill scale from the surface before being dipped into a bath of molten zinc heated to around 450°C (860°F), resulting in a thick coating, 400-800 g/m2. Coating the wire after manufacture can cause panel distortion during the dipping process and may result in a rough finish that can be difficult to quality control. After cooling in a quench tank, the zinc coating is then metallurgically bonded to the steel and is ready for use. Hot Dip Galvanised must adhere to the quality standard BS EN ISO 1461:2022 as a minimum.

Tensile wire strength:

Maintaining consistent tensile wire strength throughout a batch or coil is crucial to prevent breakages. When the tensile strength is uniform, it ensures that the wire can withstand the expected forces and stresses without weak points that might lead to failure. In applications like welded mesh fencing, where structural integrity is paramount, even a slight variation in tensile strength could compromise the overall strength and durability of the final product.

Raw Material Control:

All materials used to produce welded mesh panels are subject to rigorous quality checks to ensure proper machine compatibility.? It is crucial that all regulated standards are adhered to; our team of technicians are fully trained in the applications of all relevant British Standards. At Siddall & ?Hilton we are committed to responsible and ethical sourcing and ensure the Material Specification is fully adopted.

Manufacturing Process Excellence:

As well as ensuring we focus on the highest quality materials and equipment, we also understand the importance of the operatives who are involved in the production process.?We have implemented a rigorous training process for all Siddall and Hilton operatives, adhering to our high-quality standards which are based on industry best practices.?

Our machines are regularly monitored and undergo a programme of routine planned maintenance as well as regular performance testing to ensure consistent quality and optimum performance.? Further checks are in place for quality and process control, including work instructions, standard operating procedures and measurement equipment.

Panel Robustness and Testing:

Each welded mesh panel is fully tested to a range of tests, including:

• Tensile strength – particularly important for high-security use, each panel is tested for tensile strength and assessed against security levels certification criteria, such as SR1, SR2 and SR3
• Panel robustness – including stress testing, load-bearing capacity and wind force resistance
• Static load testing – in line with the requirements of BS 1722-14:2017
• Flexibility testing – to ensure there is no warping and that bendability is within a specified tolerance, there are quality checks for flatness tolerance, quality checks for square corners and overall checks to capture how easy the panels are to work with

Quality Control and ISO9001 Accreditation:

All quality control is managed by Siddall and Hilton’s highly-qualified Quality Control Manager, who ensures we are working in line with the requirements of the quality management system ISO9001 accreditation we have achieved, and the robust processes it demands.

Established by the International Organisation for Standardisation, ISO 9001 helps organisations implement clear, repeatable processes to maintain a quality service for their customers every time. It requires accredited organisations to maintain documented information to the extent necessary to support the operation of processes and retain documented information to the extent necessary to have confidence that the processes are being carried out as planned.

In addition to ISO9001, Siddall & Hilton has a comprehensive internal audit programme in place to ensure quality and process standards are being adhered to, as well as biannual accreditation audits by all relevant industry bodies.

Conclusion

At Siddall & Hilton, we pride ourselves on delivering the highest quality and performing welded mesh products to our customers.? We are committed to durable, reliable and consistently top-performing products to meet the needs of the industries we work with. With robust and well-documented processes and ways of working in place, we believe our focus on quality and training means we deliver what you need, time after time.

To talk to us about welded mesh panels for your next project, talk to our team of experts today. You can call us on 01484 401610 or fill in our quick contact form here and we’ll get straight back to you.

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