Why membrane keypads continue to be a turn on for the security sector
The digital age has meant the mere mention of the word ‘security’ is usually related to information/cybersecurity not the wider UK security sector, which increasingly plays an important role in supporting both personal and national security. In 2015, a report by ADS Outlook valued the UK security industry at a staggering £9.1billion, with over 120,000 high value jobs.
An important component of security systems are the control panels which need to incorporate a simplified, but effective design. As a result, graphic overlays and membrane keypads have been growing in popularity across the industry over the last few years, as manufacturers avoid older and more bulky keypads.
Manufacturers choose membrane keypads as they are extremely robust and can handle a variety of extreme conditions. Keypads are also versatile, and can be used on a variety of different products including; electronic access control panels and CCTV, intruder alarms, radio systems, gates, barriers, and door entry systems.
The most prevalent use of membrane keypads is either in the manufacture of access control systems (particularly those that use a pin number for access) or alarm systems, where a membrane keypad is often used on the control panel at the entrance to a property.
Membrane keypads are made up of three main elements which include a graphic overlay, an electrically insulating spacer, and a printed film circuit. They can be tactile or non-tactile, and are an ideal option for many products across a wide range of industries. But, if you’re considering using them for the first time, the following factors must be considered:
Why should I use a membrane keypad?
Membrane keypads can also be compact, in some cases assemblies can be designed as thin as 0.4mm, giving a more modern look than other keypads – for example a rubber keymat mounted onto a PCB switch. Advances in manufacturing means that silver circuits can be printed double sided to produce the equivalent of four layer PCBs that can fit smaller and more compact applications.
In many cases, flame retardants can be incorporated into the manufacturing process. For instance, Fascia manufactures keypads and overlays which incorporate Lexan flame retardant clear polycarbonate films that have a listing of UL94-V0. These films are suitable for most applications and can be used effectively when thermoforming, hydroforming, embossing, die-cutting, folding, and bending.
Before going into production, it’s also a good idea to get some advice on the different features you may want to consider. These include:
Appearance – Tailor-made in design, shape and colour, membrane keypads can incorporate a range of finishes to give a sleek and modern look. A wide selection of surface finishes can be combined with a variety of embossing techniques. For instance, a hardcoat polyester film gives a brushed stainless-steel effect, and chrome ink technology gives a bright metallic finish. Selective UV finishes together with insertable legend systems can also be incorporated to provide maximum adaptability.
Shielding – Overlays and keypads must be impervious to interference from energy to protect internal components. In particular, products must be shielded from radio frequency interference (RFI) and electromagnetic waves (EMC) to reduce the risk of the product malfunctioning without compromising its reliability.
Sealability – IP (Ingress Protection) ratings define the level of protection a membrane keypad has from the intrusion of dirt and moisture. The first digit represents the protection of ingress from solid objects, and the second, from the ingress of liquids. Fascia can IP rate keypads up to IP68, to prevent both water and dirt intrusion. This ensures the keypad is sealed and cannot be damaged even when submerged in water.
Meeting these high standards are not common place across the UK industry. In fact, we have been approached by a number of security manufacturers recently who have had IP related problems. For instance, a manufacturer approached us as they had a water ingress issue with a product they were working on with their incumbent membrane supplier.
Having looked at the design of the product, we ascertained that the IP rating of 54 was not appropriate for where the product would be situated, and this was causing the failures. IP54 will protect against dust and limited ingress, while IP67 will provide total protection against dust and against the effect of immersion between 15cm and 1m. We therefore recommended the best solution was to change to a fully water proof IP67 rated membrane. Since these changes were introduced the customer hasn’t experienced any failures.
Backlighting or LEDs – Membrane keypads can include a wealth of specialist features, such as a ‘secret-til-lit’ function, fibre optics, electro-luminescent back illumination, or surface mounted light emitting diodes (LEDs) – which can be used as warning or indicator lights, due to their effective way of communicating the status of the device to the user.
Finally, it is also important that each membrane keypad is value engineered. At Fascia, we identify cost savings by taking a value engineering approach to make suggestions about materials, adhesives, and specification of parts, to ensure customers receive the most cost effective, high-quality product possible.
