There are a number of factors to take into account when specifying an enclosure for handheld or portable electronics equipment. To meet requirements, OKW and ROLEC offer a number of solutions

If you are specifying an enclosure for a portable or handheld device, you will need to think about a number of factors. Housing a product or device that will be carried by the user means the enclosure needs to be relatively light, not too large, yet robust enough to withstand everyday use – which could include rough treatment and even the possibility of being dropped. It will also have to be comfortable to use and hold, visually pleasing, and be capable of surviving the environment in which it is to be used – in a dusty factory, or outdoors, for example. It may also need a battery compartment.

To help, OKW and ROLEC have developed a range of enclosures specifically for such devices.

Handheld devices

For handheld electronics which are to be used in harsh indoor or outdoor environments, ROLEC offers its handCASE range, which has recently been extended with four new models with a full format top recess for membrane keypads or product labels.

Rated to IP66, these are manufactured from diecast aluminium GD AL Si 12 and have a high degree of EMC shielding. In fact, the range consists of three separate diecastings: top, base and battery compartment lid, plus two moulded TPE sealing gaskets and four screw gaskets.

Suitable applications for these are said to include test and measurement equipment, machine and robot controllers, detection equipment, and data logging units.

There are now two versions available – type S which has a ‘T’ shaped top recesss and is painted in black and silver; and type ‘R’ which has a full format top recess for membrane keypads or product labels and is painted light grey.

As for sizes, the four new models mean the range now consists of eight versions with external dimensions of 180 x 80 x 42mm, 220 x 100 x 42mm, or 220 x 100 x 62mm. The two smaller sizes have an integral battery compartment for four 1.5V AA cells or two 9V cells.

Also for portable electronics equipment is OKW’s CARRYTEC range of plastic enclosures, which have a contoured design and an ergonomic integrated handle for carrying the enclosure during operation. These are suitable for such applications as medical and wellness equipment, data recording and monitoring, communications technology, safety systems, measuring and control instruments, and agricultural and forest management electronics.

This range is moulded in off-white ABS, which is suitable for indoor applications such as medical equipment; and also in lava grey fibreglass reinforced polyamide which is suitable for tougher outdoor applications.

For extra protection, an IP54 rated sealing kit is available.

These enclosures are moulded in three parts: top, bottom and handle, while the handle grip is moulded in soft touch TPE. Furthermore, the top section has a recessed area for mounting pushbuttons, membrane keypads, displays or touchscreens; while the inset sections on the underside are for cable connections and switches. Accessories include battery compartments for five 1.5V AA cells and a medical holding clamp for round tubes or rails.

A third product suitable for such applications is the BLOB series. During the development of these, the company set out to create a different style of housing that, it claims, ‘would employ touch and feel to impart the functionality of the electronics’. The forms employed had to be suitable for a wide range of users with different hand sizes and grasping volumes.

The result is a range of contoured enclosures with which the users’ fingers naturally rest in the control areas. As a result, explains OKW, the user naturally understands how to use the electronics without instructions. Keypads and controls can be easily located in these areas.

There are three different types in the range. The handheld UNIT version has external dimensions of 130 x 60 x 30mm, with a lower grasp area and a recessed keypad/control section. This is suitable for left or right handed operation. The CONTROL version has external dimensions of 114 x 76 x 31mm and can be held with one hand and operated with the other. Depending on the position and definition of the display and operating area, different sensory gripping options are available.

The third product is the PANEL model. Measuring 200 x 165 x 36mm, this is designed for handheld or desktop operation. All models can be operated with round (1.5V AAA or AA) or button cells.

Renewable materials

It is also now possible to specify

OKW’s design-oriented standard plastic enclosures in a bioplastic material, manufactured entirely from renewable raw materials.

Bioplastics are largely CO2 neutral – after use, materials made from plants release only the same amount of CO2 as they absorbed from the atmosphere during their growth phase, explains the company.

Following comprehensive testing, OKW selected BIOGRADE C7500 plastic, produced by FkuR Kunststoff of Germany. This is obtained from 100% renewable raw materials, with the initial products being cotton or wood. At the start of the process, the purified cellulose is esterified to obtain cellulose acetate (CA), which is then only slightly modified. This material has similar properties to ABS and can be processed using the normal injection moulding method.

For indoor applications there are no restrictions to the lifecycle of the enclosure; and the heat distortion temperature is up to 123°C. Parts made from this material are biodegradeable. In addition, customer-specific colouring is possible through the use of 15 natural dyes.