Metzingen. When industrial accidents involving chemical substances occur, immediate treatment of affected skin and eyes is vital. To make sure no time is lost, the rinsing station from Prevor is designed to guarantee instantaneous opening and removal. The latest version of the rinsing station, which comes with a frost-proof box, also complies with this requirement. The contents are easily accessible within the Storopack container, while assuring lasting protection from outside influences. Nothing can penetrate to spoil the emergency rinsing agent or impair its effect – including temperatures down to -40°C, ultra-fine dust or salty splash water.
For more than 50 years, Prevor has been involved in research and development work for the safe handling of hazardous materials. The specialist supplier from France is based in Valmondois, and has representations in and around 100 countries. The rinsing station is part of the company’s first-aid equipment portfolio. It is available with the polyvalent rinsing solution Previn for all kinds of chemicals, or with Hexafluorine specifically for hydrofluoric acid and its derivatives. The solutions prevent chemicals from penetrating the tissue and causing caustic burns.
With the number of countries playing an active role in the world economy growing ever larger, the proportion of industrial plant and equipment installed in regions at risk from extreme weather conditions is also on the rise. As a result, there is an ever more pressing need for safety equipment capable of permanently withstanding adverse climate conditions.
Although the Prevor product range already included a frost-proof version of its rinsing station, in order to ensure maintenance of the required mean temperature of between +5°C and + 8°C, an integrated heating device was needed. The container itself was made of thermoplastic without any specific protection against low temperatures.
Having decided to find a way of improving the eco balance of the box, Prevor opted in favor of a new solution made of insulating plastic. Even in cases where the heating device is still necessary, it now has to be activated less frequently. As a positive added bonus, an integrated passive low temperature protection helps simplify the achievement of even temperature regulation.
The heating device comprises two grounded metal plates and a self-regulating heating cable with room thermostat. If the temperature drops below a threshold of +5°C, the device switches itself on. A safety thermostat (50°C) is located at the plate contacts.
The basic appearance and internal structure of the container have remained the same. It is fitted with three vertical holding fixtures, on the outside for the 500 ml bottles of Previn or Hexafluorine, and in the center, one bottle of after-wash (200 ml). Because the bottle containing the after-wash is located further back behind the rinsing solution bottles, errors in the sequence of use are reliably eliminated. Horizontally below is a plug-in facility which contains either a spray can with 200 ml of Previn for small splashes on the skin or, in the case of the Hexafluorine rinsing station, a tube of calcium gluconate gel containing 28 g for direct skin application.
The order to develop the new box was awarded to Storopack in Anetz (France). The design by the molding experts had to fulfill two functions: Firstly it had to comply with the specified design and functionality requirements, and in addition, these requirements had to be implemented in a form which allowed for affordable manufacture.
The team used the material EPP (expanded polypropylene), which fulfils all the necessary conditions. As well as being non-brittle, it offers very good thermal insulation, is UV resistant, and is insensitive to water as well as most oils and chemicals. The container can be exposed to all kinds of weather conditions.
Because speed is of the essence in any emergency situation, the most important task for Storopack was how to configure the opening mechanism. The boxes are mounted at around shoulder height on the wall. In the event of an emergency, the rinsing station should be capable of being opened with a simple downward movement without the exertion of force. Consequently, the handle was designed to work by a downward pushing action. It has sufficient clamping force to ensure the housing remains shut and sealed tight, and at the same time is shaped to allow one-handed opening. There is no recessed grip, as this would encourage the collection of water.
Another challenge which faced the design team in terms of achieving precisely the right material tension was the design of the bottle fixtures. The webs had to be strong enough to withstand the replacement of rinsing solution without breaking. Previn is exchanged once a year, Hexafluorine every two years. To allow the air to circulate freely in the box, the bottles should also not lie flush against another surface.
The overall box comprises a base on which the heating plates are positioned, the main box body and the hinged lid. The click locking mechanism between the base and body is designed to provide a tight seal while still reliably withstanding any tendency to break off during the joining process. A similar requirement is imposed on the insertion-type hinge, whose components are formed as a continuation of the body and lid. The hinging movement is sturdy and smooth running.
Which mechanism to choose and in which shape and thickness in order to achieve the optimum functionality of the bottle fixture, the plug-in connection or the hinge for the lid: All these were questions which were addressed initially by the Storopack team using suitable calculations, as well as CAD design and simulation software.
This process was followed by creating a model using the CNC milling machine and the execution of suitable tests. An appraisal of the prototypes encompasses more than just the calculable facts and material indicators – it also takes in practical experience from the production process. After all, the housing is not produced in the same way as the model by milling from solid, but foamed in the mold. As Storopack is commissioned not only to design but also produce the box, the necessary level of expertise is guaranteed.
All the design decisions along the way were checked for their compliance with the requirement for affordable production. By using a small-format tool, it is possible to work on a machine capable of producing at competitive piece costs. By “tweaking” and making detail adjustments, the Storopack team managed to ensure that all the molded parts fitted into the dimensions of this tool type.
After being granted the necessary certifications, Prevor was able to add the frost-proof EPP rinsing station to its offered product range by September 2009. The Previn rinsing station is orange, while black has become the established identifying color for the Hexafluorine rinsing station.
The responsible Project Manager at Prevor, Aymeric Laout, is extremely satisfied with the outcome: “We were pretty frustrated after another supplier had failed to find a solution which addressed all our requirements. We turned a corner with Storopack, and we were quickly able to see light at the end of the tunnel. The experience gathered by the company from similar past development assignments clearly shone through. The result has impressed not only us but also our customers – the proof is in sales figures
50 per cent above our expectations.” A follow-on project is already in the test phase: this entails the integration of a Perspex window in the lid. Storopack has also been given an order to produce a PPE box with no insulating function
