The performance of DuPont Delrin acetal resin in terms of its strength, flexibility and fatigue resistance is critical to the reliable operation of tray arresters fitted in Medstor medical cabinets from Mailbox Mouldings International Ltd. (Stalybridge, England). Used in combination with two-way angled liners, the arresters prevent accidental removal of storage trays from the cabinet while, simultaneously, allowing them to be extended at an angle for easier retrieval of stock at high levels.
The Medstor two-way angled liners are fitted as standard throughout the Medstor cabinet range and are also available as separate panels for self-fit applications. They can be installed in two directions determined by contours moulded in the high-impact polystyrene liner – either to provide a drop-down angle for use above head height or, by turning them through 180 degrees, for smooth horizontal tray retrieval. Either way, the key role of the arresters, moulded in Delrin and push-fit assembled to the liners (one is used for each side of the tray), is to securely retain the tray in the cabinet and avoid its accidental removal. This is achieved by a flexible arm as part of the arrester’s design, which presses against the edge of a moulded groove in the polycarbonate tray when it is fully extended. The flexibility and elastic memory of the arrester ensures its reliable operation at both the angled and horizontal tray position.
- The performance of Delrin was critical to the design and function of the
arrester - explains Allison Seabourne, sales director at the healthcare division of Mailbox Mouldings. - Its mechanical strength is sufficient to secure the tray in the cabinet, while it is flexible enough to allow the tray to be drawn out at the angle determined by the liner.
The intrinsically good wear resistance and frictional behaviour of Delrin acetal resins facilitate a smooth and virtually noiseless retrieval of the trays without lubrication. Rigorous in-house testing confirmed that the arrester would return reliably and effectively to its rest position without breaking after 15,000 cycles of extending and returning the tray at an angle. - As a result, we can confidently predict that the combined system of the arrester, liner and tray will comfortably outlive their life cycle of 15 years - confirms Allison Seabourne.
The push-fit arresters, which work with all Medstor trays, do not require tools for assembly to the liners and can easily be removed by hand for cleaning or repositioning. Launched during November 2008, they are available for both left and right hand fittings and come complete with a universal blanking piece.
