A particularly easy and neat way of fitting panels into aluminium frames has been developed recently by Item. Compared with the two main alternatives, the new clamping strips are effective, neat and save time and cost.
One of the traditional methods of inserting panels into aluminium frames is to build the frame around an oversized panel such that the panel fits into the T-slots, and use a lip-seal or cover-profile to eliminate rattles. This has the advantages of low material cost and high security, but has a high labour cost (it takes longer to build the frame, and the panel may even have to be cut out around the fasteners), and it can create difficulties, for example, if a panel subsequently breaks and must be replaced, as the frame must be stripped down.
The second common method is to use multiblocks, several of which are push-and-twisted into the appropriate T-slots, and the panel cut slightly smaller than the aperture, drilled near its edge and then screwed onto the blocks. This method has three advantages: it is very quick despite the drilling; the panels may be retrofitted to the assembled frame and removed at will; and it has a low material cost. Some users, however, do not like the appearance of multiblocks, which inevitably are seen through clear panels, and drilling holes in the panels can pose its own problems.
A third method is by some form of panel clamping system, a particularly elegant version of which has recently been developed by Item. Four Panel-Clamping Strips 8 Al (a thin Z-shaped aluminium extrusion) hook into the main frame T-slots, forming a neat and strong rebate. The panel is then cut slightly smaller than the aperture (it does not matter if the cutting is not good, as the edge will not be seen), and four more securing strips (in a grey polypropylene with a thin thermoplastic elastomer lip) are pushed into the same slot, the lip deforming to fill the gap and maintain pressure on the panel.
From one side, normally the presentation side of the machine, the panel is nearly flush with the outer frame profiles, and is very secure because the panel cannot be removed from this side. From the other side, the plastic securing strips are designed to give a smooth finish, assisting where cleaning or laminar airflow is important. Because only the very thin lip right against the panel distorts when fitted, it is easy to achieve a neat appearance in the corners - which tends to be a bugbear with this type of panel fixing.
This method of securing panels offers both speed and simplicity, may be retrofitted to any Line-8 frame, and does not require accurate panel cutting. It also is very neat looking and works well in, for example, a clean-room environment.
Panel Clamping Strips 8 are available ex-stock from Machine Building Systems.