the polymeric panel 7 once the leading edge of the first polymeric panel has been provided with a flexible extension portion the next panel is moved into a position such that its leading edge and the trailing edge of the first panel can be provided with respective flexible extension portions simultaneously this process can then be repeated for subsequent panels making the injection molding process more efficient as an alternative the extension portions may be injection molded in place by using an injection molding clamp such as model wdh 35 s vertical clamp horizontal injection insert molding machine commercially available from autojectors inc of albion indiana fig6 shows a top trim piece 42 for an office partition trim piece 42 comprises thermoplastic portion 40 and end sealing thermoplastic portion 44 injection molded onto surface 41 see fig6 a and extending therefrom thermoplastic portion 44 also has groove 43 fig6 a shows the underside 41 of thermoplastic portion 40 shown in fig7 fig7 shows office partition 50 having wall portion 53 and top trim piece 42 shown sectioned so as to show the position of flexible portion 44 injection molded onto the underside thereof flexible portion 44 extends from top trim piece 42 so as to be able to engage side trim piece 45 via groove 43 to form a trim perimeter and to help to hold the trim pieces together by virtue of being flexible portion 44 is able to engage side trim piece 45 by side trim piece 45 being slid vertically into place note directional arrows in fig7 so as to engage groove 43 in portion 44 this can be appreciated f farther by reference to fig9 which shows side trim piece 45 having lip portion 46 which engages groove.