Now in use on Line 4 at RxPak is a new CR closure concept called the One Piece Squeeze-Lok® Low-Profile Child-Resistant Closure or SQL-LP. It was developed jointly by closure maker Rexam (Evansville IN) and bottle supplier Setco (Anaheim CA). RxPak is among the first to use it commercially.
Injection molded of polypropylene the one-piece SQL-LP is double-shelled. Molded into the inside wall of the outer shell are two “loks” that match two more “loks” in the neck finish of the injection blow-molded high-density polyethylene bottle. These interlocking features prevent the cap from rotating unless opposing finger pads on the skirt of the outside shell are pressed. Pressing the finger pads causes the outer shell to deform from a circle to an oval thus disengaging the “loks” and allowing the cap to be easily removed. The idea is to defeat inquisitive children yet provide ease of opening for adults especially seniors. According to Rexam and Setco seniors liked the closure concept in focus studies because it’s easily squeezed open.
Before the new package arrived RxPak had been using a HDPE bottle with a standard SP-400 threaded neck finish. Applied to it was a two-piece press-and-turn CR closure injection-molded of PP.
RxPak’s Dan White likes the new package because unlike the one it replaces it never requires retorquing after the capped container passes through the induction sealer. The injection-molded “loks” prevent caps from backing off.
“We used to retorque every single bottle by hand which was labor-intensive and unsound from an ergonomics standpoint” says White. Adding a retorquing machine was always an option of course but by switching to the SQL-LP that capital investment becomes unnecessary.
Material cost comparisons between old and new packages were not available from RxPak. But according to Rexam’s Phil Lambert a material cost savings of about 20% can be expected when a two-piece press-and-turn closure is replaced by the one-piece SQL-LP.