The solution developed by SIPA, unique in the industry and the subject of a patent application, makes it possible to adjust the core alignment from the front face of the cold half, in contrast to competing solutions that require accessthe back of the core plate. This makes any adjustments easier and faster to carry out during production.Production of high-quality blood collection tubes demands that wall thickness around the circumference is within very tight tolerances. This can only be guaranteed by precise design and especially accurate production of the various elements in the injection mold. While such criteria also apply to more common PET products like bottle preforms, consistently high performance over long-term production is more difficult to ensure with BCTs.
Why is this? There are two specific reasons. First, because BCTs have a diameter much smaller than regular preforms, the various components of the mold also have reduced dimensions. In the specific case of the cores, these obviously also have a small diameter, which means that their stiffness is lower than preform cores. As a result, they are more likely to flex under the pressure of the PET melt if the wave front during injection is not perfectly symmetrical.