Experimental study of preform reheat temperature in two‐stage injection stretch blow molding

Abstract

Plastic bottles used for carbonated soft drink (CSD) packages are most commonly made from poly(ethylene terephthalate) (PET) by injection stretch blow molding (ISBM). The required bottle performance criteria vary with its application but typically include top‐load strength, burst strength, optical clarity, thermal stability, and barrier properties. An experimental study of the preform reheat temperature was carried out for a 1.5‐l PET bottle produced by a two‐stage ISBM machine. The overall temperature of the preform was changed by controlling the reheat temperature of the preform; all the other process variables and preform dimensions were kept constant. Performance of the PET bottles for differing preform reheat temperatures was measured experimentally in terms of top‐load strength, burst pressure resistance, environmental stress cracking resistance (ESCR), and thermal stability. It was observed that the ESCR values and the burst strength decreased with the increasing reheat temperature, whereas the top‐load strength increased. Thermal stability tests confirmed that high‐preform reheat temperatures had a detrimental effect on the self‐standing feature of the bottles. Decreasing the reheat temperature as low as possible, while maintaining a certain preform temperature profile, ensured high ESCR and burst strength values and prevented the concaveness at the bottom of the bottle. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

Mechanical reprocessing of polyolefin waste: A review

“…Extensive research has been carried out in this stage, especially in terms of collection and sorting techniques, such as flotation , optical sorting, density separation , electrical separation , etc. In the second stage, the recycled plastic pellets, powder or flakes are molten and reprocessed into final products by resin molding techniques , including extrusion molding , injection molding , blow molding , vacuum molding , inflation molding , melt spinning , etc.…”

Development of Recycled Polypropylene Plastic Fibres to Reinforce Concrete

“…Extensive research has been carried out in this stage, especially in terms of collection and sorting techniques (Carvalho et al, 2012), such as flotation, optical sorting, density separation, electrical separation, etc. In the second stage the recycled plastic pellets, powder or flakes are molten and reprocessed into final products by resin moulding techniques (Demirel and Daver, 2013), including extrusion moulding, injection moulding, blow moulding, vacuum moulding, inflation moulding, etc.…”

Infrared heating modeling of recycled PET preforms in injection stretch blow molding process

“…This is explained by the fact that this temperature distribution has a significant impact on the viscoplastic properties of PET during forming and, thus on the dynamics of the SBM phase, which determine the final thickness distribution of the bottle. Previous works showed that the optimal temperature distribution is hard to obtain experimentally [9,10]. Additionally, rPET represents variability of optical properties due to contaminants and recycling process.…”