With the BASF polyphenylsulphone (PPSU) portfolio, bottles can be manufactured by injection stretch blow moulding, extrusion blow moulding, and injection moulding.
BASF has expanded its Ultrason P portfolio for the use to manufacture bottles by all three processing methods. The two polyphenylsulphone (PPSU) grades Ultrason P 2010 and P 3010 can be used in injection stretch blow moulding, extrusion blow moulding, and injection moulding to manufacture bottles for adults and babies that are safe to use, robust and chemically resistant as well as available in several designs, shapes and colours.
All three processing methods benefits from the customised properties of the high-temperature thermoplastic – it contains no harmful substances, is approved for food contact, and has strength, chemical resistance and long-term high-temperature stability up to 180-degree Celsius, BASF claimed. Bottles made from the transparent, slightly honey-coloured BASF polyphenylsulphone can withstand sterilisation in a microwave or in hot water.
Georg Grässel, global business development for Ultrason at BASF, commented: “The production of high-quality, safe and stylish bottles for adults and babies presents a challenge that cannot be compared to that of conventional PET, PP or co-polyester bottles.
“The globally widespread processing methods all have their own specific requirements of the materials used – and this is where Ultrason P has proven its value to customers in many different countries. They can choose the most suitable material from our portfolio, and can also benefit from our on-site technical application support and the global availability of the different grades.”
During extrusion blow moulding, the plastic melt is extruded from top to bottom through a circular die to form a tube-shaped parison. Internal pressure is then used to inflate the parison within a mould thus giving the part its shape. The medium-viscosity Ultrason P 3010 is particularly designed for this process due to its inherent high melt strength in contrast to other PPSU materials on the market. This allows the hot, elongated parison to remain stable even near the die, ensuring uniform blow moulding. For complex geometries with different wall thickness and designs, a programmed parison control can be used. This prevents elongation of the parison caused by the parison’s weight and results in uniform wall thickness over the complete length of the bottle.
When injection moulding is used, the bottle body can be injection moulded with or without a cap thread and base, which provides flexibility when it comes to the bottle design or the method used to vent baby bottles. Today, the manufacturing with single and multi-cavity moulds in combination with an upstream hot runner system. The high-flow, low-viscosity Ultrason P 2010 is particularly suited for this, as it makes thin walls possible even when there are long flow paths.
Another widespread manufacturing process, especially for baby bottles in Asia, is injection stretch blow moulding. First a parison looking like a test tube with cap thread is produced in an injection mould, then re-heated and finally stretched and inflated in a blow mould that models the bottle design as a negative. The advantages of Ultrason P 3010 can be primarily found in the rapid cycle times and exact moulding of the bottle cap thread.
Both Ultrason P grades are designed for injection moulding and injection stretch blow moulding because they are particularly easy to process using configured hot runner systems without scrap losses. This makes it possible to produce bottles with Ultrason P that can be used for a long time, and in many different applications areas without compromising the quality of the mechanical and optical properties.