MHT technology used in ASB Nissei single-stage process
128, 144 or even 192 preforms in a single shot. Everything in the drinks industry is geared towards high flow rates, and the two-stage procedure, where preforms are only later blown into bottles, has become established. But for special applications and moderate item quantities, the single-stage process also has its strengths. ASB Nissei and MHT have been working on this together for several years.
MHT Mold & Hotrunner Technology is well-known for its multi-cavity moulds and for pushing the cavity count just a little higher on each machine type. But since 2006, also almost 200 hot halves with up to 24 cavities have been created for one special customer: ASB Nissei.
In the Japanese company’s single-stage procedure, the entire process from granulate to finished container takes place in one complete system which is also interesting regarding the energy consumption. The preforms are injection moulded, then immediately conditioned and stretch-blown into the final shape. The cold mould halves need to be easily movable in terms of size and weight so they can transport the preforms to their subsequent production stage. For this reason, they have a lower number of cavities than usual. Horizontal injection moulding machines dominate elsewhere in the PET sector but here, a vertical construction is used. This means that the cold half is already in the correct position for the subsequent process and the preforms can be demoulded using gravity.
In the hot half, the filling of the cavities is effected not in the usual way but by using a lateral sprue bushing. The balancing of the hot runner therefore becomes more sophisticated so as to avoid crystallinity and other preform flaws. MHT builds its hot runners in-house and in 1998 was a sector pioneer for vertical moulds. Itself a pioneer since 1979 in the single-stage process, ASB Japan uses this experience for ambitious projects or its own capacity bottlenecks. Since 2012, the Indian subsidiary has also been placing orders with the mould specialist from Hesse in Germany. CEO Christian Wagner, Jérémie Cuny (Business Development Director) and Sales Manager Prince Rudra have already visited the site in Maharashtra.
The single-stage procedure is especially suitable for applications with somewhat lower quantity requirements, for example in the food or cosmetics sector, and also for reusable PET bottles.