Moulders look to innovative techniques
2020年04月23日

Whether it be furniture, automotive or electronics, the plastics processing industry is making more use of assisted moulding techniques

At the Italian Plast fair in Milan in March, Romi Sandretto hosted what was billed as the world's first "live" demonstration of a steam-powered mould temperature cycling production process.

UK-based Gas Injection Worldwide's (GIWW) Rapid Temperature Cycling - RTC - technology was running throughout the show producing a high gloss surface test component.

RTC does exactly what the name suggests; it cycles the mould temperature so that melt is injected into a hot steam-heated mould before rapid cooling is applied to the filled cavity. The technology has long been used in the electronics sector in Asia, where it can eliminate visible flow lines and surface marking.

However, the use of steam has limited its appeal to newer users.

GIWW believes it can overcome that reluctance with its newly developed DSG steam generation unit, which can be located beside the press to eliminate the usual trailing pipework.

"We have developed the DSG system to make RTC technology more attractive to the SME moulder, specifically automotive suppliers," says Raymond Foad, sales director at GIWW.

GIWW also showed its new SWC03V5 steam / water controller on the stand, which can integrate gas assisted moulding. Foad says there is a really strong synergy between the two technologies. He believes that the next generation of LCD TVs, which will be even thinner than today's models, will make use of both technologies.

Microcellular foam moulding can help achieve effective filling of complex and long flow path components. The US subsidiary of Inalfa Roof Systems is producing a large one-piece sunroof frame for a US OEM using Mucell technology from Trexel.

Felice Bonucci, who is manager for value management for Inalfa Roof Systems at Auburn Hills in the US, says the 1.5m2 part was challenging for more than its size.

"In addition to its size, there are metal inserts, along with four metal tubes and this makes production difficult. The tubes do not allow for material shrinkage as the parts warp," he says.

Elsewhere in the automotive sector, Visteon Interiors Slovakia is using the Plastic Expulsion Process (PEP) from Cinpres Gas Injection to improve the appearance and durability of lightweighted injection moulded door pockets.

"Our aim was to produce a durable component containing both thick and thin sections, without compromising cycle times or component weight," says Visteon Interiors Slovakia plant manager Rene Gralines.

Gas assisted moulding is also being used in the furniture industry.

Italian company Magis is no stranger to the technology - its gas assisted glass reinforced PP Air Chair design has been in production since 2000. Now, however, the company has introduced a new addition to its line - Chair First.

Designed by Stefano Giovannoni, Chair First takes the gas moulding technique one step further, using it to core out not only the frame but also elements in the seat and backrest. Magis claims this sets another first for the technology.

Gas assisted moulding is also used in production of the latest garden chair by French designers Ronan and Erwan Bouroullec for the Swiss manufacturer Vitra. The Vegetal chair, which launches this summer, is made from BASF's Miramid reinforced PA and is inspired by the organic architectural forms of late 19th century North America.

The 5.5kg chair is produced in two steps: the seat shell and the two front legs are formed in the first processing stage followed by the two rear legs. Egon Br???uning, who has worked at Vitra for 45 years, described it as the most complicated project he has ever worked on.