Rapid Granulator AB delivers a customised recycling solution for a world leader in CDs/DVDs manufacturing

MPO, the leading independent worldwide manufacturer of digital media (CDs/DVDs), based at Averton, France, has selected a recycling solution from RAPID for the closed loop recycling of sprue scrap.

CDS/DVDs are produced by injection moulding polycarbonate and generate a sprue of approximately two grammes, accounting for 14-15% of the shot size. The MPO Group being involved in mass production volumes of around 450 million units per year, required a 22 tonne-capacity silo for the Averton plant alone to collect the sprue scrap before the implementation of the RAPID recycling solution.

"Because of the increasing cost and limited availability of polycarbonate two years ago, recycling our sprue scrap was a logical step", says Guénaël Le Mouellic, Technical Director for the MPO Group worldwide and the man who initiated and supervised the programme.

"The manufacture of CDs/DVDs requires a resin with flawless optical quality, which means that the recycling solution had to avoid any risk of contamination by foreign matter during handling, and also be free from the mixing of different polycarbonate grades from different suppliers. We therefore decided to go for direct closed loop, beside-the-press recycling of the sprues generated by each injection moulding line."

Added to the fact that the recycling solution had to meet with clean room requirements, similar to those prevailing in hospitals and electronics laboratories, beside-the-press recycling required a granulator of a compact, tailored design in order that it could be installed underneath the moulding machine without it interfering with operations.

Since the granulating/recycling system combines with the moulding machine to form a fully automated, self-contained production unit that recycles 100% of its scrap, maximum reliability of the system was another essential requirement.

"Reliability and low space requirements were the major drawbacks we found with other granulators we tested", says Arnaud d'Argentré, technical manager of the Averton plant. "They would frequently get clogged because some sprues occasionally fall into the cutter-house while still hot and, moreover, their dimensions would not ideally meet the beside-the-press requirement. The result was that the other granulators had a low-level of acceptance by the operators!"

RAPID proposed a customised solution for MPO based on its Series 15 general purpose low-speed granulators. Under the name 1514 CD/DVD, this granulators of 18 kg/h capacity retains a number of Series 15 standard components, including the cutter-house, staggered rotor design with six rotating cassette-knives generating 12 cuts per revolution and a small 0,37 KW motor producing a low rotor speed of 160 rpm for minimum energy consumption.

"But,” says Frédéric Massé, Grand-Ouest Sales Manager for RAPID France, “the granulators infrastructure has been entirely custom-designed to accommodate the specific space requirements and, most importantly, the 1514 CD/DVD solution comprises a totally enclosed, closed-loop cyclone recycling system that keeps the raw material dust-free and does not allow it to come into contact with ambient air. Absolutely no contamination by dust can occur. Moreover, all machine parts in contact with the regrind are stainless steel and daily cleaning is ensured by an automatic self-cleaning system."

"Negotiations with the competition were at an advanced stage when RAPID presented its proposal to develop a granulator tailored specifically for recycling the CD/DVD sprue scrap," adds Mr Le Mouellic. "The RAPID solution enables us to recycle 100% of the regrind with no decrease in the yield. We appreciated the flexibility and speed of response by RAPID. The development process and on-site prototype testing were concluded in less than three months. And the RAPID solution is backed by a 12-month service interval guarantee and a three-year guarantee on non-wear parts."

In concluding, Frédéric Massé says, "The 1514 CD/DVD highlights RAPID's approach to granulating and recycling which combines extens

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