Transport rings made of fibreglass reinforced Exxtral PP for an innovative integrated internal transport system for pot plant growers

Machine manufacturer Flier Holland BV in Barendrecht (NL) and E&O Kunststoffen in Veenendaal (NL) have jointly developed a special transport ring for the internal logistics of pot plant nurseries, made of 10% fibreglass reinforced Exxtral polypropylene (PP) supplied by polymer distributor Distrupol. Flier Holland BV is a leading manufacturer of mechanisation and automation systems for flower and plant growers. E&O Kunststoffen designs and develops customised plastic product solutions for its clients.

The rings are part of an entirely new pot handling system using conveyor belts to move pot plants from the greenhouse to the sorting and packaging shed. The conveyor belts can be connected to an automated grading or loading system for roller containers. At present, the system is in use with three major Dutch growers of various pot plants such as Anthurium, Begonia, Bromelia, Celosia, Kalanchoë and Spathiphylum.

E&O has opted for fibreglass reinforced Exxtral polypropylene to produce these transport rings. "We first tried it with standard PP", explains E&O's Annemarie Hoogendam. "But initial tests carried out by Flier revealed that the material was not rigid enough. In a long line of rings on the conveyor belt, the ones at the front would be exposed to a pressure of about 70 kg, which caused the rings to become distorted."

Lotte Beugeling of Distrupol adds: "Distrupol then got together with E&O to discuss the available options. We advised them to go for a mix of standard and fibreglass reinforced PP. That produces a 10% reinforced material and results in the rigidity that the system requires as well as being sufficiently UV-proof for greenhouse use, a factor of major concern. The material can also be easily coloured to Flier's specifications. Though E&O had to modify the mould due to the materials' different shrinking rate, that turned out to be a more cost effective solution than to go for another polymer altogether."

"As a machinery manufacturer, Flier is above all a metal oriented company," says Annemarie Hoogendam of E&O. "For this new system they had to call on the expertise of a plastics processor for the production of the rings. Originally, when we were producing the first series for them, Flier came to us with a fully worked out design, allowing us to make minor adjustments only, such as stiffening ribs and ridges. For this new series we were involved right from the initial design."

One of the pot plant growers now operating the Flier system is LKP Plants III in Moerkapelle, the Netherlands. The company exclusively grows Bromelia on a 30,000 m2 site. The grower's internal logistics are fully automated. "In our company, hardly anyone enters the greenhouse any more these days," tells Marco Koolhaas of LKP Plants. "We indicate on the computer which growing containers are ready for despatch. A robot then picks the plants from that container and places them in the rings on a conveyor belt to transport them to the shed at the front of the nursery. There the plants are automatically sorted and moved to a buffer system where they remain for one to five days, after which they are packaged to order. The rings ensure that the plants remain safely positioned on the moving conveyor despite the bends to be negotiated. The various components of the system were already in place, such as the fully automated sorter and the conveyor belts, though not in this configuration. We approached various machine manufacturers to come up with a solution, and Flier came closest to what we were looking for. Our system has now been operational for almost a year and saves us an enormous amount of work."