Vacuums – you find them in space, Thermos flasks, and lightbulbs. But now Spanish company Ulma, headquartered in the Basque hills, is hoping to shake up the fresh produce packaging industry by utilising vacuums in its bagging machines.
Its new product is the latest breakthrough in a competitive industry, with myriad companies and machinery vying to prove their superiority. It uses a vacuum created by what’s known as a “Venturi ring” to literally suck salad leaves right to the bottom of the bag before it is sealed, signed and delivered. It may seem like a technicality, but the effect is very tangible: fewer botched seals and more efficient filling means less plastic use, as bag sizes can be shrunk.
Ulma’s patented Venturi system is already being rolled out in southern Europe, while vertical form fill seal (VFFS) business manager and UK distributor of the machines, Steve Brooks, says people are already beginning to take note in Britain, with a trial currently ongoing at a major salad supplier.
Brooks describes the process: “The Venturi ring creates a vacuum under the produce and accelerates it down the tube. This means that product is pulled down to the bottom of the bag with air at speed before then sealing the pack shut.
“This process mitigates damage, as the produce requires no manual handling. In comparison, the forming tube of conventional packaging machinery can impair the quality of delicate produce and cause bruising.”
With salad leaves properly packed into the bottom of the bag, it can be sealed lower down, cutting the size of the bags by around a third. “Supermarkets can employ the Venturi to reduce plastic film waste, saving money and the amount of plastic used. Given the current environmental focus of a growing number of supermarkets, distributors and manufacturers, it is becoming increasingly pertinent to demonstrate this.”
All good for shoppers, but producers may be equally concerned about the bottom line: costs. One of the original difficulties of packaging was produce getting caught in the seal, resulting in waste and higher costs. Brooks says: “The packing of salad leaf has typically been carried out using a vertical machine, owing to the weight of the product. However, using this method there is a greater risk of re-work required for bags with product stuck in the seal, estimated at between seven to ten per cent.”
In response to this, the ultrasonic seal packer was developed over a decade ago, which produced a more efficient seal, capable of binding through produce caught in the seal area, reducing the botch jobs to less than one per cent. It seemed like an unbeatable solution had been found. There was a caveat though. Ultrasonic sealers are expensive pieces of gear, and naturally such huge investments can make business owners nervous, costing up to £40-50,000 for a sealing unit, which also requires a backup on site, according to Brooks.
The Ulma Venturi system is used with the conventional cheaper heat-sealing method, but with a vacuum sucking salad to the bottom of the bag, the re-work rate remains below one per cent.
Furthermore, they require little maintenance. In today’s uncertain business climate, labour savings are a must, and the Venturi packer needs just two operators. “Conventionally, the use of a flow wrap machine requires between ten to 16 employees to place the product onto scales and a conveyor belt, while someone else may be tasked with tightly compacting the product in to the bag to ensure it all fits,” says Brooks. “The Venturi system requires just two – one to load the machine, and the other to operate the system”.
