Extending shelf-life with MAP
Laser micro-perforation has the ability to extend the shelf life of vegetables, fruit and salads. By laser drilling the film used to package these convenience foods, the permeability of the package is tailored to the respiration conditions of the contents, providing the right level of Oxygen and moisture to extend the shelf-life by several days, reducing waste and improving the supply chain. This technology of laser micro-perforation for Modified Atmosphere Packaging (MAP) is an area of expertise for COHERENT-ROFIN.
A number of holes (typically smaller than 0.1 mm diameter, almost invisible to the naked eye) are drilled by laser, usually on a modified Slitter Rewinder which has the laser source and optical beam delivery fitted to it. With conventional laser perforation, high winder speeds can result in oval holes (larger than programmed in the direction of travel), however COHERENT-ROFIN Web Movement Compensation (WMC) technology allows optical adjustment to enable round holes at speeds up to 350 m/min. In many cases an existing Slitter Rewinder can be retrofitted to add the laser perforation capability to a proven production system.
To assist in the design of MAP packaging, COHERENT-ROFIN has introduced a software design package StarMAP based on Oxygen transmission rates of various foods. StarMAP allows the number and diameter of holes per pack to be calculated, either based on the generic data from a database of over 160 varieties of fruits and vegetables, or using data gathered from actual foods placed in a sensor-equipped housing.
Optional vision system solutions enable the real-time monitoring of diameter and presence/absence of holes drilled, providing quality assurance to the supplier and end-user of the packaging film that the film is fit for purpose. COHERENT-ROFIN introduced VisionPerfoControl, a system optimised to image processing of small diameter holes at high speed with low contrast.
Easy opening with laser scribe lines
Many pouches and other forms of contemporary packaging benefit from the addition of easy-opening scribe lines. Where packaging needs to be opened without spilling the contents or using scissors, a laser scribe significantly improves the consumer experience. The material used in such applications is a laminate of several layers of different thicknesses that perform various functions.
Laser scribing can accurately remove one layer of material to enable selective weakening of the film, producing a tear line without damaging the sealing properties of the package before opening. Applications come from all sectors and include coffee, sugar, confectionary, pet food, cooking sauces and hygiene products.
Machinery with either web-direction or cross-web scribing is available from COHERENT-ROFIN, configurable in terms of web width, number of lines and scribing speed. Custom configuration of the machine gives the best results, so a consultation with the applications team is highly recommended to see what options and budgets are appropriate.
High Speed Cutting
Lasers have the power to cut with high speed and great flexibility, in paper, card and plastic film – which allows food, pharmaceutical and other industries to benefit from the non-contact benefits of laser cutting together with the fact that new shapes can be cut by a simple software change. The potential pay-back on the investment in a laser system from reduced tooling costs can easily justify the capital purchase in many instances.
Flexible Machinery Options from COHERENT-ROFIN
New for 2017 is an advanced machine design which combines the capabilities of perforation and scribing, with automatic adjustment of focus and software control to configure the direction and geometry of scribing or the diameter of holes to be perforated. Advanced scanners allow the drilling of holes down to 0.1 mm diameter or with a machine optical configuration and focus adjustment the machine can be re-configured to perform scribing of easy-opening lines in either the web direction or cross-web.
Previously it would have been necessary to purchase two dedicated machines if both applications were required in the same organisation – but now it is possible to achieve a more flexible approach.
See ROFIN at INTERPACK in Dusseldorf
COHERENT-ROFIN will be exhibiting at the INTERPACK Show in Dusseldorf from 4-10 May 2017 in Hall 12, Booth B39. Take the opportunity to find out what is possible in laser applications that enhance the value of packaging, and see samples of the technology available. COHERENT-ROFIN offers many solutions in the supply chain for packaging including perforation, scribing and laser marking.
Since 2016, ROFIN has merged with the leading global laser manufacturer, Coherent Inc. based in Santa Clara, California (USA). The packaging business has headquarters in Gilching, Munich (Germany), where many unique solutions have been developed to advance the technology of flexible film packaging.
ROFIN-BAASEL Lasertech GmbH & Co KG