The market demands compelling packaging that simultaneously meets a number of conflicting requirements in terms of cosmetics, functionality, and cost. Laser processing can be a key competitive advantage for manufacturers in numerous cutting, slitting, perforating, and marking tasks on a wide variety of plastics, foils, and multilayer films. Non-contact laser processing enables web-compatible, high-speed processing for maximum throughput, consistent results for high yields and superior quality, and exceptional reliability for minimum downtime.
Coherent provides laser sources, laser-based sub-systems and turnkey laser machines for a wide range of packaging tasks including slitting for easy opening, perforating for freshness preservation, and an extensive variety of marking solutions. If you have a process that can benefit from laser processing, Coherent can supply you with both the optimum product and the expertise to enable your success.
Almost all packaging foils are multilayered structures, and the properties of these various materials and the way they are processed can create challenges for converting tasks. Coherent has the breadth of product to deliver the right solution for each application, as well as the application know-how to help ensure optimum results.
Laser scribing in web-direction
For applications which require scribing in the direction of web movement, lasers equipped with fixed optics and beam splitters offer an ideal solution. Each laser beam scribes a path onto the web material via focusing optics. Scribes may be continuous or non-continuous.
For this application we recommend: StarPack WD.
About 80% of all bags and pouches require cross-web set-up in order to achieve various production processes, such as easy-open scribing. Registration marks are used to synchronize scribing geometries and film imprints. This is implemented in practice using lasers equipped with fast scanner heads which compensate for the web movement, and which can produce any kind of structure, even at high speeds using on-the-fly processing. This includes scribing of semicircular or linear tear structures on pouch edges.
For this application we recommend: StarPack CW.
For some packaging applications scribing easy-open structures can only be performed after the pouch is already shaped. The finished bag must then be scribed on the front and rear simultaneously in order to assure alignment of the scribing structures on both sides.
For these applications we recommend: StarPack Pouch.
Laser perforating for easy opening
A laser perforation can also be utilized for easy opening. Specifically, an easy-open structure utilizing a “zipper effect” can be made by a sequence of perforations.
Micro-perforation of films and foils to allow breathability for extended shelf life requires a unique combination of high-speed operation and precision. Specifically, hole size must be highly controllable and consistent in order to allow the required amount of oxygen to pass. And, this perforation must sometimes be performed on multilayer films which react differently to applied laser power.
Delivering consistent hole quality
For applications that require operation in the direction of web movement, lasers equipped with fixed optics and beam splitters offer an ideal solution. Each laser beam perforates a line onto the web material via focusing optics. These lines may be continuous or non-continuous.
Our WMC technology enables perforation with consistent shape at web speeds of up to 400 m/min. Furthermore, it offers consistent quality during web speed changes.
Packaging can be individually optimized and adapted for its specific contents by varying the exact size and number of the holes. This can have a dramatic impact on shelf life.
The regulation of pressure in the package by laser perforation improves product quality and shortens the cooking time for microwave meals.
Laser marking is ideally suited for many materials commonly used in packaging, including paper, foils, cardboard, and polymers. Laser marking is a contact-free process, avoiding any mechanical stress on the packaging. And, because laser marking is tool-free and computer-controlled, it can easily support serialization and produce a wide variety of marks, barcodes, and even greyscale images. Laser marking is also highly compatible with on-the-fly applications, like marking of moving products or roll material.
Laser marking typically operates through one of three mechanisms. First, it can remove outer layers of material to reveal a contrasting layer beneath. It can also be used to engrave into polymers and glass. Or it heats a material to produce a thermochemical color change on various lacquers, plastic films, or labels
Marking on cardboards
Laser marking of expiration dates and batch numbers on cardboard, paper, and plastics can be accomplished through ablation on a color-coated printing area.
Flexible laser processing with marking, kiss-cutting, perforating and cutting of labels
Just-in-time label processing
Within seconds, the laser marks specially developed labels just-in-time with alphanumeric text, serial numbers and barcodes. Marking contents and label shapes are freely programable. After laser marking, the labels are cut out without damaging the liner (kiss-cutting). This application is mainly used in the automotive industry and its suppliers.