Sleeve seaming shake-up

Finding a market that offers double digit growth and currently a single digit number of serious competitors may sound like a dream come true for a converter. But it is just that prospect that has driven label converter Color Craft of Memphis, USA to invest over $2M in a new facility and capital equipment to convert shrink sleeves for the US market.

In the process the company took delivery last October of what is claimed to be the fastest and most reliable sleeve seamer in the world – the first of Stanford Products recently launched SM10 Seammachine equipment.

Explaining the move vice president sales and co-owner of Color Craft David Seuss said: "In the USA there are some 3,000 pressure sensitive label converters. Six companies dictate some 60 to 80 per cent of the shrink sleeve market - I like the odds of that a bit better."

"Pressure sensitive is becoming less and less a factor and retailers such as Wal-Mart are demanding better looking packaging. For example the dry creamer market, which was previously litho labelled, has gone to shrink sleeves. 360 degree graphics make a big difference."

Founded in 1964 as a division of Memphis Engraving (established in 1924) Color Craft was an early entrant into pressure sensitive labels; 40 years on its new Flexible Packaging division is poised to make its mark on the sleeve market that is predicted to continue a 12 to 15 per cent annual growth rate for some years to come. And its capital investment in sleeve converting has been spent in a way that will maximise the margins.

The company purchased a 24,000ft² building some two blocks away from its headquarters and by October had installed a new Comco press, a Stanford slitter, the seamer and a DM10 Doctor Machine Inspector. The first commercial sleeves were being produced by mid November.

"The 10 colour MSP ProGlide flexo press is configured to print roll film and laminate labels, shrink sleeves and flexible packaging at 750ft/min. It will also laminate with water based adhesive at high speed in line and has an extended dryer. The way Comco can configure a press for you was a major factor in our choice of equipment," said David Seuss. "It also has autoregister, which is a convenient feature for start-up after a stoppage," he added, and is fitted with an Enercon film treater and BST ProMark web inspection unit.

The plant operates entirely on water based inks supplied by Environmental, Monarch and Wikoff. Pre-press is in house. Color Craft is now entirely CtP, operates an Esko Graphics Spark Imaging unit and has invested $250,000 in a DuPont digital FAST plate system. PETG and PVC base substrate is supplied by Klockner Pentaplast. "It has a good reputation for having a consistent product," explained David Seuss. "Eight out of 10 shrink sleeves would be PVC with PETG used where a higher degree of shrink is needed" (such as a necked in container).

After reverse printing, and depending on the width required, the reeled sleeve material is either slit and rewound or edge trimmed on the 738 Stanford cantilevered, differential rewind slitter rewinder. The reel is then placed on the SM10 seamer where solvent is applied, a layflat tube produced and rewound. Layflat widths of 25 – 254mm can be offered.

Speed

Just why did Color Craft choose the Stanford equipment? "We looked at other seamers and whilst we were pleased with their ability to control tension and produce a reliable machine we opted to go with a more expensive product for several reasons. To start with the machine speed was going to be 300m/min, but the delivered equipment will run at 500m/min." Current industry average is believed to be 250m/min, and could be lower according to Dr Séamus Lafferty, president of Stanford Products.

"Secondly, this seamer features a programmable oscillating rewind, historically not something you would expect from an OEM," continued David Seuss. "The issue is the control of the oscillation on the rewind. It is correlated to the web speed and we give the option on patterns of oscillation," explained Séamus Lafferty. "The sine wave pattern is the best for us," added David Suess. Basically when the layflat tube is rewound at the point of the seam there are three layers of material; if these were to be wound on top of each other the roll would be seriously deformed and difficult to use at the packer filler. Controlled oscillation gently offsets the seam line from side to side whilst maintaining a firm reel. Stanford has a patent pending on the system. In addition the nip rollers are not sitting near the edges of the layflat. This results in the much preferred "U" rather than a "V" fold, which can produce an unsightly crease mark when shrunk onto a container.

A second and arguably even more important patent that is pending concerns the method of solvent application, which, no matter the speed of the equipment, by adding less solvent consistently, is said to reduce waste of sleeve material dramatically due to poor seal when compared to other methods. "The way we are doing it really takes out the waste," said David Seuss. "On 10,000ft" (3,050m) we have less that one per cent waste." Added Séamus Lafferty: "We believe a conservative figure of 15 to 20 per cent to be the industry average."

Solvent control

Flexcraft Industries of Newark, NJ, supplies the solvent. The application needle and tank supplied by EFD are common to commercially available seamers. It is what Stanford has done in between that is different. "No one can control the solvent application to the degree we can," stressed Séamus Lafferty. "It is automatic and not reliant on the operator." A 2-3mm wide seam is produced, which is much narrower than average and is claimed to make for a far neater seam when shrunk onto the container at the packer filler. "As less solvent is used and as that solvent use is controlled a ventilation system is rarely needed," he boasted.

The solvent contains an optical brightener, which is illuminated at the nip after sealing. This allows the operator at start up of a job to set the needle just in the right spot close to, but just about 1mm above the film to deliver the solvent. The position of delivery, unlike that of competitive equipment, is sited after the film is formed over the shoe so allowing less evaporation before sealing. The shoe is adjustable; it splits in half to provide for the 25–254mm layflat range.

"Right now to the best of my knowledge David has the fastest commercially available seamer in the world," said Séamus Lafferty. "But speed is only part of the equation. If you are not careful you can just be generating waste at a higher speed! The control of solvent application and control of oscillation and the robustness of the machine combine to give him a serious competitive advantage. His scrap rates are going to be consistently far less than average."

Following seaming the reel is subjected to rigorous inspection "by sight, sound and camera" on the Stanford DM10 Doctor Machine Inspector. In between two nips air is directed from two nozzles onto the seam area. A poor seal results in a high pitched whistle. The operator also punctures the tube, inserts air and seals the hole to form a pillow between the nips. Should the operator see that deflate at anytime she knows there is a faulty seam. In addition a camera inspects the optical brightener and relays that back to a monitor near the controls. If a fault is found the web path can be reversed, and the material in question removed on the integral splicing table.

Currently the Color Craft Flexible Packaging Division operates on a one shift system, but David Seuss sees it probably going to two shifts in a few months. "Where it is difficult to get into a label account these days we have found people to be very receptive on sleeves. And 20 per cent of our existing customers were asking about them. There is such a buzz, with people looking to take products over to sleeves," he enthused.

And the future? There is a considerable amount of free floor space surrounding the new equipment in the attractively renovated building. "We have it set up to take two more presses and seamers," announced David Seuss. "The point is that no matter what size of converter you are you are still seaming singly. There is room for lots of people in this market.

"There is a real need for a converter like myself to service the multi-SKU lines. My goal is to build the business to require an additional press and seamer in the next 18 months. We are looking at a payback of three to four years on the whole investment.

"We are extremely excited about the level of interest. We feel for the dollar investment this is the way to go."

And with not far off half the capacity already likely to be on the books soon he is well on the way to being proved right.