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Bottle and Can Drying

We offer blower-powered air knives tailored to bottle and can lines. CFW’s engineers will consider your particular application before designing and installing an assembly appropriate to the facility.

bottles

Condensation, over-filling, rinsing, pasteurization all contribute to surface moisture on bottles and cans. Unfortunately, this can cause many production problems and deterioration before the product reaches the consumer.

Bottles and cans are typically dried with air knives after filling and rinsing and before labelling. Full-bottle drying is usually needed before final packing, as caps, labelling and packaging can deteriorate if there is any moisture on the bottle.

  • Shrink sleeves may be wrinkled or loose-fitting as a result of moisture-induced premature bonding. This may cause line stoppages, machine malfunctions, and poor quality in the final product. The result is delivery rejections and a negative effect on the relationship of the manufacturer with retailers and consumers.
  • Labels may be distorted or present with bubbles if liquid is trapped under them.
  • The glue can streak underneath labels or the label can slip because the glue has foamed or been diluted by water. The problem of water contact with glue may occur when moisture enters the glue pot, at the location of labelling on the product, or by moistening of applicator heads.
  • Crown caps can rust or be discoloured as moisture build-up traps corrosive substances and bring them into contact with the cap, oxidising it. Corrosion may also damage ring-pull tabs on cans.
  • Can tops and bases can retain water, leading to a build-up and possible transfer of pathogens down the canning line, especially after pasteurisation where temperatures are between 20 and 40 °C. Air devices that are underpowered can spread bacteria without removing enough moisture. A specialised solution is needed to ensure safety and efficiency in this regard.

Poor label appearance is a significant factor in the rejection of an item by consumers. In addition, production demands and legal restrictions require that an item be traceable, leading retailers to insist on legible markings (such as "best before" dates). Illegible or otherwise inadequate marking is caused mainly by surface moisture, which can cause problems such as diluting ink. The result is smeared or faded markings.

Visual inspection systems can experience various problems when there are droplets of water on bottles. Full bottle inspections (FBIs) which check for glass fragments in the bottle, as well as empty bottle inspections (EBIs) which check for cracks and faults in the bottle, can yield false positives and cause line stoppages or higher rejection rates. In label inspections, bottle positions can be incorrectly estimated, leading to misaligned labels. Water around bottle caps and seals can also cause inspection systems to falsely detect integrity faults.

Reduced down time and wastage and lower rejection rates can be achieved through careful drying of the bottles before they reach inspection systems.

Both blowers and compressed-air designs are used for this purpose. An entry-level solution might consist of an open air-knife and blower arrangement, whereas more sophisticated bottle and can dryers may be fully enclosed, high-speed machines with adjustable air knives and panels. The undersides of screw and crown caps can be especially difficult to dry adequately. Since they constitute a small area that needs to be thoroughly dried, compressed air is often used to supplement a blower-powered solution.