CHOOSING THE RIGHT PRESSURE-SENSITIVE LABELER
Introduction 1 Common Methods of P-S Label Application 2 Special Systems 4 Basics of Label Applicators 5 Product Handling 6 Illustrated Examples of Product Handling 9 Equipment Selection 12 Parts of the Label Roll Defined 13 Types of Surfaces and Label Placement 14 Illustrated Examples of Labeling Systems 15
INTRODUCTION Pressure-Sensitive labeling, also known as self-adhesive labeling, is an efficient and cost-effective means of identifying and decorating products or packages. In every major industry, pressure-sensitive labels are applied to most types of Die Cut containers at Face Stock speeds matching Adhesive many product or packaging lines. The label consists Release Coat Label Gap of a face stock Liner or backing paper material, coated on one side with an active adhesive. The face stock material can be paper, plastic, foil, polyester, vinyl, or laminate and can be of varied thickness and weight. The label is carried on a silicone-coated backing paper or film to allow easy release on demand. The backing paper is of translucent composition so that the label can be identified by photocell scanning for automatic application. The substrate weight, adhesive and the adhesive thickness are formulated for Die Cut Edges many application requirements. Backing Paper or Liner The label adhesive can have characteristics such as permanent, removable, cold temperature-resistant, or water- soluble. Label Face Stock Active Adhesive Pressure-Sensitive labels are Release Coat supplied in sheet, roll or fanfold forms. Roll form, with a predetermined specification for automatic application, is favored for easy and efficient handling. Among the printing processes used to produce roll-form labels are flexography, thermal transfer, ion deposition, gravure, rotary silkscreen, rotary letterpress or a combination. In North America alone, there are thousands of label printing companies including many that specialize in producing labels for use on automatic pressure-sensitive labeling equipment.
The availability of pressure-sensitive labels has enabled machinery designers to produce labeling equipment, which is fast, efficient, simple to operate, and service, and accurate in label placement. The machines are economical to purchase, require no extensive change parts, and are cost effective in production.
COMMON METHODS OF P-S LABEL APPLICATION There are three basic methods of automatic pressure-sensitive label application: direct transfer (roll-on or wipe-on); tamp (tamp-on); and air- jet (air-applied, air-blow, blow-on) Direct transfer - (also called roll-on or wipe-on) the label is dispensed directly onto the package or product and rolled or wiped on as the product passes the labeler. The label must be dispensed in the same direction that the product is moving and at Label approximately the same Unwind Reel Dancer rate of speed. Direct Arm transfer application is Idler primarily used on flat, Roller Rewind non-irregular surfaces for Spindle Drive prime, secondary and Shaft wrap-around labeling. (Roller) Tamp application - (tamp-on) The label is dispensed from the web backing and then held in position, on a tamp pad, by vacuum. The tamp pad is connected to an actuator which, when signaled by the operator or product detector, is extended to the product for label attachment. Tamp applicators are used for applying labels into deep recesses or where accessibility to the product is restricted. The label is driven to the product Liner/W eb by the air cylinder and applied to the product by direct pressure.