Shrink Wrap - The Material
Heat Shrink Wrap - Also referred to as shrink film, is a thin film-like material made up of polymer plastic blends. When heat is applied to the material it shrinks tightly over the object that it is covering. Heat can be applied manually with a handheld heat gun or the product can pass through heat applicators in a heat tunnel or on a conveyor. Oftentimes, the term shrink wrap is used to describe products used in product bundling including stretch wrap, hooder films, or bundling films. These products only shrink after being stretched rather than with heat and though very useful in many applications, are quite different from heat shrink wrap.
Common Characteristics of Heat Shrink Films carried by Mr. Shrinkwrap
Gauge or Thickness – Gauge is measured in increments of one one-thousandth of an inch or MIL; for example, our six mil films measure .006” or six-thousandths of an inch to avoid confusion the industry simplifies this to six mil. Mr. Shrinkwrap stocks rolled films ranging from six to twelve mil and shrink film pallet bags in four mil; many of our customers request custom mil thicknesses and sheet dimensions to accommodate their specific applications
Tensile Properties – under strict testing guidelines, all of our stock film's tensile strength has been tested by pulling a strip of the plastic shrink wrap material until it breaks in order to measure elongation strength under load and strength at break. For example, our stock of seven (7) mil shrink films has an elongation or stretchability of 650% and a breakpoint of 3000 PSI.
Shrink Temperature – the temperature that our stock 6 through 10 mil shrink film begins to shrink is 275 degrees Fahrenheit, and twelve mil films begin to shrink at 300 degrees Fahrenheit.
Flammability – our stock Husky Brand Flame Retardant Shrink Films meet the standards of NFPA 701 (2004) Test 2 Flammability.
Anti Static – shrink film having anti-static properties is available in custom sizes and thicknesses, minimum quantities apply based on product specifics.
How is shrink wrapping film made? In general terms, the film extrusion process starts with mixing the blend of plastic beads and other additives for characteristics such as shrink, UV inhibiting, or flame-resistant additives and heating it to a molten state. The molten plastic blend is pushed through a precision machine called an extruder and then blown with air, usually upwards to cool then slit and wound on a roll to the desired film length. The “film bubble” forms a tube whose circumference, when cut lengthwise along the “tube”, produces the desired film width. The size of the bubble and the thickness of the film is precisely controlled by the extruder machine. The quality of any shrink film can be judged both by its consistency in thickness across the product as well as the performance of the blend under its intended conditions.
While the blend of polymers and additives can be tightly controlled through basic mixing procedures and readily available virgin plastic resin products, film thickness consistency is most often the differentiator in quality. High-quality precision extruding machines are the only way to achieve the acceptable industry tolerance of 10% variance in gauge. Among industrial shrink film producers are several leading manufacturers producing the highest quality films on precision world-class extrusion machinery. Generally, shrink film producers make a high volume of one size of the product on any given “run” of a specified gauge, color, width, and other characteristics. Mr. Shrinkwrap is a global distributor of both stock and custom shrink films and shrink wrap. Let us put our expertise in product characteristics and application uses to work for you.
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