There are many types of stretch wrap film. Each type has qualities that are particularly suitable in addressing the specific needs of your stretch wrapping operation, such as load size and type, performance requirements as well as budget. The following lists some of the most important types of stretch film, their attributes and applications.
Cast stretch film, like blown stretch film, is created using an extensive manufacturing process known as cast extrusion. This process requires the continuous propelling of thermoplastic material through a flat die onto a chilled roll. The film thickness is then determined by how fast the casting roll pulls the plastic away from the die. This process causes cast films to have excellent clarity, which allows users the ability to see the wrapped products.
This film, unlike blown film, is extremely quiet when coming off the roll and is easier to stretch. Cast stretch film also offers two sided cling that allows products to stay securely wrapped during shipping processes. While cast film has excellent qualities, including a lower price tag from blown film, it does not stand up to blown film in holding power and tear resistance. Cast stretch film is initially easier to stretch, but because it is less dense, the film does not have as strong of a stretch memory. See products: hand stretch wrap film cast, machine stretch wrap film – cast.
Blown stretch film is manufactured by a process known as blown extrusion. This process consists of plastic melt being pumped through a circular slit die, in order to create a thin walled tube. Air is then introduced to the tube, allowing the volume of air contained to stretch the tube to the desired width. On top of the tube an air ring blows onto the film to cool it. This process of cooling the film allows the blown film to be tougher and more resilient to other types of film.
Because blown film is tougher than most other films, is also has a higher tear resistance. This becomes an advantage when securing loads that may have sharper edges susceptible to breaking through less dense films. Blown films also have a higher degree of memory once stretched, which allows for packages to stay better secured. While blown film has the advantage of higher tear resistance and strength due to its manufacturing process, this also results in higher costs to consumers and poorer film clarity. Blown film is also a bit noisier than most films, including cast film. See products: hand stretch wrap – blown.
Hand Stretch Film is designed specifically to be applied manually is referred to as hand stretch film. It is also referred to as hand film, hand stretch wrap, hand wrap or manual pallet wrap. It is typically utilized in lower capacity packaging operations. However the efficiency of manual stretch wrap packaging should be regularly reevaluated against potential benefits of upgrading to a machine wrapper. Choosing the right stretch applicator will result in more efficient and cost effective packaging operations. See products: hand stretch film – cast, hand stretch film – blown, prestretched hand film.
Machine Stretch Film is designed to be applied with a stretch wrap machine is referred as machine stretch film. It provides many advantages over hand film including: faster and more efficient packaging, reduced packaging material costs, safer application, more secure loads and more. Common machine stretch film types: cast machine stretch film, blown machine film and pre-stretched films. See products: machine stretch wrap film – cast and pre-stretched.
Pre-Stretched Film is stretched close to its ultimate breaking point prior to being wound onto rolls. This means that the film does not require as much stretching energy as the standard stretch film to accomplish the same wrapping force. Pre-stretched film consumption can be one half of that of traditional stretch films, allowing for vast cost savings.
Color stretch films are designed to answer very specific packaging needs that more general purpose stretch packaging solutions cannot accommodate. Color stretch film is ideal for warehouse color coding, international shipments or dating inventory. Color stretch wrap is puncture resistant.
Ultra Violet film is stretch film with inhibiting additives to protect this stretch film from photo degradation in situations where wrapped loads are stored outdoors. Special Ultra-Violet inhibiting additives protect this stretch film from photo degradation in situations where wrapped loads are stored outdoors.
*Editor’s note. This post was originally published on November 4, 2011 and has been updated with the most up to date content.