Buyer's Guide on Stretch Film and Stretch Wrappers

Buyer's Guide on Stretch Film and Stretch Wrappers

What is it Stretch Films?

Stretch Films are elastic films that are frequently made from linear low density polyethylene, also referred to as LLDPE films. This LLDPE film is produced when ethylene and alpha-olefins undergone process called copolymerization. Some common alpha-olefins are octene, butene, and hexene – the higher use of these increase the elasticity features of the stretch film.

With its puncture resistant quality, high tearing capacity, and tensile strength, the LLDPE films are then used for packaging goods to preserve integrity and prevents damages that is brought about by transportation and distribution. Noting that LLDPE films are flexible enough to be stretched out up to 500%, although it is known that stretch wrapping equipment available in the market only does until 300% of the elongation. As the film elongates, it increases its tensile strength making pre-stretch films more durable than that of the standard version.

How is it Made?

The manufacturing of stretch films comes in two kinds, either produced from blown or cast processes.

Blown Stretch Film is the procedure in which resin is placed in an extruder, heated for melting, and blown vertically into a bubble. It is then cooled down by surrounding air and rolled on a paper core then after. As for Cast Stretch Film, this includes a course in which resin is still heated with an extruder, but it is next cooled down by chilled rolls that solidifies the film and made into rolls.

The differences of Blown and Cast stretch films:

 

Blown Stretch Film

Cast Stretch Film

Finish/Clarity

Foggy and dull

Glossy and clear

Noise

Loud when being unwound

Quieter when being unwound

Tensile Strength

High puncture resistance

Standard puncture resistance

Load Retention

Will not stretch after application and has great hold of palletized goods giving reliable stability

Will stretch even application is done, thus, giving a less stable finish

Film Memory

Can return to original condition even after being stretched

Has lower capability to return to its initial form

Cling

1 Side

This makes film stick to the palletized goods without sticking with other pallets

2 Sides

This makes film stick to both the palletized goods and other pallets in transit

Film Coverage

Stretches better and uses less film for same amount of pallets

Not much stretch than blown film 


What are the stretch wrapping methods?

Manual Hand Wrapping Technique

Hand wrapping method is usually being applied by industries with lower volume production needs. Palletized goods are manually being wrapped, hence, the film roll is way lighter and shorter than that of the stretch films used in machines. Then a hand dispenser aids this type of operation when it comes to the releasing of film on roll, user is the one who stretch the film to their full potential making it quite expensive and inconsistent. Although trained operators have the ability to wrap palletized goods, specially irregularly shaped ones or unstable stacks and it is better manually done than machine operated.

Semi-Automatic Pallet Wrapping Machines

These types of pallet wrapping machines are typically used for medium volume production needs to high volume. Industries that wraps 100 pallets or more a day is suggested to invest in a semi-automated machine for efficiency compared to hand wrapping method. Equipment are traditionally made with a turntable for palletized goods to move in circles for film wrapping and some may also have a rotary arm with an eliminated table for ergonomic resolve. Either way, this semi-automatic equipment performs a programmed pattern in which it wraps the load.

Fully Automatic Pallet Wrapping Machines

Industries of high volume pallet wrapping application requirements are recommended to invest in fully automated machines. Businesses with this type of wrapper comes from the large sectors since the cost of investment is high compared to manual and semi-automatic method. The whole process of packaging using stretch wrap is initially programmed and is integrated in a line of machines that the goods needed processing on – keeping in mind that the pallet wrapper equipment is the last course the goods will go through.

What suits your business best?

Looking for the best film for you depends on a couple of factors. From your machine to the products needed to be stretched wrapped.

Questions needed to be weighed are:

1.     Is manual hand wrapping used?

2.     If not, what is the machine being used? What type?

3.     What are the materials/products being wrapped?

4.     How much load does your warehouse process in a day? Or, how many completed pallets are your desired output?

5.     Where does the palletized goods go for distribution?

6.     How many variations of load is being wrapped in your warehouse?

For more needed support in finding the best wrapper and film, do not hesitate to contact us at support@sal-tech.com. We’re glad to be of assistance.