Packaging Material Suppliers in Bangalore

Stretch Film Guide

Information Guide for Stretch Film Hand Rolls and Machine Rolls

Whether you are a complete beginner or expert the information in this guide should answer the most common questions you may have. This guide covers such things as what are the different types of Stretch wrap film, what the features and benefits of each type of film are, instructions on using stretch wrap, recycling and some of the potential problems that can affect film in certain circumstances and their remedies.

The Differences between Blown, Cast, and Pre-stretched Stretch Film

Originally, all palletwrap was Blown Film and, a process much like blowing a large bubble. Resin is heated and passed over an opening through which air is blown. Blown materials are strong and ideally suited for cold room applications. The following link on You Tube shows the process.

Conventional Blown Palletwrap characteristics are:

  • Hazy, dull in appearance
  • Excellent puncture resistance
  • Very noisy unwind
  • High force on load

Cast Stretch Film

This is also called Cast Film or Cast Stretch Film and is manufactured using the cast extrusion process. It is extruded through rollers and “laid out” in sheets. This process allows the film to be made in multiple layers. The layers allow the film to be made with cling on only one side. This onesided cling film is great in situations where you don’t want one pallet to stick to the one next to it, these film layers can make the film stronger by adding tough layers to the inside.

Conventional characteristics of Cast Palletwrap are:

  • Good transparency
  • Clear and glossy film
  • Superior tear resistance
  • Quiet unwind
  • Consistent cling and film thickness

Pre-stretched Stretch Film

Pre-stretched Film or Pre-Programmed Film as it is sometimes known, is a half-way house between Blown and Cast Film. The product is made as co-extruded Blown Film with its main characteristics being its hazy, dull appearance with a certain amount of ‘tack’ although not as much as with Blown Film but more than with Cast. It has excellent puncture resistance, and is easier to apply than conventional Blown and Cast Films. Pre-stretched Film is stretched before being applied to the load and it’s main advantages are:

  • Customer uses less film per wrapped load so cost to wrap each pallet is reduced
  • Quicker and easier to wrap load, thus saving time and money
  • Less post film waste is generated, reducing packaging waste obligation
  • Excellent film memory creating superior wrapped loads.

All Hand Roll are Available in the Following Cores:

Speciality Stretch Film

Tinted Stretch Film and Opaque Stretch Wrap is also available for more specialised packaging needs that more general purpose stretch packaging solutions cannot accommodate. For example, tinted stretch wrap can be used to differentiate between pallets of products in a warehouse and blue tint is often specified by companies in the Food Industry as it is more likely to be noticed if film comes into contact with produce during packing. Opaque wrap is used in situations where the client does not wish the wrapped products to be visible. Both available in variety of colours.

Machine Rolls

Machine palletwrap is primarily made of Cast material although in more recent years low noise Blown and Pre-Stretched co-extruded film have been alternative options for customers looking to down spec but without compromising quality and strength.

Cast Machine Stretch Film

Available in Standard Stretch (stretches up to 150%) and Power Pre-Stretch (stretches up to 300% where machinery allows). Cast Stretch Film is quierter when being unwound due the nature of it being ‘tacky’ only on one side.

Cast Film width is 500mm wide and thickness of film varies between 12 to 34 mu. Often sold price per tonne, however, more and more suppliers are charging per roll as this can make their film appear cheaper.

Both have the same price per tonne but the lighter roll has less meterage making it appear a more economical film to purchase.

Blown Machine Film

High strength low noise Blown Stretch Film has developed considerably over the last five years. Thinner grades of film offering excellent strength and superior puncture resistance compared to Cast Stretch Film have seen sales increase. Although low noise, they are still noisey when unwinding compared to Cast Stretch Film and care should be taken when recommending Blown if being used in confined areas. Price per tonne for Blown Stretch Film is usually more. However when comparing price to wrap each pallet with Cast Stretch Film the savings to the customer can often be worthy of consideration.

Pre-Stretch Machine Stretch Film

Pre-Stretch Films of between 6 to 12 mu are now available, however, they can only be used on Standard Core Brake machines. For customers currently using 17-20 mu Standard Cast Stretch Film it is worth talking to them about Pre-Stretch Machine Film as cost savings can be made. It offers outstanding performance, durability and consistency and is rapidly becoming more popular with customers.

How to Wrap a Pallet using Blown and Cast Stretch Film Hand Rolls

The following instructions outline the correct way to use Blown or Cast Stretch Film. By following these instructions, it will not only significantly reduce any danger of injury or risks involved in wrapping pallets and ensure goods leaving your establishment will be sent in a safe and secure manner.

General Instructions

  • Ensure that the pallet to be used is ‘fit for purpose’ prior to any product being loaded on to it.
  • Always ensure that the area around the pallet to be wrapped is clear of any obstacles to avoid risk of tripping over.
  • Always walk forward when going around a pallet to ensure you are aware of any potential dangers.
  • To avoid dizziness when wrapping a pallet, always look straight ahead and do not look at the pallet itself.
  • Before starting to wrap the pallet, ensure that the goods are stable and will not fall as you wrap the pallet itself.
  • Wherever possible ensure heavy goods are loaded at the bottom of the pallet.

Specific Instructions to Wrap a Pallet

  • If using Cast Film (tacky one side) ensure the outside of the film is placed to the surface of the pallet. This ensures pallets do not stick together when loaded onto a truck.
  • Tie film to the base corner of the pallet. This ensures an effective hold when you start to wrap the goods.
  • Conventional Blown or Cast Film needs to be stretched whilst walking round the pallet.
  • To avoid goods sliding off the pallet during transit, you must ensure that the film covers the base of the pallet and also the bottom layer of the load. The bottom layer must be wrapped twice to ensure load is secure to the pallet.
  • When wrapping the goods the film must be kept taut and then ‘stretched’ at the corners to maximise the film’s strength. The film should be overlapped by 50% to ensure the goods are held securely at all levels.
  • The top of the load should be wrapped twice, again to ensure stability.
  • Work back down the load until reaching the bottom of the pallet where the film should then be cut or torn.
  • Stretch film by hand and ‘tuck’ the end under bottom layer of film by one of the corners to ensure film retains its strength and does not cause film to ‘flap’.

How to Wrap a Pallet using Pre-Stretched Film Hand Rolls

The following instructions outline the correct way to use Pre-programmed Stretch Film. By following these instructions, it will not only significantly reduce any danger of injury or risks involved in wrapping pallets, but will also maximise the benefits of the film.

General Instructions

  • Ensure that the pallet to be used is ‘fit for purpose’ prior to any product being loaded on to it.
  • Always ensure that the area around the pallet to be wrapped is clear of any obstacles to avoid risk of tripping over.
  • Always walk forward when going around a pallet to ensure you are aware of any potential dangers.
  • To avoid dizziness when wrapping a pallet, always look straight ahead and do not look at the pallet itself.
  • Before starting to wrap the pallet, ensure that the goods are stable and will not fall as you wrap the pallet itself.
  • Wherever possible ensure heavy goods are loaded at the bottom of the pallet.

Specific Instructions to Wrap a Pallet

  • Always place the outside of the film to the surface of the pallet. This ensures pallets do not stick together when loaded onto a truck.
  • Always tie the pre-programmed stretch film to the base corner of a pallet. This ensures an effective hold when you start to wrap the goods.
  • The film does not need to be stretched like conventional Blown or Cast film. It should simply be held taut whilst wrapping the goods and ‘tugged’ at each corner to activate the films memory.
  • To avoid goods sliding off the pallet when in transit, you must ensure that the film covers the base of the pallet and also the bottom layer of the load to be wrapped.
  • Again to ensure stability of the load, the bottom of the pallet must be wrapped twice to secure the load.
  • When wrapping the goods, the film should be overlapped by 50% to ensure that the goods are held securely at all levels.
  • For additional strength the film can be used horizontally to create a ‘strapping’ effect. Please note however that this procedure can crush or damage boxes.
  • The top of the load should be wrapped twice, again to ensure stability of the load.
  • Check the pallet load is wrapped securely prior to despatch.

Can I Recycle Stretch Film?

Stretch Film is one of the largest components of a warehouse/distribution centres waste management system. Those that do not recycle plastics must pay to have it disposed of. A large distribution centre can generate thousands of pounds of Palletwrap per year.

Recycling Stretch Film offers an attractive alternative to disposal. There are ready markets for clean waste material. Stretch Film is easy to identify and recover, it arrives at the dock in a fairly clean uncontaminated state and if kept that way has a real market value. In fact pound for pound, Stretch Film may be the most valuable scrap material a warehouse/Distribution centre can recover.

With environmental issues being at the forefront of today’s government agendas an environmental legislation concerning recycling (ISO1400) has been introduced urging all companies with a large Palletwrap waste to conform to an Industry Standard. Heavy fines have been established to those that do not conform to the new legislation.

What Is The Difference Between Stretch Film And Shrink Wrap?

Stretch Film/Palletwrap is often confused with Shrinkwrap, however the two films are very different products and applied in different ways and for different applications.

Stretch Film

This type of product is formulated from Polyethylene Plastic and generally, comes in 400mm and 500mm widths although smaller rolls known as Bundling Film measuring 150mm wide are also available. Palletwrap Machines speed up the process of wrapping goods, controls the amount of material used and maintains the stretch to a consistent level. It is an elastic film much like a wide rubber band and relies on self-adherence to keep it together on the pallet. Palletwrap is widely used in the warehouse and is considered a shipping tool.

Shrink Film

This is a packaging technique whereby the plastic film is applied loosely around an item and shrinks with the application of heat (see diagram below). Shrink-wrap is primarily used for keeping a product safely loaded and clean, from despatch to delivery, and is available in a variety of widths and thicknesses. Pre-made Pallet Covers designed to cover a whole load are quick, convenient and, although sometimes expensive, offer excellent load restraint when applied correctly.

Hand Palletwrap: Potential Problems

Problem

Cause

Remedy

Telescoping Rolls Film moves towards one end of roll. Caused by too much tack and roll wound too tightly when made. Happens more during summer/warmer months. Replace rolls, they can no longer be used.
No Tack on Film (Blown Film) Mainly occurs during winter, cold weather reduces tack levels. Alternatively, film may not have been ‘hot boxed’ prior to leaving factory. Place a box of film in a warm room overnight near a radiator. This should bring the tack out of film. Keep film in a draft-free area if possible.
Frayed Edges Film is poorly wound or has been damaged/dropped causing nicks on edge of rolls. Makes unwinding of film very difficult. Check stock for damage/misuse. Replace film if found to be faulty during manufacture.
Load becomes unstable during transit, goods move on pallet. Incorrect film used to secure load. Either wrong type of film or product not fit for purpose, ie., film too thin. Try different types of film, i.e., Cast, Blown or Pre-Stretch and thicker grade film.
Film breaks on bottom of pallet when wrapping. Pallet is incorrectly stacked. Wrong film has been used. Change film. Cast has poor puncture resistance whereas Blown and Pre-Stretch are better suited. Move loads to edge of pallet where possible.
Outer products are crushed when wrapped. Tension of film too tight when wrapped. Consider different types of film, trials needed.

Glossary

Stretch Film and Stretch Wrap Packaging Terms Defined

Banding

Applying multiple wraps of stretch film to reinforce a specific area of a pallet or to band together multiple units.

Blown Films

Stretch Films manufactured by the Blown Film Extrusion process are called Blown Films. Stretch film extruded by the blown method typically produces greater puncture resistance but less aesthetic values than Cast Films.

Cast Film

Stretch films manufactured by the Cast Film Extrusion process are called Cast Films. Stretch film extruded by the cast method typically have greater tear resistance, greater aesthetic values, are quiet to unwind, which is not typically found in film manufactured by the blown method.

Cling

Cling provides the sticking to self but not to the product attribute. Fioms will be designed as a singleside cling or a two-sided cling. The cling bonding agent is typically added in as a single side or twosided layer in the co-extrusion process.

Co-Extrusion

The process of taking materials that are: fed, melted and or pumped in through other extruders, which are then merged to create a multi-layer film.

Elastic Recovery

When the stretch film is stretched, strained and/or deformed its ability to recover and return to its original form indicates its elastic recovery capacity.

Film Memory

This is the memory of the stretch film trying to return to its original un-stretched form and in the process makes the load tighter and more consistently secure. This prevents loosening of the load that can occur later as the load settles. To achieve optimal film memory and film efficiency, proper film and application settings are essential.

Gauge

An imperial measurement used to measure stretch film thickness or calliper. An example value would read as: 70 gauge, 80 gauge or 100 gauge. Also note: often used as a synonym for film thickness. To convert gauge to micron divide by 4, i.e., 100g = 25 mu

LLDPE Stretch Film

Linear Low Density Polyethylene Stretch Film

Metallocene

New polyethylene resins developed using ‘Metallocene’ change the polytheylene chain structure resulting in a new breed of stretch films. Metallocene stretch films can achieve increased puncture resistance and clarity while blends offer balanced film properties and universal stretch percentage applications (ex: machine film, hand film)

Neckdown

Neckdown is when a film loses its dispensing roll width / breadth and narrows down while being stretched. Neckdown reduces the coverage each wrap provides thereby making it likely that more wrap rotations and more film will be needed to wrap a load or pallet.

Post-stretch (Machine Application)

Post-stretching is stretching a film by using the load to pull the film out at the same time as it applies film. Although this allows for the benefit of film tension, the tension levels are inconsistent and as such can damage many load types. Attempts to attain higher tension stretch can be done but can increase risk of damaging some load types and increase chances of stretch film breakage.

Prestretch (Machine Application)

Prestretching is stretching the film prior to application. The process can increase film strength, improve load integrity, reduce amount of stretch wrap film needed and save on stretch film packaging costs. Today many stretch films are designed to achieve optimal prestretching values that can be attained with leading edge high performance stretch wrap machines as well as pre-stretched films for manual application operations.

Roping

Bunching the stretch films full width to create a rope is known as roping. Stretch film roping is extremely strong and is often used to further secure a pallet to its load. Bunching stretch film is a feature function of many stretch wrap machines (ex. Turntable stretch wrappers)

Tackifiers

Additives used in the material fabrication process to increase the ‘tack’ of the film or material.

Tension Stretch

Tension stretch is a pulling force that stretches materials. For example, stretching a rubber band will make it longer, as it gets longer its tension increases. Also referred to as ‘post-stretch’

ADDRESS and LOCATION MAP

  • TOTAL PACK
    No. 51, Sree Nilaya, 1st Cross, Kurudu Sonnenahalli,
    near Lake Montfort School, Virgo Nagar Post, Bangalore, Karnataka 560049
  • Email:
    info@totalpack.in
  • Phone:
  • 9845722274
  • Working Hours / Working Days:
  • 09:30 A.M. to 06.00 P.M. / Monday to Saturday