6 QUESTIONS TO FIND THE IDEAL SHRINK WRAPPING MACHINE ...

Shrink wrapping is one of today’s most common secondary packaging techniques. It is widely used around the world for packaging needs, including maximizing shelf appeal, protection from external factors, bundling, multi-packaging to ease transport and storage, and last but not least, tamper-proofing. This wide array of functionality makes it an excellent option for almost all industries, from food to cosmetics or even boats and construction materials.

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Although the shrink wrapping process is relatively straightforward, many considerations go into choosing the right shrink packaging solution that best meets your needs. So, how do you identify the ideal shrink wrapping machine for your product and production needs? Here are 6 important questions and tips that will give you a head start:

• What is your product, and what is the desired outcome you expect from shrink-wrapping?
• What are the dimensions of your product, and what orientation do you want it to be packaged in?
• What production speed/capacity does your operation require?
• Do you need an inline solution or a hand-feed operation?
• What type of shrink film will you use?
• Do you need any peripheral equipment, such as extra applications or control points in the packaging line — such as a labeler, checkweigher, discard arm, etc.?”

What is your product and what result do you want to achieve with shrink-wrapping?

What is your product? Is it a frozen pizza, a wheel rim, a cosmetic product, or a book? Do you want it to be shrink-wrapped for display or logistic purposes?

Here are a few common desired results you can expect from shrink wrapping:

Display

The shiny outer packaging is to be noticed among other products while protecting the primary package. The use of printed film also adds the advantage of branding.

Protection

Fully closed shrink wrap protects the product against scratching during transport, water, dust, or any other unwanted external factors.

Tamper-Resistance

For some products, Packaging serves as proof of the first usage by the end-user. An unopened shrink wrap gives end-users the confidence to buy the product.

Grouping or Bundling of Products

Do you want to group multiple products to display or logistics purposes? Is your product heavy and do you need openings on the sides of the package to easily carry by hand? Or you have a promotion and you want to put together two products that will be sold together in the supermarket?

Logistics/Storage

To create an easy-to-carry package for heavy items.

What are the dimensions of your product and the orientation you want it to be packaged?

The minimum and maximum dimensions of the products you will shrink wrap is the second most important question to determine in terms of identifying the right shrink wrapping machine. All packages have three dimensions, the product width, length, and height. Also, the orientation that the product will be packaged is another important data needed.

Shrink wrapping machines have limitations in terms of the maximum dimensions they can package. In the L-Sealer manual or semi-automatic machine models, this limit is decided by the size of the L bar.

In fully automatic machines, there is no limit to the product length however the product height and the width do have some mechanical limitations.

Selecting the right-sized shrink wrapper optimizes the packaging cost and production capacity. Keep in mind that the size of the shrink wrapper and heat tunnel should be able to accommodate your largest product.

What is the daily production speed/capacity your operation requires?

The number of products you need to package daily is another critical piece of information in choosing the right shrink wrapping solution.

The capacity of shrink wrapping machines varies from Low Capacity to High Capacity and is typically measured as packages per minute and varies according to the length and the height of the product.

Low Capacity

These are manual shrink wrapping machines that hold the capacity to produce 5 to 10 packages per minute. These machines are run by an operator whose experience level has a considerable effect on the total packaged products per minute.

Medium Capacity

Semi-Automatic L sealers fall into this category. In semi-automatic shrink wrappers, the sealing arm is automatic. This automatic motion gives the operator time to prepare the product in line for sealing. The average output expectation for semi-automatic shrink wrapping machines is anywhere from 10 to 25 packages per minute.

High Capacity

High capacity shrink wrapping machines are Fully Automatic Shrink Wrappers. These systems can integrate into your production line if wanted. Equipped with conveyors and multiple sensors they don’t require an operator which in return maximizes the output and saves cost. The capacity of automatic shrink wrappers is 25 to 80 packages per minute.

It’s important to take into consideration your production volume growth projections at least for the following year.

Does your operation require an inline or a stand-alone hand fed shrink wrapping solution?

Do you want to integrate the shrink wrapping station into your production line is another defining question you need to answer when choosing the right shrink wrapping machine. If the answer is yes, then you would require a fully automatic shrink wrapper. In an inline system, the alignment, rotation, separation, collation, upending, dividing, or even bonding of the products must be well projected initially.

If the answer is no, then a stand-alone shrink wrapping system that will be hand-fed is what you are looking into. In this case, an operator manually feeds the products to the conveyor.

What type of shrink film will you use?

This takes us to this question – What is the desired result you are aiming for with shrink wrapping? To achieve the right outcome the shrink film you choose the film with proper specifications for your product and shrink wrapper.

You can be directed to the right film by the shrink wrapper manufacturer or your film supplier. But before doing that the following information will allow you to get familiar with shrink films.

Types of Shrink Film and Use Areas

There are different types and thicknesses of shrink film and which one you need to use depends on what you want to achieve by shrink wrapping your product. If you want to package a box of chocolate to be displayed on a market shelf then preference should be a film that gives your package an extra shine making it stand out among other products. In the case, you have multiple and/or heavy products such as a pack of soft drinks or a steel spare part then you will need a film that is strong and durable.

In choosing the right shrink film the product’s shape, shrink wrapping machine being used, and temperature restrictions all play a role. It is best to get a professional opinion for your unique product before purchasing a shrink film.

Polyolefin (POF) Shrink Film

Polyolefin aka POF film is preferred almost in all industries due to its versatile and environment-friendly nature. It is also safe to use for edible and non-edible products. The film is highly clear making the content of the package visible to the end-user and has a glossy appearance that makes the product presentable and attractive on the market shelf. Especially cross-linked POF film provides extra clarity and is stronger than the regular POF film. It is widely applied to products including food, toys, cosmetics, books, and stationary just being a few.

Polyethylene (PE) Shrink Film

The clarity of Polyethylene shrink film is lower than POF film. It is mostly used for heavy products mostly for industrial products. It is a highly durable and strong film making it ideal for protection and transit purposes. It is also the most cost-effective Packaging material. It is widely used for packaging products such as spare parts, doors, and window frames, bundling of cans or glass jars to name a few.

PVC Shrink Film

PVC film is a lightweight and inexpensive film option. However, the hazardous fumes, it releases when heated making it the least ideal choice of film. However, it still finds use for industrial products.

Gauge (Thickness) of The Shrink Film

Using the right thickness of shrink film will support you in a good-looking and functioning packaging. Also, the right shrink film will help you save money as the price of the film is defined by its width and thickness.

Do you need any peripheral equipment such as extra applications or control points in the packaging line  – such as labeler, checkweigher, or discard arm?

Labeling Unit

A labeling unit can be integrated into the shrink wrapper to add labels to the product or the package. Used to apply barcodes, product labels, etc.

Checkweigher

Checkweighers serve as a control point to ensure the correct weight of the product being packaged. If the product is lighter or heavier than indicated it will be pushed off the line with a discarded arm.

Feeders

Feeders can be used to place items on the product before it is packaged such as a sheet of paper.

Discard arm

Products that are found unfit by the sensors or the checkweigher are pushed off the packaging line via a discard arm for future inspection.

Introduction

Shrink sleeve label is the No.3 labeling method in the world today after self-adhesive labels and wet glue labels. It allows for 360° decoration on any shape of packaging container, such as bottles, cans, jars, and more, providing the best visual impact on the shelf to attract consumer attention. Therefore, an in-depth understanding of the materials, inks and printing processes used for shrink sleeve label can help users make informed decisions to choose best shrink sleeve labels for the optimal shrink performance and product appearance.

Additional resources:
Self-Adhesive Aluminum Sheets vs. Traditional Materials: Which Wins?

For more information, please visit Good Gloss Shrink Film.

The materials of shrink sleeve label substrates are made from a variety of polymers, including PVC, white opaque film, oriented polystyrene, polyester, polyolefin, and hybrid/multilayer films. The most commonly used substrates are OPS (oriented polystyrene), PVC (polyvinyl chloride), PETG (modified polyethylene terephthalate_ol), and polyolefins. In addition, composite, hybrid or multilayer films, as well as specialty films (e.g., white opaque films), also expand and enrich the substrates for shrink sleeve labels, providing more options.

Commonly Used Shrink Sleeve Label Materials

In order to ensure the beauty, safety and durability of shrink sleeve labels, the best shrink sleeve label solution should be selected based on the nature and characteristics of different shrink films. Following is the most commonly used shrink sleeve label materials in today’s market.

PVC Film

PVC shrink film is one of the first material used for shrink sleeve labels. PVC shrink film is easy to process, has good transparency, high shrinkage rate, large shrinkage curve and good printing effect. Its shrinkage rate is between 40% and 60%, and it has high tensile strength and large temperature shrinkage range.

With good printing adaptability, PVC shrink film can be processed by rotogravure printing, letterpress printing, offset printing and flexographic printing and other methods, and can be used with UV, solvent or water-based inks. The corresponding UV protection level and optical whitening level can also be provided for PVC shrink film.

Compared with other shrink film materials, the cost of PVC film is relatively low. And, shrink sleeve label made of PVC shrink film does not require a high heat source. The main processing heat source is hot air, infrared or a combination of these two.

However, PVC shrink film is difficult to recycle and will produce toxic gas when burned, which is not good for the environment. PVC has been banned in Europe and Japan. For regions where the environmental requirements are not very strict, PVC is still the most important material in the field of shrink sleeve labels.

PET Film

PET shrink film, an internationally recognized environmentally friendly materials for shrink sleeve labels, is the advanced unidirectional shrinkable film at present. Its technical indexes, physical properties, application scope and usage are close to that of PVC shrink film. Its transverse shrinkage rate is about 70%, longitudinal shrinkage rate is less than 3%. Moreover, due to non-toxic and non-polluting, PET film is the most ideal material to replace PVC film for shrink sleeve label production.

• PETG Film

PETG film, a modified film, is often referred to as just PET, or commonly referred to as PETG. PETG film is transparent and has the highest shrinkage of all shrink film substrates. Among all types of shrink films, PETG films are environmentally friendly, can shrink up to 78% and can be pre-adjusted for shrinkage. PETG film is the only substrate choice for distributors requiring shrinkage of 75% or more. PETG film will shrink all the way to the narrow neck of a wine bottle or 2L beverage bottle.

However, its high cost and excessive shrinkage rate limit its use. Its current market share in shrink sleeve label section is about 15% to 20%.

• White Opaque PETG Film

Currently, there are several white opaque films on the market, including PET films with various mineral fillers. There are glossy and non-glossy ones. If shading is required, white opaque film will provide 70%~80% shading. If 99% to 100% opacity is required, black printing on the back of the film is needed. There are examples of this with products such as Nesquik or Fairlife dairy drinks in the USA. When the label is removed, the inside of the sleeve will show 100% black.

The shrinkage of white opaque films is very similar to that of clear PET films, which is about 75%. A new product on the market is a two-color film that is white on one side and black or gray on the other. These films provide complete blackout without the need to print 100% black on the reverse side.

PET is a great alternative when brand owners don’t allow PVC. It has a good feel to the touch and has an excellent print surface with a vibrant appearance and better print results than that of PVC film. PET substrates are also UV resistant and have the ability to protect labels or even the product contents when a higher level of protection is required.

OPS Film

OPS (Oriented Polystyrene) film is a transparent film with special applications. It has a good shrinkage performance of up to 65% and is also good for the environment and is widely used as an alternative to PVC film. However, OPS film is difficult to process and requires very fine handling. Special care should be taken when printing with solvent-based inks. Gravure printing requires less acetate because it corrodes OPS film.

Compared with PVC shrink film, OPS shrink film has excellent environmental protection; Compared with PETG shrink film, OPS shrink film is less expensive and more economical. OPS shrink film currently has a market share of 5%, and maintains a rapid growth momentum of development in shrink sleeve label sector.

0PP Film

OPP films have a low shrinkage rate and are mainly used for shrink wrap-around labels. OPP films are of good quality and low price and are very competitive, with approximately l8% to 20% of the market share.
In order to improve the scratch resistance of the ink layer, better protection of printed graphics, OPP film is suitable for containers that require low shrinkage, close to the cylindrical shape. The biggest difference between OPP film and above mentioned shrink sleeve label substrates is that it is designed for ring canister.

In addition to shrink sleeve label materials mentioned above, other film materials used for the production of shrink sleeve labels include Polyethylene (PE), Polylactic Acid (PLA), Polyolefin (PO), hybrid or multilayer polymer films. Material properties, overall cost and other factors should be considered when selecting materials.

Properties Comparison of Commonly Used Shrink Sleeve Label Materials

The main materials for shrink sleeve labels are PVC film, PETG film and OPS film, of which, PET heat-shrinkable film is particularly prominent. The comprehensive performance of the three shrink film materials are as below:

Gloss

In term of gloss, the three kinds of shrink film all have good gloss and can ensure excellent label printing effect.

Stiffness

In term of stiffness, PVC film is the best, followed by PET film, OPS film is the worst.

Shrinkage

In term of shrinkage, here is the comparison.

• PVC film lateral shrinkage moderate, between 40% to 60%, more suitable for ordinary bottle type;
• OPS film shrinkage is higher, up to 75%;
• while PET film shrinkage is the highest, up to 80% or more, and therefore can be applied to a variety of shaped containers (such as thin neck and wide-bottomed conical bottles, elliptical three-dimensional flat bottles, a single side of the bottle with a recessed handle, etc.), and more. After shrinking, it realizes the full wrapping of the label on the bottle body.

Environmental Protection

In term of enviornmental protion, PET film is more conducive to environmental protection comparing with PVC film and OPS film.

Price

Currently, the price of PET shrink film is approaching the price of PVC. Therefore, PET film is the most ideal material to replace PVC film.

How to Choose Ideal Materials for Shrink Sleeve Labels?

The above discussed the comprehensive performance of several film materials, as well as their respective advantages and disadvantages. So, which film material should be selected for your shrink sleeve labels? Actully, the selection of shirnk film materials for shrink sleeve labels should take many factor into considerations, such as its functions of labelling, its costs and more. The base principle is to fulfill the function of the label while minimizing the cost. Following factors are usually considered when choosing the most suitable film material for shrink sleeve labels.

Functional Requirements of Shrink Sleeve Labels

Meeting customer’s functional requirements is the primary factor to consider when designing shrink sleeve labels. If shrink sleeve labels are not able to meet customer’s requirements, it is useless even if the cost is low. According to above mentioned comparison table, if bottle type belongs to shaped bottles and shrinkage rate needs to be higher than 70%, PET film is the best choice. PVC film is only suitable for ordinary bottle types.

In addition, the stiffness of PET film and PVC film is significantly higher than that of OPS film. So, if there is a need to label the appearance of a better feel, PET film or PVC film are more suitable. And, the gloss of PET film’s appearance after printing is also better than that of the other two films.

Cost of Film Materials

The cost of shrink sleeve label materials is undoubtedly the most important factor in the common concern for both end-users and label printing manufacturer. When it comes to material costs, people are often accustomed to convert it to the price per ton so as to measure the price of materials. But, a more scientific approach should be to consider the cost of materials required per unit area. In other words, the unit cost of the film should be considered ($/kg), the density of the film material and label thickness.

Generally, the lowest cost of shrink film label materials is OPS film. PVC shrink sleeve labels has slightly higher prices, PET shrink sleeve labels are the most expensive. The density of OPS is much lower than that of PVC film and PET film. Correspondingly, the thickness of PVC is the thickest, followed by PET, and OPS is the thinnest.

Storage Cost

In most cases, storage cost includes the storage of film materials and the storage of finished labels. PET film hardly shrinks below 60℃. And it has very high stability for transportation and is more stable than PVC film. So, there is no problem for PET shrink sleeve labels to withstand long-distance sea and land transportation.

The transportation requirements of OPS are relatively strict because it has a certain natural shrinkage rate. Its transportation process generally needs to use thermal insulation measures, such as foam insulation layer or refrigerated trucks. In addition, the storage time of OPS films is shorter.

In addition, PET films and PVC films can be stored for six months from the date of manufacturing, while OPS films can be stored for three months from the date of shipment. Compared with the other two films, OPS film will have problems in printing after long-term storage because this film will become brittle, its shrinkage rate will decrease or become unstable.

Label Processing Technology & Packaging Methods

From the point of view of production process, the printing ink required for PET film and PVC film is basically the same. However, the adhesion of inks originally used for PVC shrink film printing is slightly reduced on PET film surface, and only a slight adjustment of the white ink is required. As the solvent resistance of the film surface is much lower than that of PVC film, OPS film requires the use of new low corrosion inks. The total demand for these inks is very small, so the ink cost of OPS films is usually higher than that of PET and PVC printing inks.

In addition, if the same automatic sleeve labeling is adopted, OPS shrink sleeve labels have more precise requirements for the customer’s automatic sleeve labeling equipment. Therefore, only a small number of customers will choose OPS film as their shrink sleeve label material.

Conclusion

After more than ten years of development, the total demand for shrink sleeve labels is still growing steadily. Especially, more and more high-end customers put forward environmental protection requirements. And, more products will be packaged in shaped bottles to enhance the display effect, so many customers tend to PET film when they are choosing substrate materials for their shrink sleeve labels.

For more Environmentally Friendly Shrink Filminformation, please contact us. We will provide professional answers.