Label Media

Type and characteristic of label media

(1) Label : Cut, printer paper which is attached to a product using an image and/or text to promote a product name, manufacturer or the product itself, often including other information as well.

(2) Sticker : Small paper attached with adhesiveas a trademark, advertisement or type of cover.

(3) Label Sticker
“Adhesive label” is used as a generic term to describe a label (see (1) above) that is backed by an adhesive which allows it to be attached to the customer’s product. Adhesive labels have wide-ranging applications throughout all major industries.

Labels today represent products, trademarks, trade names, and the recording of general product contents, quality, constituents and methodsof useeven boosting the value of the company brand and logo.

Reference: KOSTIC, "Label technology”,http://eng.kostic.co.kr/technology/01_labelinfo_01.html, 2014. 1. 29
>> Click to download Definition of Label, Sticker and Label Sticker

- A label is generally composed of three layers and the label solution is provided by the type of lithographic plate or roll. Every quality of the materials in the label solution should be suitable for the specific purpose and this should be taken into consideration in the manufacturing, process producing the label.
(1) General paper

- Desired text is printed on general paper to be final product. Material suitable for printing is selected or quality is changed to be suitable for printing, always considering that most of the surface of the label solution is printed.
* Type of Paper: vellum paper, art(coated) paper, golden, silver paper, thermal paper, drawing paper, Kraft paper, fluorescent paper, sterilizing paper, photographic paper
* Type of film: PET, PP, PVC, PE, PS, PI and synthetic paper
* Others: cellophane, textile, acetate, rayon, non-woven fabric, metal foil, etc.

(2) Adhesive

- Adhesive includes glue in its general definition. Generally, glue, in liquid state, pulls the object to be bonded and bonds it by through the solidification process. On the other hand, adhesive has an active attraction at all times. To use it knowing these characteristics enables you to use adhesive effectively and avoid the occurrence of unnecessary problems.
● Classification of adhesive according to raw material
* Adhesive: rubber system- natural rubber, synthetic rubber
* Acrylic system
* Other(Silicon)

● Classification by type of adhesive
* Adhesive: Acrylic system- Emulsion system
* Solvent system: Bridge type, Non-bridge type
* Rubber system: Solvent system, Hot melt system

● Classification by function
* Strong adhesion: Adhesive types that have adhesive strength more than 800-1,000g/25mm used in standard bonding are generally referred to as strong adhesives. Considering the level of this adhesion, normal paper is destroyed when being separated again after attached.
* Weak adhesion: The case where adhesive strength is less than 500-800g/25mm used in standard bonding. This is used when the adhesive strength at the level that re-separation is possible is required. It is also used in attaching label temporarily, in the case of using normal paper.
* Removable adhesion: This name is used, in some cases, for nearly same term as weak adhesion, and this is used for attaching a label temporarily. It means that the adhesive is not transferred to the object to be bonded. Removable adhesive not always differentiated from weak adhesive but it is better to use the terms independently.

● Classification by use
* Adhesive for low temperature vs High temperature : The temperature of the substrate at the time the adhesives are applied has a critical impact on the performance of the adhesives. General adhesives are designed to perform best around the room temperature and do not function out of this temperature range. low temperature/high temperature adhesives are specially designed to be able to work best at an extremely low temperature/high temperature environment. The adhesion of the labels that have been applied on a certain type of objects, could be reduced or increased. In some cases, the adhesion could be increased to become a permanent adhesive or could be completely lost.
* Adhesive with water resistance/ water solubility: The adhesive itself is water resistant, the water could penetrate between the substrate and the adhesive, resulting in edge lifting. Especially emulsion based adhesives are more likely to be affected by water than solvent based adhesives. The special adhesive designed to better withstand water is described as the water resistant adhesive. The adhesive designed to dissolve in water or absorb water is called as water based emulsion adhesive.

(3) Release paper

- Release liner is thrown away right after the label is applied to the substrate but it provides a variety of critical functions such as protecting the adhesive from contamination, providing support to the face stock through the manufacturing process. The liner decision should be made considering the process requirements and commercial values as well as its dispensability (which is described as liner release) or ready separability. Ready release, ability of long-term protection, resistance to curling, dimensional stability, and physical strength should be met. Liners are manufactured primarily from Kraft papers, glassine, and films. Release coating is, in most cases, a silicone-based material.

● Release paper: Glassine paper (directly release processed, polylami processed)
- Both kraft paper and glassine paper as can be used as release papers. Kraft paper which is used for release paper is specially manufactured differently from common paper in order to maintain strength of paper, but kraft paper cannot be directly coated by silicon, rather it is done after being coated by Polylami or Clay. Glassine paper can be processed by silicon because it has high strength and excellent smoothness on the surface. In some cases, it is also processed by silicon after being treated with Polylami in the case in which smoothness is required or to improve release strength. Release paper has low stability because it absorbs and releases water and can cause curling. In order to prevent this, a vapor-proof layer is made on the back of the release paper after being processed by Polylami in some cases.

● Kraft paper : treated by Polylami, coated with clay

● Film : PET, PP
- Release paper for which paper and not film is used may lack smoothness on the surface to be silicon-processed even though it may be processed by Polylami. Therefore, if extreme smoothness is required, film release paper should be used and should be used also when the transparency of the release paper is designed. However, because film release paper generates electrostatic charges quite easily, impurities can be attracted to its surface. The back side of it is sometimes processed by MATT or given a separate treatment to solve for this problem.

Reference: KOSTIC, "Label technology”,http://eng.kostic.co.kr/technology/01_labelinfo_01.html, 2014. 1. 29
>> Click to download Composition of label

System Kind Characteristic and use
Paper Art paper It is mostly used in general cases and has an excellent adhesion strength at the initial stage.
– it is used on general boxes,plastic, steel plate, or for general advertisement
Vellum paper For the use of various computer labels or labels for bar codes
-For sending DM, index, stationary, formal purpose, advertisement, plastic container, etc.
Miraa paper It has excellent surface gloss and it dries quickly after printing.
It is mainly used for high quality products like cosmetics and medicine and medical supplies
Thermal paper It is printed by a thermo-sensitive method without ribbon.
Department store, wholesale/retail store, supermarket, for measurement, for packing foods
Film Oilcloth paper It has strong moisture resistance and a quick drying nature, but it cannot be torn easily.
Cold and frozen products, products by PE or PP
PET It has excellent surface gloss. Generally, silver color is mainly used.
Electronic product, agricultural equipment, metal product
PE It has excellent surface gloss. Generally, silver color is mainly used.
Electronic product, agricultural equipment, metal product
PP It has excellent transparency, chemical resistance and wear resistance.
PP container product
PVC It has excellent durability, chemical resistance and can be used indoors/outdoors.
Recently, it is banned from being used due to toxic contamination of the environment.

Reference: KOSTIC, "Label technology”,http://eng.kostic.co.kr/technology/01_labelinfo_01.html, 2014. 1. 29
>> Click to download Use by each paper

- Labels are diversified to the extent that the scope that they are used and applied is so wide nowadays that there is no field in which label are not used.

Use Example for use
Labels for food, beverage Meat processing product, wrapping paper for cold and frozen foods, etc,
for beverage containers for attachment to milk cartons, and liquor bottles.
Labels for household items Used for containers for household items such as cosmetics, perfume bottles, cleanser,
containers tissue boxes, etc.
Labels for stationary and computer For sending mail, for indicating classifications, for computer items, paper for exclusive inkjet usage.
Labels for stationary and formal purposes Teaching materials, study papers, toys, stationary, for formal purposes.
Labels for bar code, distribution For measuring scales, bar codes, home-delivery services.
Labels for electric, electronic product Copy machines, printers, components for electronic products, mobile phones, gas ranges,and computer terminals
Labels for construction, building Building materials, construction materials, attachment to furniture and machines.
Labels for medicine and medical supplies Attachment to blood packs, containers for medicine, casts for attachment to lenses.
Labels for automobile parts Automobile parts, safety belts, airbags, for attachment to car glass.
Labels for interior use For indoor interior use, for lighting, for outdoor advertisements.
For special products Dry cells, batteries, for steel works, for vessels, for attachment to the human body.
For clothing For attachment of trademarks to clothing, for clothing label.

Reference: KOSTIC, "Label technology",http://eng.kostic.co.kr/technology/01_labelinfo_01.html, 2014. 1. 29
>> Click to download Use of labels

(1) Definition of an adhesive

- An adhesive is a material which is not solidified and is in a semi-liquid state in order to be attached easily to the object to be bonded with by only slight finger pressure or a material of viscoelasticity which maintains adhesive power all the time, maintaining semi-permanent elasticity. (Products for which an adhesive is used have many uses as labels, double-sided tape, adhesive tape, and post-its. The reason why the use of adhesive products varies is due to the precise function and convenience of the adhesive and from the fact that the product is developed in various fields by assigning various functions according to its use.)

(2) Three major physical properties of an adhesive

-(TACK) Initial adhesive power (TACK)
Having only a transient adhesive property, it is related to ease of adhesion and is measured by the power that is necessary for detaching the adhesive from the bonded object in a short time.

- ADHESION
This is a physical property that represents resistance generated when separating the adhesive or adhesive tape from the surface of a bonded object, i.e. it is the coherence power between the interface of the adhesive and the bonded object and is standard whether adhesive tape is attached firmly or not.

- COHESION
This refers to the internal cohesion of the cohesive itself. It means the degree that adhesive resists internal destruction, as resistance against being pushed under a certain load. It is related to the thickness of the adhesive, the power between the molecular, bridge condition and the molecular weight.

(3) Classification according to the function of the adhesive

- An adhesive can be classified into a permanent type adhesive which is attached permanently or a removable-type adhesive which can be separated again.

Classification Classification of adhesive Use
Permanent Strength PE, PP injected materials, drums, pallets.
general uses Glass bottles, boxes, computer sheets, plastic-injected materials.
Weakness Study papers, teaching materials, aluminum plates, glass, etc.
Removable Strength Steel plates, shopping bags, hangers, boxes, diskettes, video indexes, etc.
General point Cassettes, tape indexes, portable wet tissues, electronic products, etc.
Weakness Study papers, teaching materials, glass, general plastic-injected materials
(4) considerations when selecting an adhesive

- The important point in all label products is that an optimal product can be manufactured only when several factors are considered, i.e. what kind of original paper is used, by which method is it printed, under which condition is the product used after printing, to what substance is the object to be bonded and what kind of physical property of adhesive is required. A sufficient review and inspection are also necessary because even the same product may represent various physical properties, depending on the kind of adhesive, method of adhesion and improvement of performance. Though there may be factors for selection according to various changes, let us examine several points briefly.

Classification Factors for selection of adhesive
Quality of material of original paper, surface condition of original paper Is adhesion with material excellent?
Is there any interaction with the adhesive?
Is there any problem in forming adhesive layer?
Condition of release paper Is the peel strength excellent?
Does transfer phenomenon occur?
Does the adhesive affect the release paper?
Quality and condition of surface of material to be bonded Is the surface flat or round?
What is the quality of the material to be bonded?
Is it flat or embossed?
Is there any water, or other pollutant?
Is there a possibility that the label can be spoiled after attachment?
Performance of physical property Are initial adhesion, later adhesion, heat resistance, cold resistance,
water resistance, moisture resistance, acid resistance, or chemical resistance called for?
Which characteristic is preferred-adhesive power or cohesive force?
Condition about additional function Are fire retardant, conductivity, water solubility and light resistance is required separately?
Process suitability Is aging resistance excellent?
Is there a dryness problem?
Is aging condition excellent?
Are the processing capabilities of the adhesive coating excellent?
Usage suitability for use Is the adhesive glue flow excellent?
Does it smell after adhesion?
Is it selected according to the most economical design?
(5) Basic explanations about adhesives
a. Rubber adhesives

- This is an adhesive which is designed to have adhesive power at ordinary temperatures by mixing macromolecule (rubber) having –Tg with resin which has an adhesive providing a +Tg characteristic.
- This adhesive has excellent adhesive power, cohesive force and TACK.

b. Acrylic adhesives

- The main monomer is composed of acryl ester of carbon numbers 2~10, and for cross-linkage, the polymer is generally used which a monomer with calling for a small amount to be copolymerized.
- It is used in a place where cohesive force is enhanced with a select monomer that provides improvement in adhesive power and transparency.

c. Silicon adhesives

These are adhesives which have greatly different characteristics from that of other adhesive due to the Si-O combined structure.
These are stable adhesives that resist oxidation and heat.
The flexibility and adhesion of the basic material is excellent at low temperatures due to the low power between molecules, but the mechanical strength is low.
They can be used where such characteristics as heat resistance, cold resistance, weather resistance, electricity resistance are required.

d. Hot melt adhesives

- There adhesives, being 100% solid at ordinary temperature, are made by non-volatile, non-flammable, thermoplastic resins without any solvent at all.
- Being a solventless adhesive, there is no danger of pollution and fire.
- There are several kinds of this adhesive such as EVA, PE, POLYURETHANE, POLYAMIDE POLYESTER.

e. Solvent adhesives

This is used more often for various adhesive products than other adhesive type.
It has the advantage of demonstrating variable performance and excellent effectiveness of its physical properties.
A hydrocarbon system is widely used as a common.

f. Emulsion adhesives

When an acryl emulsion-type adhesive is polymerized, the emulsifying agent (surface active agent), a high molecule protecting colloid polymerization initiator is commonly used in addition to the monomer.
After the polymerization reaction, the pH conditioning agent, thickener, and defoaming agent is used.
It has the advantage of low price compared with that of a solvent type but water resistance is low.

Reference: KOSTIC, "Label technology”,http://eng.kostic.co.kr/technology/01_labelinfo_01.html, 2014. 1. 29
>> Click to download Adhesive

(1) Definition of release paper

- This product is coated on one or both sides of the paper or film with a material possessing desquamation characteristics. It is a consumable material that protectsthe surface of the adhesive treatment.

(2) Comparison of physical properties between release paper and release film

- Adhesives can be classified into permanent typesof adhesives which are attached permanently and removable type adhesives which can be separated again.

Classification Paper Film
Water resistance
Dimensional stability
Transparency
Formability
Surface condition
Curling
Heat resistance
Scratch resistance
Detachability

Reference: KOSTIC, "Label technology”,http://eng.kostic.co.kr/technology/01_labelinfo_01.html, 2014. 1. 29
>> Click to download Release paper

Various factor enter into your decision to select the best quality label for your specific needs : usage, methods, condition of the object to be bonded and the working environment itself. In this regard, let us further elaborate to maximize the effectiveness of your selection.

(1) To what kind of surface will the label be attached, and what is the condition of the surface to which the label will is attached?

- An adhesive suitable for use can be selected and developed effectively only when the strength and the kind of adhesive is selected with due consideration of the surface of the object that label is to be bonded. The reason that the kind of object that it will be bonded to is an important factor is that grasping the difference between the adhesive power which the label has and the surface tension of the object is the most important factor. Also, you can only select a stable label when the adhesive is specifically selected, depending on whether label is to be attached to a flat surface or a round surface, or if there is embossing and what size the embossing is.

(2) To what is the method of the label attachment?

- Labels can be manufactured to comply with customer’s use only when it is exactly determined whether it is to be attached by automatic labeler or attached manually after printing. There would be no adverse ramifications in the case of manual work or general labeling, but, the flow of adhesive glue could be a deleterious factor using a barcode machine or automatic labeler.

(3) What is the condition of the working environment where the labels are made?

- A stable label can be manufactured only when it is considered that during the work, any contamination of the object to be attached, with impurities will decrease the final adhesive properties, as will an excessive time between adhesive coating and attachment to the intended object.
For example, it stores liquid of 80°C after label is attached at ordinary temperature.

(4) How to store the label after attachment?

- Even though label is attached stably, the kind of label and condition of adhesion should be checked without fail, depending on how store it and what the condition of surroundings is. If, after attachment, it is affected directly by moisture or outdoor temperature, the film style product is more stable than paper style and the solvent type is much more stable than the emulsion type.

(5) For which purpose is the label to be used?

- A label can be manufactured to comply with the customer’s requirement only when it is considered whether the label shall be attached permanently to the object, or desquamation is required again, whether it is used for a universal purpose or some special physical property is required such as heat resistance, cold resistance, water resistance, moisture resistance etc.

(6) How much dimorphism of the label is required?

- The product can be optimized according to what general weight is required or dimorphism should be separated heavily as middle weight, considering the method of printing, kind of laminating after printing work, tension of the printer, and the use of the machine during label work.

(7) How do you maintain the labels optimum properties?

- Label product is affected a lot depending on how you store the original material during use and/or how you store the remaining material after use.
- Do you store it under condition of uniform temperature and humidity?
- Do you properly pack it for storage?
- Do you comply with the first-in, first-out method?
- Do you store the rolls horizontally?

Reference: KOSTIC, "Label technology”,http://eng.kostic.co.kr/technology/01_labelinfo_01.html, 2014. 1. 29
>> Click to download Considerations when selecting labels

- Some problems might arise during the printing of or application of our label product. Although the possibility exists that a problem may arise due to a defect in the product itself, many times it is the result of careless handling which causes damage to the product. We will outline below some important quality-control issues that can help you avoid problems.

(1) How to store our adhesive label solution product properly

- Keep it under temperature of +20/-3℃, humidity of +50/-5%RH constantly during the four seasons
- Store it for extended periods as it was packed when you first received it.
- Please avoid direct sunlight when storing it before use
- When products are packed in several layers, please use the product at bottom first so that oldest product will be used first (management of Lot#, first-in, first-out and inventory control)
- When storing a printed product, keep it horizontally and safely without fail.
- The core of the product can be damaged if you keep roll product on a hanger, nail, or wooden peg.
Keep remaining label (Roll product) after use by repacking it in the same condition that it was packed originally.

(2) Points to be considered when rewinding

- Do not use excessive tension when rewinding the product or rewinding it to re-adjust the length of after printing. Because, if adhesive the label product is rolled too firmly, adhesive may be squeezed out of the product. Various problems may occur if adhesive were to flow out from the roll. During barcode printing work, it may damage the barcode printer and ribbon seriously. Therefore, when rewinding the product or cutting and processing the product, it should not be damaged by winding both sides of label roll simultaneously. And it is better for you to arrange the size of the core which you want to rewind, to be same as that of the original core.

(3) How to handle the adhesive label product properly

- The product should be handled carefully at all the times during transport because the surface of it can be damaged easily. If it is handled harshly, both sides of the label (roll) are damaged, which causes label cutting during printing. When the label (in roll condition) is kept on the floor, it should be located on a clean and flat place for further use. Following is a summary of common problems that can occur during the injection of the adhesive label solution into production-line automatic labelers. We offer troubleshooting advice with each one.

a. The release paper (liner) of label is cut when providing adhesive label automatically

- The release paper (liner) of the label is damaged due to excessive knife-cutting work during printing
- Label (label product) is torn due to careless handling of product
- Inexact product rolling (Label roll winding)

b. Prior separation or defect in separation when attaching adhesive label to container

- Excessive cutting work when printing
- Silicon imbalance on release paper (Liner) or damaged release paper

c. The label is not released from the automatic releasing area of the adhesive label

- The label cutting work was done with the wrong knife (Die cut)
- Silicon imbalance on release paper (Liner) or damaged release paper
- Too soft label, especially film style
- The tension of the label roll is too low
- Static electricity was generated between the product and the machine. (It is required to install an anti-static device to resolve this.)

d. The label is stripped or transferred to the direction of release paper when the adhesive label product is released from the roll.

- Improper label cutting
- Quality of label material is too stiff, especially paper style
- Adhesive flows out because the product is rolled too tightly.
Improper storage :avoid exposure to direct sunlight.

e. Position of adhesive label attachment on container is wrong

- Splice on label was misaligned.
- Slitting of label roll was not done properly.
- Width of label was not constantly adjusted.
- The surface of the object (container) where the label is to be attached was contaminated.
- Generation of static electricity.

f. Two adhesive labels are attached to container continuously at a time or no label is attached.

- Selection of improper release paper
- Automatic labeler sensor malfunctioned.
- Generation of static electricity.

g. Adhesive label peels off from the surface after it is attached to a certain container.

- Label is too stiff due to excessive thickness of the material.
- Improper adhesion power.
- The surface of the object to be attached is contaminated.
- The size of the label was improperly selected and is not suitable for the container.

h. Crease of adhesive label after attachment

- The surface of object is contaminated (The contents of container overflows)
- Style of label is improperly designed for container.
- Excessive humidity in the production environment.
- Improper storage of product

Reference: KOSTIC, "Label technology”,http://eng.kostic.co.kr/technology/01_labelinfo_01.html, 2014. 1. 29
>> Click to download Considerations when selecting labels