Are you still one of those people who go to shops and department stores to buy food, clothes, and electrical appliances, etc.? Or are you a user of the modern, virtual shopping malls that are open at any time of the day or night and whose range of goods far surpasses that of physical shops? Whichever group you belong to: just read on.

Online trading and shipping

Online trading is growing every year. Unlike in local shops, however, the customer cannot simply take the goods home after giving them a thorough inspection; instead, they must be brought to the customer. For large products, such as refrigerators, this is done by a forwarding agent, for smaller articles, in a parcel, and for small, flexible products, such as textiles, in an opaque plastic or paper envelope which is sealed with an adhesive.

Temperature-resistant adhesive for padded envelopes

This envelope has several functions at once, e.g.

• It must be opaque so that no one can see which product is contained within.
• It must protect the product against environmental influences.
• It must be closed in such a way that nobody can take or add anything unnoticed.

And this at any time of day or night and in summer as well as in winter!

These requirements also place high demands on the adhesive, which is responsible for the secure closure of the envelope.

On the one hand, the adhesive, which is simply coated onto the closure flap of the envelope as a narrow strip a few millimeters wide, must have a high initial adhesion. This is because the envelope is filled, sealed, labelled and shipped immediately. There is no time to press the closure tab of the envelope firmly and wait until the adhesive finally sticks. Afterwards, the envelope will go on journeys all over the world. In tropical regions with high temperatures and high humidity or in areas as cold as the Arctic. And the adhesive must always keep the envelope neatly sealed.

This requirement can only be met with carefully selected and tested adhesive formulations. An incorrectly selected adhesive will see the padded envelope open during transport. The goods will fall out and get damaged or get lost. Complaints are inevitable.

Although it is only a matter of sending goods or simple documents, the requirements placed on the envelope are already very high.

Adhesive applications for shipping in the security sector

Applications in the security sector have even higher requirements. Here we are talking about the dispatch of cash, highly valuable documents or forensic samples. You can read about the requirements placed on an envelope in this sector and the special solutions that exist in our blog “What is important when transporting money and valuable items?”

Summary

I'll sum it up:

• Padded envelopes made of plastic must fulfill several functions.
• The adhesive must ensure the secure closure of the envelope.
• It must do so in regions with extremely hot or cold conditions.
• Applications in security areas require special solutions.

Talk to our adhesive experts to find the right adhesive for your application. We look forward to hearing from you and are at your disposal.

UV curable adhesives are a modern adhesive technology that offers many advantages. We at artimelt can look back on more than 20 years of experience in the development of radiation curable UV adhesives and are happy to pass on our artimelt knowledge to you for the switch to UV technology. This artimelt blog is intended to help processors of adhesives make the decision to switch to UV technology.

Change from rubber-based hot melt to UV-curable adhesives

artimelt assumes that, up to this point, you have been processing classic rubber-based hot melt. In this case the step to UV curable adhesives is a small one. You will already be familiar with hot melt, know how it is processed and have the appropriate equipment, such as a barrel melter, buffer tank and a coating plant in-house. You will also be familiar with the advantages and disadvantages of rubber-based hot melt, such as easy processing, good adhesion at low temperatures, or low weather resistance or temperature resistance. The first question to be answered now is whether you need the positive properties of UV curable adhesives for your products, such as:

• High temperature resistance up to 200°C
• High chemical resistance
• High UV resistance and therefore suitable for outdoor applications
• Approval for direct food contact
• Good punching properties

artimelt UV adhesives fulfill all these positive properties. In close cooperation, artimelt develops tailor-made UV adhesives for you, which are perfectly suited to your processing possibilities and fields of application.

Upgrade your coating systems with UV lamps

You can continue to use your existing coating system, but you will have to “upgrade” it. artimelt recommends the following: Talk to a UV equipment manufacturer and tell them what you want to do. Tell him you need UV lamps that emit in the UVC range so that artimelt adhesives can be cross-linked. Also consider the following points:

• How wide is my system?
• At what speed do I want to operate my system?
• How high is the coating weight going to be?
• How much space do I have on my existing hot melt system for UV lamp installation?
• Would I like to have the latest measurement and control technology that measures the UV output during system operation and adjusts it to the target value, or would I like to check and readjust it manually?

All these points ultimately have an influence on the entirety of the equipment and thus also on your investment costs.

Invest for the future: more UV lamps, separate barrel melting units, buffer tank and hose lines

A very important artimelt tip: Don't just have the UV system designed to meet your current needs. Think about the future and invest in more lamp units than you need today. This has the following advantages:

• You can coat a higher coating weight and network safely.
• You can increase the coating speed.
• If the existing lamp fails, you can switch on the spare lamp and continue production.

artimelt also recommends investing in separate barrel melting units, buffer tanks and hose lines to the application head. UV curable adhesives are not compatible with other hot melt systems and can lead to gel formation when mixed, resulting in a poor coating appearance.

With this additional equipment you can kill several birds with one stone:

• You can very quickly switch from classic hot melt to UV adhesives.
• You will save yourself the time-consuming cleaning of barrel melter, buffer tank and hose lines every time the adhesive is changed.
• You will avoid the risk of gel formation.

Summary

artimelt has summarized the most important points for you:

• First answer the question whether you need the properties of the UV adhesives.
• You will need lamps that emit in the UVC range.
• Think about the future and invest in more lamp units than you need today.
• Invest in additional peripheral equipment such as a barrel melter, buffer tank and hose lines.

artimelt has comprehensive know-how regarding UV adhesives and the best contacts to equipment manufacturers. Let your artimelt Key Account Manager advise you.

UV-curing adhesives can now be used for a wide range of applications. Although originally developed to replace solvent-based adhesives, UV adhesives can do much more. Due to the artimelt base polymer formulations, removable adhesives and adhesives with a strong bond can be manufactured using one and the same raw adhesive mixture. artimelt UV adhesives can therefore be used in a wide range of different applications.

Applications of artimelt UV adhesives

A typical example of the way in which UV adhesives can be used is in the manufacture of removable labels for wet-wipe packaging. In this application, the adhesives comes into contact with the wet wipe materials, which can include alcohols, perfumes, paraffin oils and emulsifying agents. All of these constituents do not impair the functionality of the artimelt removable UV adhesives. Even after being opened and closed dozens of times, the adhesive retains its original properties with barely any changes.

Another interesting example of the way in which UV adhesives can be used is in washable bottle labels. Glass bottles are very frequently recycled. As part of the bottle cleaning process, the labels must be able to be removed from the bottle without leaving any residue. This is not always possible with every type of adhesive. Many adhesives form a bond that is too strong and thus prevent the labels from being able to be removed cleanly.

Due to their low weight, plastic bottles (PET) are also being used increasingly in the drinks industry. These also feature labels, but are shredded instead of being reused. The PET flakes generated in this process are reused to manufacture PET bottles and other items made from PET. However, due to labels and adhesives having a negative effect on the PET recycling process, they both must be removed from the PET flakes. This is where artimelt comes in.

Due to the careful selection of raw materials used, artimelt UV adhesives can also come into direct contact with foodstuffs. For example, labels for resealable cookie packaging, as are commonly used nowadays, are manufactured using artimelt UV adhesives.

As the UV adhesives are resistant to light and ageing, they can also be applied to transparent film materials. Even after spending several months in storage, they remain transparent and do not turn a yellow color. Thanks to artimelt’s high level of specialist knowledge in the development of adhesives, the same raw adhesive mixture can also be used to manufacture adhesive tapes. The adhesives used in these tapes must have totally different properties, e.g. the ability to form a strong adhesive bond on a wide range of surfaces, a high level of resistance to shear stress and a resistance to high temperatures. For example, adhesive tapes can be produced for use in the automotive industry.

A great many strongly adhesive labels are also used in this industry. The labels used here feature important information and must not be able to come loose, otherwise this information will be lost. An example of such an application would be car battery labels. These labels are exposed to high temperatures and the effects of chemicals in the engine area, e.g. battery acid, engine oil, fuel, cold cleaning solvent, etc. The adhesives must ensure that contact with none of these substances will cause the label to come loose and fall off.

artimelt UV adhesives are the right solution for this job, as they form a strong adhesive bond on a variety of surfaces and are resistant to high temperatures and chemicals. This resistance to chemicals is also extremely important for labels affixed to chemical containers. Just imagine, you order a number of different chemical and upon receiving them, you find that there is no way to differentiate between the containers, as the labels have fallen off. You won’t know which chemicals are stored in each container. You won’t know how dangerous each substance is. And you won’t know how to handle each chemical. By using the right artimelt UV adhesive, you can make sure you do not run any risks in such situations.

artimelt has the right solutions for you.

Summary

To summarize:

• artimelt UV adhesives can be used for both removable and permanently affixed labels.
• artimelt UV adhesives are characterized by their resistance to high temperatures and chemicals.
• artimelt UV adhesives can be used in the manufacture of products that come into direct contact with foodstuffs.

If you require more information on finding the right adhesive for your application, our adhesive experts would be happy to help.

Infographic artimelt UV adhesives and their Fields of Use

Labels in the supermarket

When walking through the supermarket, have you ever noticed how many products feature labels? By labels, I don’t mean the small price tags – these have in recent years been almost completely done away with and prices are instead displayed on shelves – but rather the larger labels that are used as an advertising medium and to display the product information. 

If you look closely, you will see that a large number of products – mainly sausages and cheese – are labelled in this way. This is not the only place in which these labels are used – in the fruit and vegetables section, you choose your products, weigh them and stick the price and product label that is printed at the scales to the plastic bag in which they are weighed or even directly to the fruit or vegetable.

Fresh cheese and sausages are placed in a plastic bag at the deli counter, weighed and a self-adhesive label on which the price information is printed is used to seal the bag. Other products, such as seasoning sauces, spice jars and drinks bottles also feature labels that are used as advertising media.

You have, however, probably never thought about whether the adhesive used in these labels is allowed to be used for this purpose. We at artimelt deal with this on a daily basis.

Regulations for materials/adhesive that come into contact with foodstuffs

There are strict regulations for the packaging and materials, including adhesive, that are allowed to come into contact with foodstuffs! Within the EU, these regulations are set out by the European Commission. The Swiss Federal Food Safety and Veterinary Office and the US Food & Drug Administration (FDA) are responsible for this task in Switzerland and the US, respectively. For artimelt it is a matter of course to adhere to these regulations and to develop and produce the adhesive accordingly.

Approved lists for direct and indirect contract with foodstuffs in the US

Although there are differences between the regulations and legislation, there are so-called approved lists in the US. These lists define the materials (including adhesive) that are permitted to come into contact with foodstuffs as well as the ways in which they are allowed to be applied to foodstuffs. The lists also specify whether the materials are permitted to come into direct or indirect contact with foodstuffs.

Direct contact with foodstuffs means that the adhesive is allowed to touch the foodstuff itself. Indirect contact is where the adhesive is applied to another material that comes into direct contact with the foodstuff.

For example, you create a label that you want to attach to an apple. The label comes into “direct” contact with the foodstuff when applied. Another label is stuck to the packaging for a piece of cheese. This means that the label does not come into direct contact with the foodstuff, but with the packaging instead. This is what is referred to as “indirect” contact with foodstuffs.

The FDA only approves substances that have undergone thorough prior testing which shows that no components of the substance that could pose a hazard to the health of consumers are transferred to foodstuffs.

artimelt must therefore know exactly whether the adhesive comes into direct or indirect contact with foodstuffs. This is the only way to ensure that artimelt select the right raw materials for the adhesive mixture.

Regulations in Europe

In Europe, the distributor of the foodstuff must prove that the foodstuff and the packaging including adhesive in which the foodstuff is contained are safe and the consumption of the foodstuff does not pose any risks to consumers.

In order to help with this, there is also a wide range of resources available for the distributor to use, e.g. approved lists for plastics that are permitted to come into contact with foodstuffs (EU Regulation 10/2011). This regulation clearly stipulates the raw materials that have been tested and have been found to be suitable for coming into contact with foodstuffs. These raw materials are subsequently allowed to be used in the manufacture of foodstuff packaging made from plastic, provided that they also comply with global migration values and/or specific migration limits. The limits specify the maximum amounts of substances or of a specific substance that are allowed to be transferred to foodstuffs.

Testing by independent institutes

It has become common practice for suppliers to support the distributors by having the individual components of foodstuff packaging tested by independent institutes to prove that the components supplied by them are safe. artimelt thus also has selected adhesive tested to determine whether it can come into contact with foodstuffs.

For the purpose of this testing, artimelt sends the testing institute samples of the adhesive and information on the exact way in which it is intended to be used. The testing institute then carries out its testing in accordance with the generally binding testing standards to determine whether components of the adhesive are transferred to a food simulant. The food simulants used in the testing include, for example, olive oil (which simulates contact with greasy foodstuffs) and Tenax® (which simulates contact with dry foodstuffs).

The institutes’ testing programs and final reports

Depending on the conditions in which the foodstuffs are stored (sausages and cheese are usually stored in a fridge, while biscuits are usually stored at room temperature), a wide range of testing programs can be selected. At the end of the test series, the institute draws up a final report as well as a certificate which specify the types of food (dry, wet, greasy) to which the adhesive is permitted to come into contact.

This ensures that only adhesive that do not release any substances that could negatively affect the health of consumers is used.

Summary

In summary:

• Labels are attached to a great many foodstuffs and foodstuff packaging nowadays.
• The adhesive (and its components) used for these labels must be tested to determine whether they can come into contact with foodstuffs and assessed as being safe.
• Approved substances lists make it easier to select the right components in the development of the adhesive.

Our brochure about the UV-technology is available in the download zone.

If you require more information on finding the right adhesive for your foodstuff application, our adhesive experts would be happy to help.

Nowadays, a wide range of different labels are available. In addition to various shapes and formats – such as round or rectangular labels with and without rounded corners – an unbelievable amount of different colors are on offer. Labels used in industrial applications are already available in all kinds of colors and printed with an array of motifs. Meanwhile, labels for private use are usually made of paper and are left blank in most cases. These paper labels can then be written on by hand or printed using a standard domestic inkjet or laser printer.

Affixing labels at room temperature
After printing or marking, the labels are then affixed in their intended position. In manual processing – such as in the home – these are usually items that are stored at room temperature. One example of this is removal boxes, which are made of cardboard and are stored in the home in everyday ambient conditions. A paper label attached to the cardboard surface only has to be pressed down firmly for it to remain securely in place.

A similar example is address labels for envelopes. These are either written by hand or printed, then removed from the silicone liner and affixed to the envelope.

In industry, labels for logistics applications are also applied at room temperature.

General purpose adhesives – suitable for use at room temperature – are used here. The formulation of these adhesives means they have to be affixed at temperatures above +10 °C. Below this temperature, the initial tack of the adhesive is insufficient to achieve a suitable bond on the corresponding surface. Once they have been affixed and their final adhesive bond has been reached after 24 hours, these labels remain securely attached to the surface when kept at temperatures ranging from around -10 °C to around +70 °C.

Semi-deep-freeze adhesives for applications at temperatures as low as -5 °C
However, not all applications are set up for labeling at +10 °C and above. In industrial applications, temperatures in unheated halls can fall below +10 °C in winter months. General purpose adhesives are too hard in such cases, meaning they can no longer achieve a suitable bond on the corresponding surface. In such situations, a softer adhesive formulation is required. These are often called semi-deep-freeze adhesives. Thanks to their special formulation, they are soft enough to achieve a good initial tack at temperatures as low as -5 °C. Labels with semi-deep-freeze adhesives can then be used for labeling plastic containers stored in the refrigerator, for example.

As these adhesives have an excellent initial tack, they are also often repurposed for applications at room temperature – such as on rough cardboard, for example. Here, the adhesives can also demonstrate their excellent adhesive qualities.

Labeling at -25 °C with deep-freeze adhesives
Foodstuffs such as meat and sausages are frozen for storage as they would otherwise spoil quickly. As these products also have to be marked accordingly, labels are also used here. However, the storage temperatures are significantly below -5 °C – freezers in the home have a temperature of -18 °C – which means semi-deep-freeze adhesives cannot be used here. An even softer adhesive is required here so that the labels also achieve a sufficient bond at temperatures as low as -25 °C. Sometimes, the surface to be labeled also has a fine layer of condensation, which makes labeling even more difficult.

Deep-freeze adhesives are available for such applications. These achieve a good bond at temperatures as low as -25 °C – including on slightly moist surfaces. These adhesives are very aggressive and tacky. As they achieve a rapid bond with the surface, labels are manufactured in this way for use on high-speed labelers. One to two labels are dispensed per second. In some cases, labels are no longer applied using pressure, but are instead blown onto the surface by an air jet. The labels must achieve a secure bond with the surface and must not become detached. This poses some significant challenges in terms of the adhesive.

Deep-freeze adhesives are so soft that they can be used at temperatures between -40 °C and +40 °C. However, the adhesive bond at room temperature is not particularly high.

Nonetheless, this characteristic also allows them to be used in applications where the label has to be removed after carrying out its function.

Different applications for deep-freeze adhesives
Deep-freeze adhesives are thus also a popular choice where easily detachable labels are required.

Applications at low temperatures continue to be dominated by hot melts.

Dispersion adhesives can also be used for applications at room temperature. While the focus remains on hot melts when it comes to semi-deep-freeze adhesives, dispersion adhesives have made some major advances and are also seen in certain semi-deep-freeze applications.

Adhesives for temperatures as low as -200 °C
Additionally, there are also applications in the medical field where significantly lower storage temperatures of as low as -200 °C are the norm. Of course, samples that are stored in ampules or test tubes and cooled with nitrogen have to be clearly labeled and identifiable. Labels for such applications use special cryogenic adhesives containing acrylate. Labeling is often made at room temperature here, after which cooling takes place.

Summary
To summarize:

• Products are labeled at different temperatures
• After labeling, products are stored at different temperatures
• Users must choose between general purpose adhesives, semi-deep-freeze adhesives, deep-freeze adhesives or cryogenic adhesives
• The appropriate adhesive must be selected according to the applicable temperature range

Introduction
Labels are an integral part of our everyday life. They are used for carrying advertising and information and we perceive them both consciously and often also unconsciously.

But did you know that 50% of a label ends up as waste?

Usually, labels are supplied on a release liner. This liner is disposed of as waste after the label has been applied. If a label could be supplied without a liner, then hundreds of tons of non-recyclable paper waste could be saved.

What does a linerless label consist of?
Classic labels are supplied on a release liner. After the label has been applied, this liner is disposed of as waste.

As the name suggests, linerless labels do without this liner. Instead, the adhesive layer is attached directly to the paper layer underneath in a similar way to a roll of adhesive tape.

Which applications are covered by linerless labels?
Linerless labels are manufactured from transparent foils or paper. The labels can be printed in color or – as in many cases – left unprinted. Thermal papers are normally used. The labels are printed with information using a thermal printer immediately before application. As they have no liner, they cannot be punched in various different shapes. While the label length is variable, the label format can only be rectangular. As a result, linerless labels are the ideal solution when it comes to displaying short-term, informative content. Labels that are used at the point of sale to persuade consumers to buy products should still be manufactured with classic release liners as before.

What are the advantages of linerless labels?
As linerless labels do not require a liner, they have several advantages:

• 50 to 60% more labels per roll
• Less storage space required for the same number of labels
• Fewer roll changes
• Variable label length and flexible print format
• No scrap web waste
• No liner waste
• No storage space required for release liner waste
• No transport and disposal costs for release liner and scrap web waste
• Saves resources
• Environmentally friendly
• 30% reduction in material costs
• Up to 15% savings in total costs

What do I need to manufacture a linerless label?

• Paper, foil or thermal paper
• Silicone
• Adhesive

Can I use any paper, silicone or adhesive?
The answer here is a resounding “no”!

Only use high-quality thermal papers, silicones and adhesives. The thermal papers must be such that good fixation of the adhesive to the reverse side is possible. At the same time, they must also be impermeable so that no part of the adhesive can penetrate through the paper into the thermal layer and render the printed information illegible. The surface must be such that good fixation of the silicone is guaranteed without the silicone being absorbed into the surface and eliminating the separation effect.

The silicones are usually UV-curing. Pay attention to the correct viscosity! When the viscosity is low, the silicone penetrates the surface of the paper and can then no longer be cured sufficiently.

A decisive factor is selecting the right adhesive. Aqueous adhesives penetrate the paper structure and have to then dry out. The paper warps during drying and renders the label roll unusable. This rules out both dispersion adhesives and solvent-based adhesives, thus leaving classic hot melts and radiation hot melts. Classic hot melts are easy to apply – simply melt, coat, wind and you’re done. Selecting the right product is also important when using hot melts! After all, the adhesive has to meet not just one but several different requirements in this case:

1. It must be possible to detach it from the silicone layer
2. It must not soil the rollers of the printing system
3. It must not soil the cutting device
4. It must ensure secure adhesion of the label on the corresponding product

All of these requirements can only be met when adhesives of the highest quality are used.

Summary
Linerless labels are currently a cost-effective and environmentally friendly alternative to classic labels. While the area of application is limited, it is absolutely sufficient for labels with short-term, informative content – such as labels used in logistics.

Ensure the components used are of high quality to prevent unpleasant surprises.

Want to find out more about artimeltlinerless? Contact artimelt today.