Although the stickiness of a label may not be something that is often at the forefront of business owners’ minds, it is definitely an important aspect to consider. No matter what type of security or inkjet label being printed, its stickiness will be affected by several factors. Every label application will be unique to the customer.
The four factors that affect the stickiness of labels are temperature, strength, time and surface.
Application and Storage Temperature
When a label is applied for the first time, a reaction takes place to cause the label to adhere to a surface. The higher the temperature, the faster this reaction will be, which is why labels applied at high temperatures usually stick better than those applied in cooler temperatures.
Attempting to apply a label in cold temperatures can slow the adhesion reaction, which can mean it takes longer for a label to stick. Cold temperatures can also completely prevent the adhesion reaction.
Most all label packages will display a minimum application temperature, which serves as a guide for optimal application.
The storage temperature of new label packages can also affect their stickiness. Any extreme heat or cold that a label comes into contact with during storage can affect its ability to bond once applied.
Adhesive Strength and Tack
Every type of the many adhesives on the market today has been manufactured with specific properties. The permanency of an adhesive is one crucial characteristic. Adhesive permanence will determine whether or not a label is removable.
The tack of a label is what determines its stickiness. The initial tack of a label refers to the strength of the bond when a label’s adhesive first makes contact with a surface. Once it’s been applied, the adhesive on a label will set. Ultimate tack refers to the bond strength between surface and label once the adhesive has set fully.
Those wanting a temporary label that’s easy to remove should look for one with low initial and low ultimate tack. For situations where a strong and permanent bond is needed, the adhesive should have excellent initial and final tack.
Whether a label is temporary or permanent, one fact remains: adhesives become stronger with time. The bond starts strengthening when a label is first applied, and continues to strengthen until the adhesive sets.
Regardless of label type, it needs time to set properly. That being said, you should refrain from trying to test the adhesive by pulling up a corner of a label; this will only weaken that all-important initial bond.
A word about removable labels; if you are considering storing purchased removable labels for future use, remember that these labels are created to have the low initial and ultimate tack so as to make them cleanly and easily removable when they are no longer needed. As such, leaving them for a long period of time in storage will cause the adhesive to harden and set before they can be used. To avoid this, store temporary labels in a cool and dry environment that is out of the sunlight.
How strong of a bond an adhesive will form with a surface will depend on the properties of that surface. The texture of a surface, along with the surface’s construction material and its shape are the most important factors.
A surface with too few troughs or troughs that are shallow will not have enough surface area to adhere effectively. The same is true of a surface with too many deep troughs. A flat surface is best for good adhesion, and any coatings already on a material should also be taken into consideration.
The best way to test the adhesion of a label is to first choose the right adhesive, and then test it in the conditions in which you plan to use it.