One of the most common reasons why a reclosable fastener solution can fail: An incompatibility between the hook and loop materials being mated. Without the proper “marriage,” a fastener union is destined to fail, perhaps at the outset, or prematurely during the intended lifespan of the reclosable fastener or the intended life of the product or the application.
For the proper performance from the first cycle to the last – whatever the number of cycles might be – consider these three areas of potential problems and how to avoid them.
HOOK AND LOOP MISMATCH
Frequently, it is assumed that hook and loop fasteners are ordered in precisely matching sets, but that may not always be the case, as the requirements of an application may require an “out of the box” solution.
It is important to note that not all hook materials work with all loop materials. And conversely, not all loop materials will work with all hook materials. They may vary in either height and size, or both. Additionally, not all hook and loop materials are alike. Some hook materials are designed to be used with a very thin loop (low nap) and others for a much thicker loop (regular/tall nap). A hook designed to engage/cycle with a regular nap loop may not hold well or engage at all with a very thin loop (low nap). Sometimes, a traditional woven hook, regardless of the manufacturer, will not work engage/cycle with certain loop materials.
Most manufacturers have known pairings of the hook and loop materials they sell. They are typically tested/evaluated by the manufacturer and can be sold together or separately. To prevent a failure, our team of experts understands what is required to prevent a mismatch and help you make the Right Choice of an ideal hook and loop configuration, even when a mismatch may be exactly what your application requires.
ADHESIVE FAILURE
After selecting the correct hook and loop combination, do not forget about the pressure sensitive adhesive backing which must be selected properly to hold the hook and loop materials in place cycle after cycle. Adhesive-backed reclosable fasteners should bond to a substrate at least 2x the force required to disengage the hook and loop fasteners. Different surfaces such as glass, metal, plastic, and others can require a different adhesive solution to bond to the reclosable fastener and remain in place for the fastener’s entire lifecycle of use.
Failures may also occur when the surface of a substrate has not been properly cleaned or prepared. In these scenarios, the adhesive may not hold on the first or subsequent uses of the reclosable fastener, even though the adhesive meets the 2x peel strength requirements. To assure a strong and lasting bond, proper preparation, or cleaning of the surface area to which the adhesive will be applied will assure the best possible bond.
Additionally, environmental conditions should be evaluated when making the final decision. Exposure to high and low temperatures, humidity, moisture, and direct exposure to UV rays are among the other factors that are taken into consideration when specifying the right adhesive.
Gleicher adhesive specialists are aware of all current best practice guidelines that determine the Right Choice of adhesive to use on certain substrates to ensure that an adhesive will properly bond throughout the lifespan of the application.
PERFORMANCE MISMATCH
The failure of a reclosable fastener can also happen when the strength and durability requirements of an application are not precisely matched to the known performance characteristics of the selected materials. This can take place when the sheer force – the gravity and weight of the application – exceeds the adhesive sheer strength of the product being used. One must consider the sheer, peel, and tensile strengths of the adhesive backing as well as the hook and loop performance. An example of this would be a wearable medical monitoring device where a weak reclosure may cause the device to unwantedly fall off, or a closure that is too strong which prevents easy removal of the device.
Confidently and consistently avoiding reclosable fastener failure is a matter of consultation, testing, and understanding the requirements and use for each application in order to recommend a solution that is not too weak or too strong, but precisely the Right Choice for the intended use.
If you have the need for a reclosable fastener, we welcome the opportunity to answer your questions and design the ideal solution for your specific needs. You can reach a Gleicher fastener solutions specialist with your questions at 908-233-2211 or email sales@gleicher.com.
