When adhesive tape is found as evidence at a crime scene, it is the forensic scientist’s job to match it to its source with little or no knowledge of tape construction.
The criminal element has discovered the thousands of uses for adhesive tape, and it is being found more and more often as trace evidence at crime scenes. By far the most common tape found as evidence in two out of three cases involving adhesive tape is duct tape.
Many biodegradable polymers are suited for adhesive applications, such as environmentally friendly packaging, recyclable envelope adhesives and biomedical devices.
Significant advances have been made over the past 20 years in the development of biodegradable polymers. These materials have been developed in a variety of forms, and thus have potential use in a range of industries, including adhesives.
While cured adhesives and sealants are generally considered safe, care must be taken with airborne particles, decomposition products, and uncured components.
Completely cured adhesives and sealants are generally considered safe and non-toxic, although caution must be exercised when machining or grinding joints due to airborne particles. Also, decomposition products may exhibit substantial vapor pressures that present health and safety issues. However, it is exposure to uncured components that can be the most harmful, and that is the subject of this article.
Pressure-sensitive adhesives (PSAs) are a combination of several materials that come together to form a "construction." A PSA construction is a combination of layers including a facestock (label) or backing (tape), an optional primer coat, an adhesive, and a silicone release coating on a protective liner. The PSA construction—whether a label, tape or transfer adhesive—is manufactured through several coating and laminating steps, including liner-release coating, adhesive coating/drying/curing, optional facestock or backing primer coating, and lamination of the facestock or backing to the liner.
What are hot-melt polyurethane reactive adhesives used for?
January 26, 2001
Although hot-melt polyurethane reactive (HMPUR) adhesives have been available for 25 years, their novel properties and the development of diverse products have accelerated their recent growth.
Testing pressure-sensitive adhesives under standard conditions of temperature and relative humidity is always a preferred means to compare data from lab to lab and from lot to lot, but it is sometimes necessary to evaluate the performance of an adhesive under conditions that it would encounter in the field.
September 11, 2000
Many adhesives exhibit different properties when subjected to variations in temperature. Some of these adhesives are thermoplastic. They soften when heated and become more brittle when cooled. [In the case of pressure-sensitive adhesives (PSAs), the nature of the bond is nearly always thermoplastic.] If for the sake of this discussion we limit our testing to tack, peel and shear, we can develop a series of observations that can be applied to most testing situations.