Лако-красочные материалы — производство

Another important property of a PSA is its resistance to creep. This property is specified by the customer, and depends on the field of application. PSAs are expected to resist shearing forces during a very short period at high temperatures (as when masking tapes hold masking paper during a curing process), or over a very […]

The peel resistance of a PSA is an important property which is determined in terms of the force needed to peel back an adhesive tape from a solid surface at a defined rate in a defined peel angle. The peel resistance depends on the adhesion of the adhesive to the surface, the viscoelastic behavior of […]

PSAs require a characteristic combination of rheological properties; first, they must wet the adherent surfaces rapidly and completely to build up a good holding force. The quality of the wetting is determined not only by the viscoelastic behavior of the PSA but also by the surface tensions of the adhesive and the adherents. During bonding, […]

Although, for a long time, natural rubber [poly (1,4-cis-isoprene); see Figure 5.1] was used as base material for PSAs, today they are made from a great variety of elastomers. In order to generate tack and adhesion, ‘tackifiers’ and other materials are mixed with the base material. These formulations stand out for their excellent adhesion features […]

5.1.1 Introduction Pressure-sensitive adhesives (PSAs) are permanently tacky at room temperature, and firmly adhere to a variety of surfaces upon contact with finger or hand pressure. They do not require any activation by either water, solvent or heat to build up a strong bond with such materials as paper, plastics, glass, wood or metals. Additionally, […]

The designations of adhesives are often derived from their base polymers, such as ‘neoprene contact adhesives’, ‘phenolic resin adhesives’ or ‘epoxy resin adhesives’. In this chapter, we will apply this classification principle to all chemically setting systems. Adhesives are rarely made from only one base polymer; more often, they are formulations of several organic or […]

In general, polymers are not very harmful — or not even harmful at all — at least for short-term human contact, as long as they are present in the form of solid substances within the adhesive layers. However, if the adhesive contains low-molecular sub­stances before the setting process takes place, then the hazard potential may […]

A primer is a coating system that is additionally applied to a surface to be bonded prior to the application of the adhesive in order to protect the surface against uncontrolled, environmentally induced changes, or to improve the adhesion of an adhesive applied subsequently. In general, primers are highly diluted polymer solutions that wet the […]

One specialized group of chemically setting adhesives incorporates microencapsu­lated, chemically setting systems that are used mainly as locking devices for screws. Both, anaerobically setting adhesives (diacrylic acid esters) and two-part or multi-part reaction adhesives may be microencapsulated. These components can be applied to the adherents, for example, in a latex solution. The capsules are only […]

Besides setting via heat, several other physical effects like absence of oxygen in the glue line or presence of moisture at the adherent surfaces can be utilized in order to initiate a curing reaction. The most common one-part adhesives are based on an initiation by irradiation (e. g. UV light), by an absence of oxygen […]