Laminating adhesives pressure-sensitive type

Adh6SiVGS. Acrylic emnlsion polymers are nsed in a wide variety of adhesives. Pressure-sensitive Adhesives, which typically have Tg values less than 20° C, are the main type of acrylic adhesive. Acrylic polymers and copolymers find use as PSAs in tapes, decals, and labels. Along with their aforementioned superior chemical resistance properties, acrylics possess an excellent balance of tack, peel, and shear properties which is crucial in the adhesives market (218,219). Other types of adhesives that employ acrylics include construction formulations and film-to-film laminates. 

Wet laminating allows for adhesive polymer selection from permanently tacky pressure-sensitive-type products in the = -40°C range to fairly stiff polymers that require some coalescence for adequate film formation. Generally, the lower Tg polymers are used to... 

Adhesives. Acryhc emulsion and solution polymers form the basis of a variety of adhesive types. The principal use is in pressure-sensitive adhesives, where a film of a very low T (<—20 " C) acrylic polymer or copolymer is used on the adherent side of tapes, decals, and labels. Acrylics provide a good balance of tack and bond strength with exceptional color stabiUty and resistance to aging (201,202). AcryUcs also find use in numerous types of constmction adhesive formulations and as film-to-film laminating adhesives (qv). 

Batteries are typically produced with deep drawn metal cans on which a pressure sensitive adhesive label is applied for product identification, branding and safety information. Customers began complaining of batteries becoming jammed in various types of equipment. Devices returned to the manufacturer showed that the pressure sensitive labels had peeled back, resulting in adhesion between the overturned label and the device. Further examination of batteries on store shelves for more than a year also indicated peeling labels in a low frequency of batteries. These labels consisted of laminates of paper and polyester. The labels are normally flat and stiff and when applied over a battery, the labels will return to the flat condition if the adhesive fails. This results in peel-back at the edges of the label. 

Acrylics Solutions and aqueous emulsions Both thermoplastic and thermoset formulations available Very wide adhesion range Excellent resistance to discolouration, hght, and oxidation Curing types are available that have wash and dry-cleaning resistance Pressure-sensitive adhesives Laminating adhesives... 

An adhesive film is laminated on a rigid board with a release sheet first. The boards are then routed by punching or by NC router. It is a very simple process if the adhesive material is pressure-sensitive adhesives (PSAs). Each piece of stiffener is placed on the flex circuits with appropriate pressure, mostly by hand.The process is more compUcated when a thermo-set type adhesive material is required. A temperature higher than 160°C with a pressure higher than 20 kg/cm is required for more than 30 min. A similar heat press used for multilayer circuit boards or film coverlay is necessary. Dummy boards should be prepared to make the pressure uniform. 

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