Adhesives for tapes and labels

Other hot melts are based on low molecular weight polyethylene, combined with tackifying agents. These tend to be lower in cost and performance than the EVA-based hot melts, and they are used primarily with paper packaging, such as cartons and multi-wall bags. Atactic PP can also be used as the base for hot melt adhesives. Pressure-sensitive hot melt adhesives for tapes and labels often employ thermoplastic elastomers, consisting of block copolymers of styrene and butadiene or isoprene. 

Vector SBS, SIS, and SB styrenic block copolymers are produced as diblock-free and diblock copolymers. The company s process to make linear SBCs yields virtually no diblock residuals. Residual styrene butadiene and styrene isoprene require endblocks at both ends of the polymer to have a load-bearing segment in the elastomeric network. However, diblocks are blended into the copolymer for certain apphcations. Vector SBCs are injection molded, extruded, and formulated into pressure-sensitive adhesives for tapes and labels, hot-melt product-assembly adhesives, construction adhesives, mastics, sealants, and asphalt modifiers. The asphalts are used to make membranes for single-ply roofing and waterproofing systems, binders for pavement construction and repair, and... 

The three main forms of adhesives for tapes and labels are ... 

Temins SC. Pressure-sensitive adhesives for tapes and labels. In Sfceist I, editor. Handbook of adhesives. 3rd ed. New York, NY Van Nostrand Reinhold 1990. Soft cover reprinted 2013 [Chapter 38]. 

Bostik, Inc., formerly Bostik Findley, Inc., is a leading global producer of adhesives and sealants. The firm operates in five segments construction and distribution performance adhesives nonwovens/tape and label global transportation and flexible laminating. The construction and distribution division manufactures flooring installation adhesives for tile, stone, hardwood, carpet and vinyl caulks, elastic adhesives, aerosol adhesives, fire-retardant adhesives, epoxies,... 

In 1966, Dahlquist(i7) defined the requirement for a good pressure-sensitive adhesive as an adhesive with one-second shear creep compliance greater than J(t) = 1 x 10cm /dyn (Figure 17). Recently, we characterized the viscoelastic properties of many conmiercial tapes and label adhesives and found that the glass transition temperature and modulus (G ) at the application temperature are the most important requirements for good performances (Figures 18, 43, and 52). The requirements for tape and label adhesives are somewhat different for... 

In general, thermoplastic elastomer hot-melt adhesives are not as strong as polyesters. However, they exhibit good flexibility, high elongation, toughness, and vibration resistance. Polyurethanes and block terpolymers are used as hot-melt pressure-sensitive adhesives in tapes and labels and for nonwoven applications. 

Pressure Sensitive Adhesives.Solution pressure sensitive adhesives (PSA s) for tapes and labels are primarily blends of rubber and tackifying materials such as resins. The low... 

Jagisch, F.C., Novel radial styrene-isoprene polymers for pressure sensitive adhesives. In Proceedings of the European Tape and Label Conference, Antwerp, Belgium, April 18, 1997. 

Release coatings are important components of pressure sensitive adhesive (PSA) products such as tapes and labels [1]. Release materials are coated onto the backside of PSA tape backings (often called low adhesion backsizes or LABs in this form) to provide the desired tape roll unwind force. They are also coated onto various substrates to form release liners for PSA products such as labels and transfer tapes. Typically the thickness of the release coating is less than 1 p,m, and often times less than 0.1 jLm. Release coatings can be thought of as the PSA delivery system, providing a controlled unwind or release force and protecting the adhesive from contamination and unintentional contact until it is applied. 

As should be apparent from the variety of applications, there are many test methods for hot melts, most of which are application specific. Many such tests were developed by adhesive suppliers and are proprietary to them. The use of standardized testing is most common for PSA tapes and labels. These tests are discussed elsewhere in this volume. 

The other major uses of acrylic latexes are in textile finishing (e.g., stain and wrinkle resistance), adhesives, and floor polishes and waxes. Adhesives are used in many applications, including pressure-sensitive tapes, contact adhesives, and construction adhesives for carpeting and floor tiles. Peelable labels and stamps probably got their start with the Post-it note, invented by Spencer Silver and Art Fry at 3M company many years ago. 

Where bonding areas are large or there is a need for shape conformity between bonded parts Where the intention is to dismantle the bond later, the use of various labels, surgical and pressure-sensitive tapes, adhesives for positioning and locating parts, in lieu of jigs, prior to assembly by other means... 

The flexibility of PVC film makes it ideal for many industrial tape and label applications. Unfortunately, PVC film can be difficult for many adhesives to bond to and transfer failure is common. This can lead to long-term debonding as well as reduced holding power and chemical resistance. An in-depth look at PVC adhesion is provided and a solventbome adhesive with superior anchorage to PVC films as well as improved heat-resistance is described. 4 refs. 

Pressure-sensitive adhesives are the essential components of adhesive tapes and labels. They are polymers with permanent tack, usually applied on substrates (plastic/metal films, siliconized papers). To enhance their tack, compounds with high inherent tack are added, for example, resins, plasticizers. Pressure-sensitive adhesives reach their adhesion on the material to be bonded by contact pressure, from which the term pressure-sensitive adhesive (PSA) derives. Apart from electron radiation, also UV-radiation curing described in Section 4.3.2 is applied in adhesive tape manufacturing. The monomer molecules to be polymerized are applied, in liquid form, to the substrates to be coated by rolling and are continuously cured to a polymer layer within seconds under a UV-radiation source. Depending on their composition, predetermined adhesion values can be adjusted. The adhesive tapes can be subsumed under the systems shown in Figure 5.4 ... 

Pressure-sensitive adhesives (PSAs) are used in various forms for packaging, medical and masking tapes and labels. PSAs are viscoelastic materials that exhibit sohd-like and liquid-like behavior so that their performance can be evaluated by tack (the capability of a PSA to adhere instantly under light pressure), peel strength (the tensile force required to remove a PSA) and shear strength (flow resistance) [1, 2]. 

Uses Release coating for hot-melt, acrylic adhesive pressure-sensitive tapes and labels of PP, PE, polyester, cellophane, foil, and paper Features Prevents delamination and tearing of the substrate Properties Wh. dry powd. sol. in toluene, heptane, hexane. Shell Cypar m.w. 135,000 m.p. 87-93 C cloud pt. < 25 C (5% in toluene) 99.5% min. assay... 

Uses Water repellent, release agent used on paper/paperboard for water-repellent pkg. materials, food pkg., grease-resistant and release paper when used with PVA, release and grease-crawl-resist, paper for industrial release sheets for prep, of plastic laminates, food separators and pan liners, separator sheets for pressure-sensitive tapes and labels, water-repellent coatings and adhesives Regulatoiy FDA approved for food pkg. 

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