Tack Retention

Effect of laminating pressure (during I min) on tack retention of a CR adhesive... 

Laminating pressure Tack retention for Neoprene AD30 (min)... 

The structure of the phenolic resin has been correlated with several characteristics of the adhesive. For example, benzylic ether linkages appear to prolong the tack retention time. Resins made in solvent, in the presence of catalysts (PTSA or MgO), have a lower content of 2,6-dimethylol-4-t-butylphenol, the species responsible for phasing problems. 

Addition of resins to solvent-borne polychloroprene adhesives serves to improve specific adhesion, increases tack retention, and increases hot cohesive strength. Para-tertiary butyl phenolic resins are the most common and amounts between 35 and 50 phr are generally added. In general, tack increases by increasing the phenolic resin content in the polychloroprene adhesive, and bond strength reaches a maximum at about 40 phr, decreasing for high amounts of phenolic resin. 

Natural rubber has an excellent flexibility, high initial tack, and good tack retention properties. Typical applications include its use as an adhesive in self-sealing envelopes, and, in general, as pressure sensitive adhesive. It also has wide applications in the footwear and upholstery industries, for the attachment of leather, fabrics, and ruhher to one another or to wood and metal, bonding of paper, felt and textiles in the manufacturing of stationery, packaging, etc. 

Tack and building tack Retention of rubberlike properties at low temperatures over long periods of time... 

Examples of some of the current uses for these adhesives include retention of automotive gaskets, weather stripping, side trim, and wiring harnesses athletic shoes swim masks shotgun recoil pads arrow feathers dolls and doll furniture circuit board component mounting and wire tacking and lipstick tube and compact mirrors. Aledical devices include balloon catheters and tubing sets the adhesives are used by morticians to seal eyes and lips. 

Top layer considerations, including temperature and color, water retention (size, consist, and organics), mulching, and tacking... 

Before World War II (1939-1945) natural rubber was used for practically all rubber applications. Natural rubber is preferred in many products because of its superior building tack, green stock strength, better processability, high strength in non-black formulations, hot tear resistance, retention of strength at elevated temperatures, better resilience, low heat build-up, fatigue resistance, and better dynamic properties. Rubber products are broadly classified as dry rubber products and latex based products [60]. 

PROPERTIES OF SPECIAL INTEREST A tough, rubbery, cind moderately hard polymer with little or no tack at room temperature superior resistance to degradation and remarkable retention of its original properties under use conditions. 

Features GRT for general purpose compds. requiring retention of building tack and flexibility of uncured slocks vulcanizales have superior resistance to hardening by elastomer crystallization Properties Amber chips Toxicology TSCA list ... 

The choice of resin tackifier influences not only the initial adhesive performance, but also the retention of adhesive properties upon aging. Color retention and resistance to oxidation and UV degradation are key considerations in choosing a tackifying resin. Glycerine or pen-taerythritol esters of unmodified wood rosin exhibit fair tack properties initially, but have poor aging characteristics primarily because of resin oxidation. Esters of rosins which have been stabilized by hydrogenation or polymerization, e.g., Foral 85 or Foral 105, possess the best combination of properties for adhesive use. 

During PCB assembly and transportation, forces imposed on a component can cause the device to move from its original position on a PCB. Solder paste and/or flux is used to retain components in place during the assembly and transportation of the PCBs. The tackiness required of a flux or paste depends on the assembly process utilized. In-line automated assembly requires less retention force than manual batch assembly. Additionally, placement equipment utilizing table movement rather than head movement requires much greater retention forces due to high accelerations imposed on the PCBs and components. The retention force can be calculated by simply multiplying the acceleration imposed on a component by its mass. A tack test can be performed on the solder paste or flux as described in section 2.3.5 of this chapter to determine its retention capability. 

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