Flow, glue

Binder or Aggiutinont is a material, such as asphalt or bitumen, dextrin, starch, flow, glue, fossil gums, gelatin, milk sugar, petrolatum, resins, shellac, stearin, paraffin wax, sugar, syn-... 

Oriented strandboard (OSB) resins are quite similar to plywood resins, though they tend to be lower in alkalinity and higher in solids. Sinee OSB resins are sprayed onto dry wood in small discrete droplets rather than applied in glue lines, the problems associated with holding the glue on the wood surfaee are not usually issues of coneem. Adhesive dry-out and loss of flow displace over-penetration as major difficulties. 

The thermal conductance of each glue spot below 150 mK was very low because of the two contact resistances Rc (Kapton-glue and glue-copper), and the power Ph delivered to the copper sample did not flow through the Kapton foil. To be sure of that, however, 1 mm large, 56 xm thick copper ribbon was internally glued around the upper end of the Kapton support. A heater Hk and a thermometer Tk (Fig. 11.6) were fixed on the ribbon and a power Pk was delivered to the Kapton support in such a way that T = Th. 

There are dozens of other examples around the house for which we have similar quality standards in terms of their resistance to flow. Examples include other food products such as honey, pancake syrup, gravy, and ice cream toppings. Hygiene products include shampoo, hand lotion, and liquid soap. We might also cite pharmaceutical formulations, such as cough medicines, milk of magnesia, and liquid dietary supplements, as well as home and car care products such as caulks, glues, and motor oils. 

Polymers are also used as sutures. Fighters and other athletes have used poly(alpha-cyanoacrylates), super glues, to quickly stop blood flow in surface cuts. Today, super glue is also used for, in place of or along with, more traditional polymeric suture threads for selected surface wounds, internal surgery, and retinal and corneal surgery. The alpha-cyanoacrylate polymers (structure 19.22) undergo anionic polymerization in the presence of water. More about sutures is explained in Section 19.6. 

The ink for inkjet printers is essentially colored water, and the current formulation of ink is about 75% water, plus dye and glue (Kang 1991, Le 1998, Pond 1999). The ink should flow readily from ihe inkwell to the nozzle, and then to the paper, without dripping or clogging. The viscosity of current inkjet ink is from 2 to 8 cP. The droplets formed should be very uniform in size, and should be as small as possible to increase the resolution. When the droplet hits the paper, the droplet should penetrate the fibers without splatter, which would increase the diameter of the dot on the printed text or picture. The surface tension of current ink is around 45 to 50 dynes/cm, which is much lower than water at 70 dynes/cm. It is believed that if the surface tension is raised from 45 to 65 dynes/cm, the spread (or ratio of diameter of spot on paper/diameter of droplet) would decrease from 3.3 to 1.1. Much higher resolutions... 

Formalin is an aqueous solution of approximately 40% formaldehyde. It was traditionally used to preserve biologic specimens, but its identification as a mild carcinogen has curtailed its use as a preservative. Formaldehyde is widely used to produce synthetic resins. Resins are sticky, liquid organic compounds that are insoluble in water. They often harden when exposed to air. Many commercial types of glue are resins. Natural resins are produced by plants as a response to damage. When a plant suffers external damage, natural resins flow to the area and harden to protect the underlying... 

Before the catalyst powder is pelletized, "binders" such as graphite or stearic acid are added. While stearic acid might act as a binder at room temperature, graphite is better known as a lubricant than as a glue. One might suspect that the "binders" work not as glue but by improvement of the flow properties of the powder. 

Finally, a large variety of hot-melt or thermoplastic adhesives have been developed in recent years. These are solid at normal temperatures, but melt and flow if heated and re solidity when cooled. A wide range of melting points and bond strengths are available, depending on the requirements of the application. These adhesives are widely used in furniture and cabinet construction and have largely replaced the hide/bone glues formedy used in these applications. 

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