Tumble dryers

Fabric Softening. The use of quaternary surfactants as fabric softeners and static control agents can be broken down into three main household product types rinse cycle softeners tumble dryer sheets and detergents containing softeners, also known as softergents. Rinse cycle softeners... 

An oven can be used instead of an oil bath. If the amount of polymer to be post-condensed is large, a tumble dryer (rotavapor apparatus) or moving bed reactor can be used. 

Tumble dryers use pressure sensors for filter measurements by measuring the differential pressure across the lint filter signalling the user when to clean the filter. 

Humidity sensors are often technologically closely linked to chemical sensors and can be used e.g. to determine the drying cycle length in tumble dryers and dishwashers, by determining the remaining air humidity caused by wet laundry or dishes. 

Household examples that result in a buildup of a static charge are walking across a rug, placing different materials in a tumble dryer, removing a sweater, and combing hair. The clinging fabrics and sometimes audible sparks are the result of the buildup of static charge. 

Rotary style valves, 20 685 Rotary tackmeters, 14 316 Rotary tumble dryers, 18 732 Rotary vane pumps, 21 71 Rotating anode X-ray tube, 26 413 Rotating arc reactor, 1 211-213 Rotating biological contactor defined, 3 759t... 

The continuous process is appropriate for the large-scale production of polyesters used in bottle manufacture. Currently, reactors with capacities of more than 600 t/d have been employed. The discontinuous technology based on tumble dryers allows for the successful production of specialities on a smaller scale, particularly for engineering plastics and with respect to the fiber industry. This route is preferred due to its flexibility, simple process control and the excellent quality of the final product. It is, however, restricted by the volume of the reactors, which is generally limited to 44 m3. 

Eabric softeners can be applied in different ways. The dominating types of products are the rinse cycle softeners, which are liquid aqueous dispersions. The softener may also be introduced as tumble dryer sheets, a practice that is relatively common in the United States but not in Europe. A smaller but growing use of the softener product is as softener-containing detergents, sometimes referred to as softergents. 

Polystyrene capacitors have exceptionally low tan S values (< 10 q, making them well suited for frequency-selective circuits in telecommunications equipment. Polymer capacitors are widely used for power-factor correction in fluorescent lighting units, and in start/run circuitry for medium-type electric motors used in washing machines, tumble-dryers and copying machines for example. They are also used in filter circuits to suppress radio frequencies transmitted along main leads. Such interference noise may originate from mechanical switches, furnace controllers and switch mode power supplies it not only spoils radio and television reception but can also cause serious faults in data-processing and computer equipment. 

Figure 6.5 Determination of removal of cationic surfactant from a tumble dryer.

Iacobucci, P. (1997) Tumble dryer sheets. Oral Presentation at the 88th AOCS National Meeting, Seattle, WA. 

Cost data for drum dryers, rotary dryers, tray dryers, and tumble dryers are presented in Figs. 16-29 through 16-32. The data available cover both atmospheric and pressure systems. 

Indirect conduction Moving solids bed Tumble dryer... 

AATCC Test Method 130-2000 has been developed to measure the ability of fabrics to release an oily stain when laundered. Fabric samples (15x15 inches) (38 X 38 cm) are stained with com oil, then a specified weight is used to force some of the oil into the fabric interior. After laundering with a specified detergent under a choice of laundering conditions, the samples are dried in a tumble dryer and compared to photographic standards (stain release replica with the usual AATCC 1-5 scale). 

Polymeric material comprising one or more poly(oxyalkylene) amine groups and an epihalohydrin-derived terminal group that acts as a lubricant to reduce fabric abrasion during the tumble dryer/wash cycle, decreasing fabric wear and color loss on collars and cuffs... 

Of course, differences of penetration are also linked to objective parameters. For instance, electrical tumble dryers have always been more common in North America than anywhere else in the world. In 1983, 65% of U.S. households owned a dryer, the proportion being only 10% in Europe [14]. In 1994 the figures were 75% in the U.S. and 20% in Germany [11], Today, the proportions are 70 to 80% in the U.S., 21% in Western Europe, only about 15% in Japan, and still less in other parts of the world [3],... 

Because of the static electricity imparted to synthetic fabrics by tumble drying, and the increasing proportion of synthetic fabrics in the U.S., the sales of dryer-sheet fabric softener rose much more in the U.S. than in the rest of the world. By 1983, these products accounted for 40% of all household fabric softener sales. Today, tumble dryer sheets and liquid softener sales are of the same order of magnitude [5,6,16], In contrast, rinse-added softeners had a much larger impact in Europe, where 100% cotton items have always been dominant and line drying is still standard practice hence, the softener effect is more noticeable to consumers. 

Chloride derivatives of the quaternaries have the drawback of causing corrosion of storage tanks, manufacturing vessels, and tumble dryers when dryer cycle fabric softeners are used (see below). Moreover, these chemicals are waxy pastes and must be melted before being dispersed in water. These problems are overcome by using methylsulfate derivatives, which do not corrode stainless steel and are usually liquid at room temperature [1],... 

Another limitation with clay softeners is that they do not exhibit any antistatic activity. This is a serious drawback in North America, where tumble dryers are very common. Several approaches have been followed to address the problem, such as introducing a neutral amine softener in the composition or encapsulating a cationic softener to avoid its interaction with clay and detergent components [10]. 

Electrical tumble dryers are much more popular in the U.S. than in Europe (see Section IV). Consequently the market penetration of dryer cycle fabric softeners is much more important in North America than anywhere else. They are usually based on the same types of actives as the rinse cycle fabric softeners [35], Two methods of delivery exist. Nonwoven sheets are impregnated with cationic softener that are incorporated in the wet load at the start of tumble drying or a fabric conditioner is sprayed from an aerosol onto the empty dryer drum before the drying process [16]. 

Dry clothes outside on a sunny day, rather than using the tumble dryer. 

Rotary dryers, batch fluid dryers, continuous or batch tray dryers, hopper dryers, multispouted bed, and vacuum tumble dryers are typical long-residence units used in polymer drying. 

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