Chemistry lecture 34

CHEMICAL TECHNOLOGY PROFILE

Chemical Technology were established in 1993, and provide specialist adhesive solutions for industrial manufacturers. Their skilled personnel have over 80 years of experience in the formulation, manufacture and application of adhesives, this gives them an advantage when analysing your particular adhesive problem and formulating an adhesive solution.

SOLVENT BASED ADHESIVES

The range of industries that use Solvent Based Adhesives and the types of substrates that are adhered with these types of adhesives are varied, from the shoe manufacturing industry to cool rooms made from styrene. Solvent based adhesives tend to be easily applied, either sprayed, brushed, or rolled and give good and in some cases instant bonds.

APPLICATIONS FOR SOLVENT BASED ADHESIVES

Polyurethane, PVC, TPR, flexible sponge rubber foam, polystyrene foam, galvanised iron, aluminium, wood, paper, cardboard, cork, felt, fabrics, leather, laminated plastics, formica, melamine, polyester, metals, neoprene rubber foams.

Chemical Technology is a provider of specialist adhesive solutions to Industrial manufacturers.

We specialise in the analysis of your particular adhesive problem, and can custom formulate an adhesive to suit your specific requirement.

Our range of products covers most adhesives in current commercial use and with our Laboratory and manufacturing facility we can produce a product specific to your needs.

Established in 1993, the Adhesive division is built around a skilled personnel base with over 81 years of experience in the formulation, manufacture and application for adhesives.

THE ADVANTAGES OF PLASMA TV

Plasma TVs offer many advantages over other television technologies, and this accounts for why they are the fastest selling 'new' TV technology on the market. Here are the main advantages that Plasma TVs provide over other types of televisions:

-Exceptional Color: Plasma TVs display up to 16.77 million colors - more than the human eye can even register - to provide a highly accurate, lifelike picture.

-High Resolution: Plasma TVs are able to display a high resolution, and are capable of displaying HDTV signals. Many Plasma TVs are capable of producing 720p pictures, and some are able to display 1080i as well. Note that not all Plasma TVs are true HD-capable. Many are considered EDTV, or Enhanced Definition TVs, as they are able to display a higher resolution than conventional TVs, but not a true HD signal in it's native format.

-Slim, Lightweight Design: A key advantage of the Plasma TV is it's thin, flat-panel design, often only inches thick. Plasma TVs are also very light, generally weighing 50-80 pounds. Compared to rear-projection TVs, which can be up to 30 inches deep and weigh up to 400 pounds. They also make great design statements.

-Price: Although still more expensive compared to direct view or rear projection TVs, Plasma TV prices have fallen dramatically, and are now quite affordable. Plasma TVs are priced lower than other new technologies such as LCD and LCoS TVs.

-Built-in Line Doubler: Most Plasma TVs include a built in line doubler; a feature that basically doubles the resolution of conventional TV signals, greatly improving their image quality. This is perfect for those times when you are not watching a HDTV or DVD source.

-Widescreen Aspect Ratio: Plasma TVs offer a dramatic widescreen 16:9 ratio display, allowing you to view HDTV signals in their native size, as well as view DVDs in their proper aspect ratio.

-Uniform Screen Brightness: Compared to rear projection TV's, Plasma TVs offer perfectly uniform screen brightness. Rear projection TVs often have 'dull spots', where the picture is a bit fuzzy or not nearly as bright, resulting in a lower display quality.

-Wide Viewing Angle: Plasma TVs offer the best viewing angles, equal to that of the best direct view (CRT) sets. Plasma TVs are noticeably superior to rear projection and LCD TVs in this regards.

-Magnetic Field Immunity: Since Plasma TVs use different technology compared to conventional TVs, they do not suffer distortion when placed in proximity to a magnetic field. Speakers can be placed next to, below, or right on top of Plasma TVs with no adverse effects.

-Flat Screens: Plasma TVs offer perfectly flat screens, cutting down on image distortion and glare.

-Computer compatibility: Most Plasma TVs are able to receive VGA and SVGA signals from computers, as well as standard television and HDTV signals. This allows them to be used for multiple purposes, including many in a commercial or retail environment. Computer gamers have also been known to make use of Plasma TVs to provide them the advantage of a larger viewing area.

The Disadvantages of Plasma TV

Of course, not all technologies are perfect, and Plasma TVs do have some disadvantages compared to other TV technologies. Take a look below, but in the end, like us, you will probably agree that Plasma TV advantages outweigh these concerns:

-Potential Burn-In: Because of the phosphor technology in Plasma TVs (see How Plasma TVs Work), it is possible for traces of an image to be 'burned-in' to the display. This is generally only a concern in commercial uses, where images are displayed for long-periods of time. Those that watch stations that offer news tickers may also need to be careful. Burn-in can generally be avoided by making sure that you do not keep a constant image on the screen for extended periods (sometimes as little as 20 minutes), either by turning the television off, or changing the channel.

-Lower Brightness: Although still considerably brighter than rear-projection TVs, direct view and LCD TVs often are able to provide a brighter picture. This is generally only readily noticeable if watching in a very brightly lit room. Latest generation Plasma TVs have improved on the brightness issue considerably, and our only real warning would be to those that plan to do the majority of their viewing in a room exposed to afternoon sun.

-Not the Lightest or Slimmest: Although Plasma TVs are MUCH lighter and thinner compared to direct view and rear projection TVs, a lighter, slimmer technology does exist: LCD TVs. LCD TVs use the same technology as used in most laptop computers. However, it should be noted that LCD TVs are not generally available in the same sizes as Plasma TVs, and in those rare cases that they are, they generally cost considerably more.

-Price: Yes, this is a disadvantage and an advantage. Although Plasma TVs are considerably cheaper than comparably-sized LCD or LCoS TVs, they do cost more than direct view and rear-projection TVs. Of course, it must be mentioned that direct view HDTVs do not exist in the sizes that Plasma TV offers (namely 42-inch and 50-inch models).

-Shorter Life: Compared to other television technologies, Plasma TVs do generally have a shorter life span, and there is no option to repair a burnt out tube or backlight. Most Plasma TVs have a life span of 20,000-30,000 hours based on manufacturer's estimates. This life span is commonly referred to as the Plasma TV half-life, as it is the number of hours over which the Plasma TV will loose approximately half of it's brightness.

Of course, we should note that a Plasma TV with a 20,000 hour life would allow you to watch 4 hours of TV per day for approximately 13.7 years. Even at 8 hours per day, your Plasma TV should provide you with nearly 7 years of enjoyment. So, for most of us, this should not be an issue, and a Plasma TV is a worthy investment.

-Fragility: Plasma TVs are a very fragile technology, and the units are quite easy to damage. Extreme care must be used when moving them, as even laying the Plasma display on it's side can have adverse effects, possibly damaging the unit irreparably.

 

WHAT IS THE DIFFERENCE BETWEEN LCD TV AND PLASMA TV?

Plasma TV Overview

Plasma television technology is based loosely on the fluorescent light bulb. The display itself consists of cells. Within each cell two glass panels are separated by a narrow gap in which neon-xenon gas is injected and sealed in plasma form during the manufacturing process. The gas is electrically charged at specific intervals when the Plasma set is in use. The charged gas then strikes red, green, and blue phosphors, thus creating a television image. Each group of red, green, and blue phosphors is called a pixel (picture element).

Although Plasma television technology eliminate the need for the bulky picture tube and electron beam scanning of traditional televisions, because it still employs the burning of phosphors to generate an image, Plasma televisions still suffer from some of the drawbacks of traditional televisions, such as heat generation and screen-burn of static images.

PLASMA LCD

The ADVANTAGES of Plasma over LCD are:

1. Larger screen size availability.

2. Better contrast ratio and ability to render deeper blacks.

3. Better color accuracy and saturation.

4. Better motion tracking (little or no motion lag in fast moving images).

The DISADVANTAGES of Plasma vs LCD include:

1. Plasma TVs are more susceptible to burn-in of static images. However, this problem has diminished greatly in recent years as a result of the incorporation "pixel orbiting" and related technologies.

2. Plasma TVs generate more heat than LCDs, due to the need to light of phosphors to create the images.

3. Does not perform as well at higher altitudes.

4. Potentially shorter display life span - this used to be the case. Early Plasmas had 30,000 hours or 8 hrs of viewing a day for 9 years, which was less than LCD. However, screen life span has now improved and 60,000 hour life span rating are now common, with some sets rated as high as 100,000 hours, due to technology improvements.

LCD television ADVANTAGES:

1. No burn-in of static images.

2. Cooler running temperature.

3. No high altitude use issues.

4. Increased image brightness over Plasma, which makes LCD TVs better for viewing in brightly lit rooms.

5. Lighter weight (when comparing same screen sizes) than Plasma counterparts.

6. Longer display life used to be a factor, but now LCD and Plasma sets both have at least 60,000 hour or higher lifespans.

DISADVANTAGES of LCD:

1. Lower contrast ratio, not as good rendering deep blacks, although the increasing incorporation of LED backlighting has narrowed this gap.

2. Not as good at tracking motion (fast moving objects may exhibit lag artifacts) - However, this is improving with the recent implementation of 120Hz screen refresh rates and 240Hz processing in higher-end LCD sets.

3. Not as common in large screen sizes above 42-inches as Plasma. However, the number is growing fast, with 46 and 47-inch screen sizes becoming more common, and some LCD sets having a screen size as large as 65-inches also available to the general public.

4. Although LCD televisions do not suffer from burn-in susceptibility, it is possible that individual pixels on an LCD televisions can burn out, causing small, visible, black or white dots to appear on the screen. Individual pixels cannot be repaired, the whole screen would need to be replaced at that point, if the individual pixel burnout becomes annoying to you.

5. LCD televisions are typically more expensive than equivalent-sized Plasma televisions (although this is changing).