Using Ecm Motors in HVAC System

HVAC (Heating, Ventilating and Air Conditioning) refers to systems that heat or cool a designated environment. HVAC systems are especially important when it comes to designing large office buildings or climate controlled environments, such as some aquatic enclosures at the zoo. To achieve heating or cooling, an HVAC system depends heavily upon the quick movement of air from one location to another. AC motors have been used in past applications to serve as the primary air driving force, but they are not always the most efficient choice because they run continuously at full power. Electronically commutated motors (ECMs) were developed to offer a greater range of operability choices, and to minimize noise.

ECM Basics

ECMs are DC motors that function using a built-in inverter and a magnet rotor, and as a result are able to achieve greater efficiency in air-flow systems than some kinds of AC motors. (Although AC current is used for ECM, the ECM’s internal rectifier converts the current to DC voltage). Permanent split capacitor (PSC) motors, often used in conjunction with electronic SCR motors, are somewhat inefficient when used in air control systems because the fan motor noise requires the motor to run at less than a full load. When turned down, PSC efficiency suffers and falls in the range of 12 to45 percent. ECMs, on the other hand, maintain a high level (65 to 75 percent) of efficiency at a variety of speeds. As a result, ECMs are cost and energy efficient and can reduce operating costs. Additionally, ECMs are not prone to overheating and do not require additional measures to offset the generation of heat, as PSCs often do.

ECMs are also relatively low-maintenance; the use of true ball bearings reduces the need for oiling, and varied start-up speeds reduce stress on mounting hardware. The operating range is significant enough to enable one ECM to replace two induction-style models, which simplifies the replacement, maintenance, and installation processes, and minimizes product choices. However, not all ECM motors run at variable speeds and selection depends heavily upon application specifications. The initial cost of an ECM can be high, but is typically balanced by overall energy savings in the long run.

ECM in HVAC Systems

When considering an ECM for application in an HVAC system, there are several factors to keep in mind. Although ECMs are often selected because many models run at variable speeds, in certain condenser applications it is preferable to select and ECM that runs at a fixed speed—an ECM running at a fixed speed s in a condenser unit still uses less energy than a typical PSC motor running at a fixed speed in a similar unit. As a result of increased energy savings, a condenser operating with an ECM will have a higher SEER (seasonal energy efficiency ratio) rating. In other HVAC units, an ECM can run at variable speeds but depends on a controller that pre-programs speed, including the rate at which the motor ramps up. Whereas typical PSC motors start and almost immediately run at full capacity, an ECM can start slowly and stop slowly, which can help reduce humidity. Additionally, the control can be set to alter the amount of air an ECM motor drives through the system, which enables a greater range of possible air-flow rates.

A typical ECM operating in an HVAC system will go through several stages, as determined beforehand by a manufacturer or a preprogrammed controller. In its first stage, and ECM runs at a lower speed to remove humidity (this is especially important in a cooling system). Next, the ECM reaches its designated peak speed, as specified for the application, maintaining high efficiency despite any shifts in operating speed. When the ECM stops, it can be programmed to stop slowly (called a soft stop).

How Wood Chippers Work

Wood chippers (or tree shredders) are frequently used in industrial lumber applications to reduce wood into chips or sawdust, as part of wood recycling or as part of a manufacturing process. Wood chippers are also used by those in the agricultural industry during property and land maintenance, or to aid in clean up after a storm or meteorological event. Typically, wood chippers are comprised of several distinct parts, including a hopper, a collar, a chipper, and a collection bin. An internal power source, typically a combustion engine, can range from 3 to 1,000 horsepower, depending on the size and type of chipper.

How Wood Chippers Work

Regardless of the size or make, wood chippers all function in the same basic manner. An internal engine, either an electric motor or a fossil-fuel engine, powers the device. A gearbox uses pulleys and v-belts to connect the engine to a set of knives—the pulley enables the engine to control the speed at which these blades rotate, and the v-belt transmits the power from the engine. Internal gears within the gearbox also help control speed and power.

Wood chippers typically have two separate chutes for processing wood. The first chute, the smaller of the two, shreds branches into chips. The second, larger chute features blades and additional devices, such as hammers, to turn excess plant material (such as leaves) into mulch. Based on the kind of blades within the chipper, a user can determine the type and thickness of wood the chipper is capable of handling. Typically, the larger the machine, the larger the load it can handle. Blades can either function on separate shafts or intermesh. If several blades are rotating on independent shafts, the wood will be repeatedly cut down the branches as they are passed through the blades at a fast pace. Intermeshed blades are somewhat slower, but are somewhat self-feeding as they draw the branches into the blades themselves. Additionally, intermeshed blades produce consistently sized chips.

Types of Wood Chippers

There are several kinds of wood chippers, ranging from those designed for residential use to larger, industrial models.

High-Torque Roller

High-torque rollers tend to be low-speed. Because they are also powered by an electric motor they are quiet, which makes them a popular choice for residential applications. Additionally, they are self-feeding, and some offer anti-jamming features.

Drum

Drum chippers are named for the large, motor-powered drum located at the center of the machine. The drum draws material in, like a feeder, and chips material while moving toward the output chute. The process is very fast and loud, and carries significant safety risks. Because the drum and engine are directly connected, any kind of drum jam can subsequently affect the engine, causing the engine to stall and pieces of wood to become lodged in the drum. Additionally, operators must exercise care when feeding the machine so as not to get clothing or appendages caught in drum, which can cause extreme injury or death. Some models offer additional safety features, which help ensure operator safety while also minimizing the sound of the machine.

Disc

A disk chipper features a disc, typically steel, with cutting blades attached. Material is drawn from the hopper via hydraulic wheels, and then moved toward the spinning disc. As the disc rotates, the blades encounter the wood, the material sliced into chips. With industrial disk choppers, the disc can be as large 160 inches in diameter, with an engine of up to 5,000 horsepower.

Crimpers Buying Guide

Crimping is the act of using a tool to deform metal or other material in order to seal a joint or fastener. Tools designed specifically for crimping, alternatively called crimpers or crimping pliers, are available in a number of sizes and designs. There are a number of differences in function and purpose that need be navigated in selecting the proper crimper for a job. The electrical and communications industries comprise a majority of crimping operations due to the high number of connectors used on wires.

Examples of applications requiring crimping include coax cable connector assemblies, bullets, and wired mesh connections. Essentially, the crimpers are used to clamp metal to a substrate and, when enough pressure is exerted, deform the metal to a point where it is securely fastened.

The types of differences in crimpers include the size or sizes of the crimping jaws, the hand grip, the material of the crimpers as well as pressure capabilities. Additionally, some crimpers are multipurpose tools that have additional features such as cutters and wire shredders, features that complement the usual applications needing crimping. While most crimpers are manual tools, hydraulic crimpers exist for users who need extra force or who perform many crimps a day.

Crimping to Wires Because many crimping applications involve the crimping of metal connectors to wire, such as coax connector assemblies, crimpers are usually rated based on the American wire gauge. This is a rating of standardized wire diameters used to determine wire sizes. The AWG rates wires with an ascending numerical system, where the higher the rating, the smaller the wire diameter. Very large wire diameters are expressed as series of zeroes, such as 0000, and the gauge goes up to 50, a very small wire. Crimpers designed with a distinct crimped shape in mind are called “died crimpers” because they employ pre-determined die sizes in their jaws. Crimpers are often designed for a range of different wire sizes, encompassing four to eight different sizes to make the crimper more applicable to various projects. Some more complex crimpers can handle more than ten gauge sizes. It is important to find a crimper that handles the appropriate wire gauges needed.

Dieless crimpers are much more common and are intended for general use crimping actions because they have no pre-determined shape.

Handheld Crimpers Because handheld crimpers are common, it is important to find crimpers with ergonomic, soft handle designs, especially when a job requires numerous crimping operations. Additionally, crimping operations can require a lot of pressure. If a hard metal like steel is being crimped, it is important to find a crimper with steel handles, otherwise they might snap during operation. Plastic crimper handles are fine for lower level operations involving softer metals or plastic crimping jobs.

Some crimpers are spring-loaded. This is only necessary for crimping operations that are numerous in number and require little preparation, because the spring is designed to speed up performance. A crimping job that needs precision and focus and involves multiple parts does not require a spring-loaded crimper, although a spring-loaded crimper can easily be used.

Extra Pressure for Crimping Applications For jobs that require a lot of pressure and precision, a ratchet crimper can be helpful. The ratchet allows the jaws of the crimper to be placed with more accuracy and limits the possibility of human error when compressing the teeth. Datacom operations might require a ratchet crimper because these operations may involve the crimping of a connector across a number of wires rather than a single wire. For simple single-wire crimping jobs, a standard crimp joint is perfectly acceptable. Hydraulic crimpers are available for heavier jobs involving metals that are harder to deform or for jobs that involve a lot of crimping operations. Because crimping requires pressure, repeating the action many times can cause hand stress and discomfort, which can even lead to serious injury if ignored. A hydraulic crimper acts as a press to crimp quickly, efficiently and mechanically, and requires little human effort. However, compared to manual crimpers, hydraulic crimpers are exponentially more expensive, and are generally recommended only for jobs in which an excess of 200 crimps are performed a day. Hydraulic crimpers can be either hand-hydraulic or remote-hydraulic. Battery actuated crimpers are also available, providing a wide range of pressures at a reduced price from hydraulic crimpers.

Alternative Crimper Styles Alternative crimpers include the hammer-style crimper. This is not a hand-held device, but actually resembles a microscope stand. The metal and substrate are placed on a small stand at the base of the crimper, just below a large cylinder that dips down and springs up to perform the crimping action. These crimpers are much more durable than hand-held crimpers because they can exert much more pressure, and as such are not recommended for small, delicate jobs, because they can break substrates. Hammer-style crimpers are available in both manual and hydraulic versions.

Many common crimping operations have standardized crimping sizes and crimping tools to match. If a connector for a wire has a standardized size, it might and often does have a standardized crimping tool to match it. In fact, many industry professionals have noted the trend towards specialized crimping tools due to an increase in quality a dedicated tool offers over a multipurpose tool.

How Glass Bottles Are Made

Although traditional glass-blowing and blow-molding methods are still used by artists and for custom applications, most bottle manufacturing is an automated process. The development of glass bottle machining peaked with the advent of feed and flow machines, which enabled manufacturers to generate larger production runs than was previously possible. Glass production is broken down into two general categories: container production and sheet production. Bottle machining is part of glass container production.

Hot End Processes

Bottle manufacturing takes place at a glass container factory in multiple steps. The first stage of glass-container making begins with the hot end processes, which typically employ high amounts of heat to produce and shape a glass container. A furnace is first used to mold molten glass, which fed to the furnace as glass feed stock. Soda-lime glass stock accounts for the majority (around 90 percent) of glass products, and is typically largely comprised of silica, with about 10 percent each of calcium oxide and lime. Small amounts of aluminum oxide, ferric oxide, barium oxide, sulfur trioxide, and magnesia also account for about 5 percent of soda-lime glass. Before melting, cullet (recycled glass) is added to the stock, accounting for anywhere between 15 and 50 percent of the final glass composition.

Once the stock has been fed into the furnace, temperatures inside can be as high as 1675 degrees Fahrenheit. Next, one of two method forming methods is applied: press-and-blow or blow-and-blow.

Press-and-Blow

Press-and-blow formation takes place in an individual section (IS) machine and is the more commonly used method in glass-container production. IS machines have between five and 20 sections, all identical, which can each carry out the glass-container forming process simultaneously and completely. The result is that five to 20 containers can be produced with one machine at the same time.

When the molten glass reaches between 1050 and 1200 degrees Celsius it is said to be in its plastic stage, and it is during this phase that press-and-blow formation begins. A shearing blade is used to cut and shape the glass into a cylindrical shape, called a gob. The cut gob falls, and using gravitational force, rolls through the appropriate passage to reach the moulds. A metal plunger presses the gob into the blank mold, where it assumes the mould’s shape and is then termed a parison. Next, the parison is moved into a final mold, where it is blown into the mould to assume its final dimensions. This process is typically used for wide-mouthed glass containers, but can also be used to manufacture thin-necked bottles.

Blow-and-Blow

Like press-and-blow formation, blow-and-blow takes place in an IS machine, where a gob is released during the plastic stage and moved along to the moulds. However, in blow-and-blow formation, the gob is forced into the blank mould using compressed air to push the gob into place. The gob, now a parison, is then flipped into a corresponding final mould where it is blown again, to form the interior side of the glass container. Glass bottles of varying neck thickness can be made using blow-and-blow formation.

After formation, bottles often undergo internal treatment, a process which makes the inside of the bottle more chemically-resistant, an important factor if the bottles are intended to hold alcohol or other degrading substances. Internal treatment can take place during formation or directly after, and typically involves treating the bottles with a gas mixture of fluorocarbon. Glass containers can also be treated externally, to strengthen the surface or reduce surface friction. Annealing

Once formation is complete, some bottles may suffer from stress as a result of unequal cooling rates. An annealing oven can be used to reheat and cool glass containers to rectify stress and make the bottle stronger. Cold End Processes

At this stage in glass production, the bottles or glass containers are inspected and packaged. Inspection is often done by a combination of automated and mechanical inspection, to ensure the integrity of the final product. Common faults include checks (cracks in the glass) and stones (pieces of the furnace that melt off and are subsequently worked into the final container), which are important to catch because they can compromise the component. Packaging methods will vary from factory to factory depending on the specific type of bottle and the size of the production run.

General Types of Bearing and How They Work

Generally speaking, a bearing is a device that is used to enable rotational or linear movement, while reducing friction and handling stress. Resembling wheels, bearings literally enable devices to roll, which reduces the friction between the surface of the bearing and the surface it’s rolling over. It’s significantly easier to move, both in a rotary or linear fashion, when friction is reduced—this also enhances speed and efficiency.

How Bearings Work

In order to serve all these functions, bearings make use of a relatively simple structure: a ball with internal and external smooth metal surfaces, to aid in rolling. The ball itself carries the weight of the load—the force of the load’s weight is what drives the bearing’s rotation. However, not all loads put force on a bearing in the same manner. There are two different kinds of loading: radial and thrust.

A radial load, as in a pulley, simply puts weight on the bearing in a manner that causes the bearing to roll or rotate as a result of tension. A thrust load is significantly different, and puts stress on the bearing in an entirely different way. If a bearing (think of a tire) is flipped on its side (think now of a tire swing) and subject to complete force at that angle (think of three children sitting on the tire swing), this is called thrust load. A bearing that is used to support a bar stool is an example of a bearing that is subject only to thrust load.

Many bearings are prone to experiencing both radial and thrust loads. Car tires, for example, carry a radial load when driving in a straight line: the tires roll forward in a rotational manner as a result of tension and the weight they are supporting. However, when a car goes around a corner, it is subject to thrust load because the tires are no longer moving solely in a radial fashion and cornering force weighs on the side of the bearing.

Types of Bearings

There are numerous different kinds of bearings that are designed to handle radial load, thrust load, or some combination of the two. Because different applications require bearings that are designed to handle a specific kind of load and different amounts of weight, the differences between types of bearings concern load type and ability to handle weight.

Ball Bearings

Ball bearings are extremely common because they can handle both radial and thrust loads, but can only handle a small amount of weight. They are found in a wide array of applications, such as roller blades and even hard drives, but are prone to deforming if they are overloaded.

Roller Bearings

Roller bearings are designed to carry heavy loads—the primary roller is a cylinder, which means the load is distributed over a larger area, enabling the bearing to handle larger amounts of weight. This structure, however, means the bearing can handle primarily radial loads, but is not suited to thrust loads. For applications where space is an issue, a needle bearing can be used. Needle bearings work with small diameter cylinders, so they are easier to fit in smaller applications.

Ball Thrust Bearings

These kinds of bearings are designed to handle almost exclusively thrust loads in low-speed low-weight applications. Bar stools, for example, make use of ball thrust bearings to support the seat.

Roller Thrust Bearings

Roller thrust bearings, much like ball thrust bearings, handle thrust loads. The difference, however, lies in the amount of weight the bearing can handle: roller thrust bearings can support significantly larger amounts of thrust load, and are therefore found in car transmissions, where they are used to support helical gears. Gear support in general is a common application for roller thrust bearings.

Tapered Roller Bearings

This style of bearing is designed to handle large radial and thrust loads—as a result of their load versatility, they are found in car hubs due to the extreme amount of both radial and thrust loads that car wheels are expected to carry.

Specialized Bearings

There are, of course, several kinds of bearings that are manufactured for specific applications, such as magnetic bearings and giant roller bearings. Magnetic bearings are found in high-speed devices because it has no moving parts—this stability enables it to support devices that move unconscionably fast. Giant roller bearings are used to move extremely large and heavy loads, such as buildings and large structural components.

Plastic Bottle Manufacturing

The manufacture of plastic bottles takes place in stages. Typically, the plastic bottles used to hold potable water and other drinks are made from polyethylene terephthalate (PET), because the material is both strong and light. To understand the manufacturing process it’s helpful to first examine the composition of PET and how this affects plastic bottles.

Polyethylene Terephthalate (PET)

PET is a thermoplastic polymer that can be either opaque or transparent, depending on the exact material composition. As with most plastics, PET is produced from petroleum hydrocarbons, through a reaction between ethylene glycol and terephthalic acid. To produce plastic bottles, the PET is first polymerized to create long molecular chains.

Polymerization itself can be a complicated process, and accounts for many of the inconsistencies between one batch of manufactured PET and another. Typically, two kinds of impurities are produced during polymerization: diethylene glycol and acetaldehyde. Although diethylene glycol is generally not produced in high-enough amounts to affect PET, acetaldehyde can not only be produced during polymerization, but also during the bottle manufacturing process. A large amount of acetaldehyde in PET used for bottle manufacturing can give the beverage inside an odd taste.

Once the plastic itself has been manufactured, the bottle manufacturing process can begin. To ensure that the PET is appropriate for use, numerous tests are done post-manufacturing to check that the bottles are impermeable by carbon dioxide (which is important for bottles that carry soda). Other factors, such as transparency, gloss, shatter resistance, thickness and pressure resistance, are also carefully monitored.

Bottle Manufacturing

The first stage in bottle manufacturing is stretch blow molding. The PET is heated and placed in a mold, where it assumes the shape of a long, thin tube. (The process by which the plastic is forced into the mold is called injection molding.)The tube of PET, now called a parison, is then transferred into a second, bottle-shaped mold. A thin steel rod, called a mandrel, is slid inside the parison where it fills the parison with highly pressurized air, and stretch blow molding begins: as a result of the pressurized air, heat and pressure, the parison is blown and stretched into the mold, assuming a bottle shape. To ensure that the bottom of the bottle retains a consistently flat shape, a separate component of plastic is simultaneously joined to the bottle during blow molding.

The mold must be cooled relatively quickly, so that that the newly formed component is set properly. There are several cooling methods, both direct and indirect, that can effectively cool the mold and the plastic. Water can be coursed through pipes surrounding the mold, which indirectly cools the mold and plastic. Direct methods include using pressurized air or carbon dioxide directly on the mold and plastic.

Once the bottle (or, in continuous manufacturing, bottles) has cooled and set, it is ready to be removed from the mold. If a continuous molding process has been used, the bottles will need to be separated by trimming the plastic in between them. If a non-continuous process has been used, sometimes excess plastic can seep through the mold during manufacturing and will require trimming. After removing the bottle from the mold and removing excess plastic, the bottles are ready for transportation.

Common Types of Pallet Racks

To maximize storage space in a facility, various businesses use pallet racks, which are essentially a materials handling system. Individual pallets, or “skids,” are fabricated from variants of wood, metals and plastics and are incorporated into larger racking systems that feature shelves on multiple levels. A decking base (fabricated in different widths) supports the storage objects that are placed on the racks. Decks are composed of wire mesh, which support items and are helpful for surveying inventory. Forklifts are required for the loading process, as some pallet rack constructions measure several feet high. In structure, pallet racks are generally roll formed (columns supported by beams) or structural (beams that are bolted). Standard pallet rack configurations include selective racks, drive-in/drive-through, push-back and flow racks.

Pallet Rack Types & Configurations

Selective racks are the most commonly used pallet system, according to manufacturing experts. Pallets are accessible from the structure’s aisle. In this system, beams act as the support system for the pallets. This system is not limited to one type of storage, but is generally associated with narrow aisle racking, standard and deep reach systems.

Configurations: Narrow aisle racking requires a specialized narrow lift truck and is used to create optimum space, as the structure allows for large storage capacity.Standard systems allow for single deep loading, whereas deep reach systems allow for double the storage amount (of the former unit).

Drive-in racks and Drive through racks are structures capable of high density storage. These systems are typically constructed from steel and allow space for a forklift to move into the structure’s bay, which is essentially a lane of stacks.

Configuration: While drive-in rack structures feature one entry/exit way, drive-through racks have entry access on both sides of the bay. The entryway differences typically affect the way materials are stored in these systems. For example, items stored in drive-in racks are typically loaded via the last-in, first-out process, also known as LIFO. Due to this method, drive-in systems are suitable for nonperishable products and items with a low turnover, as storage is not readily accessible. The drive-through system requires the FIFO (first in first out) system. Both drive in and drive-through systems operate in floor-to-ceiling structures.

Push back racking systems are fabricated in roll or structural form. They are ideal for bulk storage, as they are capable of storing products that occupy/run several pallets deep (2-5) and typically measure several levels high. When a pallet is placed or loaded on the structure, it “pushes” the next pallet back on the rails where it rests. When the pallets are unloaded from the rails, they are pushed to the front of the structure. As with the drive-in racks, these structures are loaded using the LIFO system, and are considered suitable for large storage systems. Configuration: These structures typically feature inclined rails and sliding carts, and are often constructed with double lanes.

Flow racks are also known as gravity flow racks and are generally ideal for high-density storage. Loads are stored at the higher end and removed at the lower end point, employing the FIFO loading system. As the products are loaded, the rotation becomes automatic due to the flow of the racks. Configuration: These systems feature a gravity roller that generates movement based on the rack load, as items are moved on a sloped plane. The lanes feature brakes, or speed controllers, which control the movement of the objects. The rails are generally powered by gravity, so no electric operating system is required.

Selecting a Pallet Rack Configuration

It is helpful to consider a few essential factors when selecting a pallet configuration. Manufacturing experts recommend considering the cost of materials, the space and height available (American National Standards Institute, ANSI, http://www.ansi.org lists approved pallet measurements). The types of storage items and inventory that will be stored should also be assessed, as different loading systems (FIFO and LIFO) must be matched with specific products. Additionally, some food products must fall under FDA regulations. Professionals advise considering environmental factors, as some locations and outdoor settings require heavier or stronger equipment configurations.

Cable Ties Desig and use

What are Cable Ties?

Standard cable ties are commonly fabricated from nylon grade 6.6 and are used to harness and bundle items, usually wires. Functioning like straps, cable ties are available in miniature sizes for holding small loads, and are also fabricated in long lengths and strong tensile strengths for large items or bundles. Each tie features serrated “teeth” on one end, which function by locking inside the head, or pawl, located on the other side of the strap. Various manufacturers custom design cable ties in numerous colors or dimensions, according to application requirements. Additionally, cable ties may be fabricated in UV-protected variations.

Cable Tie Applications and Types

Cable ties help organize wiring systems by grouping cables together. Specific application fields include transportation, telecommunications, speaker wires, and home theater/equipment. They are constructed for indoor and outdoor use and vary in composition.

Natural Cable Ties are usually constructed from 6.6 nylon grade. These ties are typically appropriate for general purpose applications and are resistant to chemical, grease and oil-based products. All ties should meet a flammability resistance requirement, which is indicated by the manufacturer. Many of these ties may be manually adjusted, and various pneumatic tools are available to help reduce installation time. Higher temperature nylon generally includes nylon grade 4.6.

UV Protected Cable Ties are also known as black cable ties and are used for outdoor applications. Like natural cable ties, they are resistant to oils and grease; they are different because they are resistant to environmental contaminants. These cables are commonly used for applications that require a high tensile holding strength and are often manufactured in nylon 12 grade material.

Stainless Steel Ties are typically suitablefor applications that require a high-level of protection against corrosion and environmental conditions, which may cause typical nylon cables to disintegrate. They are used for indoor, outdoor and underground applications. Manufacturers may offer black nylon sleeves for added corrosion protection.

Other Considerations

To ensure that cable ties are the most effective for an application, it is essential to store them properly. Specifically, manufacturers suggest storing nylon cables in a cool and dry area to prevent the material from disintegrating or oxidizing. Because thin versions of nylon are sensitive to bending, manufacturers also recommend being cautious when applying pressure to the bands, as they may become misshapen. Additionally, consult with individual companies to confirm whether cable ties are CE and RoHS compliant.

Food Containers Buying Guide

Food Container Packaging

To preserve, transport and store miscellaneous food items, manufacturers fabricate a variety of containers. Typically, food packaging includes a wide array of materials, such as plastic, metals glass and paper, which are processed and formed. Some containers, such as plastics, are categorized as rigid or flexible. Containers may be processed with additional treatments for preservation purposes.

Container Types and Materials

Glass containers are fabricated by an automated process involving intricate heating and molding techniques. They are suitable for microwave heating and are a standard container choice because edible grade models do not contain/transmit dangerous chemicals to foods and may be reused. For dry food storage, manufacturers may recommend using (non-edible) desiccant packages to preserve freshness. Glass is also commonly used for liquid containers, as it is transparent and displays content. Additionally, glass jars are often a suitable choice for refrigeration purposes and are also suitable for microwave heating. Glass containers also effectively prevent odors and moisture build-up. Depending on the container shape or application, glass containers may be suitable for stacking and long term storage purposes. For a description of how glass bottles are fabricated, consult “How Glass Bottles Are Made”: http://www.thomasnet.com/articles/materials-handling/glass-bottles-made.

Metal,specifically stainless steel,is a common material used for larger food processing units, such as aseptic tanks and cubic containers. Metal is suitable for protecting food contents, as it is commonly fabricated to be tamperproof in its container form. Large metal containers, called drums, are typically used for the storage of oils and liquids in the industrial food sector. Aluminum is commonly used for tray containers and is efficient for aroma and moisture prevention. In some instances, metal containers, such as cans, are treated with protective enamels and nitrogen to ensure long term storage purposes. Some cubic containers may also be equipped with galvanized frames.

Plastic Containers are a standard choice for air tight food storage, and they are commonly used for multiple, smaller storage purposes. These types of containers are ideal for multiple uses, though recycled plastic is not recommended for food processes to avoid the transmission of contaminants. Plastic containers are efficient for both liquid and dry food. They are fabricated in lightweight forms and are produced in both rigid and semi-rigid formations. While rigid containers retain their shape and can hold a variety of solid formed foods, semi-rigid formations are typically suited for dry materials and some liquid foods.

There are numerous variants of plastic, but edible grade containers fall under three specific variants: polyethylene, polyester and polypropylene. Polyethylene, specifically, is more flexible than polypropylene and is used for standard bucket storage purposes. Various polyethylene containers may have HDPE stamped on the exterior. In addition to producing containers, polyester is also fabricated as film strips and is used for container labels.

For information about plastic packaging, see “Plastic Bottle Manufacturing”: http://www.thomasnet.com/articles/materials-handling/plastic-bottle-manufacturing

Paper containers are commonly used to transport food, and are capable of retaining both cold and hot foods. They are also typically designed to be leak proof. They are suitable for recycling purposes because of their biodegradable and compostable properties; they are commonly composed of cellulose paper fibers. For business purposes (ie, take out cartons), paper cartons are printed with a nontoxic FDA approved inks to create designs.

Additional Considerations:

All materials used for food transport or storage must be edible grade variety, so it is essential to consult manufacturers before storing food. Packaging should never have adverse effect on contents. Refer to the U.S. Food and Drug Administration for any container specific processing safety standards for the aforementioned materials: http://www.fda.gov/iceci/inspections/inspectionguides/ucm074946.htm

Carboard Manufacturing

From basic storage boxes to multi-colored card stock, cardboard is available in an array of sizes and forms. A term for heavier paper-based products, cardboard can range in manufacturing method as well as aesthetic, and as a result can be found in vastly different applications. Because cardboard doesn’t refer to a specific material but rather a category of materials, it is helpful to consider it in terms of three separate groups: paperboard, corrugated fiberboard, and card stock.

Paperboard

Paperboard is typically 0.010 inches in thickness or less, and is essentially a thicker form of standard paper. The manufacturing process begins with pulping, the separation of wood (hardwood and sapwood) into individual fibers, as accomplished by mechanical methods or chemical treatment.

Mechanical pulping typically involves grinding the wood down using silicon carbide or aluminum oxide to break down the wood and separate fibers. Chemical pulping introduces a chemical component to the wood at high heat, which breaks down the fibers that bind cellulose together. There are approximately thirteen different kinds of mechanical and chemical pulping used in the U.S.

To make paperboard, bleached or unbleached kraft processes and semichecmical processes are the two types of pulping typically applied. Kraft processes achieve pulping by using a mixture of sodium hydroxide and sodium sulfate to separate the fibers that link cellulose. If the process is bleached, additional chemicals, such as surfactants and defoamers, are added to improve the efficiency and quality of the process. Other chemicals used during bleaching can literally bleach the dark pigment of the pulp, making it more desirable for certain applications.

Semichemical processes pre-treat wood with chemicals, such as sodium carbonate or sodium sulfate, then refine the wood using a mechanical process. The process is less intense than typical chemical processing because it doesn’t completely break down the fiber that binds cellulose, and can take place at lower temperatures and under less extreme conditions.

Once pulping has reduced wood to wood fibers, the resulting dilute pulp is spread out along a moving belt. Water is removed from the mixture by natural evaporation and a vacuum, and the fibers are then pressed for consolidation and to remove any excess moisture. After pressing, the pulp is stream-heated using rollers, and additional resin or starch is added as needed. A series of rollers called a calendar stack is then used to smooth and finish the final paperboard. Corrugated Fiberboard

Corrugated fiberboard is what one typically Corrugated Cardboard Boxesrefers to when using the term “cardboard,” and is often used to make various types of corrugated boxes. Corrugated fiberboard is comprised of several layers of paperboard, typically two outer layers and an inner corrugated layer. However, the internal corrugated layer is typically made of a different kind of pulp, resulting in a thinner kind of paperboard that isn’t suitable to be used in most paperboard applications but is perfect for corrugating, as it can easily assume a rippled form.

Corrugated fiberboard is manufactured using corrugators, machines that enable the material to be processed without warping and can run at high-speeds. The corrugated layer, called the medium, assumes a rippled or fluted pattern as it is heated, wetted, and formed by wheels. An adhesive, typically starch-based, is then used to join the medium to one of two outer paperboard layers.

The two outer layers of paperboard, called linerboards, are humidified so that joining the layers is easier during formation. Once the final corrugated fiberboard has been created, they component undergoes drying and pressing by hot plates.

Card Stock

The thinnest type of cardboard, card stock is till thicker than most traditional writing paper but still has the ability to bend. As a result of its flexibility, it is often used in post-cards, for catalog covers, and in some soft-cover books. Many kinds of business cards are also manufactured from card stock, because it is strong enough to resist the basic wear and tear that would destroy traditional paper. Card stock thickness is typically discussed in terms of pound weight, which is determined by the weight of 500, 20 inch by 26 inch sheets of a given type of card stock. The basic manufacturing process for cardstock is the same as for paperboard.

Medical Packaging Buying Guide

Medical packaging serves several important functions, but its primary role is to protect a packaged medical or pharmaceutical product. Because medical products can feature unique specifications and often require sterilization prior to packaging, medical packaging is designed to both uphold the highest medical standards and ergonomically protect the integrity of a product. As a result of the wide array of medical components, medical packaging ranges from pre-formed packages to customized packages for specialty parts. Variations in size, dimension, rigidity, breathability and sterility enable even the most delicate medical component to be shipped in an appropriately engineered package.

Types of Packages

Medical components are typically packaged in one of several structural configurations. Below is a description of some common types of medical packages.

Blister packaging: Often used to hold individual capsules within a larger carton, blister packaging protects a package’s contents from contamination. Depending on the nature of the film material used, blister packs can feature either a peelable layer or a push-through lidding as a way to remove the contents of a package.

Individual-wrap packages: This type of packaging is a good choice for single-use applications, such as syringes. Blister packs are often used for extra support.

Multi-compartmental trays: Typically manufactured from more rigid material, multi-compartmental trays are used to package sutures, implants and other sensitive surgical items.

Water-soluable packaging: This packaging variant dissolves in water, making it suitable for products whose end-function requires the addition of water, such as nutritional supplements.

Pouches: Pouches can hold a variety of oddly shaped applications. They can also be manufactured from a range of materials to meet sterilization requirements.

Cartons: Manufactured from fiber boards, cartons are suitable for products that can be stored at room temperature within a typical, made-to-size, boxed structure. Over the counter medicine, such as basic capsule pills, are often packaged within individual cartons. Materials can range from white lined chipboard to basic folding boxboard.

Materials

Many medical products depend on medical polymer films, an essential component in medical packaging, to protect against contaminants and maintain the products’ integrity. Medical polymer films also inhibit or enable the circulation of air, as well as guard against light, moisture and other gases.

Common types of medical film materials:

Single films Laminations Coextruded films

Laminations are comprised of two or more individual films, typically featuring the best properties of each film in the final composite. Laminations are very stable, and are often used to manufacture pouches. Materials used to create laminations include polyethylene-cellophane, polypropylene-cellophane-polyethylene and polyethylene-polycarbonate.

Whereas laminations require individual layer fabrication, coextruded films simultaneously manufacture multiple layers. Coextruded films are sometimes used in place of adhesives and coatings. Typically, coextrusion films can be made from high-density polyethylene, polystyrene, polypropylene, or polyvinyl chloride. Most coextruded films are impermeable by gas, which enables their use as packaging for sterile products.

Tyvek material is commonly used for packaging products that have been gas-sterilized, such as gloves and wound dressings.

Medical Packaging Standards

There are several codes in place to ensure the quality of medical packaging. Two of these standards include:

ISO9000: Quality Management Standard; and

PSO9000: Pharmaceutical Packaging Materials Standard.

After a package has been produced, it undergoes testing and inspection to ensure it meets the appropriate standards. For a further explanation of medical packaging codes, please visit this Web site: http://www.iso.org

Reducing struck by injuries

Struck-by hazards include objects ejected from a power tool – such as a nail gun – as well as rolling, moving or sliding objects, such as a moving vehicle. OSHA offers the following recommendations to help workers prevent struck-by injuries:

Heavy equipment

Avoid heavy equipment that is being operated, and remain alert to the location of all heavy equipment regardless of whether or not it is in use.

Stand clear of loads that are being lifted or dumped.

Exercise caution around unbalanced loads.

Never work under suspended loads.

Stay outside of the swing radius of cranes and backhoes.

Wear hard hats in areas where objects may fall from above or if any head trauma may occur because of fixed objects.

Inspect hard hats routinely for dents, cracks or deterioration.

Motor vehicles

Check vehicles before each shift to confirm that parts and accessories can be operated safely.

Bulldozers and scraper blades must be lowered or blocked when not in use. Do not exceed the rated load or lift capacity of any vehicle. Use a cab shield or canopy to protect a driver hauling materials in a vehicle loaded by cranes or power shovels, and wear safety belts.

Vehicles should only be driven on grades or roadways that are safely constructed. Wear protective clothing, such as red or orange vests, to ensure workers are highly visible, and wear reflective materials when working at night.

Avoid situations in which an escape route is not available.

Traffic should only be directed by flaggers.

Check all warning signs.

Protect Worker on Foot

Highway construction zones can create a hazardous environment for workers. According to NIOSH, workers are susceptible to injuries from moving construction vehicles and equipment within work zones, as well as from passing motor vehicle traffic.

NIOSH offers the following tips for working in construction zones :

Traffic control plans

Close the road completely and reroute traffic whenever possible.

Force traffic moving in both directions onto one side of the road.

Set up traffic control within a reasonable time before construction begins.

Keep the dimensions of the work zone suitable for the work that is being conducted.

Stop work temporarily until safe conditions are provided.

Design the workspace to reduce blind spots.

Visibility measures

Provide workers with high-visibility equipment and gear.

Use signage, warning devices and concrete barriers in a consistent manner throughout the work zone.

Lower the height of lighting equipment to reduce glare for motorists.

Use glare-free light balloons and glare screens.

Implement portable lighting and equipment-mounted lighting.

Evaluate worker performance under various lighting and weather conditions.

Equip vehicles with additional mirrors or alarms to help workers keep track of objects behind vehicles.

Reviewing the construction area

Set up a process for reviewing near-miss incidents and hazards to eliminate safety risks.

Designate areas around operations where workers are prohibited, such as the blind spots of a dump truck.

Distribute worksite-specific materials, such as an Internal Traffic Control Plan, to employees at safety meetings.

Perform regular maintenance checks before using equipment and verify that problems are corrected.

Stainless Steel Tubes

Stainless steel tubes are often used in applications that require rigid materials for potable water conveyance. Manufacturers select stainless steel because certain manmade materials have unwanted or unknown exposure effects while stainless steel has many desirable qualities for maintaining clean water. Steel tubes can also be used for structural support in buildings and vehicles. The terms “tube” and “pipe” are generally interchangeable, although technically, “tube” implies heightened engineering qualities. Tubes are generally manufactured based on standardized sizes.

Manufacturing Steel Tubes

There are three main methods of manufacturing tubing that lend their names to tubing classifications.

Seamless. Seamless steel tubes are produced through extrusion. Extruded tubes can be formed in a hot or cold process. Long sections of steel bar are forced through a die that blocks out the intended shape of the tube.

As-welded or electric resistant welded (ERW). This method involves passing a rolled sheet of steel through two weld rollers. The weld rollers have a groove around their circumference, through which the steel roll passes. There is a contact at the roll seam that transmits electricity at a high enough current to weld the seam closed. The resulting weld is very small.

Drawn-over-mandrel (DOM). A mandrel is a small piece of metal inserted into the tube to define a shape. It gives the tube extra support to prevent unwanted wrinkling during drawing. The tube is passed through a die that has a smaller diameter than the current tube size. As the tube is drawn, it shrinks to match the size of the die’s diameter. This process allows for tight tolerances and specifications.

Each of these manufacturing processes allows manufacturers the ability to form varying tube shapes and sizes. Tubes are not always cylindrical, and can be made in triangle, square or other polygonal shapes. Steel tubes destined for certain applications require extra processes as well. Applications involving hydrogen must be factory pre-cleaned or certified as instrument grade due to hydrogen’s reactive characteristics that can cause metal embrittlement or even explosions.

Generally, a steel tube manufacturing process is chosen for its interaction with the type of steel to be used. Certain types of steel react poorly to heat because of carbon content, so they can’t be easily welded. Steel types also play a role in decisions regarding use in volatile applications.

Steel Tube Applications

Steel tubing is used in high numbers in plumbing applications. The reasons are threefold. One, stainless steel is very sturdy, composed of 80-90 percent steel and 10-20 percent chromium. Steel tubing can handle the types of pressures exerted by water upon plumbing structures. Additionally, the surface of stainless steel does not allow for much adherence by particles or bacteria, so purification processes will not pass on unintended detritus. Finally, steel does not contaminate drinking water.

Steel tubes are also used in a wide variety of structural applications, such as industrial and residential construction. Examples include fences, gates, railings, playground and athletic equipment. Steel is often used for construction tubes over other metals like aluminum when extra stress resistance is necessary. Steel tubes can also be used in automotive applications and even as parts of furniture.

Titanium

Titanium, also abbreviated Ti, is noted for its low-density and high strength, and features the highest weight-to-strength ratio of any structural metal. In nature, titanium is a commonly found mineral, occurring in practically all of earth’s rocks and bodies of water. Its most common compound, titanium dioxide, is used in the production of white pigments, while other compounds can be used as chemical catalysts.

For industrial purposes, titanium is frequently alloyed with other metals to enhance its innate properties, with metals such as iron, aluminum and molybdenum comprising common alloy choices for aerospace applications. In its unalloyed form, titanium possesses as much strength as some forms of steel, but is 45 percent lighter. Titanium is also corrosion-resistant, making it a key choice for high-performance applications—medical devices, jet engines, military applications and electronic goods are just a few of the items that benefit from titaniums properties.

History

Titanium was given its name by a German Chemist, M.H. Klaproth, after he successfully separated Titanium Dioxide (TiO2) from Rutile (a mineral commonly found in igneous and metamorphic rocks) in the late 1700s. Future separations occured, but pure Titanium was not separated until 1910, by American chemist M.A. Hunter. Luxembourg native William Kroll later patented a process for producing Titanium in 1938, and major manufacturing of Titanium, Titanium Alloys, and Titanium Dioxide follow soon thereafter.

Titanium Dioxide is the most common form, and is still widely used for pigments and paints, cloth and fabrics.

Pure Titanium is mainly used as an alloy with other metals, as it provides an extremely high melting point and is very lightweight, and resistant to corrosion. These uses make it perfect for the aerospace, the marine, and medical industries.

Physical and Chemical Properties

Physically, titanium features strength, low-density and is ductile. Additionally, it features low electrical and thermal conductivity. It is 60 percent more dense than aluminum but twice as strong, and is able to retain its strength at high temperatures because of its extremely high melting point: around 1,650 degrees Celsius (C). Although titanium is hard, it is not as hard as some grades of steel, especially those that have been heat-treated.

Chemically, the most notable characteristic of titanium is its corrosion resistance—titanium can resist hydrochloric acid, chlorine and most organic acids, but is soluble when exposed to highly concentrated acids. In pure nitrogen gas, titanium burns. When exposed to water and air, titanium produces an oxide coating that further inhibits reaction. However, at higher temperatures, titanium is quick to react with air or oxygen (1,200 degrees C for air, 1,130 degrees C for pure oxygen).

Useful Titanium Resources:

International Titanium Association

Los Alamos National Laboratory Titanium Page

United States Geological Survey Titanium Information

Encyclopedia of Earth Titanium Resources

Mineral Information Institute: Titanium

Pigments through the Ages: Titanium Dioxide

Invent.org - Titanium Inventor William Kroll

Metal Chemistry Guide

Any chemical element that is an effective conductor of electricity and heat can be defined as a metal. A metal is also good at forming bonds and cations with non-metals. Atoms inside of a metal quickly lose electrons in order to make positive ions or cations. The ions in turn are surrounded by the electrons that are delocalized, which give the metal its electric conductivity.

Alkali Metals

Alkali metals are a group of metals that you can find on the periodic table, known as the Group 1 elements. Members of the alkali metals include potassium, sodium, lithium, caesium, rubidium, and then francium. One element, hydrogen, that is usually a member of this group of metals frequently does not exhibit behavior that is comparable to the rest of the alkali metals. For the rest of the alkali metals, they display one of the best instances of group trends in properties among elements on the periodic table.

Radioactive Alkali Metals: An explanation of what the alkali metals are.

Reactivity of Alkali Metals: A brief explanation of the reactivity of alkali metals.

Group of Metals called Alkali: Article on alkali metals features in-depth explanations and diagrams.

The Facts on Alkali Metals: Webpage that covers the properties of alkali metals.

Alkali Metals and their Relative Activity: An outline of the relative activity in alkali metals.

Alkali Metals and Hydrogen: Quick explanation behind the relationship of the alkali metals to hydrogen.

Period Table Group 1A: A discussion on the part of the periodic table that includes the alkali metals.

Alkaline Earth

Alkaline earth metals belong to Group 2 elements of the periodic table and are made up of radium, barium, strontium, calcium, magnesium, and beryllium. The name for this specific group of metals comes from their own oxides that, in turn, provide the basic alkaline solutions. Aside from magnesium and beryllium, the alkaline earth metals possess an identifiable flame color. These flame colors are crimson red for radium, green for Barium, bright red for strontium, and orange for calcium.

Reactivity and Alkaline Earth Metals: An experiment to demonstrate the reactivity of alkaline earth metals.

Group 2A: A lecture on Group 2A of the periodic table, where you find the alkaline earth metals.

Alkaline Earth Metals and their Chemistry: Discussion on the chemical properties of this group of metals.

Place of Alkaline Earth Metals on the Periodic Table: A webpage explaining how to read Alkaline Earth Metals on the periodic table.

About Alkaline Earth Metals: Examination of how these metals form ions.

Chemistry Glossary: A glossary that provides the definition of alkaline earth metals along with other chemistry terms.

Data on the Alkaline Earth Metals: An informative page on the alkaline earth metals.

Lanthanides

Lanthanides are the 15 elements that comprise the atomic numbers 57 to 71 on the periodic table. The series of elements ranges from lanthanum to lutetium. All lanthanide elements are f-block elements, which means they correlate to the 4f electron shell’s filling. Even though the element called lutetium is a d-block element, it is mostly considered a d-block element, too. The group of elements as a whole is called lanthanide because the more light elements in their series are similar, chemically, to lanthanum.

What are the Lanthanide Elements?: Explanation of what lanthanides truly are.

Lanthanides Introduction: A brief and concise explanation of lanthanides to those new to these elements.

Lanthanides and the Periodic Table: Webpage that displays an answered question about the placement of lanthanides on the table.

Lanthanides and Waste Transmutation: Webpage that discusses what occurs to lanthanides during the transmutation of waste.

Controversy and Lanthanides: Article on the questionable placement of lanthanides on the periodic table.

Lanthanides Resource Page: Webpage that talks about the distribution and extraction of lanthanides.

Actinides

Actinides are the 15 chemical elements that feature the numbers 89 to 103, which correspond to actinium to lawrencium. The name of this series of elements comes from the element actinium. While the majority of actinide elements are synthetic elements, uranium and thorium can be found in nature in more than just trace quantities. One property that these elements are famous for is the radioactivity that is found in all of them; plutonium, thorium, and uranium are utilized in nuclear weapons and reactors.

Actinide Health Concerns: Health concerns prompted by the use of actinides are explored.

Actinide and Calcite Co-precipitation: A discussion on the disposal of nuclear waste.

Actinide Studies: An article that talks about the electronic structure studies done on actinides.

Profiles of Actinides: Webpage featuring pictures and descriptions of the actinide metals.

Actinides Explained: Webpage that explains what actinide metals are.

Actinides Walkthrough: An introduction to actinides.

Transition metals

Transition metals are the elements that feature atoms that have an incomplete d sub-shell. Transition metals or elements are unique from other elements by their common properties. One property is that they form a lot of compounds in quite a few states of oxidation. Another property they are known for is their tendency to form a lot of paramagnetic compounds, mainly due to the low reactivity of their d electrons that are unpaired.

The Importance of Transition Metals: Transition metals and their importance are laid out.

Transition Metals Behavior: Succinct paragraph that explains the behaviors of transition metals.

Ionic Compounds and Transition Metals: An exploration of ionic compounds that involve transition metals.

Transition Metal Clusters: A look at transition metal clusters.

Colors in Transition Metal Complexes: An introduction into how color figures into transition metal complexes.

The Basics on Transition Metals: All the basics of transition metals are covered on this webpage.

List of Transition Metals: An authoritative list of transition metals is provided.

Overview: An overview of everything that needs to be known about transition metals.

Metalloids

Metalloids are chemical elements that are best defined by two criteria. They often create amphoteric oxides and behave in the same manner as semiconductors. Silicon, boron, germanium, tellurium, antimony, and arsenic are in general classified as metalloids. Sometimes, the element called polonium is also included in the metalloid classification, but there is still dispute regarding this among the experts.

Metalloids on the Periodic Table: A look at the distribution of metalloids on the periodic table.

Experiment: An experiment involving physical science and metalloids.

Metalloids (Semiconductors): An explanation of where the metalloids sit on the periodic table.

Metalloid Investigation: A science experiment that teaches students to classify and identify metalloids.

Properties of Metalloids: Webpage providing a straightforward definition of a metalloid’s properties.

Classification: Webpage providing a lesson on how to classify elements including metalloids.

Toxic Metalloids: A look at the biomethylation of toxic metalloids. Other Metals Other metals, or post-transition metals, are the group of elements on the periodic table that are situated to the right of the transition elements. Up to this day, what elements ought to be included in this group is hugely disputed. Usually, zinc, gallium, cadmium, indium, tin, mercury, thallium, lead, and bismuth are included as the other metals of the periodic table. With varying consistency, mercury, cadmium, and zinc (the so-called group 12 elements) are both included as well as excluded from lists of these other metals.

Post-transition Metal Assignment: A science lesson that involves post-transitional metals.

Definition of Post-transition Metal: An understandable definition of post-transitional metals is provided.

Profile of Zinc: A profile of this post-transition metal.

Description of Zinc: A description of this integral, other metal.

Cadmium in Kids’ Jewelry: A research article into the role of cadmium in kids’ jewelry.

Metals History: A history of metals includes a mention of mercury.

Exploration of Mercury: A look at the metal includes a comprehensive examination of its make-up.

The Element Mercury: A detailed analysis of the element mercury.