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.

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