hi meBlow molding or blow moulding (see spelling differences) is a manufacturing process by which hollow plastic parts are formed. In general, there are three main types of blow molding; Extrusion Blow Molding, Injection Blow Molding, and Stretch Blow Molding. The differences in the spellings of British English and American English are as follows: Spelling differences between U.S. usage on one side and British and Commonwealth usage on the other are generally more conspicuous than spelling differences within the Commonwealth. ... This article or section does not cite any references or sources. ...

A PET soft drink bottle

Download high resolution version (202x660, 33 KB) File links The following pages link to this file: Bottle Polyethylene terephthalate Lilt Categories: GFDL images ... Download high resolution version (202x660, 33 KB) File links The following pages link to this file: Bottle Polyethylene terephthalate Lilt Categories: GFDL images ... Polyethylene terephthalate (aka PET, PETE or the obsolete PETP or PET-P) is a thermoplastic polymer resin of the polyester family that produced by the chemical industry and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination with glass fiber. ... A soft drink is a drink that contains no alcohol. ... Composite body, painted, and glazed bottle. ...

History

U.S. Patent 237,168  was issued on February 1, 1881, to Celluloid Novelty Co. and Celluloid manufacturing Company, New York. This was the first patent for the processing of extruded polymer into a parison for blow molding. For other uses, see Patent (disambiguation). ...

The first applications for blow molding were for cellulose nitrate, and later, in the 1930's, for cellulose acetate. Blow molding remained a relatively small part of the plastics manufacturing scene until the introduction of Low Density Polyethylene (LDPE) in the 1940's. The production of LDPE squeeze bottles by Monsanto caused a rapid expansion of the industry, with containers produced to replace glass bottles for shampoos and liquid soaps. Cellulose as polymer of β-D-glucose Cellulose in 3D Cellulose (C6H10O5)n is a polysaccharide of beta-glucose. ... Cellulose acetate, first prepared in 1865, is the acetate ester of cellulose. ... Polyethylene or polyethene is one of the simplest and most inexpensive polymers. ... The Monsanto Company (NYSE: MON) is a multinational agricultural biotechnology corporation. ... This article needs additional references or sources for verification. ... A shampoo is a traditional Indian and Persian body massage given after pouring warm water over the body and rubbing it with extracts from herbs. ...

The mass production of high density polyethylene (HDPE) and polypropylene (PP) in the 1950's led to a further increase in blow molding demand, for applications such as liquid detergents, motor oil, water and milk. The lightweight HDPE one gallon milk container revolutionized the dairy industry, as glass bottles and paperboard were quickly replaced. Polyethylene or polyethene is one of the simplest and most inexpensive polymers. ... Polypropylene lid of a Tic Tacs box, with a living hinge and the resin identification code under its flap Micrograph of polypropylene Polypropylene or polypropene (PP) is a thermoplastic polymer, made by the chemical industry and used in a wide variety of applications, including food packaging, ropes, textiles, plastic parts... A typical container of motor oil, with some in a glass. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... A glass of cows milk. ...

The production of polyethylene terephthalate (PET) led to the viability of reheat stretch blow molding. The strain hardening properties of PET allowed the high volume production of bottles able to resist the carbonation pressure in soft drink applications. The high clarity and economics of PET stretch blow molding have made this a popular production method for bottles for water, detergents, and other products. Polyethylene terephthalate (aka PET, PETE or the obsolete PETP or PET-P) is a thermoplastic polymer resin of the polyester family that produced by the chemical industry and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination with glass fiber. ... Bubbles of carbon dioxide float to the surface of a soft drink. ... A soft drink is a drink that contains no alcohol. ...

Extrusion blow molding

Parison extruded from an accumulator machine head. Courtesy Graham Engineering, York, PA

In Extrusion Blow Molding (EBM), plastic is melted and extruded into a hollow tube (a parison). This parison is then captured by closing it into a cooled metal mold. Air is then blown into the parison, inflating it into the shape of the hollow bottle, container or part. After the plastic has cooled sufficiently, the mold is opened and the part is ejected. Image File history File links Parison. ... Image File history File links Parison. ... Composite body, painted, and glazed bottle. ... Look up container in Wiktionary, the free dictionary. ...

EBM processes may be either continuous (constant extrusion of the parison) or intermittent. Types of EBM equipment may be categorized as follows:

Continuous Extrusion Equipment

• rotary wheel blow molding systems
• shuttle machinery

Intermittent Extrusion Machinery Rotary wheel blow molding systems are used for the high-output production of a wide variety of plastic extrusion blow molded articles. ... Shuttle machines are a significant workhorse in the extrusion blow molding of hollow plastic articles such as bottles for food storage. ...

• reciprocating screw machinery
• accumulator head machinery

Examples of parts made by the EBM process include dairy containers, shampoo bottles, hoses/pipes, and hollow industrial parts such as drums. Reciprocating screw machinery is used for the extrusion blow molding of hollow containers. ... Typical dual head accumulator head blow molding machine near final stage of assembly. ... Bottles is a New Zealand drinking game, commonly practiced by students. ...

Basic polymers, such as PP, HDPE, PVC and PET are increasingly being coextruded with high barrier resins, such as EVOH or Nylon, to provide permeation resistance to water, oxygen, CO2 or other substances. In dairy applications, it is possible to extrude a black light-blocking layer in the center layer of containers, with opaque white resin used in the inner and outer layers. Look up pp, pp. ... Polyethylene or polyethene is one of the simplest and most inexpensive polymers. ... Polyvinyl chloride Polyvinyl chloride, (IUPAC Polychloroethene) commonly abbreviated PVC, is a widely used thermoplastic polymer. ... Polyethylene terephthalate (aka PET, PETE or the obsolete PETP or PET-P) is a thermoplastic polymer resin of the polyester family that produced by the chemical industry and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination with glass fiber. ... Nylon is a generic designation for a family of synthetic polymers first produced on February 28, 1935 by Wallace Carothers at DuPont. ... Permeation, in physics, is the penetration of a substance (permeate) through a solid. ...

Compared to injection molding, blow molding is a low pressure process, with typical blow air pressures of 25 to 150 psi. This low pressure process allows the production of economical low-force clamping stations, while parts can still be produced with surface finishes ranging from high gloss to textured. The resulting low stresses in the molded parts also help make the containers resistant to strain and environmental stress cracking. Injection molding is a manufacturing technique for making parts from thermoplastic material in production. ...

Injection blow molding

The process of Injection Blow Molding (IBM) is used for the production of hollow glass and plastic objects in large quantities. In the IBM process, the polymer is injection molded onto a core pin; then the core pin is rotated to a blow molding station to be inflated and cooled. This is the least-used of the three blow molding processes, and is typically used to make small medical and single serve bottles. The process is divided into three steps: injection, blowing and ejection. This article needs additional references or sources for verification. ... A thermoplastic is a material that is plastic or deformable, melts to a liquid when heated and freezes to a brittle, glassy state when cooled sufficiently. ... Bottles is a New Zealand drinking game, commonly practiced by students. ...

The injection blow molding machine is based on an extruder barrel and screw assembly which melts the polymer. The molten polymer is fed into a manifold where it is injected through nozzles into a hollow, heated preform mould. The preform mold forms the external shape and is clamped around a mandrel (the core rod) which forms the internal shape of the preform. The preform consists of a fully formed bottle/jar neck with a thick tube of polymer attached, which will form the body. A polymer is a substance composed of molecules with large molecular mass composed of repeating structural units, or monomers, connected by covalent chemical bonds. ... One half of a bronze mould for casting a socketed spear head dated to the period 1400-1000 BC. There are no known parallels for this mould. ... A mandrel (pronounced , and also spelled mandril; in American English also called an arbor) is either an object used to shape machined work; a tool component that grips or clamps materials to be machined; or a tool component that can be used to grip other moving tool components. ...

The preform mold opens and the core rod is rotated and clamped into the hollow, chilled blow mold. The core rod opens and allows compressed air into the preform, which inflates it to the finished article shape.

After a cooling period the blow mold opens and the core rod is rotated to the ejection position. The finished article is stripped off the core rod and leak-tested prior to packing. The preform and blow mold can have many cavities, typically three to sixteen depending on the article size and the required output. There are three sets of core rods, which allow concurrent preform injection, blow molding and ejection.

Another application of injection blow molding is in the production of soft elastic gelatin capsules for pharmaceutical applications. Two strips of gelatin are pressed together in a rotary die which cuts out the desired shape of capsule while the fill liquid is injected. Afterwards, they are cooled and dried to yield a firm, strong capsule. In pharmacology, encapsulation refers to a range of techniques used to enclose medicines in a relatively stable shell, for example to allow them to be taken orally. ...

Stretch blow molding

In the Stretch Blow Molding (SBM) process, the plastic is first molded into a "preform" using the Injection Molded Process. These preforms are produced with the necks of the bottles, including threads (the "finish") on one end. These preforms are packaged, and fed later (after cooling) into an EBM blow molding machine. In the SBM process, the preforms are heated (typically using infrared heaters) above their glass transition temperature, then blown using high pressure air into bottles using metal blow molds. Usually the preform is stretched with a core rod as part of the process. The stretching of some polymers, such as PET (Polyethylene terephthalate) results in strain hardening of the resin, allowing the bottles to resist deforming under the pressures formed by carbonated beverages, which typically approach 60 psi. Bottles is a New Zealand drinking game, commonly practiced by students. ... Bottles is a New Zealand drinking game, commonly practiced by students. ... Polyethylene terephthalate (aka PET, PETE or the obsolete PETP or PET-P) is a thermoplastic polymer resin of the polyester family that produced by the chemical industry and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination with glass fiber. ...

The stretch blow molding process. Courtesy of Ottmar Brandau, OB Plastics Consulting

The main applications are bottles, jars and other containers. The Injection blow molding process produces bottles of superior visual and dimensional quality compared to extrusion blow molding. The process is ideal for both narrow and wide-mouthed containers and produces them fully finished with no flash. A sign of injection blow molding is the seam where the two halves of the mold meet. Image File history File links Inside_the_mold. ... Image File history File links Inside_the_mold. ... Composite body, painted, and glazed bottle. ...

This picture shows what happens inside the blow mold. The preform is first stretched mechanically with a stretch rod. As the rod travels down low-pressure air of 5 to 25 bar (70 to 350 psi) is introduced blowing a 'bubble'. Once the stretch rod is fully extended, high-pressure air of up to 40 bar (580 psi) blows the expanded bubble into the shape of the blow mold.

See also

• Plastic Bottles
• Packaging
• Thermoforming
• Two-liter bottle

Packaging is the enclosing of a physical object, typically a product that will be offered for sale. ... A vacuum/pressure assist thermoforming machine with molds visible in the lower right. ... The two liter bottle is common container for soft drinks. ...

External links

• Plastic Bottle Materials and their Properties
• Blow Molding processing guide
• Blow molding animation
• Another blow molding animation