Hand mould

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Two bullet molds for lead casting BulletMolds.png
Two bullet molds for lead casting

A hand mold is a simple mold used for low quantity work. It is used in the injection molding and printing industries. It is made by a hand injection molding machine. It is a simple machine which contains a barrel, handle, nozzle, mold and heaters.

Contents

Printing

In the printing industry, a hand mold specifically refers to a two-part mold used for casting hand-made type. Inside the mold is a matrix. [1]

In particular, it refers to a system for casting movable type, pioneered by Johannes Gutenberg, which was widely used in the early era of printing in Europe (15th-16th century).

In this method, the type was made by punching a letter-shaped cavity in a matrix made of some soft metal (typically copper). Then this matrix would be held in the lower part of the mold, the upper part would close on it, and molten type metal would be poured into the cavity. Using the hand mold, the printer could quickly make any additional type he might need. [2]

Injection molding

In injection molding, hand molds refer to simple molds that have no provision for heat, cooling, or ejection. This means when a hand mold is cycled universal heating plates are required to warm the molds and the molds must be removed after each cycle to remove the moldings. This drastically increases the cycle time, which limits it to short runs, but to offset this is the low cost of the mold. They are usually single cavity molds, but may be multi-cavity if the molding is quite small. They are usually only of a two or three plate design because of the simplicity of the parts. If only a short run is required then the molds may be made from aluminum or brass, but if more parts are required then they are made from conventional steels. [3]

Bullet casting

Hand cast bullets remain popular with the handloading, muzzleloading and small custom ammunition loading communities. In a tradition dating back to the beginning of firearms, molds matched to the bore (and the chamber for breech loading weapons) are custom made for each weapon. Anywhere from one to six cavities are carved into the molding block, along with appropriate gates and sprues. As the blocks are now usually made out of aluminum, which does not allow lead alloys to stick, only a small amount of parting compound is needed. [4] [5]

Related Research Articles

<span class="mw-page-title-main">Metal casting</span> Pouring liquid metal into a mold

In metalworking and jewelry making, casting is a process in which a liquid metal is delivered into a mold that contains a negative impression of the intended shape. The metal is poured into the mold through a hollow channel called a sprue. The metal and mold are then cooled, and the metal part is extracted. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods.

<span class="mw-page-title-main">Injection moulding</span> Manufacturing process for producing parts by injecting molten material into a mould, or mold

Injection moulding is a manufacturing process for producing parts by injecting molten material into a mould, or mold. Injection moulding can be performed with a host of materials mainly including metals, glasses, elastomers, confections, and most commonly thermoplastic and thermosetting polymers. Material for the part is fed into a heated barrel, mixed, and injected into a mould cavity, where it cools and hardens to the configuration of the cavity. After a product is designed, usually by an industrial designer or an engineer, moulds are made by a mould-maker from metal, usually either steel or aluminium, and precision-machined to form the features of the desired part. Injection moulding is widely used for manufacturing a variety of parts, from the smallest components to entire body panels of cars. Advances in 3D printing technology, using photopolymers that do not melt during the injection moulding of some lower-temperature thermoplastics, can be used for some simple injection moulds.

<span class="mw-page-title-main">Molding (process)</span> Shaping a liquid or plastic material by making it conform to a more rigid mold

Molding or moulding is the process of manufacturing by shaping liquid or pliable raw material using a rigid frame called a mold or matrix. This itself may have been made using a pattern or model of the final object.

<span class="mw-page-title-main">Die casting</span> Metal casting process

Die casting is a metal casting process that is characterized by forcing molten metal under high pressure into a mold cavity. The mold cavity is created using two hardened tool steel dies which have been machined into shape and work similarly to an injection mold during the process. Most die castings are made from non-ferrous metals, specifically zinc, copper, aluminium, magnesium, lead, pewter, and tin-based alloys. Depending on the type of metal being cast, a hot- or cold-chamber machine is used.

<span class="mw-page-title-main">Sand casting</span> Metal casting process using sand as the mold material

Sand casting, also known as sand molded casting, is a metal casting process characterized by using sand as the mold material. The term "sand casting" can also refer to an object produced via the sand casting process. Sand castings are produced in specialized factories called foundries. Over 60% of all metal castings are produced via sand casting process.

<span class="mw-page-title-main">Compression molding</span> Method of molding

Compression molding is a method of molding in which the molding material, generally preheated, is first placed in an open, heated mold cavity. The mold is closed with a top force or plug member, pressure is applied to force the material into contact with all mold areas, while heat and pressure are maintained until the molding material has cured; this process is known as compression molding method and in case of rubber it is also known as 'Vulcanisation'. The process employs thermosetting resins in a partially cured stage, either in the form of granules, putty-like masses, or preforms.

<span class="mw-page-title-main">Rotational molding</span> Making hollow plastic objects in a heated mold

Rotational molding involves a heated mold which is filled with a charge or shot weight of material. It is then slowly rotated, causing the softened material to disperse and stick to the walls of the mold forming a hollow part. In order to form an even thickness throughout the part, the mold rotates at all times during the heating phase, and then continues to rotate during the cooling phase to avoid sagging or deformation. The process was applied to plastics in the 1950s but in the early years was little used because it was a slow process restricted to a small number of plastics. Over time, improvements in process control and developments with plastic powders have resulted in increased use.

Spin casting, also known as centrifugal rubber mold casting (CRMC), is a method of utilizing inertia to produce castings from a rubber mold. Typically, a disc-shaped mold is spun along its central axis at a set speed. The casting material, usually molten metal or liquid thermoset plastic, is then poured in through an opening at the top-center of the mold. The filled mold then continues to spin as the metal solidifies.

Electronic packaging is the design and production of enclosures for electronic devices ranging from individual semiconductor devices up to complete systems such as a mainframe computer. Packaging of an electronic system must consider protection from mechanical damage, cooling, radio frequency noise emission and electrostatic discharge. Product safety standards may dictate particular features of a consumer product, for example, external case temperature or grounding of exposed metal parts. Prototypes and industrial equipment made in small quantities may use standardized commercially available enclosures such as card cages or prefabricated boxes. Mass-market consumer devices may have highly specialized packaging to increase consumer appeal. Electronic packaging is a major discipline within the field of mechanical engineering.

Fusible core injection molding, also known as lost core injection molding, is a specialized plastic injection molding process used to mold internal cavities or undercuts that are not possible to mold with demoldable cores. Strictly speaking the term "fusible core injection molding" refers to the use of a fusible alloy as the core material; when the core material is made from a soluble plastic the process is known as soluble core injection molding. This process is often used for automotive parts, such as intake manifolds and brake housings, however it is also used for aerospace parts, plumbing parts, bicycle wheels, and footwear.

<span class="mw-page-title-main">Pattern (casting)</span>

In casting, a pattern is a replica of the object to be cast, used to prepare the cavity into which molten material will be poured during the casting process.

Permanent mold casting is a metal casting process that employs reusable molds, usually made from metal. The most common process uses gravity to fill the mold, however gas pressure or a vacuum are also used. A variation on the typical gravity casting process, called slush casting, produces hollow castings. Common casting metals are aluminium, magnesium, and copper alloys. Other materials include tin, zinc, and lead alloys and iron and steel are also cast in graphite molds.

<span class="mw-page-title-main">Plastisol</span>

A plastisol is a colloidal dispension of small polymer particles, usually polyvinyl chloride (PVC), in a liquid plasticizer. When heated to around 180 °C (356 °F), the plastic particles absorb the plasticizer, causing them to swell and fuse together forming a viscous gel. Once this is cooled to below 60 °C (140 °F) it becomes a flexible, permanently plasticized solid product. This process is called 'curing'.

<span class="mw-page-title-main">Casting</span> Manufacturing process in which a liquid is poured into a mold to solidify

Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process. Casting materials are usually metals or various time setting materials that cure after mixing two or more components together; examples are epoxy, concrete, plaster and clay. Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other methods. Heavy equipment like machine tool beds, ships' propellers, etc. can be cast easily in the required size, rather than fabricating by joining several small pieces. Casting is a 7,000-year-old process. The oldest surviving casting is a copper frog from 3200 BC.

Hobby injection molding machines, also known as benchtop injectors, hold molds on a smaller scale. Benchtop injectors have become more common as inexpensive CNC milling machines have reduced the cost of producing molds in a home workshop.

<span class="mw-page-title-main">Ring, slide and hook</span>

Rings, slides and hooks are the accessories used in intimate apparel/lingerie used for adjustment and decorative functions. Rings, slides and hooks are commonly made of plastic and nylon coated metal and stainless steel.

A core is a device used in casting and moulding processes to produce internal cavities and reentrant angles. The core is normally a disposable item that is destroyed to get it out of the piece. They are most commonly used in sand casting, but are also used in die casting and injection moulding.

Solid Concepts, Inc. is a custom manufacturing company engaged in engineering, manufacturing, production, and prototyping. The company is headquartered in Valencia, California, in the Los Angeles County area, with six other facilities located around the United States. Solid Concepts is an additive manufacturing service provider as well as a major manufacturer of business products, aerospace, unmanned systems, medical equipment and devices, foundry cast patterns, industrial equipment and design, and transportation parts.

Injection mold construction is the process of creating molds that are used to perform injection molding operations using an injection molding machine. These are generally used to produce plastic parts using a core and a cavity.

Transfer molding is a manufacturing process in which casting material is forced into a mold. Transfer molding is different from compression molding in that the mold is enclosed rather than open to the fill plunger resulting in higher dimensional tolerances and less environmental impact. Compared to injection molding, transfer molding uses higher pressures to uniformly fill the mold cavity. This allows thicker reinforcing fiber matrices to be more completely saturated by resin. Furthermore, unlike injection molding the transfer mold casting material may start the process as a solid. This can reduce equipment costs and time dependency. The transfer process may have a slower fill rate than an equivalent injection molding process.

References

  1. Knight, Edward Henry (1876), Knight's American mechanical dictionary, vol. 2, Houghton, Mifflin, p. 1057.
  2. Meggs, Philip B. A History of Graphic Design. John Wiley & Sons, Inc. 1998. (pp 58–69) ISBN   0-471-29198-6
  3. Harper, Charles A. (2000), Modern plastics handbook, McGraw-Hill Professional, p. 6.34, ISBN   978-0-07-026714-5.
  4. "Bullet Molds--General Information and Product Data". NEI Handtools, Inc. 2004. Archived from the original on 2011-04-30. Retrieved 2011-03-25.{{cite web}}: CS1 maint: unfit URL (link)
  5. "Bullet Mold Instructions" (PDF). Lee Precision, Inc. 1993. Archived from the original (PDF) on 2011-08-21. Retrieved 2011-03-25.