Flexible mold


Flexible mold

A mold is a hollow shape which exactly encloses the shape of a desired object. The object is usually created by pouring a liquid into the mold and allowing it to solidify: typical liquids include molten metal or plastic, plaster of Paris, epoxy resin.

Molds generally divide into two classes: solid or flexible.

There are five different types of flexible mold compounds in significant use today.

Hot-Melt

polyvinyl chloride

* inexpensive, worn molds can be melted and recast.
* hazardous to handle due to high temperatures required for melting.
* use limited to model and pattern materials that are heat resistant.

Latex

* produces a very elastic, thin-walled, strong mold
* shrinkage is high
* molds must be supported to prevent distortion.
* 10 to 20 brush coats must be applied for adequate thickness, with time allowed to "dry" in between each coat, making the mold is slow and time consuming.

ilicone rubbers

* excellent molds for casting resins and foams
* material cost is extremely high.

Polysulfide rubbers

* versatile and are especially useful for casting plaster, Hydrocal, and other water mixed cements.
* can be used for casting wax candles and some limited use for resin casting.
* easy to handle, non-adhesive and can be poured over clay or practically any type of model or pattern, using very simple release agents such as soap or Vaseline.
* can be used to take impressions directly from a waterclay or plastelene model, so that permanent master models can then be cast in plaster or Hydrocal.

Polyurethane flexible mold compounds

* limited shelf stability
* "moisture conscious"
* easy to handle with simple mixing ratios and good fluidity.
* can be used for pouring practically any type of cementitious material, casting resin or foam formulation.
* Cost of material is far below that of the silicones and appreciably lower than polysulfides.

From the standpoint of general utility and economy, the polyurethanes surpass all other typesFact|date=September 2007.

Equipment and Accessories

Mixing containers and stirring paddles should be of metal or plastic and always spotlessly clean, warm and dry. Use 1-inch fiber brushes cut down to 1-inch length for application of wax release agent. A regular short fiber scrubbing brush should be used for buffing wax from deep grain or fine design of model or pattern.

Sulphur Free Plastalina Clay (The Compleat Sculptor, New York City) is excellent for modeling, laying up and sealing models and dams. 1/4"-3/8" plywood should be used for mounting models. Scrap pieces can be sawed to rectangular shapes and used for straight side retaining dams.

Lightweight sheet metal, linoleum and heavy cardboard can be used for circular or irregular shaped retaining walls. Sash cord and masking tape are used to bind the walls to the model baseboard. 1/2" X 2" furring and "2 x 4's" cut to short lengths make good wedges. For plaster casting, use regular Molding or Casting Plaster


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Flexible mold — Гибкая матрица (для изготовления стереотипов) …   Краткий толковый словарь по полиграфии

  • Flexible — Things known as Flexible include:*Flexible electronics *Flexible response *Flexible mold *Flexible employment *Flexible fuel vehicle *Flexible rake receiver *Flexible spending account *Flexible single master operation *Flexible baton round… …   Wikipedia

  • Mold growth, assessment, and remediation — Mold assessment and mold remediation are techniques used in occupational health: mold assessment is the process of identifying the location and extent of the mold hazard in a structure, and mold remediation is the process of removal and/or… …   Wikipedia

  • sculpture — sculptural, adj. sculpturally, adv. /skulp cheuhr/, n., v., sculptured, sculpturing. n. 1. the art of carving, modeling, welding, or otherwise producing figurative or abstract works of art in three dimensions, as in relief, intaglio, or in the… …   Universalium

  • Casting (metalworking) — Casting iron in a sand mold In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which… …   Wikipedia

  • lost-wax casting — Traditional method of producing molds for metal sculpture and other castings. It requires a positive, a core made of refractory material and an outer layer of wax. The positive can be produced either by direct modeling in wax over a prepared core …   Universalium

  • Plastic — is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products. Plastics are typically polymers of high molecular weight, and may contain other substances to… …   Wikipedia

  • peel — 1) a flexible mold formed by applying a thin layer of the molding material (usually a plastic compound) to an object such as a fish fossil. The peel can then be studied or sent to a researcher without the need to examine the original fossil 2)… …   Dictionary of ichthyology

  • silicone rubber —    A cold cure molding polymer compound which can withstand the heat of molten lead. It is mixed from a rubber based solution and a catalyst. Silicone rubber is used for small scale casting. As a gel, silicone is available in tubes from any… …   Glossary of Art Terms

  • plastic — plastically, plasticly, adv. /plas tik/, n. 1. Often, plastics. any of a group of synthetic or natural organic materials that may be shaped when soft and then hardened, including many types of resins, resinoids, polymers, cellulose derivatives,… …   Universalium