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Electroforming is process to produce moulds in which a relatively thin layer of metal
(normally Nickel) is electrically deposited onto a model to create the mould tool. The
metal is usually backed up with another metal (copper) for added strength.
CNC Moulds are used when extreme precision or extended production runs are
required. Because of a higher cost, they are used only in special cases.
Epoxy Moulds use liquid thermosetting polyester and epoxy material that is formed
and cured at room temperature.
Mould Mounting:
Moulds are mounted on the spindle or arm of the rotational machine. Large moulds
are easily mounted by bolts or simple clamping systems, while a structure commonly
known as a spider is used to mount several small- to medium-sized molds on the
same spindle or arm. The spider consists of several arms or mounting legs to which
each mould is attached, usually by bolts. In turn, the spider has one, central,
mounting location that attaches to the machine spindle. This design allows two- or
three-dozen cast moulds to be mounted on one central structure. The spider or a
single large sheet metal mold may be removed easily with a forklift or crane. This is
important because the rotomolding process typically is used for short production
runs of a variety of parts.

Raw Materials: Fractional MIs of about 2 to 10 or so are recommended for rotational
moulding. The plastic pellets are grounded in to fine powder in a machine called
Pulverizer. Commonly used polymers are Polyethylene's: LLDPE, LDPE, MDPE,
HDPE and XLPE. Other materials that can be rotationally moulded include Acrylic,
ABS, Polypropylene, Nylon, PVC, Polycarbonates and TPU.
Liquid systems require a different technical approach than that of powder rotational
moulding. There are many types of liquid systems like polyurethanes, epoxies, and
unsaturated polyesters, most of which are thermosetting resins. PVC plastisol and
nylon 6 are the primary exceptions.
Applications of Rotational Moulding: Large Water tanks, Point of Sale (POS),
Specialty tanks and containers for fuel, water, and chemical, Drainage systems,
Instrument housings, Vending machines, Highway barriers and road signs,
automotive parts, children's toys or canoes, Playground Equipment, Boats and
kayaks, Childcare seats, Light globes, Tool carts, Planter pots, Medical Appliances,
Enclosures and housings Playing balls, Playground and sporting equipment,
Headrests, Agriculture, Defense and others

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