- Drive-through or drive-in racks
- Pallet racks
- Push-back racks
- Sliding racks
- Stacking frames
- Other Racks
- Shelves, bins and drawers
Materials Handling Equipment-RACK
Materials Handling Equipment Moulds may be made in several different ways:
- (1) machined in two halves from solid metal ;
- (2) assembled from steel plates ;
- (3) assembled from component block parts for each half ;
- (4) cast in type-casting metal in two halves ;
- (5) cast in two halves from metal-filled epoxy resin .
When selecting mould material, check that the two halves when assembled will fit the machine and if possible arrange the split line to coincide with the nozzle position. The screw clamp arrangement should be strong enough to keep the mould halves firmly closed.
Once these essentials have been established, the next major point is to ensure that the planned mould cavity does not encroach on the guide pin locations or get too close to the mould exterior wall. About 12mm of material should surround the cavity. All moulds need to be tapered so that the finished mouldings can be removed; however, it is possible to keep this to a minimum. The terms taper, draft angle,and angle of withdrawal，all mean the same thing.
Warning: Eye protection and heat resistant gloves must be worn to handle hot moulds and mouldings. Materials Handling Equipment Moulds must not fracture and guards must be in place during moulding. Never touch molten plastics materials.
Examine a plastics model aeroplane kit closely and you may see the sprue, ejector pin marks, and undercut cold slug impressions, as well as mould cavity numbers, cavity shapes, gates, runners and mould split lines . The expert eye can ‘read’ a moulding and can learn much about the mould.
It is essential that the mould halves match up exactly, and the first operation to ensure accurate matching is to drill the holes for the guide pins, whose centres may then act as datum points for measurement.
It is sometimes possible to mix the five typical methods of construction, but it is more usual to employ one method for each mould. When metal-filled epoxy resin is used with steel or brass filler powders, there may be problems resulting from different expansion rates with increases in temperature.