What is clamp force in injection Moulding?
Clamping force refers to the force applied to a mold by the clamping unit of an injection molding machine. In order to keep the mold closed, this force must oppose the separating force, caused by the injection of molten plastic into the mold.
What are the parts of an injection molding machine?
The main parts of the Injection molding machine are material hopper, barrel, an injection ram/ rotating screw type plunger, heating device (heater), movable pattern, ejectors, and a mold inside mold cavity. Generally injection molding machines works in horizontal manner.
What are the two basic types of clamping units?
What are the two basic types of clamping units? The clamping units are: (1) mechanical toggle clamp and (2) hydraulic. In addition, there are hydromechanical units which combine hydraulic and mechanical actuations.
Why clamping force is important in injection molding process?
What is Clamp Force? The machine needs to have enough clamp force to hold the mold closed to withstand the plastic pressure that is being developed inside the mold cavities and the cold runner.
What is clamp factor?
Clamping force is an important factor in the injection molding process. It is basically a safety measure implemented to operate the injection molding setup. A close mold is used to achieve the desired results. This mold is clamped in place during the operation using a clamping unit.
How is clamp load calculated?
Clamp load (lb.) is calculated by arbitrarily assuming usable bolt strength is 75% of bolt proof load (psi) times tensile stress area (sq. in.) of threaded section of each bolt size. Higher or lower values of clamp load can be used depending on the application require- ments and the judgement of the designer.
What are the parts of molds?
A mold is a hollowed out block that sets the shape of the product being made. It can be made of different materials, the most common of which are aluminum, steel, alloys and copper. It also has different components. These components include pins, bases, lifters, ejectors, guides, bushings, and alignment devices.
What are the three basic types of clamping units?
CLAMPING SYSTEM: MANUAL, TOGGLE, HYDRAULIC, HYDRO-MECHANICAL & T BAR LESS CLAMPING
- TOGGLE TYPE CLAMPING.
- HYDRAULIC CLAMPING.
- HYDRO-MECHANICAL CLAMPING.
- TIE BAR LESS CLAMPING.
What are the three functions of the clamping unit during the injection molding cycle?
The function of the clamp unit is to hold and close a mold, build force, open the mold, and eject the parts.
How is clamping tonnage calculated?
Now you can calculate necessary tonnage based on the projected area times the clamp factor for the material used. T = A x cf. For example, the projected area of the molded part is 150 sq/in times a clamp factor of 3 (tonnage needed/square inch from material data sheet). 150 x 3 = 450 tons needed.
What is clamp tonnage?
The clamp tonnage requirement is used to select a capable machine that will prevent part defects, such as excessive flash. The required clamping force can be calculated from the cavity pressure inside the mold and the shot projected area, on which this pressure is acting.