What are the tolerances for injection molding?

Injection molds are typically CNC machined to tolerances of +/- 0.005 inches, unless more restrictive tolerances are required. In general, “tight tolerance” injection molding refers to +/-. 002 inches in variation, and “very tight” to +/-. 001 inches.

What is tooling in injection molding?

Injection molding tooling is at the heart of injection molding. Whether it’s a complex application or simple part, plastic injection tooling – more specifically, tooling design – determines the quality of the injection molding process and the parts produced.

What is the specification of injection molding machine?

Clamping Unit

Clamping System Direct Pressure Type
Tie Bar Distance mm (inch) 420 x 420 (16.5 x 16.5)
Platen Dimension mm (inch) 600 x 616 (23.6 x 24.3)
Max. Clamping stroke mm (inch) Max. 470 (18.5)
Min. Mold Thickness mm (inch) 200 (7.9)

What are the golden rules to design a Mould?

golden rules of custom injection mold design

  • An unambiguous totally comprehensive injection molded parts drawing.
  • Specifications of the moulding material, consisting of grade and color.
  • The moulding machine technical specs.
  • All the estimating details which includes any kind of blueprints.

What is mold shrinkage?

Mold shrinkage is the phenomenon where the volume of the molten plastic filled inside the cavity of a mold is shrinking at the time as being cooled and solidifying.

How do you calculate weight tolerance for molded parts?

Is there a guideline or standard for defining the tolerance? The most common method is: Shot to shot weight variation calculated as (three standard deviations) divided by (average weight) must be less than 1% and should be less than 0,5%.

What is tooling direction in plastics?

The Tooling Direction is basically the direction that the mold pulls apart. The mold is built in two separate pieces, basically. You have a Cavity side and you have the Core side. The Core pulls apart from the Cavity and that’s the Dyeline or the Tooling Direction.

How much does an injection molding machine weigh?

The machine weight is 46,200 pounds. Each clamping stroke is 25.60 inches. The minimum mold height is 11.81 inches with the maximum mold height at 30.31 inches.

What are the advantages and disadvantages of injection Moulding?

Plastic injection moulding advantages centre around great precision and high repeatability, combined with speed, a low cost per part and a huge choice of available plastics. Disadvantages include a higher initial cost and lead time than some other processes.

What is sink mark in injection molding?

Description: Sink marks are small craters or depressions that develop in thicker areas of the injection molded prototype when shrinkage occurs in the inner portions of the finished product. The effect is somewhat similar to sinkholes in topography, but caused by shrinkage rather than erosion.

What is shrinkage formula?

Shrinkage calculation for hours Shrinkage% = (1- (Total staffed hours/Total scheduled hours)) Total Staffed hours = (Total answered calls*AHT) + Avail time + productive aux. Total scheduled hours = Total agent hours rostered for the day/week/month.

What are the safety rules for injection molding?

Safety rules for injection molding follow: 1. Do not operate the machine unless you have been instructed in its operation and safety devices. 2. Be certain all safety devices are working properly before operating the machine.

What do Tooling Engineers need to know about injection molding?

Tooling engineers also need to calculate gate/runner sizing specifications for proper filling and minimal cycle times, as well as determining the best shut-off methods for tooling durability over the life of the program. During the injection molding process molten plastic flows through channels called “runners” into the mold cavity.

What are tight tolerances in injection molding?

When we are designing injection molded parts, we’re often faced with details requiring tight tolerances such as snap fits, alignment features or interlocking parts. It’s easy to perfectly align and match these features in CAD, but it’s not that easy to repeatedly produce them during production.

What are the Common coatings used in injection molding?

Common coatings are nickel-boron and nickel-teflon the (0.0002 to 0.0004 inches in thickness). Gates are the openings at the end of the runners that direct the flow of molten plastic into the mold cavity. Gates vary in size and shape depending on the part design and resin material.