and select members of the American Mold Builders Association. We Should Applaud their Efforts to FURTHER IMPORTANT DOCUMENT.
? Does the moldmaker have to reply it at his history? As unpleasant as this topic is, it may be word setting something.
NEVER Guarantee the Longevity of a Mold.
a mold is made of head-time, Steel doesn & rsquo; t mean it & rsquo; s going to pump out hundreds of the part parts.
Fig 1 Hobbed Copper Cavity Inserts. (Photos: J. Fattori)
Pressure "was only about 10 lb B & mdash; generated by a febber bands. The point is that part geometry is when all algins, and partitimes, defines when all ends.
In, mOLDING MIATILIAL TYPE and MOLDING PROCESS USED to Make The Paster, as Well as the Mold Installation, Removal, Maintenance and Storage.
The only time a mold is considered unusable or has reacked the end of its lifespan is when the repair count exceeds its word.
a new project, moldmakers will wisly ask:
1. What is the extens annual quantity? This helps the moldmaker decide the mold classification and the number of cavities required to meet the this this annual quantities.
texturing.
From pvc at very long. If you think that stainless is too extensive, consider the count to remove the world, Re-Polishing the Cores and CAREDTHED THEDTHEND Re-Plating
a thermally confive material with size carbide filer, then of the poplinedal tool Steels with a typical hardness of about 60 Rockwell Calld.
Thermal-conductivity materials such as copper alloys may be required. UNFORTUNATELY, too fef moldmakers ask this question & mdash; unless they are also being to mold.
Heat Treatment. Usually, The Commonly used Steels are more than adequate for major parts. But ocCasionally the Properties of the Steel Should Greter Consideration.
-1 Are Also Good Steel Types for Sliding Applications.
Wear and Galling Explain WHY TheRE HAS Be a Lot of Attention to Various Surface Coatings and Surface Treatments, As Well as the Metallurgical of Diffement
7 is also good.
Galling Can Occur at any time & mdash; from the initial mold sampling up to 1 microS Later.
Events.
, When debris is Sandwiched Between Two Flat Surfaces and is Exposed to a Few Hundred Tons of Clamp Pressure, it has nowhere to go but in.
Let rsquo; s do some simple math. Assume a sub-gated part leaves 1/16-in. Diam. Flakes on the parting line. A 1/16-in. Diam. Flake.is in A 500-TON PRESS. Pressure = Force ÷ Area so in this case:
500 Tons ÷ 0.0031 in.2 = Roughly 160,000 PSI.
Platen. Figure 3 shows what kind of flashs can do to a mold when the application present is considrably greater than the yield stream of the steel.
Fig 3 sub-gate flash damage.
root cause determined and corrected when it & rsquo; s first noticed. Giving an open an operation or some other to remove the flash is not an appropr transportation.
Flash never gets better. It only gets worse.
USING A more ductile material, or make a spare cavity set as insury.
Fig 4 a hobbed parting line.
& Bull; Inferior Mold Design
& Bull; Inferior Mold Construction
& Bull; Insufficient Mold-Plate Thickness
& Bull; Insufficient Support-Pillar Area
& bull; lack of parting-line rellef
& bull; Improper mold setup
& Bull; Insufficient Clamp Pressure
& Bull; Excessive Clamp Pressure
& bull; Cavity imagece
& Bull; Poor Processing Parameters
& bull; Excessive inject or Pack Pressures
& Bull; Low Material Viscosity
& Bull; Insufficient Venting
& Bull; Excessive Vent Depth
& Bull; USING Adhesive Labels As Vents
& bull; Machine Bushing Wear
& bull; Machine Platen Wear
& bull; lack of alignment
& bull; World Shutoffs
& Bull; Abrasive Molding Material
& Bull; Abrasive Material Fillers
& bull; nozzle stringing
& bull; sub-gate flashing
& Bull; Sticking Parts or Runners
& bull; Rust or Corross
& bull; Lack of Preventive Maintenance
Several of These Factors Were Discussed in this Article. Future ArticleS Will Discuss the Remaining Ishes.
This article.