Short Shot in Metal Injection Molding

It is well known for metal injection molding supplier that short shot is a very common defect in powder injection molding process. Today we would like to discuss the reason for short shot during MIM process. Welcome your supplement.

Phenomenon
--material is not completely filled the cavity

Possible reason for short shot in injection molding

l   Inadequate  measurement set

l  injection pressure is too small

l  injection speed is too slow or injection time is too short

l  mold temperature or tube temperature is not enough

l  the back pressure is too low or no back pressure caused screw idling

l  too much release agent

l  Too short  flow distance or bad  illiquidity of material

l  sprue or runner is too small

Burrs in Metal Injection Molding

It is well known for metal injection molding supplier that short shot is a very common defect in powder injection molding process. Today we would like to discuss the reason for short shot during MIM process. Welcome your supplement.

Phenomenon:
Material overflow from mould cavity

Possible reasons for burrs
- measurement set
- injection pressure is too great
-Insufficient clamping force
-mold or feed tube temperature are too high
-Bad liquidity of material
- crystallization rate is too slow
- bad parting line airtight 

Not Powder Injection Molding Process, PC Used in Plastic Injection Molding

Though both MIM and plastic injection molding are injection process, but their materials are completely different. Now let’s see the characters for PC used in plastic injection.

Characters for PC in plastic injection molding can be conclude as follows:

1. Has a prominent impact toughness and creep properties, has high heat resistance, cold resistance is very good also, brittle temperature - 100 ℃, the  tensile strength is equal to  nylon. PC has much higher elongation and elastic modulus as well as prominent impact strength. Colorless, transparent, good coloring, better heat resistant than  nylon and methanal. Creep resistance and good electrical insulation, good corrosion resistance and abrasion resistance; low water absorption, small shrinkage, good stability.  PC can be used for all kinds of gear, turbine, rack, CAM shaft, pulley, bearings, core, transmission chain, nuts, washers, pump impeller, chimney, container, etc

2. Not alkali resistance, amine and arene. It maybe craze by stress, easy to produce stress concentration (and internal stress), and highe requirements of molding conditions.  Easy to hydrolysis in high temperature,  poor compatibility with other resins.; Poor liquidity, sensitive to temperature change, fast cooling.

3. Cylinder temperature is very important to control the quality of plastic parts. Low temperature will cause starving and matt surface; occur silver and  filaments at high temperature.

4. In case of polycarbonate material contains water, it will seriously affect the flow of the material performance. Therefore it must be dried, commonly at 110 ~ 110 ℃ temperature for 6 ~ 15 h.

If you also would like to know MIM metal injection molding process, you can go to website:  www.zcmim.com. A Chinese metal injection molding supplier with more than 8 years experience can offer you  professional advice and best solutions

Not Powder Injection Molding Process, PF Resin Used in Plastic Injection Molding

Though both MIM and plastic injection molding are injection process, but their materials are completely different. Now let’s see the characters for PC used in plastic injection.

Characters for PF Resin in plastic injection molding can be conclude as follows:

1.      Mechanical properties is very high, big rigidity, small cold flow property, high heat resistance (above 100 ℃), low friction coefficient under water lubrication (0.01 ~ 0.03).  Good electric properties and ability of resistance to acid and alkali corrosion, no deformation because of the change of temperature and humidity. Easy to molding,  low cost. It is  commonly used as car inner decoration.

2.      The disadvantage is that brittle, tonal limited, poor light fastness,  small arc resistance, not resistant to strong oxidizing acid corrosion.

If you also would like to know MIM metal injection molding process, you can go to website:  www.zcmim.com. A Chinese metal injection molding supplier with more than 8 years experience can offer you  professional advice and best solutions

Can PA(Poly A) for MIM Powder Metallurgy?

Do you know how to make Apple watch adapter?. It  is  made by metal injection molding process. Besides, metal injectionmolding can OEM custom stamping part.  Then can it make PA  products like plastic injection molding?

The answer is No…

Though both are injection process, but materials are completely different. Now let’s see the characters for PA used in plastic injection.

High fatigue strength and rigidity, good heat resistance, low friction coefficient, good wear resistance, generally suitable for medium load with temperature 100 ~ 120 ℃ or less. It can be used for  wear-resisting mechanical transmission parts which work in less lubrication or no lubrication or conditions

Great  warm-suction, less liquidity after absorbing temperature, easy appear bubble and silver silk defect. It should to dry before injection molding, drying temperature is 70 ~ 80 ℃ for 4 ~ 6 h.

Large scare of molding shrinkage, high shrinkage rate, easy appear shrinkage, dent and deformation problems, request stable molding condition.

Crystalline material has high melting point. The melting temperature range is narrow, poor molten stability. With temperature over 300 ℃ for more than 30 minutes, it is easy to decompose.

If you also would like to know MIM metal injection molding process, you can go to website:  www.zcmim.com.   A Chinese metal injection molding supplier with more than 8 years experience can offer you  professional advice and best solutions.

Can POM (Polyoxymethylene) for MIM Powder Metallurgy?

Do you know that MIM can make machine spare parts production? Maybe you know, or maybe not. But you may more familiar with plastic injection. So this chapter is to introduce the characters for POM materials used in plastic injection molding.

Good comprehensive performance; its tensile strength, impact toughness, rigidity, fatigue strength and creep resistance are all quite high. Good stability, good water absorptivity, small friction coefficient,  good resistance to chemicals; its performance no less than nylon.  POM can be used for bearings, gears, CAM, valves, pipes, nut, pump impeller, chassis, carburetor, dashboard widgets, containers, bar and various copper-instead parts for mist arrester.

Poor thermal stability, easy to burn; long-term exposure in the atmosphere will be aging.

Decomposition temperature is 240 degrees. But if kept in 200 degrees for more than 30 minutes, it will decompose immediately with stimulating and corrosive gas.

Die temperature had a great effect on the quality of plastic parts. Improving  die temperature can improve product surface dents and is helpful for material’s   fluidity.

If you also would like to know MIM metal injection molding process, you can go to website:  www.zcmim.com.A Chinese metal injection molding supplier with more than 8 years experience can offer you  professional advice and best solutions