8. Moulding and casting¶
molding¶
Molding - molding is the preferred process for manufacturing plastic parts. Injection molding is used to create many things such as electronic housings, containers, bottle caps, automotive interiors, combs, and most other plastic products available today. It is ideal for producing high volumes of plastic parts due to the fact that several parts can be produced in each cycle by using multi-cavity injection molds. Some advantages of injection molding are high tolerance precision, repeatability, large material selection, low labor cost, minimal scrap losses, and little need to finish parts after molding. Some disadvantages of this process are expensive upfront tooling investment and process limitations.
Brief about molding?¶
Molding is the process of filling a cavity (mold) using heat and/or pressure.
It used widely in manufacturing and even in our day to day life, such as, when we make ice cubes and jelly.
The main idea of molding ice cubes in our fridge is the same in manufacturing, we use heat (very cold temperature) to solidify the water and we use the mold to shape the water while it solidifies.
casting¶
Casting, on the other hand, involves pouring a molten material into a mold. The material is then allowed to cool and solidify, again taking on the shape of the mold. Common materials that are used in casting include metals, plastics, and concrete.
several types of molding processes¶
these are some of the processes that are used:
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Compression Molding
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Melt Molding
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Transfer Molding
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Injection Molding
safty¶
Don’t ingest, inject and absorb silicone in your body.
Processes & Time¶
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Mix part A and B , pour it in a vacuum to extract the air bubbles then pour it in mold to vulcanize.
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Mix Ratio : Even amount according to proportion (1:1).
silicon (A) , silicon(B)
Gloves must be worn to protect yourself from harmful substances
mix A and B equally to obtain the smooth texture of the mixture
Making the silicon mixure¶
Saftey guidelines for silicon¶
Reffering to our group Assignment.
Don’t ingest, inject and absorb silicone in your body.
Process steps: Mix ingredients A and B in equal quantities and well.
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The mixture can be placed in the vacuum to remove air bubbles from the mixture
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after the air is withdrawn, the mixture is poured into the mold until it dries well.
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Working time from 30 to 40 minutes, drying from 3 to 12 hours.
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The drying time after mixing depends mainly on the temperature of the place.
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The warmer the place, the faster the solidification rate
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Dryness also depends on the size and thickness of the mold, the higher the quantity Larger and thicker the drying time is less
Mix ratio (if applicable): 1A:1B
Work time: 1 minutes to 30 minutes Cure time: 3 hours to 12 hours Cured material state: Rubber
safty sheet¶
fuion 360¶
Milling machine¶
A milling machine is a machine that rotates a circular tool with several cutting blades placed symmetrically around its axis; the workpiece is typically held in a vise or other similar device fastened to a table that may move in three perpendicular directions.
The Roland SRM-20 was the milling machine in use. It is linked to a program made especially for the device called SRP player.
orginal file¶
Process¶
step1: open model file confirm size and orientation of model
step2: prepare wokpiece and enter its size
step3:preview cutting
step4:
- better surface finish
- model with many falt planes
- block , cut top only
X= 0.90mm , Y= 80.70mm , Z= 27.70
STEP1: First we created our mould using the machine we have in fablab by putting the plate inside the machine and the drill bit on the center of the plate
STEP2: After the mould was ready first thing we did was submerge the mould with water to make sure how much of liquid needed to fill the mould.
STEP3:After we get arround 55.4g of water, we decided to fill the mould with 60g of silicon 30 of component A and 30 of B.
wating it to dry up its take like 12 to 24 h
now remove it sloly
HERO SHOTS¶
