plastic injection molding and extruding

by:INDUSTRIAL-MAN     2019-08-29
The right equipment makes plastic injection molding simple.
All you need is a heater and some plastic.
Recycling plastic will produce the best results if the respective grouping is maintained.
Please refer to the recycle symbol and do not mix types.
ABS is the plastic of my choice and I used an old HP inkjet printer as raw material in this example.
I used commercially available temperature controls in this project, but I posted an exact precision temperature controller in another Instructable.
It took me about 2 hours and about $50 to assemble and test the project. . .
The following figure is the 3mm ABS extrusion from doneNOTE: I added a section with the example of a thick pressure bar. SAFETY….
Hot plastic is dirty and evil! ! ! !
Use gloves and masks at least.
For example. . . Hot ABS are at least 110 degrees Celsius or 230 degrees Fahrenheit and will stick to you and will continue to burn you after skin burns . . . . . . Please be very careful! ! ! !
The required material will be displayed for use. This as a free-
Form description.
Be sure to read through before deciding if you should build.
When I built it for myself, I built and recorded this in the flight . . . . . . I recommend using this in a very well ventilated place like the outside.
If the plastic is overheated, the initial setting creates smoke. . .
Large local Box retailers will produce most of the material for the project.
The selected material is driven by the type of heater that I can use.
The heater will be discussed later.
The main syringe body consists of a black pipe.
Check if there is no seam inside your pipe . . . . . . If there is no seam, you need to smooth the edges with the right size drill bit, and for the inch black pipe, you need a drill bit of 0. 5906 inches.
This will provide a gap for the piston installed at the back and will be discussed later.
I use a 3/4 inch pipe and start to be just over 20 inch cm long.
It needs to be threaded at one end.
In the absence of binding force, the piston needs to be as close to the inside of the pipe as possible.
Check the internal dimensions of the inch pipe using standard and meter mechanical socket groups.
I found that a 15mm-3/8 drive socket from Sears fits perfectly.
Check with similar tools if the inside of the pipe is tight rather than tightbinding fit.
The loose fit will allow the plastic to slip through the head and then back to the shaft, which will result in an unsatisfactory waste.
My piston shaft is extended by a 3/8 socket connected to a 15mm craftsman socket.
The socket is incorrectly placed on the extension cord and permanently fixed.
This can be drilled and fixed or welded.
Because of the fastest welding speed, I chose welding and I have the materials available.
In order to provide satisfactory results, the socket must be permanently fixed.
If you want to use an inch black tube, the tightest socket I found is a craftsman 5/8 inch drive socket.
Be sure to check if it is appropriate before using it.
Cut and shape the pipe according to the length of the heater and main piston assembly, as shown in the figure.
Cutting using a 1/8-cut angle grinder-off blade. Loud but quick. . .
The idea here is to create a loading port for the plastic to melt and a guide for the piston assembly.
After cutting with a file or a despatch, the Port needs to be free of any sharp edges and loose metal.
Cutting the pipe leaves a threaded end of the pipe, the outlet port, and should not be modified.
Heating comes from 2 Heating rods made at Ogden rating 400 W, 240 V.
These were purchased from eBay for $1. 00 each.
You need 2 under this level.
There are various prices for other products . . . . . . The length of these products will determine the entire length of the syringe body, as shown in the figure.
The heater will run the entire length of the syringe body below the previously cut plastic inlet.
You will also need a standard 1/2 copper water pipe of about 4 inch long and 2 slotted metal brackets of 8 inch long.
Using a stainless steel hose clamp, fix the heater on a black pipe using a slotted metal bracket and copper tube as a gasket, as shown in the figure.
The goal here is to create a solid metal support for the normal operation of the heater and temperature probe.
The copper tube is the hollow space where the temperature probe is placed, providing accurate heating temperature adjustment.
I used commercially available temperature controls in this project, but I posted an exact temperature controller in another Instructable.
The wiring in this regard is carried out according to the instructions normally printed on the controller\'s power relay.
The heater needs to print the voltage on it, which is 240 V in this case.
The entire assembly is wrapped in fiberglass insulation, which is available in most ceramic supply rooms.
This reduces the loss of heat and allows heating more quickly.
This is necessary and will reduce the chances of injury and will be more economical in the future.
The insulation is wrapped in aluminum tape and fixed in place, which is available from most large box retailers . . . . . . Do not compress the insulating material.
Keep it loose and secure in place with tape. . .
Place insulation in the entire heater section of the syringe body, be careful not to pack it between the syringe body and the temperature probe.
The finished part will look a bit bulky.
The frame I used was built with the same slotted angle steel as before.
The frame design depends largely on the use of the syringe assembly.
Since I originally needed to use it as a simple extrusion device, I made a frame with only two upright rods and two horizontal cross sections for the syringe body support.
The other frame designs will be presented in The instructable later.
The connection point is critical, though.
Connect the heater body to the frame above the plastic inlet cut and the bottom of the lower part of the reducer.
This will support the next urgent action.
I used a stainless steel hose clamp to connect the syringe body. .
The extrusion quality and diameter of the plastic depend entirely on the nozzle.
The 3/4 to1/2 inch reducer at the bottom of the syringe body needs to be fitted with a brass reducer from 1/2 to 1/4.
The further reduction of the nozzle is also the form of the brass hook fitting.
Many brass hook fitting sizes can be used to make plastic extrusion or ingot for later re-processing
For injection molding.
The piston needs to be a little longer than the initial welded part.
Again, you can drill and nail this or weld and I happened to weld this again with my oxygen/ethyl torch.
I added a 6 inch extension to the piston assembly.
The frame I use is the slotting angle of a large local box retailer.
It has 4 feet parts so I bought 5.
Legs and lever stands are heavy shelf stands for the same retailer.
I put a 3/4 black tube (
Rough display of demo)
The cuts do weaken the leverage, which will be corrected in future construction.
I also used a 1/2 steel pole as a lever pivot point.
This lever is rough but effective.
The lever to the piston bracket is about 3 feet long and about 8 inch long.
You may need to press the piston pivot point on the lever to make sure the piston enters the heating chamber correctly.
I found that a 1/8 brass hook fitting would squeeze the stable pressure less than 3mm evenly.
This extruded rod is useful for Makerbot products.
And allow re-
Use of failed items and further re-entry
The use of plastic that is usually thrown away. . .
The front of the piston is with my weight at t-
The handle attached to the top of the piston assembly.
This is a rough approach, in future injection mold making instructions using the same group, a drop down handle will be added to the frameup.
The plastic to be used must be cut into strips to fit the entrance opening above the insulated packaging.
You may notice some smoke when the machine is up, which is normal. Be sure to pre-
Before adding plastic, heat the machine to a few degrees above the melting point of the plastic.
Wait a few minutes and apply pressure to start squeezing.
The length of the extrusion is determined by the amount of plastic used, and after removing the piston, the length of the extrusion can be lengthened by adding more plastic at the entrance.
Note that too much heat can cause smoke and plastic to burn, both of which are very undesirable.
Do not touch it again until the extrusion is cooled.
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