Feed throat Feed Bush

The Feed throat Feed Bush is one of the most often overlooked parts of injection and extrusion processes. Nothing passes through the extruder that does not pass through the feed throat first, so its design is extremely important to the entire process.

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Product Description

Feed throat Feed bush

The feed throat is one of the most often overlooked parts of injection and extrusion processes.

Nothing passes through the extruder that does not pass through the feed throat first, so its design is extremely important to the entire process.

So is feed throat temperature. It’s been noted that injection machine “extruders” often have higher specific output than extrusion extruders with the identical screw designs and discharge pressures. This is because injection molding machines do not use a separate feed throat. As a result, the inner wall of the barrel at the resin entry point is usually much hotter than it is with an extruder having a separate feed throat.

EJS factory produces Feed throat Feed bush, in separate piece or part of the barrel, we also assemble them after a full inspection. EJS is a professional manufacturer of Twin Screw Elements, Twin Screw Extruder Elements, Extruder Spare Parts for years, with customers of OEM machine builders as well as end users.

Bore diameter available for Feed throat Feed bush

¢45~

Popular Materials used for Feed throat Feed bush

38CrMoAlA(1.8509)

34CrAlNi7(1.8550)

Surface Treatment of Feed throat Feed bush

Nitrided

Bimetallic alloy coated

Purpose of the Feed throat Feed bush:

1.It provides a clear, free-flowing path for plastic granules, powders, and liquids (such as liquid color) into the feed section of the screw.

2.It prevents the granules, etc. from sticking or clumping together (often called “bridging”) in the feed throat.

3.It provides a vent for volatiles, air, and off-gases as the polymer heats up. These gases are air, residual moisture, resin lubricants, and other additives that are volatile at the polymer’s melt temperature.

4.It connects to the feed zone of the barrel and screw without providing a condensation area for volatiles coming off the plastic and vented through the feed throat.

About E.J.S.

EJS Screw Barrels is a newly created brand name for Export business with manufacturing experiences since 1992.
A screw barrel manufacturer dedicated on producing customized screw barrel and design extruder screw barrels, injection moulding screw barrels.

Bimetallic Screw Barrels

We started to make bimetallic screw barrel at a very early age, almost the same time as the first bimetallic barrel was born in China. Now we have several types for options depending on different applications

Bimetallic Barrels
Alloy Type		EJS01 Alloy	EJS02 Alloy	EJS03 Alloy	EJS04 Alloy
Alloy Components		Fe+Ni+Cr+B (Fe:65, Ni:14, Cr8, B:3.5)	Ni+Cr+Co+B	Ni+Cr+Co+V+B	Ni+Wc+Cr+B (Ni:50, Wc:15~35,Cr:6~8, B:2.5~3.2)
Wearing Resistance		★★★	★★	★★★	★★★★
Corrosion Resistance		★★	★★★	★★★	★★★
Alloy Thickness		2~3mm	1.5~2mm	1.5~2mm	1.5~2mm
Hardness		HRC 58-65	HRC 50-58	HRC 55-60	HRC 55-65
Temperature Range		≤400	≤450	≤450	≤600
Coefficient Thermal	RT~250℃	11.0x10-6	11.0x10-6	11.5x10-6	11.0x10-6
Expansion(/℃)	RT~400℃	11.4x10-6	11.4x10-6	12.4x10-6	12x10-6
Range of Workable Length		700mm~3000mm/piece
Base Steel Vastly Used		40Cr: 42CrMo
Mark in the list: ★★★★ Excellent; ★★★ Very Good; ★★Good

Bimetallic Screws
Suitable for	Single Screw, Twin Parallel Screw, Twin Conical Screw
Alloy Type	Ni60	CoImonoy 56	CoImonoy 83
Alloy Components	Ni+Cr+Fe+Si (Ni:65, Cr:17, Fe:15, Si:5)	Ni+Cr+Si+Fe (Ni: 68, Cr:18, Si:5, Fe:5)	Ni+Wc+Cr+C (Ni:40, Wc:34, Cr:20, C:2)
Anti-Wearing Level	★★★	★★★	★★★★
Anti-Corrosion Level	★★★★	★★★★	★★★★
Alloy Thickness	1~1.5mm	1~1.5mm	1~1.5mm
Hardness	HRC 56-62	HRC 46~61	HRC 43-48
Applied Glass Fiber	Under 10%
Range of Workable Length	Any length needed
Base Steel Vastly Used	38CrMoAI(1.8509), 34CrAINi7(1.8550), 31CrMoV9(1.8519)
Mark in the list: ★★★★ Excellent; ★★★ Very Good; ★★Good

Quality Inspection

Quality is a very important step during production. For making a quality screw barrel, all tolerances should be fulfilled and all dimensions should be correct and put in records.

We provide inspection report, material certificate for every of our supplied screw barrels.

Packaging

Packaging is the last but very important step before shipping. A strong and smart packing box is also part of our quality. It is not only used to protect the screws barrels well during transportation, also provide an easy way for our customer to unpack.