Bimetallic Injection Screw with GF Less Than 30%

• Customization: Available
• After-sales Service: Engineers Available to Service Machinery Oversea
• Warranty: 2 Years
• Model NO.: BSB-01
• Standard: GB
• Technics: Casting
• Feature: Wear-Resistant&Anti-Corrosion
• Material: Stainless Steel
• Surface Roughness: Ra 0.4 Um
• Chromium Plating Thickness: 0.05 M
• Hardness After Nitriding: HRC50~70
• Thickness of Bimetallic: 1.5~3.0mm Depending on Different Alloy Coating
• Hardness for Bimetallic: HRC50~70 Depending on Different Alloys
• Straightness: 0.4~0.7mm
• Application: Injection&Exturder
• Transport Package: Wooden Package
• Specification: 12-300mm
• Trademark: G-PLAS
• Origin: Ningbo
• HS Code: 84779000
• Production Capacity: 5000
• Package Size: 29.00cm * 30.00cm * 25.00cm
• Package Gross Weight: 120.000kg

Product Description

Product Description

 

Screw and Barrel Introduction

 

In the realm of plastic processing machinery, especially in injection molding and extrusion processes, the screw and barrel play pivotal roles. They are the core components that transform solid plastic pellets into a molten, homogeneous mass ready for shaping into various products.

1. Design and Structure

Screw

 

The screw is a precision - engineered component typically made of high - quality alloy steel. It consists of three main sections: the feed section, the compression section, and the metering section.

 

• Feed Section: This is the initial part of the screw where solid plastic pellets are introduced. It has a relatively deep flight depth to facilitate the smooth entry of plastic materials. The surface of the feed section is often treated to enhance friction, ensuring efficient conveying of the pellets towards the compression section.
• Compression Section: As the name implies, this section gradually reduces the volume of the plastic material. The flight depth decreases while the pitch may remain constant or change slightly. Here, the plastic begins to melt under the combined action of mechanical shear and heat generated by the screw's rotation and the barrel's heating elements.
• Metering Section: At the end of the screw, the metering section has a uniform and shallower flight depth. Its function is to meter and pump the molten plastic at a consistent rate. The metering section ensures that a precise amount of evenly - melted plastic is delivered to the nozzle for injection or extrusion.

Barrel

 

The barrel is a cylindrical housing that encloses the screw. It is also constructed from high - strength alloy steel with excellent wear - resistance and heat - transfer properties. The inner surface of the barrel is highly polished to minimize friction as the screw rotates and the plastic moves through it. The barrel is equipped with multiple heating zones, usually controlled by thermocouples and heaters. These heating zones allow for precise temperature control along the length of the barrel, ensuring optimal plastic melting conditions.

2. Material and Manufacturing

 

High - quality materials are crucial for the performance and longevity of screws and barrels. Common materials include alloy steels such as 38CrMoAlA, which can be nitrided to enhance surface hardness and wear - resistance. For applications involving abrasive plastics or high - temperature processing, materials like tungsten - carbide - coated alloys may be used.
The manufacturing process of screws and barrels involves precision machining techniques. CNC (Computer Numerical Control) lathes and milling machines are used to achieve tight tolerances in the dimensions of the screw's flights and the barrel's inner diameter. After machining, surface treatments such as nitriding, chrome - plating, or applying anti - wear coatings are carried out to improve the performance and durability of the components.

3. Function in Plastic Processing

Injection Molding

 

In an injection molding machine, the screw rotates within the barrel to plasticize the plastic pellets. As the screw rotates, the plastic is conveyed from the feed section to the metering section, where it is melted and homogenized. Once the desired amount of molten plastic is accumulated at the front of the screw (in the injection chamber), the screw stops rotating and acts as a plunger to inject the molten plastic into the mold cavity at high pressure. The barrel's heating system and the screw's mechanical action work in tandem to ensure that the plastic is in the right molten state for accurate and high - quality mold filling.

Extrusion

 

For extrusion processes, the screw continuously conveys the plastic through the barrel. The melting and homogenization of the plastic occur in the barrel as it moves along the screw. The molten plastic is then forced through a die at the end of the barrel, taking on the shape of the die. The screw's design and the barrel's temperature profile are carefully adjusted to control the extrusion rate, the quality of the extruded product, and the uniformity of the plastic melt.

4. Performance and Maintenance

 

The performance of screws and barrels directly impacts the quality of plastic products. A well - designed and maintained screw - barrel combination can produce products with consistent dimensions, excellent surface finish, and high mechanical properties. Regular maintenance is essential to ensure long - term performance. This includes checking for wear and tear, especially in the flight tips of the screw and the inner surface of the barrel. Lubrication of the screw's bearings and regular calibration of the temperature control system are also part of the maintenance routine. In case of significant wear or damage, timely replacement of the screw or barrel is necessary to avoid production disruptions and ensure product quality.

 

In conclusion, the screw and barrel are integral components in plastic processing equipment. Their proper design, material selection, manufacturing, and maintenance are crucial for achieving efficient, high - quality plastic processing operations.

 ***Sizes:
1. Diameter of screw: D12-D300mm 
2. L/D ratio of screw: 10 - 26 

 ***Grade available:

1. Standard grade: 38CrMoAlA + nitriding 96 hours

2. Bimetallic grade: 38CrMoAlA + bimetallic alloy

3. TC-A grade: Tungsten carbide 35%

4. TC-B grade: Tungsten carbide 25%

5. TC-C grade: Tungsten carbide 15%

 ***injection screw barrel and bimetallic injection screw and barrel

1)38CrMoALA(JIS SACM645)

2)42CrMo(JIS SCM440)

3)9Cr18MoV 
4)CW6Mo5Cr4V2

5)Various high quality alloy steels,According to different usage, the choose for alloy is different, some require for abrasion-resistant while some require for corrsion-resistant. For standard, we have Fe-based, Ni-based,^W2Calloy,Tunsten alloy etc for choice.

6)The foreign material we used as following:

 *Germanysteel, GH113 ,2250 ,2842 ,1.8509 ,1.442 ,1.6582 ,1.6523 ,1.2080,1.4542,

 *USA steel, P20,420,L6,H13,W110,D3,A2,D6,O1,S1,M35,8620,3115,K52440 
 *Sweden steel, 718S,718H,S136,S136H,STAVAX,ASP-23,ASP-30 
 *Australia Steel, M202,M300,W302,K460,W300,K900,K100,W321 
 *Hardness steel, YG6X,YG 6A,YG 6,YG8N,YG8,YG8C,YG11C,YG 15,YT5,YT14,YT30 
 *Japan Steel, SKT 4,YXM 4,YXM 42,SNC 815,SK -3,SKS 3,and etc.