How to choose suitable twin screw extruder machine

I. Introduction

Two screws are fixed in a barrel with a “figure-eight” cross-section to form a twin-screw extruder. A cross-section known as a “figure-eight” is produced when two cylindrical bores with centers less than two radii apart are machined. The degree of screw intermingling and the direction of screw rotation are used to categorize twin-screw extruders.

JWP 65


A. Brief Overview of Twin Screw Extruder Machine

Three different screw setups are there. A co-rotating intermeshing type, an intermeshing counter-rotating type. A non-intermeshing counter-rotating form. An intermeshing, self-wiping, co-rotating twin-screw extruder. It is possible to use kneading components in place of screw elements in a twin-screw extruder. The co-rotating intermeshing and counter-rotating twin-screw extruders are presumably the most commonly utilized models.

B. Importance of Choosing the Right Twin Screw Extruder Machine

When choosing a plastics extrusion machine, it is crucial to ascertain if it utilizes high-quality parts from top manufacturers in the industry, including Jinwo Machinary. Compared to locally sourced, off-brand, or obsolete components, this is always preferable. By using high-quality parts, you can be sure that replacements will be readily available, making maintenance simple and ensuring optimal performance.

Regardless, investing in a new system is always a significant business decision, as selecting the best device could make the difference between accomplishing your objectives completely or squandering crucial company funds.

II. Understanding Your Requirements for Twin Screw Extruder Machine

A. Types of materials to be processed

In the food, chemical, and polymer industries, twin screw extruders machine are used to mix a range of consumer goods, including mastics, adhesives, soaps/detergents, sealants, plastics, and chemicals.

B. Output capacity needed

For high-quality PVC pipe extrusion to be done effectively, twin screw extruders are essential. These extruders are used to make a variety of items. Screw diameters ranging from 52mm – 168mm are available for them, providing output ranges of 120 to 2,000 kg/hr.

C. Specific processing requirements

Through precise control of processing parameters, extrusion processing strives to physico-chemically change continuously fluid polymeric medium and produce high-quality structured products.

Two co-rotating, intermeshing screws installed on splined shafts within a closed barrel make up a twin screw extruder machine. A multitude of screw and barrel designs allow for the configuration of different screw profiles and process functions by process requirements.

For this reason, a twin screw extruder machine can provide a great degree of versatility when it comes to compressing, transporting, cooking, mixing, shearing, chilling, pumping, heating, shaping, etc. The primary benefit of intermeshing co-rotating twin screw extruder machine is their extraordinary mixing capacity, which gives extruded products unique qualities and significantly increases the value of processing units.

III. Types of Twin Screw Extruder Machine

Co-rotating VS. Counter-rotating

The longitudinal flow channel of a co-rotating twin screw extruder machine needs to be open for the two screws to interchange materials, according to the geometric shape. The material that was initially at the bottom of one screw groove will travel to the top of the other screw groove during the exchange. To achieve the material exchange across neighboring grooves of the same screw, the longitudinal flow channel must first open before the transverse flow channel can do the same.

Co-rotating twin screw is appropriate for mixing operations because of its improved distributive mixing ability. The counter-rotating dual screw extruder’s geometric specifications allow for the closure of its longitudinal flow channel, which causes the material to be driven forward by the screw—a process known as positive displacement.

As a result, a counter-rotating twin screw extruder machine’s ability to produce stable molding extrusion is essential. Consequently, the direction of rotation for twin screws ought to be marked.

Single stage VS. Multistage

The double screw extruder is better suited for powder processing, as it can combine and plasticize the pulverized mixed PVC ingredients, whereas the single screw extruder is primarily useful for plasticizing and extruding polymers, particularly ideal for processing granular products. Single and double-screw extruder structures differ greatly from one another. A single-screw extruder primarily uses the friction force created by the material’s interaction with the barrel to achieve extrusion molding; in contrast, the majority of double-screw extruders are primarily made up of two intermeshing screws and have a relatively simpler structure.

IV. Capacity and Size Considerations

Matching machine speed to production needs

The throughput rate of a single-screw extruder is determined by its single-screw speed, and these devices are typically flood-fed. Twin-screw compounders are not flood fed; instead, the feeders set the output rate, and screw speed maximizes the process’s compounding efficiency.

Evaluating throughput requirement

The calculation of extrusion throughput involves deducting the system’s volumetric drag flow from its volumetric pressure flow. The drag flow of an extruder can be used to determine its output in pounds per hour: 2.64 x D²Nhρ. Melt density (ρ), screw speed (N) (rpm), channel depth (h) (in inches), and diameter (D) (gm/cc).

V. Material Compatibility

A. Ensuring Compatibility with Various Materials

Polyethylene Plastic: Products made of polyethylene plastic will find a larger range of applications than those made of polypropylene. As of right now, every kind of packaging that is frequently seen on the market is made of polyethylene.

PVC Plastics: PVC (polyvinyl chloride) plastics are widely used in plastic bottles, coatings, and other products, and throughout manufacture, temperature control is subject to stringent regulations.

One of the primary production tools for polyvinyl chloride products at the moment is the twin screw extruder machine, which can fulfill the goal of continuous production through constant temperature control.

Polypropylene Plastic: The colorless, translucent thermoplastic polypropylene offers excellent mechanical strength, electrical insulation, and heat resistance. The primary piece of machinery used in the production of polypropylene plastic goods is the twin screw extruder machine.

B. Special considerations for specific applications of Twin Screw Extruder Machine

Before beginning the machine, pay attention to low-speed operation: High-speed operation of the extruder cannot be performed at first because the machine’s inner tank is not preheated before the lab twin screw extruder is started.

If the machine is started immediately, there is a risk that the inner tank will burn during subsequent use, which will cause the inner tank to malfunction. As a result, before starting up, the machine might run at a low pace.

Be sure to check the fuselage barrel’s tightness beforehand: There shouldn’t be any leaks because the extruder’s entire interior is sealed and heated to a high temperature; otherwise, it would be simple for air to seep inside and raise the internal temperature.

To guarantee the safety of the plastic product melting process and the internal temperature rise during subsequent use, it is therefore important to first check whether the twin screw extruder’s internal sealing is complete before using it.

Be mindful of the screw’s installation position: After the machine is installed, take note of where the two screws should be installed. Because the twin screw extruder’s screw position controls both the machine’s efficiency and the rate at which raw materials melt.

It is simple to produce internal operation failure and have an impact on the subsequent cutting and cutting of raw materials if the two screws are switched. As a result, double-check the installation procedures and the parts’ locations beforehand.

VI. Processing Flexibility:

A. Adapting To Different Formulations

When it comes to high-dose, poorly soluble APIs, the twin-screw granulation process may be less costly to run than more intricate procedures like spray drying, nano milling, or HME. Understanding the effects of surface modification on materials and the twin-screw granulation technique, which enables precise control of mechanical and thermal factors, has led to this breakthrough.

When it comes to high-dose, poorly soluble APIs, the twin-screw granulation process may be less costly to run than more intricate procedures like spray drying, nano milling, or HME. Understanding the effects of surface modification on materials and the twin-screw granulation technique, which enables precise control of mechanical and thermal factors, has led to this breakthrough.

B. Importance of Modular Design

Twin screw extruders with modular construction enable the assembly of specific screw and barrel parts at any desired point along the extruder’s length for functions including feeding, venting, mixing, and pumping. This feature makes compounding easier for the extruder by enabling the addition, dissolution, and mixing of additives—especially those that are difficult to pump or that are temperature-sensitive.

VII. Power and Energy Efficiency:

A.Evaluating Energy Consumption

Energy consumption and extruder efficiency were found to be highly associated with screw speed and specific feeding load (SFL) using data from the double screw extrusion of maize meal. While increasing the extruder efficiency, a rise in SFL resulted in a drop in total specific mechanical energy. The extruder efficiency was more affected by SFL than by screw speed.

The extruder efficiency rose by 6 to 11% when the screw speed was increased from 300 to 450 rpm at a constant SFL level, while the extruder efficiency increased by 30% when the SFL was increased from 0.0026 to 0.0038 kg rev 1. During the twin-screw extrusion of maize meal, more than 98% of the mechanical energy required was for shearing or viscous dissipation, and less than 1.5% was for pumping.

B.Choosing a machine with optimal power efficiency

A twin-screw extruder should ideally be selected by verifying that its configuration satisfies the material’s performance requirements, including temperature zone, opening and closing technique, aspect ratio, heating power, kneading block specifications, material wear resistance, permutation, and combination. Choose the twin-screw extruder that satisfies the criteria based on these specifications. Generally, the intermeshing co-rotating twin-screw extruder is utilized when raw materials are combined, plasticized, and then pelletized.

VIII. Control Systems and Automation

A.Importance of user-friendly controls

Windows-based controls for Twin Screw Extruders lessen the need for operator training and increase accessibility for operators with different levels of technical expertise. Operators can change the parameters to get the desired results thanks to the user-friendly UI. To improve consistency and reproducibility, the extruders also have recipe storage capabilities.

B.Automation features for efficiency

The feeding system, extrusion system, rotary cutting system, heating system, transmission system, lubrication system, and control system make up the automatic twin-screw machine. The primary drive system, rotary cutting system, and twin-screw extruder feed system all use frequency conversion speed regulation, which is robust, secure, and energy-efficient.

To guarantee the twin-screw extruder operates safely and to prolong the gear’s lifespan, the gearbox is equipped with an automatic lubrication feature. The self-cleaning feature of the double screws eliminates the need to take the screws out for cleaning. The parameters are clearer and the temperature management is more user-friendly with the displayed automatic temperature control system.

IX. Maintenance and Durability

A.Assessing ease of maintenance

Equipment: Inspect for wear and tear on the machine’s transmission component, look for obstructions in each grease nipple, and add grease.

Circuit: Take care to keep the circuit board clean. Dust off the strong and weak electric boxes regularly. Maintain the electric boxes dry and away from moisture.

Oil circuit: Inspect the oil circuit to see if there are any leaks, and take prompt action if necessary. Avoid oil degradation and scratches on the piston rod.

Other Precautions: Additional safety measures include cleaning the oil sludge in the oil tank and replacing the hydraulic oil once a year. To stop the oil temperature from rising and hastening the oil’s aging process, the water cooler needs to be cleaned on time. Naturally, safety is a serious issue.

During maintenance, it is necessary to verify that the double screw extruder machine warning lights, mechanical safety block, oil circuit pressure relief valve, and circuit safety door switch are all operating normally.

B.Choosing a durable machine for long-term use

Examine the twin screw extruder’s capacity for control and its effect on material mixing

A satisfactory mixing effect is a prerequisite for a consistent extrusion molding process. These days, a high-quality, well-served twin screw extruder needs to be able to combine at a consistent pressure and quantity.

The only way to considerably increase production efficiency and quality is to make sure that the twin screw system operates more stably. To guarantee that the blending modification production technology of this system is more stable, customers must comprehend the combined effects of their screw parts when choosing a twin screw extruder with dependable quality.

Check the twin screw extruder’s feed height and mixing type

The mixing and fluidization of the feeding process need to be assured by high-quality processing, and the quality-guaranteed twin screw extruder’s screw height also affects the mixing impact that follows. Consequently, while choosing a high-quality twin screw extruder, it is essential to make sure that the feeding machine’s height is suitable and that the feeding machine is efficiently combined using the mixing hopper of this type of machine.

Only a twin screw extruder with dependable quality can ensure that the feed drops from the machine at a lower height, that the hopper design can aid in the exhaust, that the feed can be effectively designed, that the feed will be more stable for use after it is produced and that the feed will meet quality standards.

X. Cost Considerations of Twin Screw Extruder Machine

A. Balancing Quality With Budget Constraints

Changing product kinds and colors during the plastic master batch manufacturing process necessitates intricate activities. These days, a variety of laws and controls can be successfully met by twin screw extrusion machines with guaranteed quality. Cleaning efficiency can be greatly increased by making precise modifications.

Additionally, this top-notch twin screw extrusion machine efficiently reduces labor intensity and maintenance time due to its improved cleaning efficiency and convenient opening manner. It also produces higher yields when utilized for shorter periods after being turned on. Additionally, it lessens the effects of frequent equipment and machinery shutdowns, which significantly raises production efficiency in contemporary processing operations.

B. Total Cost of Ownership Analysis of Twin Screw Extruder Machine

Based on the end-use industry, the twin-screw extruder market is split into four segments: food and beverage, chemical, pharmaceutical, and others. The market for twin-screw extruders is expected to grow at a compound annual growth rate of 4.5% over the course of the forecast period, from an estimated USD 1,118.2 million in 2022 to USD 1,659.7 million by 2032.

The superior mixing capacity and process flexibility of twin-screw extruders are among the many advantages that allowed the food and beverage category to have a 32.4% market share in 2023. Additionally, since twin-screw extruders are frequently employed in gum, chocolate coating, candies, and enzyme modification procedures, the market is being driven by the expanding food and beverage industry.

Based on the sales channel, the twin-screw extruder market is split into direct and indirect segments globally. The indirect segment, which held a 36.6% market share in 2023, is anticipated to expand at a compound yearly growth rate of 4.3% during the course of the forecast period. Because of the shifting market conditions over the past few years, many manufacturers have shifted toward a relationship business model and concentrated on aftermarket or indirect sales through distributors.

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