DT 900-4AT Direct drive 4 thread overlock sewing machine with auto thread trimmer&stepper motor

The DT 900-4AT is a high-performance direct drive thread overlock sewing machine equipped with an automatic thread trimmer, automatic presser foot lifting, and advanced stepper motor technology. It is designed for high-speed sewing of thin, medium, and thick fabrics, making it a versatile choice for garment factories producing T-shirts, shirts, jeans, trousers, knitwear, and more.

This machine combines precision stitch control, energy efficiency, and intelligent automation to reduce manual operations, improve sewing quality, and increase productivity—especially in continuous production environments.

Applications

The DT 900-4AT is widely used for sewing a broad range of fabrics and garment types, including:

• T-shirts – seams, hems, and cuffs on knit fabric

• Shirts – side seams and sleeve attachment

• Upper garments – general overlocking on jackets, tops, and blouses

• Jeans – overlocking on denim, especially with 5-thread configuration

• Trousers – seam finishing and edge overlocking

• Knitting wear – stretchable seams on knitwear

• Woolen – overlocking on wool and wool-blend fabrics

• Towels and non-woven fabrics – edge finishing on household and industrial textiles

Its ability to handle thin, medium, and thick materials makes it suitable for diverse production lines, from lightweight knitwear to heavy denim and workwear.

Key Features

1. Wide Fabric Compatibility

The DT 900-4AT is designed to sew a wide range of fabrics, including thin, medium, and thick materials. Typical applications include T-shirts, shirts, upper garments, jeans, trousers, knitting wear, woolen fabrics, towels, and non-woven fabrics. This flexibility makes it a valuable addition to any garment factory with mixed production requirements.

2. Automatic Thread Trimmer and Presser-Foot Lifting

The machine is equipped with an automatic thread trimmer and automatic presser-foot lifting, significantly reducing manual operations and improving sewing efficiency—especially in continuous production.

• Automatic thread trimmer: Cuts both needle and looper threads cleanly at the end of each seam, eliminating manual trimming and improving cycle time.

• Automatic presser-foot lifting: Raises the presser foot automatically when the machine stops, allowing faster fabric removal and repositioning.

These automation features reduce operator fatigue and enable one operator to handle more work, increasing overall productivity.

3. User-Friendly English Operating System

The DT 900-4AT features an English operating system with a clear English display. This intuitive interface allows operators to quickly learn and operate the machine with minimal training.

• Easy-to-read screen

• Simple parameter adjustment

• Quick access to functions such as speed control, stitch length, and thread tension

• Reduced training time for new workers

4. Electric Eye-Sensed Waste Vacuuming System

An electric eye-sensed waste vacuuming system automatically detects sewing waste and trims, ensuring a clean working area and improving overall sewing quality and productivity.

• Automatically detects loose threads and fabric waste

• Vacuums waste away from the sewing area

• Reduces manual cleaning time

• Helps prevent thread tangling and contamination of finished garments

5. Built-In LED Lighting

The built-in LED lighting system provides bright and energy-efficient illumination of the sewing area, improving accuracy during operation.

• Bright, shadow-free lighting

• Low energy consumption

• Reduces eye strain for operators

• Enhances visibility for precise stitching on dark or patterned fabrics

6. Optional Air Suction System

An optional air suction system is available to further enhance waste collection and maintain a tidy sewing environment. This system is particularly recommended for factories processing high volumes of fabric that generate significant waste.

• Not mandatory—can be selected according to production needs

• Improves waste management efficiency

• Helps maintain a clean and safe working environment

7. Direct Drive Motor with Stepper Motor Technology

The machine is powered by a direct drive motor combined with stepper motor technology, offering precise stitch control, low vibration, low noise, and stable performance.

Benefits of this drive system include:

• Energy efficiency: Direct drive consumes significantly less power than traditional clutch motors

• Low vibration and noise: Improved operator comfort and reduced machine wear

• Precise stitch control: Stepper motor ensures accurate feed and stitch length

• Stable performance: Ideal for high-speed and long-time operation in garment factories

• Fast response: Quick start/stop and accurate needle positioning

This advanced drive technology makes the DT 900-4AT suitable for demanding production environments where reliability and consistency are essential.

Common Questions

1. What's the highest speed of the machine?

The DT 900-4AT can reach a maximum speed of 7000 RPM. However, in practical use, such high speed is not always necessary. Operators can adjust the speed based on specific production needs and fabric types.

For delicate fabrics, a lower speed ensures better stitch quality and prevents fabric damage. For heavy-duty materials, a moderately high speed can be maintained while still achieving clean, consistent overlocking.

2. What automatic functions does this machine offer?

The machine is equipped with two key automatic functions:

• Automatic thread trimmer: Automatically cuts threads at the end of each sewing cycle.

• Automatic presser-foot lifting: Automatically lifts the presser foot when the machine stops.

These functions help reduce manual work, improve sewing efficiency, and allow operators to work faster and more comfortably, especially during continuous production.

3. Is the air suction system mandatory?

No. The air suction system is optional and can be selected according to production needs. It is recommended for factories that want to further enhance waste collection and maintain a cleaner working environment, but it is not required for basic operation.

4. How many thread options are available?

The DT 900-4AT supports 3, 4, 5, or 6 thread configurations, providing flexibility for different stitch requirements:

• 3-thread: Lightweight overlocking on thin fabrics

• 4-thread: Standard safety overlock for medium fabrics

• 5-thread: Combined overlock + safety stitch, most suitable for denim fabrics

• 6-thread: Extra-durable seams for heavy-duty materials

Based on practical experience, the 5-thread style is the most suitable for denim fabrics, providing both strength and stretchability for jeans and workwear.

5. How often does an overlock machine need maintenance?

Regular maintenance is recommended to ensure stable performance and extend machine life. Key maintenance tasks include:

• Regular cleaning: Remove lint, dust, and thread waste from the looper area, feed dogs, and internal mechanisms.

• Lubrication: Follow the manufacturer's lubrication schedule to keep moving parts operating smoothly.

• Timely replacement of consumable parts: Replace needles, loopers, and knives when worn to maintain stitch quality and prevent fabric damage.

Daily cleaning and periodic professional servicing will keep the DT 900-4AT running at peak performance for years.

DT 900-4AT Specifications at a Glance

• direct drive overlock sewing machine

• automatic thread trimmer overlock

• stepper motor overlock machine

• high speed overlock machine

• DT 900-4AT

• thread overlock with auto trimmer

• industrial overlock machine with auto presser foot lift

• 5 thread overlock for denim