Scientific Configuration and Equipment Selection Guide for a Production Line with an Annual Output of 50 Million Cement Bags

Release time：2026-02-03 Classification：Knowledge

In the cement packaging industry, an annual production capacity of 50 million cement bags falls into the medium to large-scale category. Achieving this target requires a scientifically sound, efficient, and stable paper bag machine configuration scheme. This article will delve into how to construct a cement bag production line that matches this production capacity, from the perspectives of capacity analysis, equipment selection, process matching, and cost control.

I. Capacity Demand Analysis and Production Cycle Calculation

First, it is necessary to clarify the actual production requirements for an annual output of 50 million cement bags:

  • Annual working hours : calculated based on 300 days, 20 hours per day (three shifts), with an annual effective working time of 6000 hours.
  • Hourly production capacity : 50 million units ÷ 300 days ÷ 20 hours ≈ 8333 units/hour.
  • Equipment utilization rate : Considering the time spent on equipment maintenance, material replacement, and debugging, the actual overall equipment efficiency (OEE) usually needs to reach above 85%. Therefore, the theoretical design capacity of the paper bag machine needs to reach: 8333 ÷ 0.85 ≈ 9800 bags/hour.

This data means that the entire line configuration must meet a stable output speed of 160-165 lines per minute , and places high demands on the reliability, automation level and mold changing efficiency of the equipment.

II. Selection and Technical Requirements of Core Host Equipment

To achieve a theoretical production capacity of 9800 pieces/hour, it is recommended to use a multi-station paste-bottom valve bag production line , with the following specific configuration:

1. Multi-layer composite paper bag forming machine

  • Structure : A special model for bags with four corner gluing valves, supporting simultaneous feeding and lamination of 3-5 layers of kraft paper or composite paper.
  • Core parameters :
  • Maximum mechanical speed: ≥200 pieces/minute
  • Applicable weight range: 70-120g/㎡
  • Bag length: 500-850mm adjustable
  • Bag width: 350-550mm adjustable
  • Key technologies :
  • Servo drive system: Each unit is independently servo controlled, ensuring registration accuracy ≤ ±0.5mm.
  • Hot melt adhesive system: Employs instant heating technology, adjustable adhesive line width, and bonding strength ≥2.0N/15mm.
  • Tension control: Closed-loop tension monitoring to prevent paper stretching and deformation.

2. Paper feeding and printing unit

  • Paper feeding mechanism : Equipped with 8-10 paper trays, supporting roll changing without stopping the machine (automatic paper splicing device optional).
  • Printing unit : Equipped with at least 2 flexographic printing units, supporting two-color double-sided printing, with a resolution ≥150 lines/inch.
  • Drying system : UV + hot air combined drying ensures instant curing of ink.

3. Base coating and molding unit

  • Valve port forming : precise positioning by a robotic arm, valve port length error ≤0.3mm
  • Bottom reinforcement plate attachment : Automatic attachment, positional deviation ≤0.5mm
  • Bottom folding : Multi-bar mechanism folds simultaneously to ensure the bag is square.

4. Counting and Stacking Output

  • Photoelectric counting : Automatic grouping in sets of 50.
  • Stacking mechanism : hydraulic stacking, adjustable from 200 to 400 stacks per pile.
  • Output method : Belt conveyor + automatic palletizing (robotic palletizing optional)

III. Auxiliary Equipment and Automation Support

To ensure continuous and stable operation of the entire production line, the following auxiliary systems need to be configured:

1. Raw material handling system

  • Automatic paper feeder : Linked with the main unit, it enables automatic feeding of raw paper.
  • Paper edge recycling system : centrally collects waste paper edges, reducing the frequency of manual cleaning.

2. Quality Inspection System

  • Visual inspection : Real-time rejection of printing defects, misaligned seals, and damaged bags.
  • Weight sampling inspection : Online weighing to ensure that the bag weight meets the standard (usually 105-110g/bag).

3. Logistics and Packaging System

  • Automatic strapping : Each stack of bags is automatically strapped 2-3 times.
  • Film wrapping : Moisture-proof and dust-proof packaging, suitable for outdoor storage.

IV. Plant and Utility Requirements

1. Factory conditions

  • Floor space required : The entire production line is approximately 35-45 meters long and 8-10 meters wide. A factory span of ≥15 meters is recommended.
  • Floor height requirement : Clear height ≥ 5 meters (considering the original paper rack height)
  • Ground load : ≥3 tons/㎡ (reinforcement required for the original paper area)

2. Energy Supply

  • Total installed capacity : Approximately 180-220kW (depending on the level of automation)
  • Compressed air : pressure 0.6-0.8MPa, flow rate ≥1.2m³/min
  • Environmental requirements : Temperature 15-30℃, humidity 40-60% (to ensure proper adhesive curing).

V. Investment Benefit Analysis

1. Equipment Investment Estimate

  • Mainframe system: Approximately 2.8-3.5 million yuan
  • Auxiliary equipment: approximately 800,000 to 1,200,000 yuan
  • Installation and commissioning: Approximately 200,000-300,000 yuan
  • Total investment : Approximately 3.8-5 million yuan (depending on the level of investment).

2. Operating Cost Analysis

  • Raw materials : Approximately 0.38-0.42 yuan per piece (based on current paper prices)
  • Energy consumption : approximately 45-55 yuan per hour
  • Staffing : 3-4 people per shift, 10-12 people in total for three shifts.
  • Total cost : Approximately 0.48-0.55 yuan per bag.

3.
Based on the current ex-factory price of cement bags of 0.65-0.75 yuan/bag, the annual gross profit is about 8 million-13.5 million yuan, and the normal payback period is 1.5-2.5 years.

VI. Technological Development Trends and Recommendations

Current paper bag machine technology is developing in the following directions:

  • Intelligentization : Real-time monitoring and analysis of production data through the MES system.
  • Modular design : Quick changeover technology, adaptable to multi-variety, small-batch production.
  • Greening : Application of environmentally friendly materials such as water-based inks and low-temperature adhesives

Investors are advised to pay close attention to the following when selecting equipment:

  1. Technology maturity : Prioritize stable models that have been proven in the market.
  2. After-sales service : Manufacturers must have the ability to respond quickly and provide technical support.
  3. Upgrade potential : The equipment should have reserved interfaces to support future intelligent upgrades.

Building a production line capable of producing 50 million cement bags annually requires not only high-performance main equipment but also systematic planning of the entire line's processes, automation systems, and operational management. Selecting the appropriate paper bag machine configuration must meet current production capacity needs while also allowing for future technological upgrades and market changes. Through scientific configuration and meticulous management, this production line will become a solid guarantee for the company's sustainable development.

(Note: The data in this article is based on the industry average. Specific projects need to be adjusted and calculated according to actual circumstances.)