Before choosing a paper bag machine, it is necessary to read: clarify the requirements and avoid pitfalls!

I have been deeply involved in the paper packaging industry for many years and have seen too many "pitfalls" that customers have stepped on when choosing a paper bag machine. Some factory owners have invested millions of yuan to introduce high-speed fully automatic equipment, only to find that the order structure is mainly based on small batches and multiple varieties, with machines idle for a long time and a dismal input-output ratio; There are also purchasing managers who, in order to save budget in the short term, purchase semi automated machines with insufficient configuration. As a result, when faced with large and urgent orders, their production capacity is severely limited, resulting in delayed delivery and fines, as well as loss of valuable customer trust. The root of these real lessons often lies in one thing: unclear demand in the early stage. Choosing a paper bag machine is not simply about "buying a machine", it is an important production investment decision. This article will provide an in-depth analysis to help you thoroughly clarify your thoughts before making a purchase, accurately match your needs, and spend your money wisely, truly achieving cost reduction and efficiency improvement.
1、 Deep into the bone marrow: why is "clear needs" the primary iron rule?
The paper bag machine is not a universal device. Different types of machines (flat bottom bag machine, square bottom bag machine, handbag machine, valve bag machine, etc.) have significant differences in functionality, efficiency, and price. A high-speed automatic machine suitable for producing exquisite clothing handbags, used to produce large quantities of cement valve pockets, is undoubtedly a huge waste; Vice versa. Unclear requirements can easily lead to:
Investment waste: Buying expensive high-end models that far exceed actual needs, or conversely, buying "chicken ribs" equipment that simply cannot meet production requirements.
Production bottleneck: Insufficient equipment performance (speed, accuracy, stability) has become a bottleneck for the entire production line.
Soaring operating costs: high energy consumption, high scrap rates, and maintenance and downtime losses caused by frequent malfunctions.
Difficulty in transformation: Poor flexibility of equipment, unable to adapt to changes in future order structures or product types.
2、 Tearing apart the threads: What exactly are your core needs?
Before contacting any supplier, please make sure to gather core departments such as production, sales, procurement, and finance to sit down and carefully review the following issues:
Paper bag type and structure
What type or types of paper bags do you mainly produce? This is the most fundamental issue!
Flat bottomed bag: commonly used in food packaging and retail small commodity bags. The structure is relatively simple.
Square bottom bag/automatic square bottom bag: After the bottom is formed, it can stand on its own and has good load-bearing capacity. It is widely used in industries such as food, chemical, building materials, and clothing. It is currently the mainstream in the market.
Handbag: A shopping bag or gift bag with a handle made of paper rope, cotton rope, or cardboard, which requires high aesthetic appeal and handle adhesion strength.
Valve pocket: used for filling granular materials (such as cement, flour, chemical raw materials), requiring precise valve sealing and good sealing performance.
Other special bag types such as M-shaped folding bottom bag, self-supporting zipper bag, etc?
Key point: Different bag types require completely different molding processes and equipment. A machine is usually only capable of producing one or a limited number of bags with similar structures. Clearly define your 'main bag type' and the range of bag types that may be expanded in the future.
Order structure and production mode:
Batch size: Is it mainly based on large and long orders (such as fixed supply for a certain chain supermarket), or is it mainly based on small batches, multiple varieties, and quick order changes (such as undertaking various customized gift bags)? This directly determines the requirements for the degree of equipment automation and the efficiency of plate replacement.
Delivery Time: What is the regular delivery time requested by the customer? Do you often have emergency orders inserted? This is related to the stable production speed that the equipment needs to achieve.
Production mode: Is it 24-hour continuous operation or single shift/double shift production? This affects the requirements for equipment durability and stability.
Paper bag specifications:
Size range: What are the minimum and maximum values for the length, width, and height (especially the bottom width and height) of the bags you need to produce? The device has its adjustable range limitations, so be sure to cover your product line requirements.
Paper weight: What is the weight range of commonly used paper (such as 70gsm-250gsm)? The adaptability of equipment to different paper weights (such as paper feeding, forming, and gluing) varies, especially when producing high weight or ultra-thin paper, special attention should be paid.
Paper type: mainly using pure wood pulp kraft paper, white cardboard, coated paper, recycled paper, or special paper (such as laminated paper, aluminum foil composite paper)? The surface characteristics, stiffness, and adhesion of different types of paper have specific requirements for equipment (such as paper feeding, gluing, heat sealing, etc.).
Bag bottom/bag mouth treatment: Do you need to open ventilation holes? Is the bag opening flat cut, serrated cut, or needs to be folded (such as M-fold)? Is the bottom adhesive flat, cross adhesive, or other methods? What are the types of handles (flat rope, round rope, cardboard handle) and bonding methods (hot melt adhesive, cold glue)? These process details determine which functional modules are required for the equipment.
Capacity requirements:
Based on the current order volume and business growth forecast for the next 1-3 years, how many stable outputs per hour or minute do you need the equipment to achieve? Pay attention to distinguishing between "theoretical maximum speed" and "actual sustainable production speed", the latter being influenced by multiple factors such as paper performance, glue drying, worker operation, equipment stability, etc., usually only 60% -80% of the theoretical speed.
How many shifts are needed to meet production capacity? This is related to equipment quantity planning and automation level.
Quality and accuracy requirements:
What specific requirements do your customers have for the appearance (such as printing accuracy, forming squareness, cleanliness) and functionality (such as handle tension strength, sealing performance of the bottom/valve) of paper bags? The requirements of high-end brand customers are often much higher than those of ordinary customers.
This determines the standards that the equipment needs to meet in terms of paper feeding accuracy, forming station stability, glue control, pressure control, and other aspects.
Raw materials and auxiliary materials:
What type of adhesive is used (cold glue, hot melt glue, PVA)? The adhesive properties (viscosity, solid content, drying time) have requirements for the coating system.
Do you need equipment to integrate auxiliary devices such as automatic gluing, automatic rope (handle), and automatic valve opening?
Are there any special requirements for the diameter of the roll paper and the inner diameter of the paper core? This is related to the design of the unwinding device.
Factory buildings and infrastructure:
What is the reserved installation space for equipment (length, width, height)? Is there a height limit?
Electricity supply (voltage, power, number of phases)? Does the gas source (pressure, flow rate, cleanliness) meet the equipment requirements?
Ground bearing capacity? Is the logistics channel unobstructed?
Budget and Investment Return:
What is the overall budget range for equipment procurement? This determines which level of equipment you can watch (domestic mid-range, domestic high-end, imported brands).
What are the expectations for the investment return period? Is the initial procurement cost of equipment more important, or is the overall cost of long-term operation (energy consumption, labor, maintenance, scrap rate) and the efficiency improvement it brings?
3、 Follow the diagram to find the right solution: match the key characteristics of the equipment according to the requirements
Only by clarifying one's own needs can equipment be inspected in a targeted manner:
Equipment type and degree of automation:
Semi automatic machine: requires manual paper feeding, bag retrieval, or completion of some processes. Low investment, strong flexibility, suitable for small batches, multiple varieties, startups, or specific complex bag types. But the efficiency is low, relying on skilled workers, and the labor cost is high.
Fully automated machine: It automatically completes the entire process from feeding the roll paper to outputting the finished bag (even stacking and counting). High efficiency (speed up to 80-200+bags/min), saving labor, and stable quality. Suitable for medium to large-scale production. The investment is relatively high, and the requirements for version swapping and debugging technology are also high.
Key choice: Within budget constraints, the degree of automation should match your order volume and labor cost pressures. In the long run, automation is the trend.
Core performance indicators:
Production speed: It is important to focus on sustainable and stable production speed, rather than peak values as advertised in promotional materials. Request suppliers to provide measured data or videos on your commonly used paper and bag types.
Applicable size range: Confirm that the device can be easily and quickly adjusted to the minimum and maximum size you need, especially the bottom width and height. Check the convenience and accuracy maintenance of the adjustment mechanism.
Paper adaptability: Clearly define the weight range and type of paper that the equipment can handle stably (especially difficult points such as laminated paper and high weight paper). Inquire about the type (standard, vacuum adsorption, etc.) and adjustment capability of the paper feeding system (Feida).
Accuracy and stability: The focus is on examining the accuracy of color matching (if printed), forming squareness, precision of adhesive position and amount, and adhesive strength of the handle. The rigidity of the equipment structure, the material and processing accuracy of key moving parts (like step belt/gear drive), and the progressiveness of the control system (such as the number of servo motors) are the basic guarantees. Require continuous testing for a long period of time (such as more than 4 hours).
Scrap rate: A low and stable scrap rate is the key to efficient production and cost reduction. Inquire about the typical scrap rate range and influencing factors under normal production conditions.
Key functional modules and configurations:
Paper feeding unit: High speed and stable paper feeding is the foundation. Vacuum adsorption Feida has better adaptability to thin paper and laminated paper. Is it equipped with a correction device?
Glue application system: glue type (dispensing, strip glue, spraying)? What type of adhesive is applicable? What is the precision of adhesive quantity control? Heating and insulation function (for hot melt adhesive)? Is it easy to clean and prevent dryness?
Forming unit: Is the forming principle reasonable and reliable? What are the mold materials (steel/copper/bakelite) and processing accuracy? Is it convenient and time-consuming to replace molds? This is the key to determining whether the bag type is standard.
Handle device (if required): applicable handle type? Rope/cardboard delivery mechanism? Adhesive method (hot pressing, ultrasonic)? Is the adhesive strength adjustable and measurable?
Counting stack output: a must-have for fully automated machines. Stacking neatness and counting accuracy? Output method (belt conveyor, hopper)?
Control system: Is the human-machine interface user-friendly? Is it convenient to set, store, and call parameters? Is the fault diagnosis function complete? Does it support remote monitoring/maintenance?
Maintainability and operability:
Version change time: What is the time required to change molds and adjust parameters when producing different sizes/bag shapes? This is crucial for small-scale and multi variety production. Modular design can greatly shorten the time for changing versions.
Maintenance convenience: Is the equipment easy to clean, lubricate, and perform daily inspections? Is it easy to purchase and replace key vulnerable parts? Is the structural design easy for maintenance personnel to access?
User friendliness: How about ergonomic design? Is the operation and debugging interface intuitive? What are the technical requirements for operators and debuggers?
4、 Fire Eye and Golden Eye: Supplier Evaluation and Selection
Equipment selection also involves choosing partners:
Technical strength and industry experience:
What type of bag type equipment does the supplier focus on? How many years have you accumulated in the industry?
Assess its R&D team, patented technology, and self-produced capabilities of core components (machining, electrical control).
Request to provide successful cases that are similar to your needs, preferably by visiting or contacting their clients for verification.
Equipment quality and craftsmanship:
On site testing! On site testing! On site testing! Important things are to be repeated for 3 times. Look at the equipment being assembled or the machines running in the factory.
Pay attention to details: thickness of frame steel, welding process, surface treatment (anti rust spraying); Brand and grade of key moving parts (guide rails, bearings, screws); Brands of electrical components (PLC, servo drives, sensors) (Siemens, Mitsubishi, Delta, etc.); Is the layout of cables standardized and neat.
Listen to the sound: Is the device running smoothly and at a low noise level? Is there any abnormal vibration or noise?
Hands on trial: Try adjusting the size, replacing simple components, and feel whether it is convenient and whether the design is user-friendly.
After sales service capability:
Service Network: Do you have localized service engineers? Response time commitment (such as 24/48 hour attendance)?
Spare parts supply: Are commonly used spare parts in stock? Is the price transparent and reasonable? How long is the procurement cycle?
Technical support: Is the installation and debugging, operation training, and maintenance training professional and in place? Do you provide long-term technical consultation?
Word of mouth survey: Understand the service reputation of the supplier through industry channels, especially in terms of fault handling efficiency and attitude.
Price and Payment Method:
Obtain a detailed itemized quotation, specifying equipment configuration, prices, shipping costs, installation fees, taxes, training fees, etc.
Compare the prices of different suppliers under the same configuration, but do not just aim for affordability. Comprehensively consider equipment performance, quality, service, and long-term operating costs.
Negotiate reasonable payment methods (such as deposit, payment for goods, acceptance payment, quality guarantee deposit) and delivery time.
5、 Avoiding pitfalls: Common pitfalls on the procurement road
The trap of "speed only theory": blindly pursuing the highest theoretical speed, ignoring practical stability, applicability, and efficiency of plate replacement, resulting in equipment being unable to perform as expected.
The trap of "low price temptation": being attracted by low quotes, purchasing equipment with shoddy workmanship, reduced configuration, and inferior core components, resulting in frequent failures, huge maintenance costs, and downtime losses.
The trap of "over configuration": purchasing high-end all-in-one models that far exceed actual needs, with idle functions, long investment payback periods, and occupying valuable funds.
Fuzzy configuration trap: Unclear descriptions of key component brands, models, and specifications in contracts or quotations leave room for suppliers to pass off inferior products as good in the future.
The trap of 'no way out for after-sales service': Trusting sales promises without carefully examining the supplier's service network and spare parts supply capabilities, resulting in equipment problems that are difficult to handle.
The trap of "ignoring machine testing": placing an order based solely on samples, videos, or verbal promises, without requiring strict and prolonged on-site production testing using one's own paper and bag type.
6、 Steady and far-reaching: Key action suggestions for you
Establish a cross departmental team: procurement, production, technology, and finance jointly participate in decision-making.
Write a detailed requirements specification: Formulate clear requirements (bag type, size, paper, production capacity, quality, etc.) into a written document as a benchmark for communication and comparison with suppliers.
Extensive research and in-depth communication: Contact multiple powerful suppliers, bring your requirements document to communicate, and request them to provide targeted solutions and quotations.
Strict on-site inspection and machine testing: Priority is given to inspecting factories and actual user sites. Persist in conducting sufficient production testing with your materials and requirements (at least 2-4 hours of continuous operation), testing speed, stability, scrap rate, plate replacement operation, etc.
Pay attention to contract details: clarify equipment specifications and configuration list, acceptance criteria, payment milestones, delivery time, after-sales service terms (response time, warranty scope, spare parts supply, training content), breach of contract liability, etc. All commitments are written into the contract!
Pay attention to installation, debugging, and training: reserve sufficient time to ensure that professional engineers from suppliers are in place. Operators and maintenance personnel must study diligently throughout the entire process and master core skills.
Choosing a paper bag machine is a systematic project, and the time and effort invested in the early stage will directly determine the production efficiency, product quality, and profitability in the coming years. Clear requirements are the cornerstone of precise selection, in-depth research is the armor to avoid risks, on-site verification is the discerning eye to clear the fog, and rigorous contracts are the shield to protect rights and interests. Instead of regretting when equipment failures occur frequently, production capacity is insufficient, and costs are out of control, it is better to take steps and plan before making decisions. I hope this detailed guide can help you accurately identify the true "wealth generating tool" that belongs to you in the complex market, avoid pitfalls, and stride forward!