Square Bottom Open Mouth Paper-Plastic Composite Bag

1. Product Introduction

1.1 Industry Pain Points

Nowadays, the packaging of industrial powder and granular materials is plagued by four prominent problems, which greatly cut down corporate production efficiency and raise warehousing and logistics costs. Firstly, common packaging bags feature poor moisture resistance without compact protective structures. Chemical powders and food additives readily absorb moisture from the air, resulting in caking, deterioration and scrapped goods, which leads to high material wastage. Secondly, traditional bags have no shaped square base. Once filled with materials, they turn limp and distorted and cannot stand upright. They tend to topple and collapse during stacking, leading to extremely low utilization rates of pallets and shipping containers and higher logistics expenditure. Thirdly, regular bags come with uneven, non-standard openings that cannot match fully automatic filling machines. They only support manual filling, which causes frequent material spilling and leakage, low productivity and severe dust pollution in workshops. Fourthly, low-end composite bags adopt simple bonding techniques with weak adhesion between paper and plastic layers. Delamination, cracking and bag breakage often occur after long-distance transportation and multi-layer stacking, bringing massive transportation losses and numerous after-sales troubles.

1.2 Product Solutions

Our square bottom open mouth paper-plastic composite bag is tailor-made to solve the above packaging drawbacks. It adopts a double-layer protective structure: high-strength kraft paper as the outer layer and integrated laminated moisture-proof plastic film as the inner layer. Boasting great airtightness, dustproof and moistureproof performance, it effectively blocks water vapor and dust intrusion and prevents materials from caking and deteriorating due to moisture absorption. With an integrally mechanically molded square flat bottom, the bag forms a neat three-dimensional shape after loading goods and owns excellent self-supporting performance. It can be stacked neatly in multiple layers, greatly boosting the space utilization of warehouses and containers and saving your warehousing and logistics expenses. The standard full open top is flat and dimensionally unified, compatible with manual, semi-automatic and fully automatic powder filling production lines. Materials can be fed smoothly without machine jamming or spilling. Manufactured via high-temperature and high-pressure thermal lamination technology, the paper and plastic layers are tightly bonded together, featuring strong tensile and crack resistance without delamination under extrusion. Custom high-definition printing is available as well. Balancing practicality, durability and brand display value, this bag is widely used for packing chemical powders, food additives, building dry powders, feed pellets and other materials.

2. Product Technical Parameters

Product Name: Square Bottom Open Mouth Paper-Plastic Composite Bag Material Structure: Outer layer: 80-180g natural color / white kraft paper; Inner layer: high-density PE moisture-proof plastic film (PP woven reinforcement layer can be customized) Conventional Load Capacity: 10kg, 20kg, 25kg, 50kg; non-standard sizes and load-bearing capacities are customizable Production Technology: High-temperature high-pressure thermal lamination, automatic square bottom forming, hot melt sealing bottom, double-line reinforced sewing Core Performance: Moisture-proof, dust-proof, leakage-proof, tear-resistant, puncture-resistant, stacking-resistant, resistant to bumps during long-distance transportation Stacking Performance: Can be stably stacked for 8 to 10 layers under full load without deformation or collapse Printing Technology: Eco-friendly water-based flexographic printing, high-definition color registration, wear-resistant, fade-proof and odor-free Applicable Equipment: Manual filling machines, semi-automatic filling machines, fully automatic quantitative powder filling production lines Applicable Industries: Fine chemicals, food additives, dry powder building materials, livestock and poultry feed, new energy powders, inorganic salt particles Implemented Standards: GB/T 8946-2018, national food packaging safety standard, SGS international environmental protection testing standard

3. Product Advantages

Composite Technology

Ordinary counterparts: Adopt low-temperature cold lamination and ordinary adhesive. Uneven glue layers easily cause foaming and delamination, and the bags fail quickly in humid environments. Our upgraded bags: Integrated high-temperature and high-pressure thermal lamination enables deep fusion of paper and plastic materials. No hollowing or degumming occurs; the bags are moisture-resistant and tensile-resistant and maintain stable performance for long-term use.

Moisture Resistance & Sealing Performance

Ordinary counterparts: Thin inner film and large gaps at the bottom allow water vapor to penetrate easily, causing powder caking and deterioration. Our upgraded bags: Thickened dense moisture-proof film matched with hot-melt seamless bottom sealing achieves full closed protection, perfectly suitable for maritime transportation and humid warehouse storage conditions.

Bag Shape Stability

Ordinary counterparts: Manually folded bottoms deliver poor shaping effect. Bags turn soft and skewed after filling and cannot stand alone, prone to tipping and collapsing when stacked. Our upgraded bags: Automatically integrally molded square bottoms ensure even stress and regular shaping. The bags stand firmly and can be stacked tidily to save space.

Equipment Adaptability

Ordinary counterparts: Roughly cut uneven openings lead to machine jamming, deviation and material spilling during automatic filling, resulting in low production output. Our upgraded bags: CNC precision cutting creates standard flat openings compatible with all types of filling equipment; zero jamming and zero material spilling during mass production.

Raw Material Quality

Ordinary counterparts: Marked gram weights are falsified, recycled materials are mixed into production. Poor load-bearing capacity makes bags easy to tear and break under heavy-load transportation. Our upgraded bags: Brand-new virgin kraft paper and moisture-proof film are adopted with accurate labeled gram weights. Woven reinforcement layers are optional, leading to an extremely low damage rate.

Printing Effect

Ordinary counterparts: Inferior ink leads to blurry printed patterns, ghosting and color fading, presenting shabby appearance and damaging brand image. Our upgraded bags: Food-grade eco-friendly ink is used for precise high-definition overprinting. The printed surface resists abrasion and sunlight exposure without fading or ink peeling after long-term storage.

Customization Service

Ordinary counterparts: Only fixed specifications are available, with high minimum order quantities, long production cycles and no support for small trial orders. Our upgraded bags: Full-range personalized customization covering specifications, materials, printing and production processes. Flexible MOQ is offered, and rush orders are acceptable.

4. Company Profile & Strength

Founding Time & Industry Experience: Established in 2007, Yishuo Packaging Products Co., Ltd. has been deeply engaged in the paper-plastic composite industrial packaging sector for 19 years. We focus on the R&D and mass production of square bottom open bags, valve bags and customized packaging for export. We are proficient in domestic industrial standards and export compliance regulations of various countries, and possess abundant practical experience in developing customized packaging solutions for powder and granular materials.

Factory Scale: Covering a total area of 6,000 square meters, our standardized modern production base consists of a dust-free production workshop, precision quality inspection laboratory, constant-temperature raw material warehouse, finished goods storage area and exclusive delivery sorting zone. Standardized functional divisions realize closed-loop integrated operation covering production, quality inspection, warehousing and delivery.

R&D Team: We employ 18 professional packaging R&D engineers and 12 senior process technicians. They devote themselves to raw material upgrading, eco-friendly process optimization and non-standard customized scheme development, continuously upgrading product performance to meet stringent application scenarios including high-end chemical production, food export and cross-border maritime transportation.

Production Lines & Annual Output: We are equipped with 15 intelligent automatic production lines, including paper-plastic composite lines, intelligent square bottom bag making lines, high-definition color printing lines and automatic sewing sealing lines with full automatic operation. Our stable daily output reaches 100,000 bags, and the annual total output exceeds 40 million bags. We are capable of fulfilling large-volume bulk procurement orders, annual framework cooperation orders and full-container export orders with sufficient supply capacity.

Customization Experience: We provide one-stop customized packaging services for domestic and overseas brand owners, trading companies and manufacturers. In accordance with customers' material characteristics, load-bearing requirements, equipment matching demands, brand VI systems and export regulations of target countries, we conduct independent design, layout proofing and mass production to deliver exclusive solutions. We have served multiple listed enterprises and leading cross-border trading companies.

Certifications: Our company holds a full set of authoritative qualifications including ISO9001 Quality Management System Certification and Export Commodity Quality Inspection Certificate. All products comply with domestic sales standards and global export requirements.

Core Partners: Our long-term cooperative clients span fine chemicals, food additives, dry powder building materials, livestock feed, new energy materials and other industries, including numerous domestic listed enterprises, large industrial and trading groups, well-known food raw material manufacturers and cross-border trading companies, featuring high customer repurchase rates and stable cooperation.

5. Qualification Certificates

(High-definition photos of certificates can be inserted here)

ISO9001 Quality Management System Certification, Certificate No.: QMS-20250209158

Export Product Quality Inspection Qualification Certificate, Certificate No.: CCIC20250518092

6. Exhibition Activities, Quality Inspection System, Production Technology, Manufacturing Process and Supply Capacity

6.1 Brand Exhibition Activities

We participate in top domestic and international packaging exhibitions all year round, including the Canton Fair, Shanghai International Packaging & Printing Expo, Yiwu Packaging Industry Exhibition and Southeast Asia Cross-border Packaging Exhibition. Through exhibitions, we keep updated on cutting-edge global packaging technologies, latest environmental standards and market trends to continuously optimize our product portfolio and customized service system. Meanwhile, we showcase our factory strength, core products and customization capabilities to global purchasers, expand domestic and overseas sales channels and maintain our forward-looking competitiveness in the industry.

6.2 Full-Range Quality Inspection System

We set up an independent quality inspection department and professional testing laboratory furnished with complete precision testing equipment, such as tensile testers, airtightness testers, moisture penetration testers, stacking compression testers, ink adhesion testers and tear resistance testers. We implement a three-tier inspection mechanism: sampling inspection for incoming raw materials, patrol inspection during production and full inspection for finished products. Every batch of goods is comprehensively tested for paper gram weight, composite peeling strength, sealing moisture resistance, bottom load-bearing capacity, printing fastness and tear resistance. All production procedures are traceable, and the qualified rate of finished products remains above 99.8%, ensuring no defective goods are delivered to customers.

6.3 Advantages of Core Production Technology

We abandon outdated traditional processes including low-temperature cold lamination and simple glue bonding, and adopt a new generation of constant-temperature high-pressure thermal lamination technology matched with eco-friendly residue-free water-based adhesive. The paper and plastic layers are bonded tightly and evenly without bubbles or hollow gaps, resistant to high temperature and humidity and free from delamination after long-term storage. The bag bottom adopts automatic hot-melt integrated folding and sealing technology to achieve seamless sealing against dust and leakage, completely solving the problems of bottom powder leakage and cracking. The bag opening is processed by CNC precision cutting plus edge reinforcement to be flat, wear-resistant and burr-free. The whole production process applies eco-friendly water-based flexographic printing with no peculiar smell, no color fading and no pollution, meeting food-grade safety standards and international export environmental requirements.

6.4 Standard Closed-Loop Production Process

Raw material incoming inspection → Raw material specification debugging → Automatic constant-temperature composite molding → Constant-temperature standing for performance stabilization → Intelligent integrated square bottom sealing → Precision cutting and trimming → Custom pattern printing → Double-line reinforced side sewing → Air tightness and compression resistance test → Manual detailed sorting → Standardized warehousing → Sampling inspection before delivery. Twelve closed-loop standard procedures are strictly implemented at every stage. Full mechanized standardized mass production guarantees consistent stable quality across all batches.

6.5 Stable and Powerful Supply Capacity

We build a 10,000-ton constant-temperature raw material storage warehouse, which stores sufficient core materials all year round, including kraft paper, moisture-proof film, eco-friendly printing ink and sewing accessories. This effectively avoids delivery delays caused by raw material shortages, price hikes and stock breaks. Fifteen intelligent production lines operate in shifts around the clock to ensure adequate and stable supply. Standard specifications are always in stock for same-day order placement and shipment. Custom orders can be scheduled for priority rush production. We maintain long-term in-depth cooperation with leading domestic logistics providers and international freight forwarders. Domestically, we provide parcel delivery, less-than-truckload and full-truck transportation covering the whole country. For export business, we offer full-container and less-than-container sea transportation. We guarantee uninterrupted supply all year round without delivery delays and accept long-term annual strategic cooperation orders.

7. Customer Cases

Case 1: Cooperation with Fine Chemical Industry

We have long-term customized 25kg and 50kg dedicated powder packaging bags for fine chemical manufacturers located in Jiangsu, Shandong, Zhejiang and other provinces. Our moisture-proof, leak-proof and compression-resistant bags perfectly match automatic filling assembly lines, effectively solving customers' key problems including powder caking due to moisture absorption, material leakage during transportation and stacking collapse. Our annual supply volume exceeds 2.6 million bags with stable in-depth cooperation lasting for years.

Case 2: Cooperation with Food Additive Industry

We supply food-grade compliant packaging to numerous domestic food ingredient and food additive manufacturers. The raw materials are non-toxic, odorless and eco-friendly, having passed food contact safety tests with excellent dust and moisture resistance. Customizable brand logos, product parameters and traceability codes are available with high compliance. The bags are widely used for warehousing, transportation and terminal circulation of food powder raw materials.

Case 3: Export Cooperation with Overseas Clients

We undertake long-term export orders from Southeast Asia, the Middle East, Africa, South America and other overseas regions. We customize eco-friendly raw materials, English printed layouts and compliant parameters in accordance with the import regulations of destination countries, and provide complete documents including SGS reports, commodity inspection certificates and system certification files. The bags are adaptable to high-humidity maritime transportation and long-distance bumpy transit. Our annual export volume exceeds 1.8 million bags with an extremely high repurchase rate among overseas buyers.

Case 4: Cooperation with Building Material & Livestock Husbandry Industry

We develop heavy-duty reinforced packaging bags for dry mortar, putty powder, feed pellets and mineral particle manufacturers. With excellent tear resistance, high load-bearing capacity and stable stacking performance, our bags greatly reduce material damage and wastage during transportation, helping enterprises effectively cut packaging and logistics costs and satisfy packaging demands for large-scale industrial production.

8. Frequently Asked Questions

Q1: What is your minimum order quantity? Do you support small-batch customization? A: The MOQ for standard blank in-stock bags is 1000 pieces for small-batch purchases. The MOQ for customized bags with logo printing, special sizes or thickened materials is 3000 pieces. Long-term cooperative customers can enjoy flexible MOQ policies. We accept small trial orders, pilot orders and large centralized procurement orders.

Q2: Can you provide samples? Are samples free of charge? A: We offer 3-10 pieces of standard blank samples free of charge; customers only need to bear the courier shipping fee. Free proofing is available for customized printed bags, special-process bags and non-standard size bags. The proofing fee will be fully refunded once bulk orders are confirmed. We support customers to conduct machine adaptation tests and quality comparison tests with our samples.

Q3: How long is the order delivery cycle? Can you arrange rush production? A: In-stock orders will be shipped within 24 to 48 hours. Ordinary customized orders take 3-5 working days for production. Large-volume orders, complex-process orders and export customized orders require 7-10 working days. Rush orders are acceptable; we will arrange priority production to shorten the delivery period.

Q4: Do you support OEM and ODM customization? What items can be customized? A: We fully support OEM processing and in-depth ODM customization. Customizable items include dimension specifications, kraft paper gram weight, thickness of moisture-proof film, woven reinforcement layers, color logos, Chinese & English texts, product parameters, anti-counterfeit marks and special sealing processes. We can tailor exclusive packaging solutions one-on-one according to your material features and application scenarios.

Q5: What logistics options do you offer? What is your after-sales policy? A: Domestically, we provide express delivery, less-than-truckload logistics and full-truck delivery covering the whole nation with stable transit time. For export orders, sea, air and land transportation are available, and we can assist you in preparing complete customs declaration and commodity inspection documents. Finished bags are double packed with woven bags and cartons to prevent abrasion damage during transit. Any damaged or defective goods caused by our production quality problems will be reissued free of charge with comprehensive after-sales service guaranteed.

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