Table of Contents
Chapter 1: Understanding honeycomb paper bags
1.1 What is a honeycomb paper bag?
A honeycomb paper bag is made by bonding three layers: kraft paper, honeycomb paper, and kraft paper again, with honeycomb paper as the primary material. With the growing environmental consciousness, honeycomb paper bags are emerging as a new star in the express delivery and logistics industry, gradually replacing many plastic products due to their eco-friendly and biodegradable nature. These bags feature a hexagonal cell structure similar to a honeycomb, providing lightweight, durable, and eco-friendly packaging solutions for industries such as shipping, logistics, and e-commerce.
1.2 What are the materials of honeycomb paper bags?
1.2.1 Honeycomb paper
Honeycomb paper, also known as honeycomb packaging paper or honeycomb kraft paper, is a type of cushioning protective material made by die-cutting kraft paper into a mesh-like structure that can be expanded into a honeycomb pattern. It is used as an eco-friendly alternative to plastic-based materials like bubble wrap or foam in protective packaging, suitable for shipping, cross-border e-commerce, courier transport, and product packaging, providing strong protection for goods. The paper is initially flat after die-cutting from kraft paper but expands into a honeycomb pattern when used or made into bags.
Honeycomb paper must be made from the long fibers of coniferous trees to achieve high tensile strength, recyclability, biodegradability, and environmental protection. After stretching, honeycomb paper forms a three-dimensional structure without the need for any adhesive, making it convenient to use. Precision roll cutting of honeycomb paper can increase its size by approximately 1.4-1.6 times after stretching, saving material costs and providing cushioning protection.
For honeycomb paper used in mailbags, the standard raw material is kraft paper with a weight of 40-60 GSM. Using materials with weights that are too low or too high can increase the difficulty of production and reduce productivity in both honeycomb paper manufacturing and mailbag production.
1.2.2 Kraft paper
The surface paper and liner paper used in honeycomb paper mailbags are typically made from the same material, primarily natural kraft paper.
Kraft paper is a type of packaging material known for its high strength and usually comes in a light brown color. It can also be semi-bleached or fully bleached, ranging in shades from light brown to cream or white, with a weight of 80-120 g/m2. Kraft paper has a tear length generally exceeding 6000m and exhibits excellent tear resistance, bursting strength, and dynamic strength. It is commonly supplied in roll form but can also be in sheet form. Kraft paper is manufactured from sulfate coniferous wood pulp through pulping and papermaking on a long net paper machine. It finds applications in various industries such as cement bags, envelope paper, adhesive tape backing, asphalt paper, cable protection paper, insulation paper, and more.
Kraft paper typically retains its natural brown color and is well-suited for making bags and packaging paper. Depending on its characteristics and intended use, kraft paper is classified into different types, including natural kraft paper, white kraft paper, matte kraft paper, glossy kraft paper, red kraft paper, two-color kraft paper, among others. Natural and white kraft paper are commonly used varieties.
Dual adhesive paper can also serve as surface paper, but whether it’s surface paper or liner paper, it should not exceed 150 GSM (grams per square meter) in weight.
1.3 What are the uses of honeycomb paper bags?
Electronic product packaging: Electronics such as smartphones, tablets, and laptops require adequate protection due to their fragility.
Household items packaging: Household goods like furniture, tableware, and kitchen utensils need to be protected from damage and scratches during transport.
Artwork packaging: Whether it’s paintings, sculptures, or glass items, honeycomb paper bags provide a secure cushioning environment.
Courier and logistics: Honeycomb paper bags used for clothing, food items, accessories, documents, books, electronic components, and other products in courier services effectively reduce shock and impact, thus lowering accident rates and complaint rates.
Industrial component packaging: The customizable nature of honeycomb paper bags allows for tailored protection solutions for components of various sizes and shapes. Moreover, their reusability helps in reducing packaging costs.
1.4 What are the benefits of honeycomb paper bags?
Minimal material consumption, lightweight: Honeycomb structures use minimal materials yet create the largest and most durable configurations. Scientifically proven to enhance compressive strength by 100 times due to their arch-like geometry, honeycomb paper bags achieve maximum volume and strength with minimal material usage.
Excellent cushioning and shock absorption: The combination of outer kraft paper and inner paper honeycomb structure provides honeycomb paper envelopes with exceptional cushioning and protective properties.
Good thermal and sound insulation: The closed-cell honeycomb core filled with air offers excellent thermal and sound insulation capabilities.
Special processing for unique functions: Honeycomb paper, being entirely paper-based, can undergo special processing for waterproofing, flame retardancy, mold resistance, and enhanced rigidity.
No fumigation required for export, quarantine-free: Honeycomb paper undergoes disinfection and sterilization during production through infrared or microwave drying, eliminating the need for fumigation during export and making it suitable for packaging export products.
Convenient and customizable: Honeycomb paper bags are easy to seal without additional tools, available in various sizes, and can be customized for printing content as per specific requirements.
1.5 Packaging and storing
To ensure optimal cushioning performance of honeycomb paper bags, they must not be subjected to heavy pressure. If the internal honeycomb paper is flattened, it greatly reduces the protective capabilities for the enclosed products. Therefore, as standard practice, we pack the mail bags within five-layer BC corrugated paper boxes for shipment to customers.
Environmental sustainability is a key advantage of honeycomb paper bags. Our raw materials consist of eco-friendly kraft paper or virgin wood pulp honeycomb paper. Considering environmental concerns and transit duration, we typically package every 10-50 bags into plastic sleeves based on size and thickness, before placing them into boxes.
Store the paper bags in a dry, well-ventilated, and light-shielded environment to prevent them from becoming damp, deformed, or faded. Avoid exposing the bags to direct sunlight or excessively humid conditions.
When stacking mail bags, ensure the bottom of each bag remains flat and free from pressure to prevent creasing or damage. Utilizing cardboard or wooden boards as separators can minimize friction and potential damage between the bags.
For efficient organization, it’s advisable to store mail bags of different sizes and types separately to facilitate easy retrieval.
Furthermore, it’s important to monitor the storage duration of the mail bags. Extended storage periods may lead to material aging, deformation, or color fading. Therefore, regular inspection and replacement of the bags are recommended to uphold their quality and appearance.
Chapter 2: Eco-friendliness of honeycomb paper bags
2.1 Are honeycomb paper bags eco-friendly?
Honeycomb paper boasts excellent environmental performance.
Not only is it biodegradable, thus reducing environmental pollution, but it’s also crafted from the long fibers of trees, making it a kraft paper material. This type of kraft paper has high tensile strength, good elongation, elasticity, and resistance to tearing and compression. Therefore, honeycomb paper stands as an excellent alternative to plastic packaging materials.
Moreover, the recyclability of honeycomb paper is a key aspect of its environmental friendliness. It can be recycled and reused, reducing material consumption, cutting costs, and enhancing aesthetics. This quality makes honeycomb paper widely applicable in the packaging industry, particularly for items requiring protection during transit, thereby minimizing environmental impact.
Additionally, honeycomb kraft paper is made from 100% FSC-certified materials, lacks coatings, and is entirely recyclable.
2.2 Certifications from authorities
Our raw material suppliers have obtained certification from renowned international authoritative institutions.
Furthermore, there are several global certification bodies such as SGS, BV, TUV, etc., that offer certification services for paper products. These organizations typically enjoy broad international recognition and possess extensive certification expertise, enabling them to provide professional certification services to businesses.
We are committed to continually learning and understanding relevant certification standards and requirements, aiming to enhance both product quality and management standards.
Chapter 3: Performance of honeycomb paper bags
3.1 Physical Performance
Stretch comparison of honeycomb paper
Physical strength index of honeycomb paper bags
3.2 Chemical properties of honeycomb paper bags
3.2.1 Main components of kraft paper
Kraft paper is a specialized type of paper made from natural plant fibers. It undergoes multiple processing steps including pulping, blending, pressing, drying, and waxing. The primary components of kraft paper are cellulose and hemicellulose, with cellulose content reaching over 80%.
3.2.2 Other material components of kraft paper
In addition to cellulose and hemicellulose, kraft paper also contains various additives, including:
Wax: Used to enhance the tear resistance and water resistance of kraft paper.
Binders: Enhance the abrasion resistance and tensile strength of kraft paper.
Waterproofing agents: Improve the waterproof properties of kraft paper, increasing its reliability.
Moisture-proof agents: Help maintain the relative humidity of kraft paper, preventing it from becoming damp.
Dyes: Provide kraft paper with certain colors and aesthetics.
Chapter 4: Prices of honeycomb paper bags
4.1 Cost control strategies
As an environmentally friendly product, if the surface paper requires design content, it’s best to utilize single-color printing whenever possible. Since most surface papers are made of kraft paper, colorful designs may not be fully represented.
Because it’s a composite paper bag, once printing is completed, the assembly line generally forms the bags in a single process. Therefore, there’s a relatively high requirement for the initial quantity, and bulk purchasing can help mitigate the costs associated with the initial quantity.
The basis weight of the surface paper and inner paper should ideally not exceed 150 GSM (Grams per Square Meter), typically ranging from 60 to 100 GSM. For honeycomb web paper, the basis weight usually ranges from 40 to 80 GSM. Exceeding these ranges can significantly impact the speed of the production line and increase processing costs.
Larger order quantities generally result in lower unit prices. Additionally, when considering order quantity and transportation warehousing, it’s important to optimize space utilization. Honeycomb mail bags have a large volume but are lightweight, so maximizing space usage is essential. Batch production exceeding the capacity of a full container load can effectively reduce freight costs.
Chapter 5: Customization of honeycomb paper bags
5.1 Different types of honeycomb paper bags
Kraft paper honeycomb bags: These are classified based on the color of the kraft paper used for the surface, such as natural kraft paper honeycomb mail bags and white kraft paper honeycomb mail bags.
Double adhesive paper honeycomb bags: These bags feature double adhesive paper for the surface, while the inner paper is primarily kraft paper unless there are specific requirements.
Moisture-resistant kraft paper honeycomb bags: These bags are made from honeycomb paper treated with a flexible liquid and kraft paper soaked in waterproof adhesive.
5.2 What design files should be provided
PSD (Photoshop Document): PSD is a file format specific to Adobe Photoshop. It is a layered format that allows extensive editing and manipulation of images. While PSD files can be used for printing, they are typically reserved for graphics or images requiring advanced editing.
EPS (Encapsulated PostScript): EPS format is suitable for storing vector graphics and is supported by most vector drawing and page layout software. When opening EPS files containing vector graphics created in other applications in Photoshop, the software rasterizes the file, converting vector graphics into bitmap images.
AI (Adobe Illustrator): AI is a vector-based file format designed for Adobe Illustrator. It is commonly used for printing logos, graphics, and other designs. AI files can be scaled up or down without loss of quality and support transparency and other special effects.
PDF (Portable Document Format): PDF is a cross-platform file format that encapsulates text, fonts, graphics, images, colors, layout, and printing-related parameters into a single file.
Chapter 6: How are honeycomb paper bags made
6.1 Production process
Surface paper printing: If the surface paper contains content, it needs to be printed first according to customer requirements and documents, ensuring accurate colors and positioning.
Material preparation: According to the process requirements, the types, colors, basis weights, and widths of the surface paper, honeycomb paper, and inner paper must be carefully verified.
Composite processing: When the three types of paper pass through the composite line segment, white latex is sprayed at the edges 1-3cm (0.4-1.2 inches, adjusting the glue amount according to the size of the mail bag). Then, the edges are rolled to better bond the three types of paper together, improving the strength and durability of the mail bag.
Cutting and bag making: The compressed materials are cut into specific shapes according to certain specifications to make the bags. This step ensures that the size and shape of the bags meet the requirements, with bag cutting being completed.
Next, a long strip of hot melt adhesive is applied at the sealing edge of the mail bag, and a release paper is attached. The width and amount of hot melt adhesive are designed to adhere to environmental principles while ensuring strong adhesion and controlling usage.
Inspection and packaging: The final step is to inspect and package the composite bags. Inspection includes aspects such as the size, strength, and sealing of the mail bag to ensure that the quality meets requirements. Additionally, the bags need to be packaged to ensure safe transportation to the customer.
6.2 About moisture-resistant honeycomb paper bags
Preparation steps:
-Die-cut the kraft paper into naturally honeycomb-shaped paper cores, soak them in a flexible agent solution for 20-40 minutes, remove, and air dry to obtain honeycomb-shaped core paper.
-Soak the kraft paper in waterproof adhesive, remove, dry to obtain surface paper.
-Apply adhesive to both sides of the honeycomb paper core, then laminate the surface paper on both sides of the honeycomb paper core to obtain honeycomb composite kraft paper.
-Prepare the honeycomb composite kraft paper into honeycomb paper bags.
Preparation of flexible agent solution:
-Dissolve polylactic acid in chloroform to obtain a polylactic acid solution, add graft monomers and initiators, reflux at 50-60°C for 4-6 hours, cool, add polyethylene glycol, heat to 70-80°C, recover chloroform to obtain a viscous polylactic acid.
-Mix carboxymethyl cellulose, Tween, water, and xanthan gum evenly, stir to a viscous state to obtain a mixed solution.
-Mix the polylactic acid emulsion, mixed solution, and ethanol evenly to obtain a flexible agent solution.
-The waterproof adhesive is prepared by mixing waterproof acrylic resin, ethylene glycol ether acetate, and solvent in a weight ratio of (9-13):(4-8):1.
-The adhesive can be corn starch glue, white latex, cyclodextrin glue, or graft copolymerized starch resin glue.
Characteristics of moisture-proof honeycomb paper bags:
Performance:
The honeycomb kraft paper bags prepared using the above technology exhibit good moisture resistance. They maintain excellent tensile strength, stiffness, compression resistance, tear resistance, and cushioning and shock absorption properties in humid environments. Additionally, this process has low cost, the products are recyclable, and environmentally friendly.
Improvement:
Untreated kraft paper lacks flexibility, resulting in poor tear resistance, workability, and tensile strength. In this process, thorough impregnation of the flexible agent into the paper core improves tear resistance, tensile strength, and workability of the honeycomb core paper, enabling repeated use. Preferably, the flexible agent solution can be water-based polyurethane adhesive or water-based acrylic adhesive.
Waterproofing effect:
The waterproof adhesive imparts moisture resistance to the kraft paper, providing good cushioning, fracture resistance, and vibration isolation capabilities in natural honeycomb paper cores in humid environments. However, its tear resistance, tensile strength, and workability are poor, limiting its reusability.
6.2 Printing consideration
Printing considerations for kraft paper used in honeycomb paper bags are crucial due to the material’s unique characteristics. Firstly, achieving vibrant printing colors on kraft paper poses challenges compared to coated papers, as its inherent dark brown color affects ink replication. Using vibrant ink colors is recommended to compensate for this limitation and ensure desired color effects.
Additionally, kraft paper’s rough surface and poor smoothness require increased printing pressure to achieve satisfactory results. For higher printing quality standards, applying varnish oil for two base coats can help fill and cover the paper’s rough surface before printing, resulting in improved glossiness and ink thickness uniformity.
Lastly, paper slack between the printing press and folding machine can occur due to various factors, including low tension of the roll paper and improper settings of the folding machine components. Addressing these considerations ensures optimal printing quality and performance in honeycomb paper mail bag production.
6.3 Turnaround
The current production capacity of one assembly line is 80 units per minute. However, depending on the size and material, the speed may gradually decrease to 40-70 units per minute. We ensure high-quality delivery within the agreed-upon timeframe according to customer needs.
Chapter 7: Quality inspection
7.1 Importance of quality inspection
Quality inspection is crucial for several reasons:
Packaging that prioritizes cushioning and shock absorption indicates that the products themselves are fragile. Therefore, drop tests and pressure tests for mail bags are essential to ensure their ability to protect the contents during transit.
Conventional honeycomb paper bags typically use thin kraft paper made from low basis weight wood pulp, making them susceptible to punctures. Therefore, careful examination of the appearance is necessary to detect any defects or weaknesses that could compromise the bag’s integrity.
The cushioning performance of mail bags primarily relies on the honeycomb paper in the middle. However, the raw material of honeycomb paper is flat, so it’s essential to ensure thorough expansion during production, from a flat state to an expanded three-dimensional state.
7.2 How many samples will be checked
7.3 Quality inspection standards
Visual inspection:
The appearance of the paper bag should be flat, smooth, and free from obvious wrinkles, folds, or damage.
The sealing of the paper bag should be tight, without any leaks, and should have clear line imprints.
The patterns, text, and colors on the paper bag should be clear, neat, and free from obvious misprints, omissions, or color deviations.
Printed markings on the paper bag should be clear, easy to identify, and include information such as product name, production date, shelf life, manufacturer name, etc.
Dimensional inspection:
The dimensions of the paper bag should meet the design requirements, with errors in length, width, and height within the specified range.
The handles of the paper bag should meet the design requirements, being of appropriate size and easy to grip.
Load-bearing inspection:
The load-bearing capacity of the paper bag should meet the design requirements, able to withstand the specified weight of items.
During load-bearing testing, the paper bag should not exhibit any signs of rupture or damage.
Compression resistance inspection:
The paper bag should remain flat and intact when subjected to certain pressure.
During compression resistance testing, the paper bag should be able to withstand the specified pressure value and maintain structural stability.
Tear resistance inspection:
The paper bag should not exhibit significant tearing when subjected to tearing force.
During tear resistance testing, the paper bag should be tested according to the specified method to ensure it has a certain level of tear resistance.
Microbial printing inspection:
The paper bag should meet hygiene standards, with no pathogenic microorganisms present.
During microbial testing, the paper bag should be tested according to the specified method to ensure its hygiene quality.
Composition inspection:
The main components of the paper bag should be environmentally friendly paper materials.
During composition testing, chemical analysis should be conducted to ensure that the paper bag does not contain any toxic or harmful substances.
Printing quality inspection:
The printing quality on the paper bag should meet the requirements, with bright colors and high clarity.
During printing quality inspection, the clarity of the printing content and the correctness of the patterns and text should be checked.
7.4 Who does quality inspection for you
During the production process, self-inspections are conducted regularly by the captain, operators, and other personnel, either every 10 minutes or every 1000 units. On-site QC sampling inspections occur at each stage of the process. Additionally, workshop patrols include regular and quantitative sampling inspections. Upon entry into the warehouse, finished products undergo QC sampling inspections. During shipment, personnel responsible for loading, QC, and business documentation supervise inspections. Third-party inspection agencies provide testing and inspection reports as well.
7.5 Common issues and solutions
One common issue arises during printing, where blurred edges and discontinuous lines occur. The solution involves conducting pre-printing hanging and humidification treatment for the kraft paper to improve print quality.
Another prevalent issue relates to composite strength, which manifests in two ways: first, ensuring the honeycomb paper is fully sandwiched in the middle during the three-layer composite process with tight sealing around, and second, ensuring the bonding of the paper bag sides remains intact. Solutions include selecting appropriate adhesives and conducting thorough experimental testing on adhesive quantity, bonding strength, and drying time.
Furthermore, cutting problems may arise, leading to uneven and jagged edges. To address this, regular replacement of the cutting blade and thorough checking for any looseness in the fixed cutting mechanism is recommended.
Chapter 8: Development trends
With the continuous increase in market demand, the application scope of honeycomb paper bags is also expanding. They are not only widely used in the e-commerce logistics field but also gradually penetrating into basic needs sectors such as daily chemical products, consumer electronics, agricultural and sideline products, and food. While the overall operational status of the paper packaging industry remains relatively good, many paper packaging enterprises still face challenges such as severe product homogenization and shrinking market scale. However, the emergence of honeycomb paper bags provides these enterprises with new development opportunities.
Currently, the structure of honeycomb paper bags is relatively simple, primarily adhering to the concept of environmental protection and cost reduction. Moreover, since it is still in the early stages of development, the variety of types is limited. However, as honeycomb paper and composite methods mature and develop, the variety is bound to become more diverse.
Chapter 9: Conclusion
In summary, the emergence and application of honeycomb paper bags represent an ongoing process of innovation and refinement. It combines the achievements of scientific research with environmental protection concepts, making it an ideal choice for modern express packaging. With technological advancements and market changes, it is believed that honeycomb paper envelopes will continue to leverage their advantages in future development, making greater contributions to the environmental protection cause and the development of e-commerce logistics industry.
