Packaging bag cost accounting, let's talk about everyone's most concerned topic!

Many new customers always inquire about prices on the phone and website. After quoting, many customers will have questions: Where do your prices come from? What is the basis? Is it based on experience, or is it truly calculated based on needs? Or does the quality of your packaging have any advantages at this price?

Shunxingyuan Packaging would like to emphasize here: "Good flexible packaging must be from the customer's perspective, carefully produced, and win with quality." Shunxingyuan Packaging's goal is simple: to make every decision of the customer reasonable and well-founded!

1. Five unique advantages of Shunxingyuan Packaging:

Shunxingyuan has been professionally engaged in the packaging industry for 19 years. Focus leads to professionalism. Since its establishment, the company has always adhered to the tenet of "mutual cooperation, mutual benefit, and common development," constantly improving and strengthening its capabilities, and leading the flexible packaging industry. Shunxingyuan Packaging's customers are spread across many countries around the world, with well-known brands such as ADIDAS, AAPE, IZZUE, I.T, and Calvin Klein as deep cooperation partners.

Honest Material Selection: There must be no malicious deception of customers, arbitrary changes to film materials during the process, or cutting corners.

Reasonable Pricing: Shunxingyuan Packaging can provide customers with the most comprehensive and reasonable quotations based on different materials and processes.

Exquisite Printing: Shunxingyuan Packaging adheres to a meticulous style, with many professional masters with over 20 years of experience in color matching and printing, and professional quality inspectors to check the quality of the printing surface, ensuring that every detail of the packaging bag is exquisite and beautiful.

High Efficiency: Shunxingyuan Packaging is adept at coordinating the supply chain and has a complete process from order entry to finished product delivery, truly achieving high efficiency from raw material supply to finished product delivery, saving customers a lot of time costs.

Excellent Service: Shunxingyuan Packaging is good at capturing customer needs, and based on the principle of maximizing customer peace of mind, it saves costs as much as possible in material selection and controls every production link, aiming to improve product satisfaction from 99% to 100%.

2. Order

Take a new order received by the business department as an example. The customer ordered 200,000 three-side sealed food packaging bags with dimensions of 255mm × 190mm.

3. Order Analysis

After the salesperson receives the order, the price is confirmed, and then the raw and auxiliary materials are prepared according to the production and processing needs. After passing the inspection and acceptance by the quality inspection department, the production process of the food packaging bag is followed.

4. Product Pricing

The sales price of packaging bags is mainly composed of three parts: material cost, production loss, and enterprise profit margin, namely:

Flexible packaging product quotation = packaging material cost + production loss + enterprise profit margin (due to fluctuations in raw material prices at different times, only the calculation formula is given, and no specific numerical statistics are provided.)

1. Packaging Material Cost

① BOPP material cost

Unit price per square meter: unit price × density × thickness / 1000

Weight per square meter: per square meter × density × thickness

② Printing and processing cost

Full-color printing ink is calculated as 8g/㎡, and full-color printing with white backing is calculated as 128g/㎡.

Unit price per square meter: unit price × ink amount / 1000

Weight per square meter: per square meter × density × thickness

③ CPP material cost

Unit price per square meter: unit price × density × thickness / 1000

Weight per square meter: per square meter × density × thickness

④ Lamination processing cost

Cost of dry base adhesive amount = dry base adhesive amount × adhesive solid content price / 1000

Solvent cost = solvent amount × adhesive solvent price / 1000

2. Loss

Loss is related to the order quantity. The size of the three-side sealed bag in this case is 255mm × 190mm. According to the layout, the repeatable length in the horizontal direction is 190mm, and the number of horizontal rows is 2. A width of 10mm is left in the middle and on both sides, so the required film width is 790mm, and the plate width is 510mm. That is, 4 bags are printed per rotation of the printing plate. Therefore, the length of the film required for 200,000 bags is 25500m. Since the production process of three-side sealed bags is printing—lamination—bag making, no slitting is required.

① Printing loss

It is known that the machine trial loss for new orders of this production enterprise is 1500m, and the machine trial loss for old orders is 500m. In this example, it is calculated according to new orders, and the loss rate is 1500/(25500+1500) = 5.6%.

② Lamination loss

The specific lamination loss is approximately 1.5% for one lamination, 3% for two laminations, and 4.5% for three laminations. This case is a single lamination, so the loss is approximately 1.5%.

③ Bag making loss

In production, if the number of bags made is >50,000, the loss is approximately 1.5%, and if it is <50,000, the loss is approximately 2%. In this case, it is 200,000, so the loss is 1.5%.

④ Edge loss

According to the width of the three-side sealed bag, the film width required in production is 190 × 4 = 760mm, but the printing film width is 790mm, so the edge loss is 30/790 = 3.8%.

3. Profit Margin

When setting the sales price, the enterprise also needs to consider the cost of auxiliary materials used in production (such as paper cores, adhesive tapes, etc.), labor costs, water and electricity costs, management costs, transportation, and profit. According to the complexity of the bag processing technology, the enterprise generally adds a profit margin of 10%~40%. Since the structure of this bag is relatively simple, the profit margin can be set at 20%.

4. Sales Price

Based on the above analysis, the final composite film quotation is determined.

5. Raw Material Procurement and Inspection

Based on customer requirements and combined with the company's actual production, the performance requirements of raw materials used for food packaging bags, product packaging bags, etc., and the corresponding project testing methods and standards are formulated.

1. Raw and auxiliary material inspection

Testing of BOPP, CPP, ink, adhesive, and solvent is conducted according to relevant routine testing items for main raw and auxiliary materials, based on national standards, industry standards, and enterprise standards.

2. Printing Plate Production

Based on bag specifications and material requirements, the printing color number, plate perimeter, and plate factory are determined. Printing plates are produced by a professional plate-making company.

6. Product Production

1. Raw Material Requisition: Determine the amount of raw materials required based on order quantity, product specifications, layout, and the loss ratio of the lamination and bag-making processes.

2. Production Process: Determine the printing, lamination, and bag-making processes.

7. Semi-finished and Finished Product Performance Testing

Inspection items for printed semi-finished products: color, register error, dot gain, pattern layout, ink adhesion, and gloss.

Inspection items for laminated semi-finished products: appearance, initial adhesive strength, flatness of cross-section, and gloss.

Inspection items for finished bag-making products: length deviation, width deviation, sealing width deviation, bag pattern position deviation, gusset deviation, punching position deviation, tear notch position, appearance quality, and sealing quality.

Inspection items for finished bag-making products: tensile strength, elongation at break, peel strength of lamination, peel strength of sealing, pressure resistance, drop resistance, and quantity.

8. Packaging and Warehousing

Finished bags produced through printing, lamination, and bag-making processes are randomly inspected by the quality inspection department at a certain ratio. After passing inspection, the finished products are packaged according to process requirements, and the outer packaging bags are arranged and temporarily stored in the designated storage area. Ensure that the seals are flat and the appearance is good.

9. Common Misconceptions in Material Selection for Food Packaging Bags

1. Polyethylene film is not suitable for packaging food that is deep-fried in vegetable oil or contains vegetable oil.

In the actual extrusion or blown film production of PE (polyethylene) plastic film, in order to enhance or complement the properties of the film, high-pressure polyethylene, low-pressure polyethylene, and linear polyethylene are often used in a certain proportion. The film is named after the substance that accounts for the largest proportion. For example, milk packaging film contains more high-pressure polyethylene, so it is called high-pressure polyethylene film. Yogurt and convenience bag packaging films contain more low-pressure polyethylene, so they are called low-pressure polyethylene plastic films.

Although PE (polyethylene) fresh-keeping film has good air permeability (packaging fruits and vegetables has the effect of retaining moisture and releasing carbon dioxide), PE (polyethylene) film will quickly penetrate, swell, and discolor after contact with vegetable oil. If packaging food containing vegetable oil, it will not only greatly shorten the shelf life of the food, but also the "naphthalene" in the PE (polyethylene) film will leach into the vegetable oil after long-term contact, which is harmful to human health. Therefore, PE (polyethylene) film is not suitable for packaging fried food and food containing vegetable oil, nor is it suitable for packaging oily melon seeds, dried fruit seeds, and nut seeds.

2. PE plastic films with less than five layers of co-extrusion are not suitable for making dairy packaging.

Co-extruded PE (polyethylene) plastic film packaging. The currently popular milk packaging, dairy product packaging, soy sauce, and vinegar packaging are typical examples of co-extruded plastic film packaging. Transparent, unprinted vacuum or retort pouches are also co-extruded plastic film packaging. Although current milk packaging uses black and white co-extruded plastic film with white outside and black inside, it extends the shelf life. However, if a three-layer co-extruded plastic film is used, due to the lack of a barrier layer, it is rarely able to reach the shelf life indicated on the packaging.

Five-layer co-extruded plastic films with an added EVOH (ethylene/vinyl alcohol copolymer) barrier layer and plastic films with a coated PVA (polyvinyl alcohol) barrier layer can extend the shelf life, but the cost is higher. In today's market, which only has price competition, some companies therefore use two-layer or three-layer co-extruded black and white plastic films and PE films with symbolically applied barrier materials to package milk, dairy products, and soy sauce and vinegar. If the PE (polyethylene) film containing black color masterbatch directly contacts milk, dairy products, and soy sauce and vinegar, the inert carbon black pigment will penetrate (the packaged product will be contaminated). The plastic film with symbolically applied barrier material can withstand inspection and testing, but it does not play a barrier role and cannot guarantee the shelf life of the contents.

Many PE (polyethylene) convenience bags and roll-tear inner packaging bags on the market are thickened, but many bag manufacturers add a large amount of filler to reduce costs, resulting in poor transparency, poor opening properties, low strength, and strong odor. Although the bags are printed with environmental protection and food safety marks and words, they actually do not use degradable materials or environmentally friendly inks for printing, which not only increases production costs but also increases solvent residue, raising safety concerns.

3. DAL vacuum-aluminized film in plastic flexible packaging cannot replace Al metal aluminum foil.

Al metal aluminum foil has a bright metallic luster, is non-toxic and odorless, has excellent light-shielding properties, and a reflectivity of up to 95%. It is stable at high and low temperatures and does not expand or deform in the range of 73-371℃; it has good barrier properties, blocking gas, oxygen, moisture, and aroma, making it an excellent middle-layer base film for high-end packaging; it is widely used in high-end packaging and blister packaging of pharmaceuticals, moisture-proof and aroma-retaining paper for cigarettes, high-end packaging for chocolates, leak-proof packaging for daily necessities, sealing lids for instant noodle bowls, sealing labels for beer and champagne, paper/aluminum/plastic composite packaging for milk and dairy products and juices, high-end aroma-retaining packaging for food and condiments, retort packaging for cooked meat, roast chicken, roast duck, etc., and moisture-proof and anti-static packaging for integrated circuit boards, etc.

Vacuum-aluminized plastic film is a product where aluminum with a purity of 99.99% or higher is deposited onto plastic films such as BPET (biaxially oriented polyethylene terephthalate), BOPP (biaxially oriented polypropylene), PVC (polyvinyl chloride), CPP (cast polypropylene), and CPE (chlorinated polyethylene) using a vapor deposition method under vacuum conditions. The gas and oxygen barrier properties of the aluminized film primarily depend on the base film itself, not the aluminum layer, which serves only as a decorative element. However, BOPP, PVC, CPP, and CPE films do not have good barrier properties; therefore, vacuum-aluminized films made with these base materials cannot be used for vacuum packaging. Only plastic films with good barrier properties, either laminated or aluminized, can be used for vacuum packaging. BPET vacuum-aluminized film can only be used for vacuum packaging, not retort packaging. Using aluminized film as a cost-saving alternative to aluminum foil for packaging is incorrect.

The biggest advantage of aluminized packaging is its excellent decorative properties. Therefore, the design should be as open as possible to fully showcase the bright silver and the colorful effects after dyeing. Using poorly designed packaging patterns, such as those with full-coverage white ink or spot color printing on aluminized composite packaging, increases ink and solvent residue, reduces the bonding strength of the plastic composite film, and hinders printing speed, ultimately increasing packaging costs and failing to ensure that the food inside meets the shelf life indicated on the packaging.

In addition, although vacuum-aluminized plastic films have good mechanical properties, a smooth and bright aluminum surface, are resistant to pinholes, and have strong decorative properties, providing some gas barrier, light shielding, and shielding effects, they can compensate for the shortcomings of rolled aluminum foil, such as low strength, easy tearing, breakage during folding, susceptibility to pinholes, and poor acid and alkali resistance. However, the aluminum layer of vacuum-aluminized plastic films has poor water resistance and will peel off when wet, causing delamination of the composite packaging bag. Furthermore, the aluminum layer is too thin (only 400 Å); that is, only about 1 kg of high-purity aluminum is needed to coat 50,000 m² of plastic film. Its light shielding and shielding performance is far lower than that of rolled aluminum foil (pure aluminum foil), so aluminized film cannot replace rolled aluminum foil as a substrate in plastic composite packaging.

PET (polyester) film cannot replace PA (nylon) film for retort packaging.

The function of retort packaging is to kill bacteria in food through high-temperature sterilization during the retort process, thereby extending the shelf life of the food. Only by transferring the high temperature to the food inside the packaging can the bacteria be killed. PA (nylon) film has a high water vapor transmission rate, and aluminum foil is a good heat conductor. However, PET (polyester) film, with its excellent insulation and good gas barrier properties, has poor thermal conductivity and a very low water vapor transmission rate, which can prevent or reduce the introduction of retort temperatures. In addition, PET (polyester) film itself has high hardness and stiffness, making it difficult to remove air completely. Although it has excellent barrier properties, it weakens the sterilization effect of the retort process; therefore, PET (polyester) film is only suitable for vacuum packaging and cannot be used for retort packaging.

Using PET (polyester) film to replace PA (nylon) film for retort packaging or adding a four-layer retort packaging with PET (polyester) film can only reduce costs but does not achieve the sterilization effect and long shelf life of three-layer composite retort packaging with PA (nylon)/AL (aluminum foil)/CPP (cast polypropylene).

Paper-plastic composite film packaging is not necessarily environmentally friendly.

Paper-plastic composite film packaging is a composite packaging of paper and plastic, usually made using a composite processing technology that combines paper with cast PE (polyethylene) and PP (polypropylene) (dry lamination is more expensive). Paper-plastic packaging has better air permeability, but worse waterproofness and barrier properties than plastic packaging, so it is often used for packaging items that need to release and absorb moisture, such as the inner packaging of camphor tablets and moisture-absorbing agents (desiccants). Paper can only be heat-sealed into bags after being laminated with plastic, but the laminated plastic is difficult to recycle or naturally decompose. In addition, the raw material for paper is wood, and its large-scale use is a waste of natural resources. Therefore, it is unreasonable for some people to consider paper-plastic composite packaging to be more environmentally friendly than plastic packaging. The rationality of using paper-plastic composite packaging for melon seeds and dried fruits is also worth discussing.

Table of commonly used plastic flexible packaging materials