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What Manufacturing Process are Shampoo Bottles Dade by

What manufacturing process are shampoo bottles made by

Everyone uses shampoo, but most people may only pay attention to the shampoo products. However, some of them may also keep an eye on the plastic container holding the shampoo. They may wonder what the manufacturing process of plastic containers is. In this article, you can better understand the plastic container holding the shampoo and its manufacturing process.

 

PET bottle

PET material is safe, has no plasticizer, and is sufficiently flexible, with a high transparency grade. Many colors are available for PET bottles, like transparent, semi-transparent, and solid colors. Some brands prefer the PET bottle to be strong and hard to squeeze, while some products need to be squeezable, such as hair conditioners. How is PET material a safe material? You can see many drinking bottles using PET material; it is good evidence. But PET material cannot be put into a high-temperature container; its heat-resistant temperature is about 70℃, so PET bottles can only be stored at room temperature or cold beverages. For shampoo, there is no worry to use PET bottle at all.

 

PE bottle

PE plastic is one of the most commonly used materials for shampoo; its natural color is opaque and can hold some large-capacity shampoo products. Therefore, PE bottles can resist the erosion of many chemical products; they are widely used for storing cosmetics, detergents, and more. Moreover, PE bottles are cheaper than PET bottles and incompatible with plasticizers. It can also be used as a material for food preservation, so it is non-toxic.

 

PP bottle

PP material is milky white and translucent, which looks like the milky white of body milk, not pure white or transparent.PP bottles are soft and squeezable, but the transparency is not as good as PET bottles, so some opaque shampoo bottles also prefer to use PP bottles, such as hair dye products and hydrogen peroxides. For colored PP bottles, it is made by adding a color master, which means adding the color master in mixing material. PP plastic products are safe and non-toxic, too, and there is no plasticizer.

The above paragraphs have explained the three main plastic materials for shampoo bottles: PET, PP, and PP. The following is the manufacturing process of these three types of plastic materials.

The manufacturing process of PET bottles and PP bottles typically have two methods:

one is a step process, and the other is a two-step process. Now, many PET bottles are produced by a two-step process: Use the injection machine to cast a preform(like a tube), then put this bottle preform into a bottle blowing mold, blow it to match the bottle mold perfectly, and the preform tube will be expanded into the mold shape, take it off and make it cool down.

 

The ingredients of shampoo are mainly used for increasing the glossiness of hair and to sterilize, clean, and foam, which will not be harmful to PE bottles, and PE material is not soluble in water, with low water absorption, it is very safe to use PE bottle too.

PE bottles are usually manufactured by hollow extrusion blow molding process, which is to melt and plasticize the PE material by the extruder, extrude the tubular parison, and then place the parison in the blow molding mold, blow it with compressed air, and cool the PE bottle of the exact shape of the mold obtained.

Plastic Bottle Manufacturing Process: Step by Step Introduction

Plastic Bottle Manufacturing Process: Step by Step Introduction

Cosmetic plastic bottle raw materials must comply with national standards, and many plastic bottle raw materials are of food-grade quality, especially medicinal bottles that must meet medical and health requirements. Common raw materials for plastic bottles include polyethylene terephthalate (PET), polypropylene (PP), acrylonitrile butadiene styrene (ABS), and polyethylene (PE).

What are plastic bottles made of?

As mentioned above, plastic bottles are typically made from PET, PP, ABS, and PE. PE is often referred to as LDPE (Low-Density Polyethylene) or HDPE (High-Density Polyethylene). We will explore below how each material affects the bottle manufacturing process.

PET (Polyethylene Terephthalate)

PET bottles are usually transparent, but after adding color masterbatch, they can be made opaque or in rich colors. PET bottles are available in various grades, such as daily chemical series of shampoo bottles, facial personal care products like eye cream bottles, toner bottles, and medicinal bottles, etc. They are characterized by high temperature resistance, high strength, low density, chemical corrosion resistance, no heavy metals, non-toxicity, odorlessness, and good weather resistance.

PP (Polypropylene)

PP bottles are generally translucent, and this semi-transparency gives them a certain degree of light-shielding, suitable for light-sensitive products. Furthermore, the semi-transparent packaging of PP bottles has some transparent characteristics, allowing consumers to see the product inside, especially some foods that can be attractive. In addition, PP bottles are temperature-resistant, suitable for hot canned packaging of some beverages and foods. They have a lower density and are stronger, harder, and more heat-resistant than high-density polyethylene but become brittle at low temperatures, are not wear-resistant, and are prone to aging. However, they can be modified with appropriate additives to reach the performance level of HDPE.

AS (Styrene-acrylonitrile Copolymer)

It is a hard, transparent material, brittle (produces a clear sound when knocked), with good transparency, and can be in direct contact with cosmetics and food. It can be formed by injection molding, extrusion, blow molding, and vacuum forming, commonly used as the material for ordinary lotion bottles, airless pump bottles, and also for small-capacity cream jars, presenting a transparent appearance, such as cream jars, powder boxes, eyeshadow boxes.

LDPE/HDPE (Low- and High-Density Polyethylene)

Polyethylene is divided into low-density polyethylene LDPE and high-density polyethylene HDPE. LDPE is suitable for injection-molded products and blow-molded hollow products. LDPE bottles are more flexible than HDPE bottles, suitable for packaging items that need to be squeezed. Commonly seen in the fields of shampoo, shower gel, etc. High-density polyethylene HDPE has strong resistance to heat, cold, and outstanding chemical physical properties, primarily used for medicinal plastic bottles, suitable for packaging different types of items like liquids, powders, etc. Commonly seen in the fields of oil products, cleaners, etc.

How are plastic bottles manufactured?

The following process are widely used in the manufacture of plastic bottle, they are blow molding, injection molding, extrusion molding and compression molding.

Blow Molding

This method involves placing thermoplastic pellets into a plastifying machine to make plastic pellets, which are then fed into a mold. Under the action of heating and blowing, hollow containers and bottles are formed. Blow molding is suitable for manufacturing hollow containers and bottles, with the advantages of fast production speed and low cost, but the disadvantage is that the product walls are thin and easily deformed.

Injection Molding

Injection molding involves injecting heated thermoplastic material into a mold, where it is pressurized, cooled, and solidified. This method is suitable for manufacturing various plastic products, such as plastic cups, plastic barrels, etc. The advantages are high forming precision and good product appearance, but the disadvantages include a long production line, high cost, and relatively long production time.

Extrusion Molding

The extrusion method involves heating and softening thermoplastic material, then extruding it through an extrusion machine to form a columnar shape, followed by cutting and shaping into products. This method is suitable for manufacturing plastic pipes, window frames, etc., with the advantages of high production efficiency and low cost, but the disadvantages are high surface roughness and low precision of finished products.

Compression Molding

Compression molding involves heating and softening acrylic sheets, then cutting, shaping, and bonding to make products. This method is suitable for manufacturing transparent plastic products, such as cosmetic bottles, display frames, etc. The advantages are high-quality products, good transparency, and high gloss, but the relative cost is high, and the production cycle is longer.

Summary

In summary, the manufacturing of plastic bottles is a complex process that utilizes various raw materials like PET, PP, ABS, and PE, each offering distinct properties to the final product. The production methods—blow molding, injection molding, extrusion molding, and compression molding—each play a crucial role in shaping the bottles, catering to different requirements in terms of flexibility, transparency, and durability. These processes ensure that the bottles meet the stringent standards required for their use in industries such as cosmetics, food, and medicine, emphasizing safety, functionality, and aesthetic appeal.

A Detailed Guide to Selecting Plastic Materials for Beauty Products

A Detailed Guide to Selecting Plastic Materials for Beauty Products

In the vast domain of the cosmetics industry, product varieties are extensive, primarily divided into 20 core categories, covering comprehensive needs from daily care to professional beauty.

Cosmetic product categories will be listed as follows:

  • Creams, Lotions, Liquids, Gels, and Oils (for Hands, Face, Feet, etc.): This category encompasses facial, body, and hand/foot care products such as moisturizers, anti-aging lotions, cleansing gels, whitening serums, and nourishing oils. The aim is to hydrate, nourish, cleanse, or address specific skin concerns.
  • Face Masks (excluding chemical peeling products): Face masks vary from sheet masks, clay masks, gel masks to overnight masks, catering to different skin needs like deep cleansing, moisturizing, firming, and brightening.
  • Color Fixatives: Products used to maintain hair color post-dyeing, prevent fading, and prolong the coloration effect. This also includes products for setting makeup such as sprays or liquids.
  • Powders, After-bath Powders, Sanitary Powders, etc.: Includes loose powder, compact powder, and body powder, used for oil control, makeup setting, and keeping the body dry.
  • Cleansing Soaps, Deodorant Soaps, etc.: Specifically refers to soap products for body cleansing, including handmade soap, antibacterial soap, whitening soap, etc.
  • Perfumes, Toilet Waters, Colognes: Encompasses a variety of fragrances, including gentler colognes, used to enhance personal allure and add fragrance.
  • Bathing and Showering Products (Bath Salts, Bubble Baths, Bath Oils, Gels, etc.): Includes products used for enhancing the cleansing effect and relaxation during bathing, such as bath salts for stimulating blood circulation and bath oils for nourishing the skin.
  • Depilatories: Comprises products like hair removal creams, waxes, and strips, used for removing unwanted body hair.
  • Deodorants and Antiperspirants: Products designed to control body odor and reduce sweating, such as deodorant sprays, roll-ons, and sticks.
  • Hair Products: Covers a wide range of products including hair dyes and bleaches, curling, straightening and styling agents, cleansing products (liquids, powders, shampoos), conditioning products (liquids, creams, oils), and hair beautification products (liquids, shine enhancers, oils), aimed at beautifying, protecting, and maintaining healthy hair.
  • Shaving Products (Creams, Foams, Liquids, etc.): Includes products for pre-shave preparation and post-shave care, such as shaving cream, shaving foam, and aftershave.
  • Facial and Eye Makeup and Remover Products: Comprises various foundation products, eyeshadows, eyeliners, mascaras, makeup removers, and cleansing waters, used for makeup application and removal.
  • Lip Products: Includes lipsticks, lip glosses, lip liners, and lip balms, offering both beautification and protection.
  • Dental and Oral Care Products: Includes toothpaste, tooth powder, mouthwash, etc., used for cleaning teeth and maintaining oral hygiene.
  • Nail Care and Makeup Products: Comprises nail polish, nail strengtheners, cuticle creams, etc., used for beautifying and protecting nails.
  • External Personal Hygiene Products: Refers to external products for personal hygiene protection, such as feminine hygiene pads, antiseptic liquids, etc.
  • Sunbathing Products: Includes sunscreen, after-sun repair products, etc., used to protect the skin from UV damage.
  • Self-tanning Products (Non-sun-induced Skin Darkening Products): Comprises self-tanning creams, darkening lotions, etc., used for achieving a tanned skin effect without sun exposure.
  • Skin Whitening Products: Includes whitening creams, whitening serums, etc., used for improving skin tone and reducing pigmentation.
  • Anti-wrinkle Products: Comprises anti-wrinkle creams, serums, etc., used for reducing fine lines and wrinkles, restoring skin elasticity.

Plastic Packaging Materials for Cosmetic Products:

  1. Creams, Lotions, Liquids, Gels, and Oils:
    • PE (Polyethylene): Suitable for soft tube packaging of lotions, liquids, and gels due to its flexibility and ease of squeezing.
    • PET (Polyethylene Terephthalate): Commonly used for oil products in bottles, showcasing the product’s natural color with good chemical stability.
  2. Face Masks:
    • PET: Applicable for bottle packaging of mask serums and the outer plastic seal of mask packaging, providing good sealing and transparent display.
    • PE: Used for individual mask packaging bags, given its moisture resistance and flexibility.
  3. Color Fixatives:
    • PET: Suitable for spray bottles of color fixatives, benefiting from its clear appearance and pressure resistance, ideal for spray products.
  4. Powders, After-bath Powders, Sanitary Powders, etc.:
    • PP (Polypropylene): Commonly used for compact powder cases due to its rigidity and heat resistance, accommodating accessories like powder puffs.
  5. Cleansing Soaps, Deodorant Soaps, etc.:
    • PE: Suitable for the packaging film of solid soaps, given its waterproof properties and cost-effectiveness.
  6. Perfumes, Toilet Waters, Colognes:
    • Acrylic Boxes: Luxury perfume packaging often uses acrylic for its high transparency and quality feel, enhancing product luxury.
  7. Bathing and Showering Products:
    • PET: Used for large bottle packaging of shower gels and bath oils, displaying liquid color and texture.
    • PE: Suitable for shampoo and shower gel soft tube packaging, facilitating easy squeezing.
  8. Depilatories:
    • PE, PP: Used for containers of hair removal creams and waxes, considering product viscosity and convenience of use.
  9. Deodorants and Antiperspirants:
    • PP: Often used for solid deodorant casings, due to its good chemical resistance, suitable for products in direct contact with skin.
  10. Hair Products:
    • PET: Suitable for shampoo and conditioner bottles, chosen for its transparency and pressure resistance.
    • PE: Used for hair dye and hair mask soft tube packaging, allowing easy control of product quantity by squeezing.
  11. Shaving Products:
    • PE, PP: Used for shaving foam or cream, especially in squeeze packaging, for convenience during use.
  12. Facial and Eye Makeup and Remover Products:
    • PET: Applicable for makeup remover bottles, showcasing product purity and transparency.
    • PP: Used for eyeshadow palettes and foundation liquid packaging, given its wear resistance and rigidity.
  13. Lip Products:
    • ABS (Acrylonitrile Butadiene Styrene): Used for lipstick cases due to its high strength and smooth surface, suitable for precision mold forming.
  14. Dental and Oral Care Products:
    • PET, PE: Commonly used for toothpaste and mouthwash bottles or tubes, chosen for their sealing properties and ease of squeezing.
  15. Nail Care and Makeup Products:
    • PET: Used for nail polish bottles, favored for its transparency, allowing users to easily choose colors.
  16. External Personal Hygiene Products:
    • PE: Suitable for the packaging of sanitary pads and liners, considering moisture resistance and hygienic factors.
  17. Sunbathing Products:
    • PET, PE: Used for sunscreen and after-sun repair product bottles or tubes, for portability and use convenience.
  18. Self-tanning Products:
    • PET: Used for self-tanning cream bottles, chosen for its transparency and chemical resistance.
  19. Skin Whitening Products:
    • PE, PP: Used for whitening serum and cream containers, facilitating product stability protection.
  20. Anti-wrinkle Products:
    • PET, PP: Commonly used for anti-wrinkle serum and cream bottles or pump bottles, to maintain the stability of active ingredients.

In summary, choosing the right plastic material for cosmetic packaging is crucial, balancing product protection, consumer experience, and sustainability. Materials like PE, PET, and PP cater to diverse needs across cosmetic categories, ensuring safety and enhancing brand value in the competitive beauty market.

What are the different methods of extrusion blow molding?

What are the different methods of extrusion blow molding?

What are their advantages and disadvantages?

Based on the different ways of discharging in extrusion blow molding, it can be divided into two molding processes: direct extrusion blow molding and extrusion-storage-pressure blow molding.

Direct extrusion blow molding. This method directly extrudes a parison from the extruder.

Its advantages include: simple structure of molding equipment and mold, less investment, low production cost of products, easy operation, suitable for thin-walled, complex-shaped, and irregular products, and suitable for blow molding of various plastics.

It is currently the basic molding method commonly adopted by small enterprises in our country. Its disadvantage is: since the extrusion speed of the parison is slow, a larger parison will sag due to its own weight, causing the parison wall to be uneven and produce internal stress, thereby leading to uneven thickness of the blow molded product.

Therefore, this method is suitable for the production of small containers. As for the problem of post-processing of plastic parts to remove flash, as the level of automation increases, manual operations to remove flash are decreasing, and product quality is getting higher.

Extrusion-storage-pressure blow molding. Its production process involves extruding the plastic melt into a storage cylinder. When the material in the storage cylinder reaches a certain amount, it is pressed out by a hydraulic cylinder in a measured and pressurized way, and a hollow container consistent with the shape of the mold cavity wall is obtained through the machine head.

The parisons produced by this process have the following advantages:

Firstly, using the storage device, larger containers can be produced with smaller equipment. For example, a medium 65 extruder can produce a 50L barrel.

Secondly, the plastic melt is rapidly pressed out by the pressure system, allowing for the required length of the parison to be obtained in a short time, greatly reducing the sagging phenomenon of the parison, thereby ensuring product wall thickness uniformity.

The disadvantages are: due to the addition of a storage and pressure system, the equipment structure is complex. The design and maintenance of the hydraulic system bring some difficulties to production, and the equipment investment is larger than direct extrusion blow molding process.

How to Choose a High-Quality Airless Bottle Supplier in the Market?

How to Choose a High-Quality Airless Bottle Supplier in the Market?

With the widespread application of airless bottles in the skincare industry, selecting a high-quality supplier is crucial for ensuring product quality and successful marketing. In China, a global manufacturing hub, there are numerous airless bottle suppliers. This article aims to guide you on how to choose a high-quality airless bottle supplier in the market and provides key considerations.

Supplier Reputation and Credibility:

Examine the supplier’s history and experience to understand their time and performance in the industry.

Research customer reviews and feedback about the supplier to gauge their satisfaction with the products and services.

Verify if the supplier has necessary certifications and qualifications, such as ISO certification.

Product Quality and Innovation:

Request samples from the supplier to assess the quality and performance of their products.

Investigate if the supplier consistently engages in product innovation and research to adapt to market changes and demands.

Understand the supplier’s quality control processes and standards, including material selection and production techniques.

Production Capacity and Timely Delivery:

Inquire about the supplier’s production capacity and scale to ensure they can meet your large-volume orders.

Understand the supplier’s production facilities and technological capabilities to ensure they can guarantee the quality and quantity of products.

Discuss delivery schedules and deadlines with the supplier to ensure they can deliver the products on time.

Customer Service and Support:

A good supplier should provide excellent customer service and support to ensure a smooth collaboration. Consider the following aspects of the supplier’s customer service:

Understand the supplier’s customer support channels and response time to ensure timely assistance and support when needed.

Communicate with the supplier and observe their communication skills and professionalism to ensure a harmonious cooperation.

When selecting a high-quality airless bottle supplier, Canvard Packaging is a noteworthy option. With over 10 years of collaboration with clients, they demonstrate long-term stability and reliability in the industry. Here are the advantages and features of Canvard Packaging as a supplier:

Long-term Collaboration: Canvard Packaging has established over 10 years of collaboration with clients, indicating their reliability and credibility in the supplier market. This long-term collaboration showcases Canvard Packaging’s ability to provide high-quality products and excellent services.

Stable and High-Quality Packaging Containers: Canvard Packaging offers stable and high-quality packaging containers to meet client requirements. Their products are carefully designed and manufactured to ensure quality and performance that align with industry standards. Canvard Packaging may provide various types of airless bottles to cater to different client needs.

After-Sales Service Guarantee: Canvard Packaging provides satisfactory after-sales service for any quality issues. Clients can rely on Canvard Packaging for timely after-sales support and solutions if they encounter quality problems while using Canvard Packaging’s airless bottles. This commitment to after-sales service highlights Canvard Packaging’s focus on customer satisfaction.

Customer Support and Communication: Canvard Packaging values customer support and communication. They offer multiple communication channels to ensure effective communication and prompt responses with clients. Whether clients encounter any issues or require assistance during the ordering process, Canvard Packaging will provide professional support and solutions.

Can cosmetics still be used if they are left in a car?

Can cosmetics still be used if they are left in a car?

If cosmetics are left in a car for too long, it is not recommended to use them because skincare products are sealed in containers. When placed in a closed car space where the temperature rises, some components of the cosmetics can undergo changes.

Skincare products should ideally be stored in a cool and dry place under normal pressure and humidity. After use, it is important to tightly close the bottle cap. Additionally, it is not advisable to store cosmetics in the bathroom or outdoors, as the high temperature and humidity in these environments can cause mold growth and affect the safety of the products.

What can be done to remedy skincare products affected by high temperatures?

There is no way to remedy skincare products once they have been affected by high temperatures. Therefore, it is important to store skincare products in a place away from direct sunlight and at an appropriate temperature.

Although skincare products undergo high-temperature stages during development, it is still recommended not to store them in high-temperature areas, regardless of whether the packaging has been opened or not. Especially in summer, when purchasing skincare products, some delivery boxes are often exposed to direct sunlight, which can affect the active ingredients inside the products, particularly for serums and similar items. Furthermore, some people tend to store all their skincare and cosmetic products on the bathroom vanity, but this is not advisable because the steam from showers can penetrate the products and also affect their effectiveness.

Please follow Canvard Packaging as we regularly update our knowledge about product usage. Thank you for your attention!

Canvard Packaging specializes in the manufacturing and selling of cosmetic packaging such as airless pump bottles, foam pump bottles, cream jars, PET bottles, and acrylic bottles.

Sealing layer in the aluminum foil sealing liner

The heat sealing property of the sealing layer:

The primary condition for aluminum foil sealing liner to fuse and seal with the bottle mouth is that the sealing layer of the aluminum foil gasket must have heat sealing property. The heat sealing property of plastic refers to the thermal bonding property that the plastic has with itself or other types of plastic after being heated to a molten state.

The commonly used films with heat sealing layers are: PE (including HDPE, LLDPE, LDPE, etc.), CPP, modified PET, and other polymer resins (such as hot melt adhesive).aluminum foil seal

Correspondence between sealing layer materials and bottle materials:

When using aluminum foil sealing gaskets, it is important to note that the material used for the sealing layer must correspond to the bottle material. The corresponding relationship between them is as follows: Sealing layer material Bottle material PE heat sealing film LDPE, HDPE CPP heat sealing film PP Modified PET heat sealing film PET Hot melt adhesive LDPE, HDPE, PP, PET, glass, ceramics

Note: Aluminum foil gaskets with hot melt adhesive as the sealing layer can seal bottles of various materials, but the sealed object cannot be volatile or corrosive. If it is a liquid substance, it cannot be sealed in a hot filling environment.

Tear ability of sealing layer materials:

Due to the continuous demand for user-friendly packaging design, the sealing layer materials of aluminum foil sealing gaskets have also been continuously improved. In recent years, heat sealing material manufacturers have developed easy-to-tear films of different materials, which makes it so that the bottle mouth does not leave any aluminum foil or sealing layer material when the aluminum foil gasket is torn open after sealing. Examples of such easy-to-tear heat sealing films include CPP (PE) easy-to-tear heat sealing film, PET easy-to-tear heat sealing film, and other high-polymer material heat films. However, these easy-to-tear heat sealing films can usually only package products that are non-volatile and solvent-free.

A good packaging container for refill——airless pump bottles

A good packaging container for refill-airless pump bottles

Airless pump packaging bottles are indeed useful. They effectively prevent air and bacteria from entering the bottle. By removing the air inside the airless pump packaging bottle, the exposed surface area of the product is reduced, which slows down the oxidation process and extends the product’s shelf life.

One of the main advantages of airless pump packaging bottles is that they prevent product evaporation. For cosmetics or skincare products with volatile ingredients, such as essential oils or perfumes, airless pump packaging bottles can effectively reduce the loss of these components. Additionally, the airless pump environment prevents oxygen from affecting the product, thereby maintaining its original texture and efficacy and avoiding texture changes or diminished effectiveness.

Another advantage of airless pump packaging bottles is that they allow for the transfer of large volumes of cosmetics or skincare products into smaller containers. This is particularly useful for carrying personal care products during travel or outings. You can transfer the desired amount into smaller bottles, making them convenient to carry and use without having to carry the entire large bottle. This not only saves space but also reduces the weight of your luggage.

Furthermore, airless pump packaging bottles help reduce waste. By controlling the amount used each time, you can better manage the product and avoid excessive usage that leads to waste. The airless pump environment also reduces the product’s exposure to air, lowering the risk of bacterial contamination and minimizing the possibility of pollution.

Airless pump packaging bottles are practical and beneficial for refilling lotion/perfume/serum/liquid. They protect the quality and efficacy of products, extend shelf life, and provide convenient portability and usability. Whether for travel convenience or waste reduction, airless pump packaging bottles are worth considering.

PET bottle blow molding production process

PET blow-molded bottles can be divided into two categories: one is pressurized bottles, such as bottles filled with carbonated drinks; the other is unpressurized bottles, such as bottles filled with water, tea, oil, and other beverages. Tea beverage bottles are modified PET bottles or composite bottles of PET and thermoplastic aromatic polyester blended with polyethylene naphthalate (PEN), which belong to the hot bottles category and can withstand temperatures above 80℃. Water bottles belong to the cold bottles category and have no requirement for heat resistance. The molding process for hot and cold bottles is similar. Today, we will mainly discuss the molding process of pressurized beverage bottles in cold bottles.

1, Equipment

With the continuous advancement of technology and the scale of production, the automation level of PET blow molding machines has become increasingly higher, and the production efficiency has also increased. The production capacity of equipment has been continuously improved, from producing thousands of bottles per hour in the past to producing tens of thousands of bottles per hour now. The operation has also developed from the previous manual button operation to the current full computer control, greatly reducing the difficulty of process operation and increasing the stability of the process.

2, Blow-molding process

The important factors affecting the PET bottle blow-molding process include the preform, heating, pre-blowing, mold, and environment, etc.

3, Preform

When preparing blow-molded bottles, PET chips are first injection molded into preforms, which require that the proportion of recycled materials for secondary use should not be too high (less than 5%), the number of recycling times should not exceed two times, and the molecular weight and viscosity should not be too low (molecular weight 31,000-50,000, intrinsic viscosity 0.78-0.85 cm3/g). The injection-molded preforms need to be stored for more than 48 hours before use. Preforms that have not been used after heating must be stored for more than 48 hours before being reheated for use. The storage time of preforms cannot exceed six months.

The quality of preforms depends largely on the quality of PET materials. Materials that are easy to blow and shape should be selected, and a reasonable preform molding process should be developed. Experiments have shown that preforms made from PET materials with the same viscosity, imported raw materials are easier to blow and shape than domestic materials, and preforms from the same batch, but with different production dates, may also have significant differences in blow molding process. The quality of the preform determines the difficulty of the blow-molding process, and the requirements for the preform are purity, transparency, no impurities, no off-color, and appropriate injection point length and peripheral halo.

4, Heating

The preform is heated in a heating oven, the temperature of which is manually set and automatically adjusted. Far-infrared lamps in the oven radiate the preform with far-infrared rays, and the bottom fan circulates heat in the oven, making the temperature inside the oven uniform. The preform moves forward in the oven while rotating, making the preform wall evenly heated.

The arrangement of the lamps in the oven is generally in the shape of a “zone” from top to bottom, with more lamps at both ends and fewer in the middle. The oven temperature is controlled by the number of lamps opened, the overall temperature setting, the oven power, and the heating ratio of each section. The opening of the lamps should be adjusted in combination with the pre-blowing bottle.

To make the oven work better, it is important to adjust the height and cooling plate properly. If the adjustment is not appropriate, defects such as swollen bottle mouths.

The production process of pharmaceutical plastic bottle caps

The production and processing process of pharmaceutical plastic bottle caps is similar to the requirements of the bottle body, except that the main raw material for the bottle body is blow molding grade, while the main raw material for the bottle cap is injection molding grade. The production process of pharmaceutical plastic bottle caps is injection molding.

The main process of this technology is:

Firstly, material addition. The material mixture is mainly transported to the injection molding machine hopper by pipelines. After the machine is opened, the material in the hopper enters the feeding barrel, completing the process of feeding the machine.

Secondly, plasticization is the process of heating the plastic material mixture that enters the feeding barrel into a flowable state with good plasticity. The requirement is that the plastic should reach the specified forming temperature before entering the mold cavity, and provide a sufficient amount of molten plastic within the specified time.

Thirdly, injection. The plasticized melt is injected into the mold under the pushing pressure of the screw (injection process). When the molten material enters the injection mold cavity, it needs to pass through the nozzle, main (branch) runner, and gate, and the resistance is high. The injection pressure loss is 30%-70%, so the process requires sufficient injection pressure to ensure complete filling. Then comes the molding stage, which includes four steps: mold release, compaction, backflow, and gate solidification. The plastic melt injected into the mold cavity is cooled and shaped into a plastic cap.

Fourthly, cooling and demolding. It mainly refers to the stage from the complete freezing of the plastic at the gate to the stage where the cap is released from the mold. Demolding can be achieved through strong demolding and rotary demolding.