Glossary 101: Plastic Packaging Terminologies & Definitions

Ever struggled to understand terms used by your plastic packaging supplier? You’re not alone. Whilst there are occasions where unfortunately there is no alternative to a particular term, such terms cannot be easily avoided. Therefore, Blowplast has put together this valuable glossary to help customers navigate the complexities of plastic terminologies used in the plastic packaging industry. In addition to receiving a clear definition of these terms, you may utilise it to perhaps boost your understanding too. This is exactly what this guide aims to fulfill. 

Bottle- A plastic container with a narrow neck, used for storing liquids such as water, soda, juice, household cleaning products etc. Plastic bottles come in various shapes, sizes, and colours.

Blow Moulding – A process in which molten material is extruded into a parison. The parison is then clamped into a mould, and the air is blown into it to expand and shape it against the mould cavity. It’s used to manufacture hollow plastic parts, such as bottles, containers, and other hollow-shaped objects.

Cap- A type of closure used to seal the openings of containers to protect the contents inside from contamination, evaporation, or spillage. Plastic caps come in various shapes, sizes, colors, designs and materials to suit different types of containers.

Cavity- The upper half of a mould used in manufacturing processes, particularly injection molding and blow molding. Moulds are designated as a single cavity or multi-cavity.

Closures:  A general name for caps, lids, pump dispensers, and spray nozzles, used to seal the opening of a container.  They play a crucial role in preserving the contents of the container and preventing spillage, contamination, and deterioration.

Drop Test- A method used to assess the impact resistance of a plastic container by subjecting it to controlled drops from a specified height onto a hard surface. Drop testing measures the impact within which plastic containers (2ltrs and above) can withstand during handling, transportation, or use.

Label- A piece of material attached to a plastic packaging surface with contents of the container, branding, instructions, warnings, or other relevant details. Labels play a crucial role in conveying information to consumers and users about the product inside the container.

Lid- A type of plastic closure used to seal the opening of a container, such as a jar or bucket. Lids come in various shapes, sizes, and materials depending on the type of container and its intended use.

HDPE– An acronym forHigh-density polyethylene.  Due to its excellent strength, durability, chemical resistance, and low moisture absorption properties, HDPE is a popular choice for a wide range of applications across different industries such as edible oil, lubricants, cosmetics, agrochemicals, pharmaceuticals,  to name a few.

Injection Moulding – A moulding process in which, under pressure, melted plastic is injected into a mould cavity.

Injection Blow Moulding- A two-stage process used to produce hollow plastic containers. It combines elements of both injection moulding and blow moulding to create parts with precise dimensions, smooth finishes, and uniform wall thickness.

In Mould Labelling– A process used in plastic packaging manufacturing where a pre-printed label is placed into the mould cavity before plastic resin is injected.

Jar– A plastic container that is typically cylindrical or rectangular in shape with a wide mouth opening for storing solids such as food, cosmetics, personal care products, or household items.

Jerrycan– A plastic container for storing or transporting liquids such as petrol, water or chemicals. They usually have a rectangular or square shape with a handle on the top for easy carrying.

Masterbatch- Small pellets or granules used in plastic manufacturing to add different colours to plastic products during the manufacturing process.

Mould – A tool used to form the shape of the desired product in a repetitive manner.

Neck – The neck of a bottle is where a plastic closure is affixed by rotating until the bottle is sealed against the neck bead.

• Short-neck- Short-neck containers have a shorter neck compared to the body of the container. These containers often have a wide opening at the top, making them suitable for products that need to be easily accessed or dispensed, such as beverages, condiments, or personal care products like shampoo or lotion.
• Long-neck- Long-neck containers have a neck that extends higher compared to the body of the container. These containers have a narrower opening at the top. Long-neck containers are often used for products that require controlled dispensing, such as cooking oils, sauces, or industrial chemicals.

PET- An acronym for Polyethylene terephthalate.  It’s a clear, strong, and lightweight thermoplastic polymer resin that is widely used in various applications across different industries such as water, sauces, beverages, cosmetics etc.

PP- An acronym for Polypropylene. Bottles and containers made from polypropylene have a high melting point compared to other plastics and are widely used for food, pharmaceutical packaging, and others.

Preform – Serves as the precursor to the final plastic container and is shaped like a test tube with a threaded neck.  It’s an intermediate product used in the manufacturing process of PET plastic containers by heating through a method called injection stretch blow molding.

Screen printing- A process where ink is transferred through a mesh screen onto a plastic surface. Screen printing on plastic containers is commonly used for branding, labelling, and adding decorative elements to cosmetics, food, beverages, and household plastic containers.

Sleeves- A type of packaging component that covers a plastic container. Some of the common types of sleeves include;

• Shrink Sleeves: They are plastic films that are placed around a container and then heated to shrink tightly around the item, conforming to its shape.
• Decorative Sleeves: Decorative sleeves are used to enhance the aesthetic appeal of a product. They are printed with vibrant graphics, patterns, or promotional messages to attract consumer attention and differentiate the product on the shelf.
  

Stickers-Stickers are adhesive labels or tags applied to the surface of plastic containers. The following are some of the common uses of stickers in plastic packaging;

• Product Information: To provide essential product information such as product name, brand logo, product features, and usage instructions.
• Tamper-Evident Seals: To provide evidence of tampering or unauthorized opening of the plastic packaging.
• Barcodes and QR Codes: To encode information such as product identification or pricing.
• Certifications and Labels: Display certifications, quality marks, or eco-friendly labels to communicate compliance with industry standards, environmental certifications, or regulatory requirements.

Wadds- They are liners made of materials like foil or foam, which are used to create a tamper-evident seal on plastic containers, particularly bottles and jars with screw caps.

• Induction/Aluminium Wadd: They consist of a layer of aluminium foil bonded to a heat-sealable polymer layer and placed inside the closure and sealed onto the container using electromagnetic induction heating.
• PU/Foam Wadd: They are made from foam materials such as polyurethane (PU). PU wadds are commonly used for sealing dry or liquid products in plastic containers.
  

If you would like to discuss any aspect of plastic packaging, Blowplast can help. Contact us at +254 722 438 477 / +254 733 438 47.

Written by,

Angela Kaberia
Marketing Manager