3 Things You Need to Know About Plastic Resins

3 Things You Need to Know About Plastic Resins

We are often surrounded by plastics, also known as plastic resins, in our world today. Plastic is popular and overwhelmingly used due to the fact that their properties and design technologies provide your customers with advantages beyond any other materials.

Plastic resins are not any one material, but rather they are a family of related materials with various properties that can be formed to meet the requirements for the bottles, containers, and caps used for your medication, vitamins, and other pharmaceutical and medical products. The success of any product often relies on choosing the correct plastic resin and its corresponding properties to best hold the individual product.

Now we will be looking into 3 of the most commonly asked questions for plastic resins:-


How are Plastic Resins Manufactured? 


Plastic resins are manufactured by heating hydrocarbons in a process known as the “cracking process.” This is to break down the larger molecules into ethylene or propylene, that come from the crude oil refining process, or other types of hydrocarbons. The amount of these two compounds produced will rely on the cracking temperature used.

The monomers will then undergo polymerization reactions to produce polymer resins. These resins are collected and processed further. This processing can include the addition of dyes, flame-retardant chemicals, or plasticizers.

Following the completion of the cracking process, the compounds are formed into chains known as polymers. Each different polymer is combined to make the plastic resin that has the characteristics for various applications that in turn make the bottles, containers, closures, and caps for your products.

Once the various hydrocarbons are obtained from cracking, they are further processed to make hydrocarbon monomers and carbon monomers such as styrene and polyvinyl chloride that are used in plastic resins.

The polymer resins are later processed into the final plastic products. The polymer resins are heated, molded, and allowed to cool. Varying on the products desired, there are several processes that are involved in this stage. The final polymer resins are usually in the forms of beads or pellets. A process that is known as injection molding is used to form your bottle caps while blow molding is used to make your plastic bottles.


What are the Types of Plastic Resins Available?


  • Acetal
  • Acrylics
  • Acrylonitrile-butadiene-styrene (ABS)
  • Epoxy
  • Fluoropolymer
  • Melamine-formaldehyde
  • Nylon
  • Petroleum resins
  • Polyamide-imide
  • Polyarylates
  • Polyethylene (terephthalate)
  • Polyimides
  • Polyphenylene oxide, Modified
  • Polyphenylene sulfide
  • Polypropylene
  • Polystyrene
  • Polyurethanes
  • Polyvinyl Acetate (PVAc) and other vinyls
  • Polyvinyl chloride
  • Styrene acrylonitrile
  • Styrene butadiene latexes and other styrene co-polymers
  • Sulfone polymers
  • (Saturated) Thermoplastic polyester
  • Unsaturated polyester


What are the Uses of Plastic Resins?


Plastic resins have a large range of uses that are often used in a large number of industries. For the pharmaceutical industry, there are several that are currently being used. Here are some of the types of plastic resins and how they are used: –


1. Polyethylene (PE)

  • Polyethylene comes in a wide number of forms, varying on its molecular weight, density, and branching. 
  • The most common for your pharmaceutical containers, closures, caps, and other items are often made of High-density polyethylene, Low-density polyethylene, and Medium-density polyethylene. Other forms include: 
    • Ultra-high-molecular-weight polyethylene (UHMWPE)
    • Ultra-low-molecular-weight polyethylene (ULMWPE or PE-WAX)
    • High-molecular-weight polyethylene (HMWPE)
    • High-density polyethylene (HDPE)
    • High-density cross-linked polyethylene (HDXLPE)
    • Cross-linked polyethylene (PEX or XLPE)
    • Medium-density polyethylene (MDPE)
    • Linear low-density polyethylene (LLDPE)
    • Low-density polyethylene (LDPE)
    • Very-low-density polyethylene (VLDPE)
    • Chlorinated polyethylene (CPE)


2. Polypropylene (PP) 

  • Polypropylene is a naturally translucent material that provides contact clarity and an excellent moisture barrier. 
  • PP is easily processed through injection molding for your jars and closures, and by injection, extrusion, or stretch blow-molding for your bottles. 
  • One major benefit of polypropylene is it has stability to tolerate high temperatures up to 200°F. 
  • PP is used to produce medical components such as bottle caps and closures.


3. Polyethylene terephthalate (PET) 

  • Polyethylene terephthalate (PET) is a durable material that has outstanding clarity, good impact and scratch resistance, high gloss finish and good barrier properties. 
  • Its containers are lightweight and safe compared to glass, thus ensuring no breakage on filling lines wherever they are stored. 
  • Containers manufactured with PET resin are suitable for packaging a wide range of uses, including pharmaceutical products.


4. Polystyrene (PS)

  • Polystyrene has excellent stiffness and clarity at an affordable cost. 
  • While polystyrene does not have good barrier properties and exhibits poor impact resistance, it is suitable for vitamin packaging.


5. Polyvinyl Chloride (PVC) 

  • Polyvinyl chloride is naturally clear, has a high resistance to oils, and has very low oxygen transmission. 
  • PVC functions as an excellent barrier to most gases and its drop impact resistance is also very good. 
  • This semi-rigid material has a high resistance towards chemicals, but it is vulnerable to solvents. Its applications include:
    • Versatile containers and tubing
    • Shatter-proof bottles and jars
    • Containers used for blood and blood components
    • Catheters
    • Urine and ostomy products
    • Heart-lung bypass sets
    • Blister and dosage pack


Now that you know about these facts about plastic resins, this might deepen your understanding when you are purchasing plastic resins that are most suitable for your needs.