Do you need assistance with your new project?
Introduction to Plastics
Introducción a los plásticos
General information on plastics
Did you know that the word “plastic” means that it can be heat-molded? The term “plastic” or “plastics” is usually employed with regards to the manufacturing on an endless number of products, therefore, in order to better define it, the term “Polymer” is used. A polymer is a material made up of many units called “monomers”, which are low molecular-weight molecules that can bind to other small molecules (be it the same or different) to form long-chain macromolecules commonly known as polymers.
In the 19th century the use of natural plastics was already known. Due to the industrial revolution, the increase in population and the standard of living in the cities, the demand on material goods made from plastic escalated considerably.
The use of plastic displaced that of metal, natural fibers and wood, and established itself as a cheaper substitute good. It is until the fifties of the twentieth, when quality of the plastic products started to improve, not just from being a substitute good for other materials, but also to create new adaptable products with greater applications and more attractive designs.
Familias del polímeros: termoplásticos y termoestables.
The evolution of plastics
With the introduction of high-density polyethylene and a generation of lighter and more malleable plastics, such as fiberglass and carbon fiber, plastic has become an essential part of the production processes of many products today. (Inegi, 2017). The development of very efficient transformation processes altogether opened the door for the generation of many applications.
Plastics are grouped into two large families of polymers: thermoplastics (soften when heated and harden when cooled) and thermosets (never soften once they are molded). However, it is important to mention that the way of classifying plastics is diverse.
Classification of Plastics and Recycling
The SPI (Society of the Plastics Industry) designated a triangle formed by 3 arrows as the classification code for recyclable materials, starting from the largest number of materials that are recycled, and as such, their order is as follows:
PET – POLYETHYLENE TEREPHTHALATE
USES
- Microwavable trays
- Oven bags
- Video and audio tapes
- Containers for soft drinks, oils and mineral water, and vacuum
- Textile fibers
- Geotextiles (paving/trucks)
- Barrier laminates (food products)
- Radiographic films
ADVANTAGES
- Barrier to gases
- Waterproof
- Inert
- Lightweight
- Not toxic
- Resistance to tearing, puncture and fracture
- Transparent
HDPE – HIGH DENSITY POLYETHYLENE
USES
- Applications and uses in agricultura such as:
- Padded
- Greenhouses
- Water pots, etc.
- Commercial and woven bags
- Boxes, buckets and drums
- Various items for the medical industry
- Containers for detergents and shampoo
- Containers for automotive oils
- Dairy packaging
- Pots
- Piping for gas, telephony, drinking water, mining, drainage and sanitary use.
ADVANTAGES
- Excellent gloss and high chemical resistance
- Waterproof
- Inert
- Lightweight
- Not toxic
- Resistance to tearing, puncture and fracture
- Resistant to low temperatures.
PVC – POLYVINYL CHLORIDE
USES
- Blister for medicines and batteries
- Cables
- Catheters, blood and plasma bags
- Appliances and computers
- Packaging
- Candy wrappers
- Toys
- Hoses
- Flexible films for meat and vegetable packaging
- Profiles for window and door frames
- Floors and coatings
- Furniture plates
- Pipes for drainage and drinking water networks.
ADVANTAGES
- Good permeability properties
- Fire retardant
- Inert
- It is not attacked by bacteria, insects or fungi
- Not toxic
- Impact resistence
- Weather and corrosion resistant
- Transparent.
LDPE – LOW DENSITY POLYSTYLENE
USES
- Bags for industrial and commercial use
- Woven bags
- Films for packaging
- Uses in agriculture:
-
- Padded
- Greenhouses
- Water pots
- Etc.
- Uses in the medical industry
ADVANTAGES
- High chemical resistance
- Excellent gloss
- Inert
- Lightweight waterproof
- Not toxic
- Resistance to low temperatures
- Resistance to tearing, puncture and fracture.
PP – POLYPROPYLENE
USES
- Carpets
- Woven raffia bags
- Boxes and buckets
- Battery boxes and auto parts
- Industrial packaging
- Threads, ropes of thread and cordage
- Chairs and tables
- Non-woven fabrics such as disposable diapers
- Piping for hot and cold water
- Film for foods and candy.
ADVANTAGES
- High chemical resistance
- Barrier to odors
- Brightness
- Waterproof
- Inert
- Lightweight
- Not toxic
- Resistance to tearing, puncture and fracture
- Temperature resistant
- Transparent in films.
PS – POLYSTYRENE
USeS
- Shelves
- Blisters
- Containers for dairy products, ice cream and sweets,
- Cassettes
- Supermarket and rotisserie trays
- Storm doors
- Various containers
- Coolers
- Toys
- Disposable razors
- Glasses, plates and cutlery
- Others.
ADVANTAGES
- Brightness
- Easy cleaning
- Fire retardant
- Waterproof
- Inert and non-toxic
- Lightweight
- Transparent.
OTHER PLASTICS
They include a wide variety of plastics such as:
- ABS
- Acrylics
- PC
- PMMA
- Polyamides (PA)
- Polycarbonate
- Polyurethanes (PU)
- Etc.
USES
- Nautical and sports accessories
- Medical items
- Auto parts
- Water bottles
- Computer cases
- Chips
- Compact discs and DVDs
- Household appliances in general
- Pharmacology and cosmetology
- Clothing
- Aerospace engineering
- Furniture
- Parts for cell phones
- Among others.
ADVANTAGES
- Flexibility
- Great resistance to high temperatures
- Lightweight
- Not toxic
- Mechanical properties and chemicals
- Corrosion resistant.
Production process of Plastics
The production of plastic begins with the extraction of hydrocarbons (oil and gas) and their transformation into petrochemicals (olefins and aromatics) which are then converted into resins and then transformed into a wide variety of plastic products through different manufacturing methods. Plastics from renewable sources, not petrochemicals, such as sugar cane or corn, have recently appeared and have been called bioplastics.
Automotive interiors, electronic device covers, household items, medical equipment, compact discs, dog houses, pallets, toys, crates and buckets, thin-walled food containers, promotional beverage cups, and caps for milk bottles.
PROCESS |
STAGES |
MAINRESINS |
PRODUCTS |
|---|---|---|---|
| Extrusion | Continuous process including 2 stages: plasticizing of the material and injection. | Polyethylene, polypropylene, polystyrene, PET and ABS resins and engineering resins. | Flexible packaging, industrial packaging, bags for industrial and commercial use, adhesive tapes, signaling, ropes and ropes from thread, coating for electrical cables, conduction for gas, water and drainagegas conduction, water, drainage, applications in medical, autoparts and thermoforming. |
| Blow Molding | Intermittent processing which includes: the introduction of molten mass of material to a closed mold and injection of air or inert gas into the mold cavity to expand the material. | PET, polyolefins and vinyls. | Containers of PET resin and containers of polyolefins and vinyls. |
| Injection Molding | Intermittent process that includes: the introduction of molten mass of material to a closed mold according to the geometry of the mold. | Polyurethane and polyurea. | Automotive interiors, electronic device covers, household items, medical equipment, compact discs, dog houses, pallets, toys, crates and buckets, thin-walled food containers, promotional beverage cups, and caps for milk bottles. |
| Rotational
Molding |
Continuous process that includes: powder resin feeding, heating until the material melts on the mold walls, cooling and demoulding. | Polyethylene, thermoplastic resins. | Household and industrial water-tanks, car gas tanks, toys, sporting goods, etc. |
| Foaming | Intermittent or continuous process involving an extrusion operation. Foaming can be by the injection of beads previously impregnated with a foaming agent or by extrusion of granules to which the foaming agent is in the line. | Polystyrene, polyurethane and polyethylene. | It is used in the construction sector, in the automobile industry, in internal layers to reduce the density of all types of rigid packaging such as bottles, trays, glasses and food containers
. |
| Compression molding | Intermittent process that is accompanied by a chemical reaction prior to or during molding.
After molding, an additional curing of the part at room temperature or with heat is generally required for it to acquire its final properties. . |
Epoxy resins, based on formaldehyde (phenol, urea and melamine), Unsaturated polyester, foams of thermosetting materials. | Automobile parts such as covers, fenders, bumpers, fascias, spoilers, as well as smaller, more complex parts. |
| Thermoforming | Process involving the extrusion of a thermoplastic sheet and its forming by temperature and pressure or vacuum. | Polyolefins, Polystyrene and ABS. | Plastic items such as disposable cups, industrial-use trays, domes, packaging for pharmaceutical and consumer products, and point-of-sale displays. |
| Calendering | Continuous process that involves: feeding the plastic material to form a film or a sheet, and passing it through hot rollers to give it the desired thickness or even give it texture or certain engraving, its cooling and subsequent winding prior to its final packaging. | Vinyl (PVC) and ABS, and to a lesser extent, high density polyethylene (HDPE) polypropylene and polystyrene. | Manufacture of films, tapestries for walls and vinyl floors, as well as polyolefin sheets and other resins for decoration and office items. |
Technical Specifications
Strategic Partners
Strategic Partners
Along with our commercial allies, we provide logistics and transportation services throughout the Mexican Republic and abroad, for the success of your projects.
