The Plastic Industry
Plastics have impacted human life in many ways. Using plastic bags and containers, we are able to store food, storage, and other items cheaply and securely. Plastics are used in construction, engineering, sciences, toys, tools, and so many other applications. They also paved the way for fast-food industries to exist. Could you imagine a fast food restaurant without plastic cups, utensils, or boxes? Today, plastics are still being researched and being refined. Fillers and additive materials have improved plastic properties and in some cases reduced their costs of production as well.
The Master Batch
Plastic Masterbatches are generally small pellet-like plastic pieces that are created in batches and possess particular properties and (often) color. Simplified, the process for making plastic masterbatches typically includes a mix of liquid or solid additives (and sometimes) color pigments, which is heated and then spread evenly throughout the plastic mix by carrier resins. Afterwards, it is cooled and cut into small pieces.
ATH, Aluminum Hydroxide
As a plastic additive, ATH is economical, inorganic, non-halogenated, and can also function as a smoke suppressant. It works to release water vapor when it absorbs heat (an endothermic reaction), and this dilutes surrounding the flammable oxygen gas. Additionally, the resulting char and aluminum oxide layer helps to add further resistance to fire.
MDH, Magnesium Hydroxide
Like ATH, MDH is also used in plastics as a fire retardant. It is inorganic, non-halogenated, and can function as a smoke suppressant. MDH functions as a fire retardant by releasing water vapor when it absorbs heat (an endothermic reaction), and this dilutes surrounding the flammable oxygen gas. Additionally, the resulting char and magnesium oxide layer helps to add further resistance to fire.
MDH is more expensive than ATH, but can be used in more high-temp processes where ATH would thermally decompose 180-200°C (356-392°F).
Calcium carbonate is a common plastic additive and filler/extender material. It is economical, non-hazardous, easy to process, and more environmentally friendly than many other plastic additives. Additionally, it adds useful properties to the plastic such as strength and color clarity.
Mica is a versatile material that may be added to plastics to impart properties of stiffness, general elemental resistance, electrical properties, and anti-warping thermal properties to a plastic. Additionally, mica is a clear, bright material that can be fine ground and used in plastics designed to be visually appealing as well as functional.
Talc is another very common plastic filler, extender, and property-enhancing additive. It is known to enhance the plastics properties in several areas: nucleation, dimensional stability, strength, and water/oxygen barrier properties. Talc’s high level of thermal conductivity allows for faster processing where heating and cooling is involved.
Check out the list below for the general classification information about different types of plastics:
|Type & Sign||Description & Recycling Info|
|1, PET Polyethylene Terephthalate is a readily recycled plastic. It is used in items such as carpet fiber, beverage bottles, and –; and may absorb oils and odors from the stored contents.|
|2, HDPE High-Density Polyethylene plastics are typically strong and inert materials (except around certain chlorides-verify & source). Finding use in various types of bottles including food carrying ones, HDPE plastics are non-hazardous; although non food grade ones or HDPE containers previously containing an “indigestible should not be used for food.|
|3, VPVC, Polyvinyl Chloride is most well-known for its application in plumbing pipes.|
|4, LDPELow-Density Polyethylene plastics tend to be very safe around food items, and find much application in the food (packaging) industry. They are used in items such as grocery bags, sandwich bags, flexible bottles.|
|5, PP Polypropylene plastics tend to be strong and have a higher melting point; they are often used in plastic caps.|
|6, PS Polystrene is not easy to recycle (). Many disposable plastic take-out containers and packaging foams (hence the name Styrofoam) are made of this plastic.|
|7, O/Other Class 7 is reserved for all the other types of plastics (which is a very long list!). This includes polycarbonate plastic, which is used in CD disks and other containers.|