Sandhill Plastic

Plastic Sheeting is the result of plastic extrusion. This is formed by means of a high range manufacturing process – melting and deforming a raw plastic that results to permanent file of plastic sheets.

The ranges of plastic products are compatible for the construction and engineering substances. Display sheets, prints, and signs have diverted into plastic sheeting. Special designs in fabrication of plastic sheets are in extensive service globally. These plastic products have different kinds of classification from window frames to outdoor roofing applications.

Plastic sheeting is the best alternative for the more expensive steel.

There are many types of plastic sheeting. The Acrylic Plastic Sheet combines the most reliable quality for the visor or helmet. It has the most precise optical clearness. The intensity of the color of this product combines a good illumination in a wide range of opaque colors, transparent and translucent.

You can create a design depending on your project because acrylic is easy to shape. It is blended well with tough hardness and finish surface and is resilient to chemical and weather. It is easy to clean and maintain. It is largely utilized for aquariums or tanks at homes or commercial establishments. Acrylic plastic is also best for exterior lenses of automobile lights and appropriate watcher protector.

The Plastic Aluminum Composite Sheet catches the ultimate color of red, blue, green, yellow, metallic, black and white. This generous selection of colors grabs the eye of customers. These are lightweight, making it perfect for loading. It is also rust-proof and weather-proof. The material in aluminum plastic sheet is considered as first class thermal insulation. It has the best proven properties of light polythene core and varnish of baked aluminum polyester. It is ideal for all around indoor and outdoor purposes.

Plastic Aluminum Composite Sheet is recommended to use as panels for canopy and ceiling, display boards and billiards, stand for exhibitions and showrooms, copings for parapet walls, covers for column, wraps for beam, parts for furniture, elevators and stairways, panels for partition, and cladding canopy and balcony

The Polycarbonate Plastic Sheeting is the most natural among all plastic products. It comprises of clear and translucent quality and is heat resistant up to 145 degrees. It is unaffected by acids and water substances. These types of plastic sheeting are best for electronic application such as conduction of electrical properties.

The polycarbonate sheets are stabilized in advanced engineering practice to meet the reinforced shape, a great advantage for those who want to fabricate their own forms of design. Polycarbonate plastic sheeting substance has the best dimensional stability suitable for food exposure. It has the advantage of having superior resistance against heat and temperature and has massive mechanical potency. It also provides high endurance and strength compared to glass.

Polycarbonate plastic sheets are suitable for insulating electrical parts. It can be used also in components for medical and pharmaceutical apparatus, for glazing task, and tough materials for electrical engineers.

Polypropylene Plastic Sheets come in natural, beige, grey, black and white. It possesses superb resistance to solvents and degreasing substance as well as in the attack of electrolytic. The polypropylene Sheets are preferred for all applications exposed to cold state. It is lightweight, easy to form, bendable and welded.

These are used mainly in packaging purposes, cassette holder, pipes, tanks and linings, shells for seats and other automotive parts, containers and fibers.

The underground piping market in North America has seen tremendous growth over the last 30 years in the use of thermoplastic materials. Benefits such as corrosion resistance, improved hydraulics, and reduced installation costs have been paying large dividends for owners of watermain, sanitary and storm sewer systems.

The most widely used and accepted of this group of nonmetallic polymers is Polyvinyl Chloride, also known as ‘PVC’ or ‘vinyl’. Vinyl has a successful track-record in the application of underground pipe dating back to the rebuilding of post-WWI Germany. It has long been considered to be one of the most durable polymers for both underground and above-ground piping systems.

Another thermoplastic used in the underground pipe market is High-Density Polyethylene (HDPE). This material has been used for well pipe, gas piping and drainage tubing before recent entry into the watermain and sewage forcemain markets.

HDPE and PVC are remarkably similar in their nature of responses to such stress loadings as internal pressure and soil loads. Although responses are similar, they are not identical. In fact the magnitudes of their respective strengths are dramatically different.

This report is intended to investigate some of the similarities and differences between the design of PVC and HDPE in terms of the application of underground pressure piping.

PRESSURE RATING

The long-term pressure rating of a thermoplastic pipe is defined as the maximum internal pressure at which the pipe can operate continuously. The ratings of both PVC and HDPE are found using the ISO Equation for thermoplastics:

Equation (1) P = 2S / (DR-1)

where P = pressure rating of the pipe

S = design stress of pipe material

DR = dimension ratio of the pipe, (OD/t)

The main difference between PVC and HDPE pressure capacity lies in the value of the design stress. For PVC 1120 compounds, the design stress is 2000 psi while that of HDPE 3408 is only 800 psi. These design stresses were both derived in exactly the same fashion. A factor of safety of 2.0 was applied to the long-term hydrostatic strength (i.e. the Hydrostatic Design Basis – HDB) of each material. The HDB for PVC 1120 is 4000 psi while that of HDPE 3408 is 1600 psi.

The following examples illustrate the use of the ISO Equation to determine pressure ratings.

Example 1 – Find pressure ratings of DR21 pipe for both (a) PVC, and (b) HDPE.

Solution – use equation (1)

P = 2S / (DR-1)

(a) for PVC, S = 2000 psi

Substituting, P = (2) x (2000 psi) / (21 – 1)

= 200 psi

(b) for HDPE, S = 800 psi

Substituting, P = (2) x (800 psi) / (21 – 1)

= 80 psi

Example 2 – (a) Find the pressure rating of PVC DR41 and then (b) find the equivalent DR of HDPE to yield the same rating.

Solution – use equation (1)

(a) P = 2S / (DR-1)

= (2 x 2000 psi) / (41-1)

= 100 psi

(b) rearranging equation (1),

DR = (2S / P) + 1

= [(2 x 800 psi) / 100 psi] + 1

= 17

Therefore, to obtain a 100 psi pressure pipe, the 2 options would be PVC – DR41 or HDPE – DR17.

The following points can be concluded from the above information:

(a) The ratio of PVC to HDPE in terms of tensile strength is equal to the ratio of the design stresses, i.e. 2000:800 which is 2.5:1, and
(b) The wall thickness of HDPE must be 2.5 times thicker than that of PVC to obtain pipe with equal pressure ratings.

Below is a summary of long-term pressure ratings for both PVC and HDPE derived using the ISO Equation and a S.F. of 2.0.

Table 1 – Pressure Ratings
PVC HDPE
DR Rating (psi) DR Rating (psi)
51 80 21 80
41 100 17 100
32.5 125 13.5 128
25 165 11 160
21 200 9 200
18 235 7.3 254
14 305 6.3 300

Although CSA B137.3, AWWA C905 and ASTM D2241 all use a S.F. = 2.0, there is one PVC standard that uses a S.F. = 2.5, namely AWWA C900-97 (note – this standard will soon be changing to be similar to AWWA C905). As well in this C900 standard, the pipe is further de-rated by a 2 ft/s surge. (Designers should not confuse the ‘Pressure Class’ terminology of C900 with the long-term ratings of HDPE.) If one wishes to select a HDPE pipe that is equivalent to a particular PVC Pressure Class, the identical design criteria should be used to determine a Pressure Class of HDPE. In other words, the design stress must be derived using S.F. = 2.5, and the pipe must be de-rated with the surge of a 2 ft/s velocity. To determine equivalent pressure classes of HDPE and PVC, refer to Table 3 presented later in the text and use Equation (2) shown below.

Equation (2) P.C.= P’- 2 Ps

Where P.C. = pressure class of pipe

P’ = pressure rating of pipe using S.F. = 2.5

Ps = surge pressure for 1 fps velocity change

Note: Ps for PVC and HDPE are given in Table 3.

Example 3 – (a) Find the pressure class of DR25 PVC and (b) find the DR of HDPE to give the same pressure class.

Solution – First solve for new design stresses.

PVC: S = HDB / S.F.

= 4000 psi / (2.5)

= 1600 psi

HDPE: S = HDB / S.F.

= 1600 psi / (2.5)

= 640 psi

Now use equation (2) and the values of Table 3 to solve.

(a) PVC DR25

P.C. = [2S / (DR-1)] – 2 Ps

= [(2)(1600 psi) / (25-1)] – (2)(14.7 psi)

= 100 psi

(b) HDPE – trial and error using equation (2)

try DR11,

P.C. = (2) (640 psi) / (11-1) – (2)(13.4 psi)

= 100 psi

Below is a table of minimum DR’s of HDPE to be equivalent to the pressure classes of PVC as defined in AWWA C900.

Table 2 – Pressure Class DR’s

Pressure Class (psi) PVC-DR HDPE-DR

100 25 11

150 18 7.3

200 14 6.3

SURGES

Another tremendous benefit of using thermoplastic piping is that surges created are lower than those associated with more rigid materials such as metallic or concrete cylinder pipe. The inherent flexible nature of thermoplastics allows transient shock waves to be easily dampened and absorbed. This minimizes surge effects on the entire system.

Positive pressure surges in pipelines can be approximated by using the following two equations.

Equation (3) a = 4660 / [1 + (k/E)(DR-2)]^0.5

where,
a = wavespeed of surge wave (fps)
k = fluid bulk modulus (= 300 000 psi for water)
E = modulus of elasticity of pipeline material (psi)
DR = dimension ratio (= OD/t)

Equation (4) Ps = aV / (2.31) g

where,
Ps = pressure surge (psi)
a = wavespeed (fps)
V = velocity (fps)
g = acceleration due to gravity

= 32.2 ft/s^2

The Modulus of Elasticity of PVC 1120 at 73.4°F is 400 000 psi, while that for HDPE 3408 is 115 000 psi. The table below summarizes the surge pressures expected for every 1 ft/s instantaneous velocity change in both PVC and HDPE. For velocities other than 1 ft/s, the surge will be equal to the values in the table multiplied by the actual velocity in ft/s (i.e. if V = 3 ft/s, surge = 3 times the table value for the given material and DR).

Table 3 – One Ft/s Surges

PVC HDPE
(E=400 000 psi) (E=115 000 psi)

DR Ps (psi) DR Ps (psi)
51 10.8 21 8.8
41 11.4 17 9.9
32.5 12.8 13.5 11.3
25 14.7 11 12.7
21 16.0 9 14.3
18 17.4 7.3 16.3
14 19.8 6.3 17.9

Although HDPE is by nature a more flexible material than is PVC, the surges created in pipe of equivalent pressure ratings are very similar. For example, for a 100 psi pipeline, the surge created by a 1 ft/s velocity change would be 11.4 psi for DR41 PVC and 9.9 psi for DR17 HDPE.

Overall, the surges for both materials are well below the values of metallic pipe which typically generate surges of 50+ psi for every 1 ft/s instantaneous velocity change. Continuous pressure surges should not be ignored in any pressure pipeline design, regardless of material.

BUCKLING RESISTANCE

The ability of a soil surrounding a flexible pipe to strengthen the pipe is numerically known as the Soil Stiffness (E’). E’ numbers are derived empirically to represent the quality of soil and degree of compaction as a ‘psi’ value. E’ values are described in detail in standards ASTM D 2321 or CSA B182.11. A brief summary is presented below.

Table 4 – Soil Stiffness

Soil Stiffness E’ (psi) Material Compaction (S.P.D.)

3000 Manuf. Angular 90%

2000 Clean Sand/Gravel 90%

1000 Sand/Gravel/Fines 90%

500 Sand/Gravel/Fines 85%

Buckling may occur in any pipe if the total load in the inward direction (i.e. static soil + traffic + vacuum) exceeds the critical buckling resistance of the pipe. A thermoplastic pipe must be designed to have sufficient strength to resist inward structural collapse, or buckling. Tremendous strength can be added to any pipe’s resistance by having solid lateral soil support in the Haunch Zone of a buried pipe trench, i.e. a high soil stiffness.

Below is a summary of the critical buckling strengths of various DR’s of PVC and HDPE for (a) Pcr, an unsupported condition (i.e. subaqueous or above-ground) and (b) Pb, a buried trench condition with a specified soil stiffness, E’ (for this example, = 500 psi).

Table 5 – Buckling Strengths

PVC DR Pcr (psi) Pb (psi)

14 425.8 530.6

18 190.2 354.6

21 117.0 278.1

25 67.4 211.1

32.5 29.8 140.4

41 14.6 98.3

51 7.3 69.5

HDPE DR Pcr (psi) Pb (psi)

6.3 266.2 419.6

7.3 171.2 336.5

9 91.4 245.8

11 50.0 181.8

13.5 27.0 133.6

17 17.6 107.9

21 7.2 69.0

26 3.8 50.1

32.5 2.0 36.4

To investigate a typical situation, a pressure pipeline is buried 10 feet in soil with a density of 120 lb/ft^3 and subjected to a momentary negative 10 psi vacuum due to a transient shockwave. A total negative load of (-)18.3 psi would be created. As can be seen from the above table, this negative pressure would exceed some of the Pcr values of PVC (DR41 and 51) as well as HDPE (DR17, 21, 26 and 32.5). By having a minimum soil stiffness of 500 psi, the values of Pb for all DR’s of both materials will easily exceed the total negative load and buckling will not occur.

If any of these pipes happened to have significant voids in their backfill, it is conceivable that buckling failure could occur. It is imperative that lower pressure rated thermoplastic pipe be installed so as to have a minimum soil stiffness, E’, of 500 psi. Voids in the haunch support zone can be prevented by using proper bedding material and light compaction. This point is especially relevant if ever considering assembling thermoplastic pipe above the trench and rolling it in before backfilling. Buckling is a situation far less likely to occur if the pipe is installed using a conventional open trench with moderate compaction beside the pipe as the line installation progresses.

SUMMARY

To do a thorough comparison of PVC and HDPE, many other factors would have to be considered such as: material cost, installation cost, connection methods, and manufacturing test requirements. The designer should also ensure that each material has a successful track record for the application being considered.

This report has offered a snapshot comparison of the 2 thermoplastic materials used most often for pressure pipe in North America – PVC and HDPE. The capacity of each material was illustrated in terms of their pressure ratings, surge performance and buckling resistance to allow designer an equal comparison between PVC and HDPE.

Polyethylene thermoplastic made with the help of petroleum is known as High Density Polyethylene aka HDPE or PolyEthylene High-Density aka PEHD. If we talk in terms of raw materials to be used, about 2 kg of petroleum is used to produce one kg HDPE. The product is normally recycled with 2 being its recycling symbol.

HDPE is a bit branched substance that gives it a stronger intermolecular force. Also the tensile strength is greater than other polyethylene substances. It is hard and opaque and can easily withstand higher temperatures. However, HDPE cannot withstand autoclaving surroundings. Less branching is guaranteed by selecting right catalysts and the appropriate conditions for carrying the reactions. The product is rich in carbon and hydrogen.

Applications of HDPE plastic are many. This is mainly because of the fact that HDPE is solvent-resistant. It is used for manufacturing containers, bottles for laundry, jugs and jars. It also acts an active part in the manufacturing of fuel tanks, containers for keeping chemicals, pipes, and pipes for heat transfer, gas and water supply and distribution. HDPE is also applied to produce folding chairs and tables, sheds and plastic poly bags. The substance is highly used to produce heat-resistant mortars, cable insulators, rails, boxes, fences, hula hoops, and protector from corrosion to steel pipes.

Apart from numerous above mentioned applications, this substance is also used in the cell liners in sanitary landfills. In this area, large sheets of the substance are welded either extrusion or wedge type that helps to form a chemical-resistant barrier. This protects the product by the harmful pollution present in the soil as well as groundwater.

One of the prime and most common uses of HDPE is in the composites of the wood plastic and composite wood. This is done with the help of recycled polymers that makes it an eco-friendly process. This extremely marvelous substance also finds its use in the pyrotechnics trade world. The mortars produced by HDPE are preferred by many over steel pipes or even PVC tubes. This is because HDPE is a very durable substance and it is also very safe if compared to the other two. If any problem is encountered in the mortar, HDPE tears apart instead of shattering and scattering into infinite sharp pieces that are very harmful. This is also one of the reasons behind HDPE being so popular in so many fields.

Influenced by recycling proponents around United States, the Society of the Plastics Industry, Inc. introduced Resin identification coding system. It was in 1988 when this scheme of separating (or grouping) plastic resin types to make it easier for recyclers to sort them out and to have a more systematic waste management system, was introduced.

Guidelines in the Use of Recycling Number

The Society of the Plastics Industry in cooperation with the Federal Trade Commission (FTC) agreed on the following guidelines in using the code:

This complies with the laws in 39 states wherein the code must be used on bottles and rigid containers. This is used to identify resin (a type of plastic) content only. The code, while it helps in waste management and recycling activities, must not be conspicuous so as to affect sales of a product.

The code must, in any way, never be altered. No additional markings such as “recyclable” may be placed near the symbol, nor should there be any claims of any products recyclability placed anywhere near it.

The ½” symbol, whenever it would fit, must be molded or permanently imprinted on all gallon containers from 8 ounce to 5 gallon capacity>

Placement of the symbol must be as close to the center of the container bottom

To help you recycle efficiently, below are the 6 different symbols that are helpful in creating your own household waste management and the description of plastic items that are good for recycling.

1 PET (or PETE) – Poly(ethylene terephthalate) PET is a clear, and tough resin that can contain gas and moisture. These are commonly used in bottles and other injection molded product containers. This resin is a good candidate for recycling as they come in great volumes in waste management systems, in the form of bottles for beverages, catsup, beer, jams, peanut butter, etc. Major industries recycle these for major uses such as textiles, carpet, films, ink cartridges and moldings.

2 HDPE – High-density Polyethylene – HDPE commonly found in may types of plastic bottles. Its high resistance to chemicals makes it the preferred material for packaging household and industrial material such as detergents, conditioner, shampoo, bleach, etc. Proper waste disposal, i.e., segregating, would have these items for recycling and become plastic shopping bags, wire and cable covering, re-usable shipping containers, etc.

3V Poly (vinyl cloride) – commonly known as PVC, these are categorized into two groups, namely, rigid and flexible materials. While used containers made from these are also highly sought for recycling, these have many industrial and household uses. .

4 LDPE – Low-density Polyethylene – commonly found in film application uses because of its toughness, it is relatively transparent and flexible.

5 PP – Polypropylene – this is good for containing very hot fluids as it has very good chemical resistance and is a strong material. A very good example would be Tupperware products (which have their own recycling system), diapers, bottle caps and closures, etc.

6 PS – Polystyrene – this is a very versatile plastic material that can either be rigid or foamed. Examples are coffee cups, bakery shells, Styrofoam insulation, etc. Polystyrene can also be combined with rubber to produce high impact polystyrene, which is good for uses that require toughness.

7 OTHER – this means that the package is made up of a resin type that is not included in any of the above-mentioned six, or it usually is a package that contains a combination of the previously mentioned codes.

This Article is written by James Kara Murat, the contributor of PrintCountry Printer Ink Related Articles Read more about the subject at What Does the Recycling Numbers Mean and related resources can be found at PrintCountry Recycling Program

Plastic welding is the ability to take two pieces of plastic and weld them together. This is a type of weld that will be done on children’s toys, lawn furniture, automobile parts and other types of plastic equipment that you may use everyday or commercially.

This type of welding is used to join thermoplastics when they are heated and under pressure. Generally the pieces are fused together with filler material, but some instances do not require filler material.

Plastic often has a shorter lifespan than most types of products because there are so many things that can go into how it is maintained. Elements from nature like cold weather, UV rays from the son or chemical contamination can create damage with plastic. Plastic can also receive damage if it is hit hard like in a car bumper or other hard surface, but the purchase of the new parts can be cost prohibitive; this is when it may be a good idea to repair it instead.

There are different types of plastic so it is important to know which one you are working with in order to make sure that the proper welding material is used. It is a good idea to understand the difference between thermoplastics and thermosets because thermosets cannot be welded.

The type of plastic that needs repair will require different welding rods and if you use the wrong rod for the plastic you need to repair, there will be no bond. Materials like Polyolefines have a lower surface energy so this means they cannot usually be repaired with an adhesive or other types of glue. There are a special group of polyolefine adhesives that can do this job.

When you are making repairs on plastic there are usually two types that you will come up against — you will either have to repair a crack or a broken part. If you find a crack, it means that there is some type of stress affecting the inside of the material you are using. This means that you will have to repair the crack and make sure it doesn’t continue through the piece.

There are several types of plastic welding. A few of them are:

Hot gas welding uses a welding gun that has electric heating elements within in it that produce a heat of hot gas.

Hot plate welding uses a hot plate between the two surfaces that are being joined. Ultrasonic welding uses a high frequency acoustic vibration to weld the pieces together. These are placed under high pressure and then exposed to the vibrations until the weld is completed.

Spin welding where friction is used to weld two cylindrical parts as these parts are rotated. At a certain time the rotation stops and the weld is completed.

Vibration welding takes to pieces of plastic and exposes them to a frequency called an amplitude. The two pieces are under pressure which causes a friction that generates heat.

All of these types of welding work on plastic and they are geared towards working with a variety of polymers.

The word plastic is derived from the Latin word plasticus which means “capable of being molded.” Indeed, plastics are moldable synthetic materials made up of a large organic molecule that can be formed into a variety of products. Depending on its purpose, plastics can be made as hard as stone or as pliable and elastic as rubber. Plastic can also be made to be as strong as steel, impact-resistant and heat-resistant. The processes involved in manufacturing the different kinds of plastic varies, and like metals, may be alloyed, or even combined with other materials. The other qualities that make plastics more distinct are being lightweight, waterproof and chemical resistant; they may also be produced in almost any color. More and more types of plastic are being studied and developed daily to further enhance the quintessential product that everybody benefits from.

Plastics also come in a variety of kinds, although all share the common characteristic of malleability or plasticity, they differ in properties, production costs, and the process of making them. Although plastics may be classified in many ways, they are commonly categorized based on the polymer element that is used as the basis in their production.

Common Plastics and How We Use Them

Inevitably, plastics have become a part of our lives. Life would certainly be very difficult without them. The countless kinds of plastics have found their way into industries and our homes and have gained permanency in both settings. The most commonly used plastics are: polyethylene, which has a wide range of uses and is very inexpensive; polypropylene used for the production of food containers and appliances; polystyrene (or Styrofoam) commonly used for disposable food containers; polyamide or nylon for toothbrush bristles and fishing lines; polyester for textiles. There are also special purpose plastics such as Teflon used in frying pans and water slides; polyurethane for insulation and upholstery foams; Bakelite insulation for electrical fixtures.

Despite all the advantages of using plastics, its threat on the environment has become increasingly intense since it degrades very slowly and when burned produces toxic fumes. Also, plastic production creates chemical pollutants which affect both the air and water and uses up the limited supply of fuel fossils. In order to alleviate the losses of the environment, it is always best to recycle plastics to either be used again to be re-processed into other products.

Plastic provides detailed information on Plastic, Plastic Bags, Plastic Containers, Plastic Pants and more. Plastic is affiliated with Custom Plastic Bags.

Building your own kennel unit is a very feasible project. By constructing one on your own, you can easily incorporate the necessary specifications that your pets need.  If you have the tools and armed with the right instructions, you can get started….

A dog kennel can be designed to follow the principles of convenience for you and comfort for your pets. These considerations will guide you to choosing the right materials, layout and design of the kennels.

With convenience in cleaning and maintaining the kennel in mind, you will be able to design the unit that will allow for ease in carrying out sanitation procedures. For example, plastic instead of wood for flooring. Steel is expensive and wood can splinter.  Plastic is affordable and easy to maintain and clean.  Also allows comfort for your pet.

Concrete may also be used for the base of multi-units, however lining with plastic sheets will allow for a cleaner kennel and easier maintenance, avoiding dealing with the cracks that can form from concrete and cause parasites to fester over time.

You can also customize the kennel to slope for better drainage. You can conveniently hose down dirt from the kennel compartments and not have to wipe or mop them clean. You can eliminate odor or keep it at minimum with more frequent disinfection.  The plastic isn’t porous and allows a slick surface to properly remove all feces and dirt.

Call us and talk about your options if you are interested!  We offer colors, too if you would like a little more flair in your kennel for your dog.

Plastic plays a crucial part in our current society. It’s everywhere – the most common material used to make products for our convenience – containers, cell phone casing, plastic bags, etc. Have you ever thought, for a moment, about the meaning of those symbols found in your plastic-made items?

Plastic recycling symbols show the forms of resin used to create the material. These representations are established following the international Plastic Coding System, and are customarily delineated as a number (from 1 through 7) enclosed by a triangle or a plain triangular loop (also known as the Mobius loop), with an acronym of the specific material used, right underneath the loop.

Here are succinct descriptions of each of the 7 recycling symbols frequently used, today:

1 – PET or PETE (Polyethylene Terephalate Ethylene)

Light weight, low-priced, and easy to fabricate, Polyethylene Terephalate Ethylene is the most prevalent plastic material in use today. PET is primarily used in beverage bottles, food receptacles, and peanut butter containers. It can be remade into polar fleece, fiber, carpet, etc. The requirement for this plastic among recyclers is relatively strong, but at present, the recycling rate for this material has remained low at 20%.

2 – HDPE (High Density Polyethylene)

High Density Polyethylene is more durable and more impervious to chemical degeneration, this material poses a relatively low chance of spreading chemicals when used as container for food and drinks. It is largely used as containers for everyday household chemicals (shampoos, degreasers, etc.), juice bottles, milk jugs, etc. This can be reused into floor tile, drainage, new HDPE bottles, pipes, etc.

3 – PVC (Polyvinyl Chloride)

PVC has been tagged as a health hazard – it has been noted to typically drain chemicals when used as containers. PVC is mainly used for piping, window cleaner bottles, siding, etc. It has chlorine and will dispense toxins if burned. PVC should not be used in food preparation or food packaging. It can be reprocessed into mudflaps, panels, mats, etc.

4 – LDPE (Low Density Polyethylene )

LDPE is the material present in plastic bags, clothing, furnitures, etc. Resilient and flexible, it is perfect for packaging, insulation, and sealing. LDPE, through many curbside recycling programs, can be reconstituted into cans, compost bins, and landscaping tiles.

5 – PP (Polypropylene)

Polypropylene is most suited for boiling fluid receptacles and is likewise made into brooms, straws, ketchup bottles, etc. PP can be reprocessed into rakes, brooms, trays, etc.

6 – PS (Polystyrene)

PS is the top component for insulation and is used in foam products like expanded polystyrene (EPS), commonly known as styrofoam. It is found in carry-out food containers, meat trays, CD cases. PS contains benzene, a cancer-causing substance and should not be burned. It is reprocessed into insulation, packaging, plant beds, etc.

7 – OTHER (Polycarbonate)

Recycling symbol 7 – OTHER signifies materials not belonging to any of the other 6 resin categories. OTHER may also signify a hybrid resin made up of a mishmash of those materials. It is mainly found in children feeding bottles, flak jackets, business signages, five-gallon water jugs, etc. It can be recycled into plastic planks and other tailor-made objects.

Not all number 7 plastics are polycarbonate, a handful are even plant-based. Polycarbonate has become the axis of dispute in recent years, as it is discovered to leach BPA (bisphenol A), a hormonal disruptor that may disastrously influence gestation and fetal growth.

Plastic recycling symbols are designed essentially to help the staff in recycling plants in properly segregating materials for processing. A rudimentary knowledge of these icons can also help us in ascertaining if the plastic item were handling at home are risk-free for us and our children.

Michael Arms contributes articles the Pacebutler Recycling and Environmental blog. Pacebutler Corporation of Edmond, Oklahoma is a US trading company that pays cash for cell phones, in an online transaction. If you just want to dispose of your old cell phones in an environmentally-friendly manner, you may also recycle cell phones through Pacebutler.