HDPE and PP Sheets: What Are They?
The term HDPE refers to High-Density Polyethylene, a polyethylene thermoplastic manufactured by using petroleum. It has more tensile strength and intermolecular force due to little branching at its molecular level. These plastics consist of a string and inflexible plastic that has a colour similar to milk. These plastics are free from synthetic organic chemicals such as Bisphenol A or BPA and hence have significant uses in packaging personal care products and beverages. The HDPE plastic sheets are highly durable and never splinter or rot. Besides being highly tensile, they are corrosion resistant and hence used in a wide range of applications. HDPE plastics do not absorb harmful bacteria, so it is ideal to use them in the food industry.
In short, polypropylene, or PP, is a translucent, semi-rigid polymer belonging to the environment-friendly polyolefin family. Manufacturers derive the PP sheets after combining propylene monomers. PP sheets are thermoplastics used in different applications, such as packaging consumer goods and manufacturing unique textiles and devices. Paul Hogan and Robert Banks, a couple of Philips petroleum scientists, were the first to polymerize the PP sheets in 1951. Later, the Italian and German scientists Natta and Rehn worked on polymerizing the sheets.
Later the sheets became highly famous, and with commercial production, they began to spread faster across the globe. These sheets, by 1957, experienced a widespread explosion, which led to commercial production of the sheets across several European nations. Today, PP sheets are the most common manufactured varieties of plastics across the globe.
The PP sheets offer outstanding physical, chemical, electrical, mechanical, and thermal properties. Besides, they possess lower impact strength, superior tensile strength, and working temperature than polyethylene.
The Difference in Their Properties
Among the significant differences in the properties between HDPE Sheets and PP sheets, density is the first factor. The density of PP sheets ranges between 0.895 and 0.92 gram/cm2. People know the high-density polyethylene for its big strength-to-density ratio. The density of HDPE sheets can range between 0.93 and 0.97 grams/cm3, which makes the sheets more rigid.
HDPE has a melting point between 200 degrees F and 212 degrees F. In contrast, PP sheets’ melting point ranges between 266 degrees F to 340 degrees F.
UV and Chemical Resistance
Like HDPE sheets, PP sheets have good chemical resistance but have poor UV resistance unless stabilized with additives. In contrast, HDPE is resistant to various solvents and has various applications. It protects the environment by forming a chemical-resistant barrier and preventing soil and groundwater pollution from liquid constituents of solid waste.
HDPE sheet manufacturers manufacture these sheets by a catalytic-polymerization of ethylene. The manufacturers carry out the process of polymerization either in suspension, gas, or solution-phase reactors. To reduce branching, the manufacturers use certain chemicals such as butane, hexane, and octane.
On the other hand, PP sheet manufacturers manufacture the sheets through the process of moulding and extrusion. These processes help in melting the polypropylene, which produces spun-bond and meltdown fibres. The manufacturers use injected moulding, which is the shaping technique of PP sheets. Alternatively, the manufacturers use other methods such as injection stretch and blow moulding.
Features of HDPE and PP Sheets
The following are some of the main features of HDPE Sheets.
- The sheets have excellent shock and impact resistance capacity.
- The sheets are capable of high-impact shock applications without cracking, as they are perfect shock absorbers.
- The sheets have good corrosion and chemical resistant capacity. The sheets can tolerate acids, alkalis, and other chemicals.
- They absorb low moisture, easy to install, are more durable, toxic-free, and scratchproof.
- They possess excellent processing, electrical, and welding properties.
- These sheets are resistant to moulds, rust, and temperature and can withstand extreme weather conditions.
On the other hand, Singhal industries’ PP sheets offer the following features:
- The PP sheets offer good fatigue, heat, water, and scratch resistance.
- They are strung and durable similar to the HDPE sheets.
- You can easily recycle them, and they are non-toxic.
- These sheets are impervious to moisture, salts, and insects.
Advantages of Using HDPE and PP Sheets
HDPE sheets have a great strength-to-density ratio. It means that these sheets have the resistance to break under tension. Hence, these sheets can hold heavy materials and many liquids without damage or wear.
The density of the HDPE sheets indicates that they are not prone to absorb any materials that it holds, which makes the sheets well suited as containers for liquids and marine applications. Moreover, these sheets are resistant to corrosion, mildew, rotting, and mould, making the containers extremely durable even when exposed to various environments. Besides, these sheets are long-lasting, weather resistants’ and impervious to basic solvents, acids, waxes, and greases. Moreover, HDPE sheets are safe for use in various industries and instances. More specifically, the USDA, FDA, and NSF approve industry-grade HDPE sheets as food safe.
Easy to Mold
HDPE sheets are easy to mould and shape into plastic containers. Due to its high melting point, the sheets remain rigid longer. Once the material reaches its melting point, one can easily mould the sheet in any shape.
Advantages of PP Sheets
High melting point
Like the HDPE sheets, the PP sheets also have a high melting point. Hence, it works well when used for food containers, especially where the temperatures can reach high (up to 320 degrees F).
One can customize PP sheets in various ways. The manufacturers can add dye to polypropylene during the moulding process to suit different requirements. It makes the sheets ideal for retailers trying to create displays that would quickly attract the interest of potential customers.
PP sheets are highly flexible and lightweight. Due to this reason, it is unlikely to shatter before breaking the material.
Applications of HDPE and PP Sheets
Enlisted are the applications of HDPE sheets:
The pipe-grade HDPE sheets possess high molecular weight compared to standard HDPE sheets. The strengthening of the material in combination with UV resistance makes the material ideal for piping and outdoor applications. These separate sheets can withstand -220 to 180 degrees Fahrenheit. As these HDPE sheets are highly durable in most chemical interactions, it finds usage in several industrial applications.
As HDPE sheets are UV resistant, it helps in keeping the toys resistant to the sun’s rays that cause damage and discolouration.
Most people use the most durable plastic bottles. HDPE is great for blow-moulding applications, especially in the case of food and beverage containers. It is because the materials do not leach into the contents. Moreover, HDPE is a recyclable material, which makes it the best choice for disposable products.
With its chemical-resistant properties, HDPE is the best for shaping it into containers. Manufacturers use these sheets for making containers for shampoos, laundry, conditioners, motor oil, household cleaning products, antifreeze, and recycling bins; with the addition of colour or pigment, the strength of the bottles increases.
Enlisted are the applications of PP sheets.
High strength, good barrier properties, cost-effectiveness, and good surface finish make the material suitable for rigid and flexible packaging. The manufacturers can easily blow mould the PP sheets for producing pots, bottles, and crates. Since PP sheets have excellent optical clarity and transmit low moisture, it is an ideal choice for the food packaging industry.
Since PP sheets are cost-effective, have outstanding mechanical properties, and are easily moulded, PP sheets have wide use in automotive parts. Most of the applications of the sheets in the automotive industry include manufacturing battery cases and trays, fender liners, bumpers, interior trim, door trims, and instrumental panels.
Polypropylene (PP) is used in several residential products and consumer goods applications, including translucent parts, housewares, home & office furniture, appliances, children’s toys, and travel luggage.
Due to high chemical and bacterial resistance, PP sheets find their use in \several medical applications. Furthermore, the medical-grade PP sheets possess good resistance to steam sterilization. The disposable syringes are the most common medical application of PP sheets. Other sheet industry applications include medical vials, diagnostic devices, poetry dishes, intravenous bottles, specimen bottles, pans, pill containers, and food trays.
Polypropylene sheets find their usage in acid and chemical tanks, sheets, pipes, and returnable transport packaging in the industrial sector.
Also Read : What are the Advantages of Polypropylene Sheets?
Singhal Industries Pvt. Ltd. is one of the most prominent manufacturers and exporters of premium quality, highly durable, and cost-effective HDPE and PP sheets. All our manufactured sheets are non-toxic and are used in various applications in different sectors. Our sheets (HDPE and PP) have massive demand in the market. We strive to serve our clients with our best output. We understand the requirement of the sheets and produce HDPE and PP sheets of different sizes with varied thicknesses and colours. We also customize our sheet as requested by our clients. We are a leading abs plastic sheet manufacturers also.