Polypropylene Plastics: Characteristics, Usages, Everything You Should Know About PP Plastic

Polypropylene (PP) is a rigid and crystalline thermoplastic used widely in everyday objects. Read this article and learn everything you need to know about Polypropylene plastics include the characteristics, usages, properties, process, causes & solutions to bubbles in Polypropylene injection molding products. 

Everything You Should Know About Polypropylene PP Plastic

Characteristics of Polypropylene Plastics, What It’s Used For?

Polypropylene has no toxic, tasteless, has low density, strength, stiffness, hardness, heat resistance are better than low pressure polyethylene, can be used in about 100 degrees. It has good electrical properties and high-frequency insulation, not affected by humidity, but brittle at low temperature, not wear-resistant, easy to aging. It is suitable for making general mechanical parts, corrosion-resistant parts and insulating parts. The common organic solvents of acid and alkali have little effect on it, and the proper brand can be used for tableware.

Physical Properties of Polypropylene PP

Polypropylene is usually a translucent colorless solid, odorless and nontoxic. The melting point of polypropylene is about 164 ~ 170 ℃, and the density is 0.91g/cm. High strength, high hardness, wear resistance, bending fatigue resistance, moisture resistance and chemical resistance are good, easy processing molding, low price, so it is a general polymer variety with large output and wide application. The disadvantage is poor low temperature toughness and aging resistance. But it can be overcome by modifying and adding antioxidant respectively.

Mechanical Properties of PP

Polypropylene has excellent mechanical properties because of its high crystallinity and regular structure. However, the impact strength is poor at room temperature and low temperature due to its high molecular structure regularity. The most outstanding property of polypropylene is bending fatigue resistance.

Thermal Properties of Polypropylene PP

Polypropylene has good heat resistance, and the product can be sterilized and sterilized at temperature above 100 ℃. Under the condition of no external force, it will not deform at 150 ℃. The embrittlement temperature is – 35 ℃ and embrittlement occurs below – 35 ℃. The cold resistance of Polypropylene is not as good as that of polyethylene.

Chemical Stability of Polypropylene PP

The chemical stability of Polypropylene plastic is very good. In addition to being eroded by concentrated sulfuric acid and nitric acid, polypropylene is relatively stable to various chemical reagents. However, low molecular weight aliphatic hydrocarbons, aromatic hydrocarbons and chlorinated hydrocarbons can soften and swell polypropylene. At the same time, its chemical stability is also improved with the increase of crystallinity. Therefore, polypropylene plastic is suitable for making various chemical pipes and fittings and has anti-corrosion effect Good.

Electrical Properties of Polypropylene PP

The high frequency insulation of polypropylene plastic is excellent. Because it hardly absorbs water, it is not affected by humidity. It has a high dielectric coefficient, and with the rise of temperature, it can be used to make heated electrical insulation products. Its breakdown voltage is also very high, suitable for use as electrical accessories. It has good voltage resistance and arc resistance, but it has high static electricity and is easy to be aged in contact with copper.

Molding Characteristics of Polypropylene PP plastics

● Crystalline material, with small wettability, is easy to crack and decompose when contacting with hot metal for a long time.

● The fluidity is great, but the shrinkage range and value are large, and the shrinkage cavity is easy to occur. Dents, deformations.

● The cooling speed is fast, the pouring system and cooling system should slow heat dissipation, and pay attention to control the molding temperature. When the material temperature is lower than 50 ℃, the plastic parts are not smooth and easy to produce welding defects and flow marks. When the temperature is higher than 90 ℃, it is easy to produce warping deformation. Therefore, the temperature should be controlled at 80 ℃.

● The thickness of the plastic wall must be uniform to avoid the lack of glue and sharp corners to prevent stress concentration.

Injection Molding Process Conditions: PP Plastic Processing Technology

● Selection of injection molding machin: There are no special requirements for the selection of injection molding machines. Because PP has high crystallinity. Computer injection molding machine with high injection pressure and multi-stage control is required. The clamping force is generally determined by 3800t / m2, and the injection volume is 20% – 85%.

● Drying: Drying is not required if stored properly.

● Melting temperature: The melting point of Polypropylene (PP) is 160-175 ℃, and the decomposition temperature is 350 ℃. However, the temperature setting can not exceed 275 ℃ during injection processing. The best melting temperature is 240 ℃.

● Mold temperature: mold temperature 50-90 ℃, for size requirements of high mold temperature. The core temperature is 5 ℃ lower than the cavity temperature.

● Injection pressure: higher injection pressure (1500-1800bar) and holding pressure (about 80% of injection pressure) are used. Turn to hold pressure at 95% of the whole stroke for a long time.

● Injection speed: in order to reduce the internal stress and deformation, high-speed injection should be selected, but some grades of PP and mold are not applicable (bubbles, air lines). If there are light and dark stripes diffused by the gate on the surface of the engraved pattern, low-speed injection and high mold temperature should be used.

● Runner and gate: the diameter of runner is 4-7mm, the length of needle gate is 1-1.5mm, and the diameter can be as small as 0.7mm. The shorter the gate length is, the better it is, about 0.7mm. The depth is half of the wall thickness and the width is twice of the wall thickness, and increases with the melt length in the mold cavity. The die must have good exhaust performance. The depth of the vent hole is 0.025mm-0.038mm, and the thickness is 1.5mm. To avoid shrinkage marks, it is necessary to use a large and round nozzle and a circular runner, and the thickness of the reinforcing rib should be small (for example, 50-60% of the wall thickness). The thickness of products made of homopolymer PP should not exceed 3mm, otherwise there will be bubbles.

What Causes Bubbles In Polypropylene Injection Molded Products

– The raw material is not dry enough and contains moisture.

– The plastic stays in the barrel for too long.

– Poor mold exhaust.

– The injection pressure is too small and the injection speed is too high.

– The melt temperature is too high and the mold temperature is too low.

Solutions:

1. Increase mold temperature and reduce injection time and cycle, because Polypropylene PP bubbles are formed by internal shrinkage due to long cooling time.

2. Increase back pressure, prolong injection time, use high pressure and low speed.

3. Polypropylene PP material generally will not have bubbles, it may be that there is a problem with the filling material during PP granulation. 

If the solution in the process is: 

1 add spare material post drying material.

2. Injection back pressure increases, injection rate slows down.

3. The barrel temperature should not be too high.P

Polypropylene rugs are a beautiful sight to behold when appropriately used at home or in an office. They bring color, style, comfort, and harmony to your space, irrespective of where you use them.

Your living room, bedroom, dining room, kitchen, bathroom, or hallway, will come to life with well-placed rugs, anytime. And the reason is not far-fetched.  Polypropylene rugs have the vibes you need to make any space a perfect haven. They are made with synthetic fibers and usually come with or without rubber backings.

However, learning the polypropylene rugs' dos and don'ts is as crucial as your plans to beautify your space. Once you know them, you can give your home an overwhelming aesthetic touch.

First, what do we classify as polypropylene area rugs? Polypropylene area rugs are floor covers that do not extend to the walls. They are primarily used to beautify and unify furniture in a space.

This type of rug is quite beneficial as it is easy to clean and maintain. You can replace it easily with a newer or more appealing one if you ever get bored of the old one.

It comes in a variety of colors, shapes, styles, textures, sizes, and designs, and they can fit perfectly into just about any part of your home.

The versatility of a polypropylene rug makes it an excellent design option for spaces of every size and shape. Let’s take a look at how it changes the overall outlook of every room.

Five Ways Polypropylene Rugs Create a Hype in Your Space

1. Polypropylene Rugs Harmonize Your Living Space

If you have your living room or bedroom furniture scattered all over and you don't seem to have an idea of how to keep them together as a unit (or keep them in one piece).

Polypropylene rugs have a reputation for unifying furniture and highlighting focal points including the sitting area, conversation area, or dining area in any space they occupy.

2. Polypropylene Rugs Beautify Every Space

Polypropylene rugs come in beautiful colors, designs, patterns, and aesthetic features that can totally transform a space into a stunning sight.

You can use them to create all sorts of wonder in your home without overwhelming the area.

3. Polypropylene Rugs Protect Your Floor

Besides providing warmer, softer, and firmer floor surfaces, they also protect your floor surface from wear (especially for places with high movements, such as hallways, stairs, and doorways).

They give a firmer hold to your underfoot, preventing falls and trips that could injure you or your kid(s).

4. Polypropylene Rugs Narrate Your Unique Story

Polypropylene rugs have the character to tell a story about your home and those who live in it. As these rugs catch drips from rainy coats and become an unofficial bed for your pets, they witness all the goings-on inside your home.

Your polypropylene rug serves as a worthy narrator of your house's story. It reflects the daily activities, memories, and experiences that occur within your walls.

You can also tell stories using the process and materials used in producing your area rug. For example, if you opt for polypropylene rugs made from recycled materials, they can convey that you're an environmentally conscious person who values sustainability and an eco-friendly lifestyle. If you want to further express your unique story through your rugs, opting for custom-designed polypropylene rugs is the best way to go. 

5. Polpypropylene Rugs Help Warm Your Space

During the colder months, heating costs can have a significant impact on your wallet. Polypropylene rugs offer a more efficient and economical way to warm your house.

Beyond their aesthetic and protective benefits, polypropylene rugs are also warmer than hardwood flooring options. They provide better insulation, as they retain heat and make your environment cozier. This is especially useful in basements and corridors.

So, how do you get to make the most of your polypropylene rugs? Below are some dos and don'ts that help them live up to expectations.

Dos of Area Rugs

1. Extend Area Rugs Beyond the Furniture

Always ensure that the polypropylene rugs in your living room and bedroom extend beyond the furniture so that all the key furniture pieces are on the rug.

If this is not possible due to the rug's size or some other conditions, have at least the front legs of your furniture on the rug to create harmony within the sitting or conversation area.

Bedroom polypropylene rugs should also extend beyond and to either side of the bed. Dining room rugs should go under the table and chairs and stretch out of the dining area by a foot or two.

 2. Centralize Your Polypropylene Rugs

Remember to leave an equal size of floor space on all sides of your living and dining room rug. Keeping your rug at the center of your living room will create a focal point around the rug.

Since polypropylene rugs would naturally beautify and bring unity to your space, the rug's area should be the center of attention.

Anywhere between eight and twenty-four inches of floor space on all sides is the ideal size. However, you can make exceptions if your room has a smaller space.

3. Know how to Clean Your Polypropylene Rugs

Ensure to look out for cleaning instructions from manufacturers before and after buying a polypropylene rug. 

Some can only be hand-washed, while others can cope well with both hands and machines. Therefore, you should know how to clean and avoid damaging your Area rug. Replacing them too frequently may be pocket-draining.

4. Use the Appropriate Polypropylene Rug Size and Shape

Using a large area rug in a large living room or bedroom helps to balance your space.

Keep a square or rectangular area rug in a room with an equivalent shape. You can use a round rug in a rectangular room in some cases but ensure the shapes complement each other perfectly.

Don’ts of Area Rugs

5. Don't Use an Inappropriate Polypropylene Rug Size

Placing a small-sized area rug in a large room can have a somewhat less appealing effect on your space. It can make the room look scanty and create disharmony within your space.

For a perfect look, the size of your polypropylene rug should correspond with the size of the room you place it in.

It is the most common rug misplacement move many tend to make. Don't fall for it too.

6. Don't Buy Polypropylene Rugs Just for the Price

Prices sometimes can be deceptive because a hefty price tag may not always justify the quality. Quality rugs are relatively expensive, and most homeowners buy rugs because they are affordable or considered cheap. Inexpensive rugs usually go along with low quality.

Quality, rather than just price, should be your priority when buying an area rug for your home. However, there are some exceptions. If you buy one of Luxe Weavers' premium polypropylene rugs online, you will have cut off the middleman and other extra costs. So, you can purchase top-quality rugs for less.

7. Don’t Buy Conflicting Area Rug Patterns or Colors

Your polypropylene rug should ideally complement the shape, style, design, and color of rooms. However, many homeowners buy rugs with sentiments rather than actual befitting rug patterns, styles, and designs that correspond with their living room or bedroom.

Resist the urge to buy polypropylene rugs that are beautiful but are not complementary to your room's style, color, pattern, and other things within it.

8. Don't Shy Away From Colorful Polypropylene Rugs

Polypropylene rugs infuse playfulness, life, fun, and comfort into your room. Embrace beautiful patterns and colors when buying your rugs, as long as they match and blend smoothly with the existing furniture and colors of your room. Colorful and patterned rugs are usually more beautiful than plain or bland ones.

Why You Should  Buy Polypropylene Rugs

When considering whether to purchase polypropylene rugs, it's important to understand their key characteristics and perks. Although they may resemble sisal rugs in appearance, polypropylene rugs are not as soft as wool rugs. However, they do possess several unique qualities that make them worth the bargain.

One of the standout features of polypropylene rugs is their exceptional colorfastness. Unlike many other rug materials, polypropylene rugs maintain their vibrant colors for a long period, and they are resistant to fading. To restore the appearance of a polypropylene rug, you only need a thorough vacuuming or washing process.

Another appealing feature of polypropylene rugs is their plush and cozy feel. They are designed to provide comfort underfoot, creating a welcoming and inviting atmosphere in any space.

If you have pets or spill-prone children, consider purchasing polypropylene rugs. These rugs are resistant to mold and mildew. They are suitable for areas exposed to moisture. Many buyers equally choose polypropylene rugs due to their affordability and low maintenance requirements. They have a silky surface and are reminiscent of wool and silk.

Before you go, surf through Luxe Weavers’ collection of adorable polypropylene rugs. Make your space the talk of the town without emptying your credit cards. Pay zero shipping fees for orders above $100. Happy shopping!