Problems Bonding Plastics

Problems Bonding Plastics

Do you know that you often require a third substance, the adhesive, to link pieces in a bonded junction for normal assembly operations where you glue plastic to plastic or other material parts?

Adhesive users know that bond failures can happen, but they might not know about the causes. Often the lack of detailed instructions from adhesive manufacturers on surface preparation before bonding is a major reason of bond failures.


What are the challenges in bonding plastics?

Users can easily stop failures and form solid, long-lasting bindings by knowing about the composition of surfaces and how to prepare them properly.


1. Contamination 

The kind and degree of contamination on the bond surface can greatly influence whether or not the bonding process will be successful. The specifics of cleaning and surface preparation are essential and usually depend on the substrate.

2. Detailed knowledge

Users can easily avoid failures and form solid, long-lasting bindings by knowing about the composition of surfaces and how to prepare them properly. The specifics of cleaning and surface preparation are essential and usually depend on the substrate. They may also be particular to the source since different suppliers’ materials will often have varying levels and types of impurities, requiring various surface preparation methods to get a suitable bond surface.

3. Surface Treatments

Certain bonding applications require the usage of plastics, which are quite challenging to bind. Applying a surface preparation is required in these situations to do the adhesive work properly.

4. Roughening the plastic Surface

Most adhesive data sheets to form a good bond include instructions to “roughen the surface,” The instructions typically indicate that roughness is an important part of a bond surface.

The importance of making the surface exceptionally clean is greater than that of roughening. Additionally, cleaning must be done before any roughening steps. 


How is plastic bonded?

Here are several external factors that you should consider to properly bond plastics:

  • The adhesive must meet the primary material criteria for the planned application in terms of compliance (such as food compliance) and mechanical qualities.
  • When bonding plastic, you should consider thermal and chemical factors.
  • Finally, it is important to consider technological requirements, including surface pre-treatment and the time of adhesive application.

Please keep in mind that amorphous polymers have the risk of stress cracking. Plastics must always be pre-treated before joining.

(It is often better to have complete information from the glue provider to help select the optimum adhesive. Specific testing should be carried out for any project involving the bonding of polymers.


What you need to know about bonding plastics

Seven families of adhesives are most frequently used to join plastics. Each provides a special mix of processing and performance advantages.

  • Cyanoacrylates
  • Light-cure Acrylics 
  • Light-cure Cyanoacrylate 
  • Hot-melt glues
  • Epoxies
  • Polyurethanes
  • Two-part acrylics


What is the best to bond plastic?

Plastics may be permanently attached to one another or other materials thanks to bonding technology, which is a very effective joining technique. The best way to bind plastic is by chemical joining or bonding.


What is the importance of bonding plastics?

When compared to alternative joining techniques, chemical joining (bonding) of plastics have several advantages:

  • Even stress distribution 
  • No material damage
  • No linked parts’ warping
  • Various material combinations can be connected.
  • The joint is simultaneously sealed.
  • There are fewer parts needed.
  • They connect surfaces with uneven shapes more readily than mechanical or thermal fastening.

Guideline for bonding plastic:

  • Selecting the right mechanism, preparing the surface finish, and following a few basic guidelines are the first steps in securely bonding plastics.
  • Check the mechanical, primer, and thermal characteristics of the substrate and the plastic to ensure they are correctly prepared.
  • After cleaning the substrate, clean it one more time! Even a tiny bit of dirt or oil remaining on the surface might stop a proper bonding process.
  • Prove that the glue and the plastic are compatible. Amorphous (see-through) polymers may haze and break when exposed to certain adhesives.
  • We advise against using fast-cure adhesives since they will likely break after 24 hours of curing. Even materials specifically made to cure more quickly might result in crystallization and cracking.
  • Consider using a primer before applying the adhesive when working with materials like nylon, acetal, and polyester to increase bond strength. 
  • Bonding PTFE? All PTFE and PTFE mixes must be ready with one side etched before the bonding may start with this material.


Frequently asked questions

Does bonding stick to plastic? Or Are all plastics bondable?

Due to their partial dissolvability, some plastics, such as various amorphous polymers, such as PC, PSU, PPSU, PES, PEI, PMMA, PS, and some PI, are simpler to bind.

Certain plastics, including ABS and acrylic, are simple to stick to one another using adhesives and solvent cement. Some materials, including HDPE and PP, are more challenging to bind.

What is polypropylene?

Do you know that in 1954, German and Italian chemists Karl Rehn and Giulio Natta first polymerized polypropylene to create a crystalline isotactic polymer? However, manufacturing of polypropylene on a large scale began in 1957 after its discovery.

Propylene serves as the polymer’s monomer in polypropylene (PP) (an organic hydrocarbon with the chemical formula C3H6). (C3H6)n is the chemical formula for polypropylene. Normally, a chain-growth polymerization procedure having propylene is used to create polypropylene. This material can also be remoulded since it is a thermoplastic polymer, which softens when heated. Additionally, it should be noted that polypropylene has a partly crystalline structure and is non-polar.

Types of polypropylene

You will find two main types of Polypropylene thermoplastics: 

  • Polypropylene copolymers 
  • Polypropylene homopolymers.

Only semi-crystalline propylene monomers are found in homopolymers. The most common applications of homopolymers are in textiles, packaging, pipelines, medical equipment, and electrical devices.

When propene and ethene are polymerized, two types of copolymers are created: random and block copolymers. The polypropylene in copolymers has more desired characteristics because of the greater ethylene content. They have greater impact strength but are softer than homopolymers.

Key characteristics of polypropylene

The main traits shared by practically all varieties of polypropylene are: 

  • It has a great melting point, which makes it a popular material for microwave containers. 
  • It won’t degrade readily since it doesn’t react with water, detergents, acids, or bases.
  • Even when bent, it resists tension and fracture.
  • Because of its great durability, it can resist normal use.
  • Polypropylene is a substance that burns easily.
  • It is vulnerable to microbial assaults from things like bacteria and mould.

What is polypropylene used for?

Do you know polypropylene is used in various industries; some of them are as follows:

Packaging Industry:

Polypropylene is used to make Pallets, bottles, jars, yoghurt containers, hot beverage cups, food packaging, and other items.

Industrial Applications:

It is useful for returnable transport packaging (RTP), chemical tanks, sheets, pipes, etc.

Medical Applications:

You can use polypropylene for making disposable syringes, meal trays, pans, intravenous bottles, specimen bottles, Petri dishes, diagnostic tools, and other items.

Consumer Products:

It is used for making products like transparent components, household goods, furniture, electronics, bags, toys, and more.

Automotive Applications:

It can also be found in door trims, instrument panels, interior trim, bumpers, fender liners, battery cases, and trays.

Fibres and Fabrics:

Raffia/slit-film, tape, strapping, bulk continuous filament, staple fibres, spun bond, and continuous filament are examples of polypropylene used in the fabric industry.

Frequently Asked Questions on Polypropylene

Here are some frequently asked questions about polypropylene.


1. How can you increase the surface energy of polypropylene?

Because it has a high percentage of C-H bonds, polypropylene has a low energy surface. None of the atoms near the surface has lone pairs that may interact with external dipoles, and these have no visible dipole moment.

In order to form polar C-O-H groups, the surface energy is often increased by oxidizing it. Because the surface is often static, it is challenging to achieve this chemically. Instead, the surface is often etched using oxygen plasma. Although the essential tools seem complex, they are surprisingly simple and generally accessible.


2. What does a low surface energy mean?

The surplus interaction energy at a substrate’s surface is referred to as surface energy. Depending on their chemical composition, surfaces have a range of energies from high to low, which impacts the molecular force of attraction. A strong molecular attraction indicates high surface energy (HSE), which makes bonding easier. A weak molecular attraction indicates low surface energy (LSE), making bonding more difficult.


3. How do they increase surface activity?

There are generally two ways to increase the surface energy:

4. Is polypropylene low surface energy?

Yes! Polypropylene and polyethylene often have low surface energies.

5. Best practice for bonding low surface energy plastic

Low surface energy polymers needed these types of treatments:

  • Abrasion
  • Flame treatment
  • Coronary Discharge Therapy (CDT)
  • Surface Plasma Treatment
  • Chemical Remediation 
  • Before bonding, use primers or adhesion promoters.

Flame treatment of polypropylene

Do you know that flame treatment is the process of applying a gas flame to a material’s surface in order to increase adhesion? Since polyethylene and polypropylene have weak bonds, coatings like glue and ink cannot be applied to them without a particular process. Polar functional groups are introduced, and molecular chains are disrupted by rapidly applying high temperatures to a surface.

How do you flame treat polypropylene?

Numerous gas jets (propane torches) are arranged in a continuous row on a single burner to treat a surface quickly. Simply oxidizing the plastic’s top layer invisible will make it more “hydrophilic” and improve its connection ability.

The treated material is quickly passed in front of or beneath the inner cones. Less than a second passes when the surface is in contact with the flame. The surface is treated immediately before the material has a chance to melt.

The reactive chemical species break long-chain molecules in the plastic material in the gas flame and connect to the break sites to form polar point charges on the surface. The surface also grows rougher, and the adhesion level rises to a microscopic level.

Soil microorganism profiling service

Soil microorganism profiling service

The role of microbes is vital for the health of the human population. These organisms are largely responsible for maintaining the fertility of the soil and are indispensable to the development of food, biofuels, and chemicals. Some even act as weapons. In addition to their various functions, microbes play important roles in all aspects of human life. This article discusses some of these essential roles. 


Microorganism into molecule

Microorganisms participate in chemical reactions in nearly every environment on Earth. These microbes need liquid water, light, and nutrients to survive and thrive. They have evolved to adapt to various environments and have developed a variety of strategies to meet these needs. They gain energy from light, which is converted into chemical energy or oxidation of reduced molecules. These molecules may be organic or inorganic.


The different functions of the microbes 

Microbes have different functions. Some of the functions of microorganisms help plants grow, while others use the energy from light absorption to produce ATP, the cellular energy storage. This energy is used by microbes to carry out a variety of tasks. Some, such as bacteria, use the light they absorb to produce energy. Lastly, they act as carriers of toxins and waste materials. The function of microorganisms is crucial for the health of humans and the environment.


The Role of Microorganisms in Soil

In agriculture, microorganisms play an important role. These organisms can help with soil degradation, nutrient cycling, and even disease suppression. Bacteria in the soil decompose organic matter and produce nutrients. They also make phosphorus available for plants and increase the availability of the mineral. Despite their tiny size, bacteria play an essential role in agricultural production. In the long run, their presence in the soil is beneficial for plants and farmers alike.

There are two types of soil microbes: 

  • fungi
  • bacteria.

Fungi are unusual organisms that group together in hyphae. These hyphae are less than 0.8 mm wide and hundreds of meters long. These fungi play an important role in the agricultural sector. 

  • They help maintain soil structure and improve drainage. 
  • They help convert stored nutrients to forms that plants can use. 

However, some of these organisms are harmful and can affect crops. Slugs and nematodes are pests that cause crop yield. These organisms release toxins into the soil and eat plant roots. Soil fungi also provide beneficial relationships with plants.


Agricultural processes 

Soil organisms play an important role in agricultural processes. Many of them are beneficial to plants. Some are beneficial to humans and other animals. Some are useful indicators of soil quality. While others are harmful, most play a critical role in decomposing organic matter and cycle nutrients. They are essential to the overall health of the soil. They are also an important indicator of the health of crops and other plants.


Profiling Services

If you’re a researcher looking to understand the diversity of microbiome communities in the human body, it’s worth learning more about microbial profiling services. This comprehensive analysis includes multiple features and can help you identify any potential diseases. There are many different methods for determining microbial composition, and there are companies that specialize in different kinds of samples. To find out which one is right for your needs, read on for more information.


Get more insight 

If you’re a biotechnologist or scientist wanting to study the microbial composition of your sample, 16S/ITS microbiome profiling services are a great way to move quickly from challenging samples to valuable insights. These services also include a method for detecting rare bacterial and fungal taxa, which can be difficult to isolate using conventional PCR. And since these types of microbiome profiles often require highly purified samples, these services are a good option for researchers who need to identify the bacteria and fungi in their microbial communities.


Choose the right for you 

The best microbiome profiling services also offer advanced techniques to eliminate PCR inhibitors and heavy metals. Using 16S/ITS amplicon sequencing, microbiome profiles can be completed in a matter of weeks, with results delivered within two to three days. This method also eliminates the need for PhiX spike-ins, which decreases background contamination in low-DNA input samples. The microbial profiling services that you choose should provide you with a personalized report to support your research.

Is there an end in sight for lost airline baggage?

airport airplane

Sponsored Article

Imagine the scene; you’ve arrived at your holiday or business destination and are waiting patiently at the baggage carousel for the cases to start arriving from the plane, the alarm sounds, the carousel starts to move, and bags start to appear. Half an hour or so later, with almost everyone else having come and gone, there’s just you and a random bag going around and around. It’s not your bag. Fearing the worst, you head to the information or lost baggage desk to be told your luggage is, as yet, nowhere to be found and you have that hideous sinking feeling that you might well be wearing the same pair of socks for the next week or so, unless the bag gets found. Read more

Plasma etching applications

Plasma etching used in industries

Plasma etchers can be used to show failure analysis

A form of plasma processing used to fabricate integrated circuits is called plasma etching. A high-speed stream of plasma discharge or glow with an appropriate mixture of gas being shot in pulses at a sample truly defines the plasma etching. Analysis is performed in many different businesses and companies, for instance data analysis can be used to understand complex patterns.

However – Another technique to surface treat, is to use liquid etchers. However, this comes at a environmental cost, and is often a lot more costly.  The source of plasma known as etch species can be charged ions or atoms and radicals that are neutral. During the plasma process volatile etch products are generated at room temperature from the reactions of chemicals between the elements of the material etched and the reactive species that has generated the plasma. Furthermore, the atoms eventually embed themselves at or just below the surface of the target and this modifies the target’s physical properties. This is a very environmentally safe method. Read more

Calibrating your measurement microphone

Measurement microphones are, of course, designed to take measurements with scientific accuracy. In the same way that you wouldn’t use a microscope without first calibrating it, the same applies to the microphone equipment you’re using too.

What is calibration?

Simply put, calibration is the fine tuning to the set up of your equipment to maximise performance and accuracy of output. Just as Formula One engineers will calibrate their tyre pressures for optimal grip and durability, by calibrating your microphones and equipment, you can ensure consistent performance and measurements. Read more