Bondyram TL Multilayer Adhesive Resins
Bonyram® TL –Bonding is more than just sticking together.
When looking for the right bonding resin to tie layers together, the search for the ideal candidate can sometimes
resemble looking for a marriage partner. After all, we all want to find the best suitable match. Luckily, with a bonding
agent, the search can be systemized by asking three questions and defining your requirements accordingly.
Why? – To what end are you looking to create a bond between two materials and in which applications will the final product be used?
What? – What substances are being bonded and in which conditions will the required bonding level be achieved?
How? – How is your final product produced and what costs and equipment does this entail?
These questions may seem simple enough, but the answer, as is often the case with industrial products is more
complex. Read more to learn about the Why, What and How that will allow you to make an informed decision when
selecting a bonding agent to match your needs.
Why – Did you know bonding is used in food packaging and other applications?
Tying layers with a bonding agent is a solution implemented in many industries. For example, food packaging to prolong
shelf life, reinforced piping for construction. , and sealed packaging of various products
Ethylene vinyl alcohol (or EVOH) is a formal copolymer of ethylene and vinyl alcohol, which is composed of carbon,
oxygen and hydrogen. It has outstanding barrier properties and is transparent. Thus it is ideal for being used in
innovative food packaging for blocking out oxygen. Other layers can also prevent penetration of water and light (not just
air). Food producers thus prolong shelf life without preservatives.
Pipes that are made with combined layers of polymers and aluminum are stronger, more stable, and easier to install
with less joints. Piping manufacturers, installers and users all enjoy many benefits with this type of product. Plastic resin
bonded carbon fibers are the core material in combat and civil aviation constructions.
With medical and cosmetic products, chemicals and detergents the main point of concern in packaging and
transportation is that nothing comes in or out. It is important that the products remain unaffected by the environment
(humidity, light or air) and will not be contaminated, (for example – so it can maintain its medicinal integrity). On the other
hand some substances can be dangerous or bad for the environment and must not leak out during delivery and storage.
Polyram’s Bondyram® TL adhesive resins allow for creating a multilayer structure of dissimilar materials that are bonded
together for applications such as coextruded food, cosmetic and pharmaceutical packaging or barrier packages with
EVOH. Bondyram® TL4108 is certified for direct contact with foods. It is not common to receive such certification as the
guidelines are very strict.
Other Bondyram® applications include multilayer pipes and pipe coating, fuel tanks and aluminum composite panels.
How to select an optimal bonding agent? Let’s look at that next.
What – The holy trinity for bonding: Time, temperature, pressure
After having set up a list of bonding candidates with suitable chemical affinity, selecting the bonding agent will affect the
production process of the final product. This is why it is best to look for a match to existing and familiar production
procedures. When looking at production, the first definitions relate to what we like to call “The Holy Trinity”:
Time, temperature and pressure. These three factors are responsible for creating the desired bond – a chemical
connection between materials on the molecular level.
Matching a high quality bonding agent with the materials it bonds and the conditions of the bonding procedure will
enable a high level of bonding, even in extreme conditions.
Polyram tests its Bondyram® TL adhesive resins using the Film Casting method. In an article in Sciencedirect.com
Film Casting is defined as “a widely used manufacturing process used to shape polymers into high quality films for
packaging or other industrial and commercial purposes.
The relevant steps of the manufacturing process are the longitudinal and transverse stretching, in which the
material assumes the required dimensions and mechanical properties.”
One can be assured that if the bonding did not fail in the typical minimal time of the film cast, bonding will not fail in
other, less extreme methods, such as blown film, thermoforming sheets, molded bottles and tubes, coextruded pipes
and extruded coatings. At Polyram the pre-production testing phase ensures we get “The Holy Trinity” of bonding just
How – Chemical bonding in production
Now that the materials bonded and conditions of the bonding process have been determined, the next step is looking
into the production procedure, with its operational, cost and quality concerns.
Questions regarding the equipment and production procedure include:
- What type of machinery is involved in creating the final bonded product?
- What production procedure is used? Cast or blown film? Thermoforming? Extrusion? Injection? Molding?
- Are round grains important – will they enable faster transition of raw materials in the production pipeline?
Polyram is one of a few companies that specializes in the production of bonding resins for multilayer products (as well
as other coupling agents). We have a large variety of products suited to many uses in industry. We go the extra mile to
find the perfect solution or tailor it for our customers.
Operational considerations can affect production decisions and logistics.
- Conservative Innovation! Henry Ford is quoted to have said“Any customer can have a car painted any color that he wants so long as it is black” . This remark makes sense to any manufacturer. In industry, keeping things simple is key. Maintaining a well-practiced procedure in production while introducing innovative materials makes industrial business sense.
- Commerciality! Delivered cost is affected by distance, packaging (cartons or sacks), taxes, and supplier prices. In
order to reduce these, manufactures are looking for flexible models and close proximity to resources.With offices located worldwide and production facilities in Israel, China and soon in the US, delivery time can be short and batch sizes are flexible.
We provide tailored innovative solutions. We find the right bonding agent for your process. We test the bonding
quality and analyze the production procedure in our dedicated facility using small quantities, verifying all properties
and operational issues before mass production begins. Any factory downtime risks are determined and we customize
and optimize the procedure to avoid or minimize them. There are no surprises – with Polyram you know exactly what
you are going to get.
When looking at cost, there are two main questions:
- Can the bonding agent be diluted in the bonding layer? Is co-extrusion of the bonding agent with another material in the same layer possible? Dilution saves on the quantity of the bonding agent, thus reducing product costs.
- Another concern is the cost of other raw materials and the monetary significance of quality failure.
Raw materials for a multilayer film are sometimes very expensive. The bonding adhesive is only a small portion of all
the components (usually 5-10%). Selecting an unsuitable bonding agent may result in losing the entire batch and
baring considerable costs.
Quality concerns are divided into three categories:
- The quality of the raw materials
- The desired bonding level
- The required quality of the final product
It is important that the quality of the bonding agent or that of the carrier component is not degraded/crosslinked
during the production process, and the required level of bonding is achieved.
Here are typical examples of final product quality issues:
- When Polyethylene (PE) cross-links, it loses its thermoplastic characteristics, turning into a partially thermoset gel. This gel is tougher than ordinary PE which might be a disadvantage. Quality standards indicate that “Controlled Low Gel Content” is considered a high quality product.
- Oxidation/partial burning in the production process may leave black dots or cause opacity in the final product. Such defects may not substantially affect the mechanical properties of the material, but they might be indicative of gel content and in some industries they are not acceptable.
With a strict quality control procedure that is inspired by the standards of the automotive industry, Polyram ensures
only the best materials leave its gates. Polyram has achieved a gel content grade that is close to zero.
Choosing a bonding agent includes many parameters, we hope this article has helped you determine what they
might be and has assisted in organizing them.
For further information about Bondyram® TL: http://www.polyram-group.com/bondyram-tl