Gluing of plastics
Gluing plastic is a very broad subject that cannot be described with words like "easy"
"hard" or "recommend ".
The large number of different plastic materials often react far differently when glued and the design of the piece is
crucial for a good outcome.
Generally we can say that Induflex prefer producing plastic part that should not be glued, as it is often troublesome, takes a long time
and is difficult to achieve a consistent result.
Instead of gluing, we often recommend to redesign the part to be bend or use different locking systems.
Successful gluing requires usually nontransparent materials which can easily bind to the glue
and large adhesive surfaces.
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Gluing of plastics
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Gluing acrylic
Acrylic can be glued so that the join will be almost as strong the acrylic itself.
However, this requires careful preparation. The acrylic surfaces must be carefully
prepared with removing of tensions, degreasing and cleaning before the glue is applied. Next,
the surfaces most be tighted together while the glue hardens.
Many of the tasks that Induflex perform in acrylic can not economic justify the
man-hours
necessary for a very good result. Often we choose a solution
where the tensions are removed from the parts and then glued without cleaning. The result is not
as reliable, but often enough for the purpose.
Colored Acrylic
gives a better result than clear acrylic, simply because the glued surfaces are invisible. Gluing of clear acrylic is difficult because they often
visible air bubbles disfigures the outcome.
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Heat bent and glued 3 mm acrylic
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Gluing of technical plastics
Gluing of technical plastics are usually related to the plastic types resistance to chemicals - More resistance makes it difficult to glue. The two widely used materials PEHD and POM are
both chemical resistant and difficult to glue. There is no big tradition to glue technical plastics. Induflex also get few queries accordingly.
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Glued PVC
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Gluing plastics to other materials
In most designs involving glued plastic, it is parts of the same plastic type that are glued together. But sometimes the materials are different, two different types of plastics or
plastic against metal.
Gluing plastics of different types is often possible if the two types of plastics are close to each other chemically.
Some plastics cannot be glued together.
Gluing plastic to metal is also problematic but not impossible. You have to paid
attention to the different thermal expansion. Eg. the expansion coefficient of acrylic 5 times higher than steel.
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Typically polyester design when gluing to aluminium. The elongated holes takes into account
the polyester and aluminium expand differently with temperature
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Gluing with UV glue
Some glues are designed to harden when exposed to UV light. The major
advantage is that the hardening is reduced to seconds by illuminate the clue with a
powerful UV lamp.
UV glue is not
chemical linked to the plastic, but only binds the surfaces together. Thereby
UV gluing is not quite as strong as chemical cluing. Moreover, it can only be used
when one material is UV-transparent, like clear acrylic.
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UV gluing
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Alternative to gluing
Instead of gluing is often worthwhile to consider other assembling methods.
- Heat and cold bending
With a little imagination, many gluing tasks can be solved by bending the material instead. Note that not all plastics can be bent (see Bending section).
- Double adhesive
double adhesive is an inexpensive solution that can be used when the weight of the piece is relatively small in
compared to the adhesive surface. It is used in large extent with letters and
Signage
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- Locking systems
With locking systems (see image to the right) plastic sheets are
interlocked. Sometimes in combination with clue. The method has become popular for sales displays using impact-resistant acrylic.
Plain acrylic is too brittle and break if used this way.
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Locking systems can be made with impact resistant acrylic.
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Gluing of plastics
Gluing Acrylic
Gluing of technical plastics
Gluing plastics to other materials
Gluing with UV glue
Alternative to gluing
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