How to determine the type of plastic and firmly glue it with epoxy or solvent?

It’s annoying when my favorite thing is made of plastic, but he could not bear the load and broke. It is not so easy to throw out a hand, and making a seam by welding at home is not so easy. I would like to find something to glue the plastic tightly, it’s only obvious that this time we can’t do super-glue: the product is used often, constantly subjected to stresses, so you need to glue it as firmly and accurately as possible. So which glue is better to choose for such a job?

What glue is better to use?

To begin with, it is worth deciding which glue it will be more appropriate to glue the plastic parts, and the choice, in fact, is small: relatively simple, convenient, but not too strong or more complicated, but tightly.

Epoxy or polyurethane adhesive

With these types of glue, you can glue any type of plastic together, as well as plastic with other materials, which is extremely convenient, especially if you do not know and do not want to know anything about the compatibility of types of plastics and solvents. It is more difficult to use such glue than the usual “Moment”, but if needlewomen cope with it with a bang, fastening the parts of the jewelry, then you can mix the two-component glue in the right proportion according to the instructions.

These types of glue seem to cling to the plastic surface of both pieces that you want to glue, therefore the gluing strength is not so high: under heavy loads, intensive use or temperature extremes, such a seam will significantly lose in the strength, so those who need to glue the parts tightly, we do not recommend this method.

If you decide that such gluing is enough, then slightly sand the surface of both parts to improve the adhesion of the glue, wash them, dry and degrease them. Then mix glue and glue the surfaces. Epoxy glue dries for about half a day, and dries completely in more than 24 hours, so it is important to fix the parts to be glued and not to subject the product to load in the first 1-2 days after gluing.

Important!

When mixing the components of epoxy glue, take the proportions seriously and do not mix them by eye. If the surface to be bonded is small, you may need to use a syringe.

Solvent-based adhesives or solvents themselves

If such a flimsy bonding does not suit you, then solvent-based adhesives, which react with the plastic to dissolve it and when dry, will provide an extremely strong adhesion to glue the plastic firmly. The gluing process itself is simple, but you will have to prepare in advance, having understood the types of plastics: different types of solvents are suitable for different types, and there are a lot of both, so it is better to check the compatibility on the Internet or consult a consultant in a store where You will buy glue.

But you still have to understand what type of plastic you are dealing with if you do not want to bring the product to the store for examination by a consultant, and especially if you are going to choose a solvent yourself. So the search for markings will be your first step.

Determine the type of plastic

All products made of plastic are marked, so if you carefully inspect the product, you will surely find either a triangle of arrows, or a kind of quotation mark with an abbreviation or number. This is the type of plastic for which it is necessary to choose a solvent.There are many types, we list the most popular groups.

• Polyethylene and polypropylene (2, 4, 5, HDPE, LDPE, PP, UMHW). If you ever tried to glue a plastic bag, then you know that this is a bad job. These types of plastic really can not be glued, and although some manufacturers produce special adhesives, their effectiveness is several times lower than that of a conventional weld.

Tip

For plexiglass and polystyrene, dichloroethane is a good choice because of its ability to strongly dissolve and adhere firmly. But because of the strong toxicity it can not be used for gluing dishes and some other things that you often come into close contact with.

• Polystyrene (6, PS). This type of plastic is very common and, fortunately, it glues well with a large number of adhesives: from epoxy to cyanoacrylate adhesive, which is an ester - one of the best solvents for polystyrene. Amylbenzene, benzene, toluene, tetrahydrofuran or cyclohexane can also be used as a solvent.

Tip

For bonding polystyrene with other materials, it is better to choose adhesives on bitumen or polyacrylates.

• Acrylonitrile Butadiene Styrene (7.9, ABS). This plastic is imported in overwhelming volume, as well as used in imported goods: models, designers and even cartridges for 3D printers. It’s only that it is soldered, it is still better than glued together. Problems can arise with its dissolution: it is durable, and you can try to dissolve it, perhaps, only with dichloroethane. In this case, there will be little solvent and you will have to prepare the glue.

Tip

Bonding with solvents is stronger and more accurate, since it is carried out only due to the bonded material and does not involve the use of foreign substances.

Of course, this is far from all types of plastic, and about the one you are going to glue, you will have to read more on the Internet. But as soon as you find the right solvent, the scheme will be the same for all plastics.

Start gluing

For most plastics, a simple surface treatment with a solvent may suffice, although if you need to glue it firmly for centuries, and in the case of ABS plastic, you will have to make glue.

• Solvent

To glue with one solvent, you need to apply it on both surfaces to be glued, wait a little while the solvent softens the surface layer, press them firmly and fix, and then wait for complete drying, which is achieved after 1-2 days.

• Solvent based adhesive

For glue, you will need a solvent and chips of glued plastic. Chip for about 30 minutes is dissolved in the appropriate substance in a 1: 1 ratio, then the resulting homogeneous mass is applied to the parts and glued together, fixing them for the next day. When the solvent evaporates completely, a strong adhesion forms at the bonding site.

In any of these cases, the surfaces must be clean, dry and degreased before gluing: after surface treatment, try not to touch it with your hands.

If you understand the theory, then in practice gluing plastic will not be so difficult. The main thing is not too lazy to calculate the type of plastic, choose the right solvent and glue it carefully!