home · Other · Polishing and processing of products made of PLA, ABS, HIPS. How to make liquid plastic with your own hands? Manufacturing technology and scope of application What corrodes plastic

Polishing and processing of products made of PLA, ABS, HIPS. How to make liquid plastic with your own hands? Manufacturing technology and scope of application What corrodes plastic

material that is highly resistant to many chemicals and exposure to fire.

PVC has relatively low frost resistance (-15 degrees).

The heat resistance index is +65 degrees.

Let us note several main advantages of the material:

1. does not dissolve in water

2. Resistant to acids, alcohols, alkaline solutions and mineral oils

3. Compatible with some plasticizers.

4. has low flammability and high resistance to oxidation

5. Easily dissolves in the following substances: esters, ketones, hydrocarbons (both chlorinated and aromatic)

We are especially interested in the fifth point: the solubility of PVC, namely what substances can be used to do this.

Interesting! How to glue PVC panels to liquid nails,

Below are the best means for dissolving polyvinyl chloride.

Solvent for PVC

Based on the above, we conclude that ketones, ethers and hydrocarbons are ideal for dissolution.

This means that it is necessary to use products that contain one of the presented components.

There are more than enough such funds. There is no end in sight to the variety of prices and varieties. We have chosen two that meet the price-quality ratio.

TetraHydroFuran (THF) - chemical colorless liquid substance with a characteristic ether smell. It has found its application in organic synthesis.

Excellent for dissolving polyvinyl chloride to a paste-like state. Can be purchased at any specialty store.

Cyclohexanone is a clear oily liquid with a pronounced odor of mint and acetone.

The substance in question is typical representative ketones, which, based on what was written earlier, is well suited for dissolving PVC.

Interesting video of dissolving polystyrene foam in acetone

In everyday life, many have encountered such a problem as broken plastic products. These items can rarely be repaired with your own hands; it is safer to seal them. You can decide how to glue plastic tightly by considering the best adhesives for various types and adhesive technology.

Adhesive for plastic (click to enlarge)

Determining the type of plastic

Before gluing plastic, it is important to first determine the type of material of the broken item. This is important to do in order to better glue the plastic and not spoil the product - many adhesives are solvents for plastic parts.

Most often, the manufacturer labels its products with a recycling symbol, which can be used to determine the type of plastic. It is a triangle with drawn arrows on the edges, inside there are numbers from 1 to 7.

Another indication of a brand is the letter symbols inside or next to the triangle. Knowing these designations, you can determine the type of plastic and then the appropriate plastic adhesive for it.

Marking

1 or PET is polyethylene terephthalate. Main application: packaging food products. It is used in the production of artificial fibers, plastic packaging for liquid food products, and films.

2 or HDPE - high-density polyethylene using low-pressure technology. Used in the production of shrink film and packaging bags.

3 or PVC - polyvinyl chloride (PVC) is used in the manufacture of linoleum and plastic windows.

Watch the video to find out more:

4 or LDPE - low-density polyethylene technology high pressure. Food grade plastic is used to make bags, wrappers and bottles, greenhouse film, packaging containers, toys for children, and pipes.

5 or PP - polypropylene, due to its inertness and heat resistance (it can be kept under hot steam and boiled), is widely used in the production of food packaging. The material is widely used in medicine (disposable syringes, catheters), in production household appliances, heat-resistant dishes and plastic pipes for hot water supply.

6 or PS - polystyrene. Disposable tableware (cups for food products), inner plastic sheathing refrigeration devices. When foaming polystyrene foam, it becomes porous insulating material(foam plastic) widely used in construction and manufacturing.

7 or O (Other) - materials that cannot be recycled (combine a combination of foil, paper and polymer materials) or not included in previous groups.

One way to determine the brand of plastic in the absence of a sign is to test it by burning. Each material burns differently and with a different smell, from which you can determine its type.

Marking of adhesives

In addition to plastic, glue for plastic is marked with symbols, although this designation rarely coincides with the recycling marking symbols. To know how to glue plastics together, the following letters are written on the adhesives to designate the materials being glued:

Designation for plastics (click to enlarge)

  • polycarbonate - PC;
  • acrylonitrile copolymer - ABS;
  • polypropylene - PP;
  • organic glass - PMMA;
  • polyethylene - PE;
  • polyvinyl chloride - PVC;
  • polystyrene - PS;
  • polyamide - RA 66;
  • polyurethane - PUR.

Often it makes no sense to look for the markings on the glue packaging; it is enough to study the instructions in Russian, which clearly explain what types of materials the glue is intended for and how to glue the plastic.

Types of adhesives

There are many types of plastic products and they are widely used in everyday life, so gluing plastic can be done with a wide range of adhesives and different methods.

One of the gluing methods is to soften the surfaces of the parts to be glued with a suitable solvent (dichloroethane for plexiglass or polystyrene); after joining, the seam is securely soldered. In a similar way, you can make your own glue by dissolving small plastic shavings.

Kinds good adhesives for plastic (click to enlarge)

Liquid

Popular household adhesives are easy to use and come in two types: solvent-based or water based. The principle of operation of the first is as follows: water or solvent evaporates from the glue applied to the top of the plastic parts, the adhesive seam dries with further hardening, due to this the parts hold tightly.

Such adhesives can glue plastic with porous materials that allow air to pass through, otherwise the water and solvent will not evaporate and the glue will not harden.

Good liquid PVA glue is known in everyday life and industry, widely used in furniture production for reliable gluing of artificial films on wooden surfaces, in the construction industry, linoleum is often glued to PVA. Other liquid adhesives are made on the basis of rubber resins, in this case the solvents are methyl acetate, alcohol, and acetone.

Contact

The name was given because of the gluing principle: before gluing plastic to plastic, the surfaces of both glued products are coated with glue and after 10 - 15 minutes they are firmly pressed against each other. There are two types: with hardener and without hardener, the best known brands are BF-2(4), “Moment”, rubber glue.

In the video you will learn how to use contact adhesives:

Adhesives contain toxic materials, so at home, before gluing plastic, it is necessary to ensure the room is ventilated.

Reaction adhesives

There are one-component and two-component types. The former, when applied to the surface to be bonded, harden very quickly from interaction with oxygen or water vapor. These types include the well-known “Secunda”, “Superglue” and other analogues that can be sealed to form a rigid and durable seam.

Two-component ones have a hardener and a fixer that are located separately from each other. Before being used for gluing, they are combined and, after being applied to the surfaces to be bonded, under the influence of environmental conditions, they gradually begin to harden and glue the parts. Their base is various resins, most known species- polyurethane, epoxy, polyester.

Can be done using various means: acetone, methylethylethane, dichloroethane, tetrahydrofuran and dichloromethane. For safety reasons, it is preferable to use tetrahydrofuran and dichloromethane for these purposes, since methyl ethyl ketone or dichloroethane are highly toxic. Acetone is not very good for similar reasons, although it is a very affordable solvent. For materials such as ABS, PLA, HIPS, SBS and other types of plastics, solvent is used quite often. However, experts recommend as a more safe alternative D-Limonene product. In addition to being safe, this solvent also has a pleasant citrus aroma.

Safety - important condition when performing post-processing, therefore, it should be borne in mind that a number of substances, such as dichloroethane, are classified as powerful poisons, so they cannot be used. Dichloromethane is considered less toxic, but it also poses risks to human health. Not very toxic tetrahydrofuran is almost never found in the public market.

Warning:

Methods proposed in the article production process require strict adherence to safety measures. Therefore, before performing work, you should carefully read the chapter “Safety precautions when working with solvents”, safety data sheets for chemical products.

Post-processing of plastic: the essence and objectives of the process

In the FDM 3D printing process, we obtain objects with obvious traces of layering (irregularities), as well as various artifacts of the production process (traces of points of contact with fasteners and other visible surface defects). Post-processing serves to smooth out uneven surfaces and remove unnecessary artifacts, after which the processed object will look much better.

Safety rules when working with solvents

Dichloromethane

Since the 19th century, dichloromethane has been classified as relatively non-toxic and very effective means for plastics, which has been proven by numerous laboratory research. But this solvent also has disadvantages. When connecting with alkali metals Dichloromethane may cause a violent explosion. The mild volatility of the product leads to rapid and severe poisoning of the body and damage to a number of important internal organs. Therefore, it is recommended to carry out any work with dichloromethane in the presence of properly functioning exhaust ventilation.

Do not allow the substance to come into contact with fire or sparks, otherwise it may cause a fire. Do not pour dichloromethane into the toilet or sink, as the substance does not mix with water and can damage plastic fittings. In its properties, dichloromethane is very similar to acetone and tetrahydrofuran. It has the same high volatility and hazard class IV. Although the odor of dichloromethane is weaker than that of acetone, ventilation of the room should not be neglected.
D-Limonene

Among the currently known solvents used for working with plastics, D-Limonene is rightfully considered less harmful and relatively safe for humans, provided that all precautions are strictly followed. The citrus aroma makes working with the solvent more pleasant. However, it is necessary to ensure that the room is well ventilated, since prolonged exposure to the substance has a negative effect on the human body. D-Limonene soap base makes it easier to neutralize the reaction of plastic with solvent, since in such a scenario it is enough to use water and soap. The only one significant drawback substance is the fact that it interacts only in HIPS and SBS plastics.

Please note that no matter how relatively safe the solvent is, when working with it you should use gloves and ventilate the room well. Gloves will help prevent skin damage or dehydration.

Processing methods

Dip processing method

Dip processing is the simplest and most quick method, because one cycle lasts a maximum of 3 minutes. An example is immersing iodine in dichloromethane. The immersion process lasted several seconds, and after a few minutes the solvent completely disappeared from the surface of the object. If you want to get a glossy surface, the product can be immersed in the solvent again for about half a second. This will be enough so that the solvent is not absorbed and quickly evaporates, and after the operation you get a glossy surface.

The duration of the process is very short also because for such purposes a bath and acetone are not needed. For ABS, PLA, HIPS and other rare Supplies Dichloromethane is fine. One liter of product is enough for for a long time, the main thing is to maintain the tightness of the container with the solution.

Brush method

In this case, dichloromethane should be applied with a clean brush with bristles made of natural hair. The substance, by the way, is very volatile, is applied until the surface is completely smoothed at the places where the layers come into contact. Dichloromethane is excellent when selective application of solvent is required to leave corners intact and remove obvious defects. Practice shows that this method allows you to achieve the best results in the post-processing process. And, of course, do not forget about observing safety precautions.

In addition to dichloromethane, a substance such as XTC-3D from Smooth-On is very useful for high-quality surface treatment with a brush. This material is protective covering of two elements and serves for high-quality alignment and finishing 3D objects. During the processing process, two types of liquid are mixed, and then the mixture is applied to the surface of the product with a brush. The application procedure must be completed within five minutes. Curing occurs within 4 hours, depending on the mass of the object and temperature. XTC-3D has a number of important properties: It creates a hard, impact-resistant finish that can be sanded, primed or painted.

The manufacturer claims that XTC-3D can be used for products produced using SLA and SLS technology. The substance works excellently with PLA, ABS, Laywoo, polyurethane foam, wood, gypsum, cardboard and even paper. Externally, XTC-3D is similar to ordinary epoxy glue, and the substance does not have an unpleasant, persistent odor.

Steam processing method

PLA vapor processing is similar to the procedure ABS processing acetone. Tetrahydrofuran is used as a processing agent. The PLA product being processed must be placed on an insoluble support. For these purposes you can use aluminum foil or wire mesh. After this, the product is placed in an airtight container. The solvent evaporates when heated and interacts with the surface of the object being treated.

In the photo above, the shark tooth was made on a Makerbot Replicator 2 using brown PLA plastic, then treated with THF and dried.

If you look from above uneven surface, you will understand that during post-processing there was a place where the object came into contact with the support. This suggests that before work you need to think carefully about which part and where to lean the product. Calculating the time for uniform gas distribution inside the chamber becomes more difficult the smaller the volume of the printer's working chamber. The unevenness of the leveling process can be explained precisely by this reason.

Manual polishing method

The manual polishing procedure is familiar to many, and if you do not want to use the steam processing method, then you can pay attention to this quite simple and effective method. The solvent will have to be applied to a piece of fabric and polished by hand. For this procedure, use a white or undyed lint-free cloth. Otherwise, PLA particles will remain on the fabric, and then you will not be able to use it again.

The use of fabric does not exempt you from observing basic safety precautions. The room should be well ventilated, and nitrile or neoprene gloves should be worn. The fabric needs to be wetted with dichloromethane and after that you can start polishing. The result of the work is determined various factors: how the movements were performed, what forces were applied, and even how stiff the fabric was. Polishing is usually done in a circular motion unless otherwise specified.

After completing the polishing procedure, the product must be allowed to dry. In this case, the substance will completely evaporate.

The photo was taken with macro photography, the depth of field is shallow, but the main focus is highlighted in order to see the details. The middle part of the tooth was polished. The results were very good. For comparison, pay attention to the left side, where print marks are visible.

It should be remembered that the size of the object and the printing parameters determine the amount of polishing effort. How smaller product and the higher the print quality, the correspondingly less effort.

Other post-processing methods

There are many other post-processing methods. For example, ABS plastic can be treated well with regular sandpaper. You can achieve smooth surface using several types of sandpaper and a fine sanding sponge. At the same time, do not forget about the thickness of the walls, otherwise you will rub a noticeable hole in the product. Sandpaper or a file is usually good for removing support marks or noticeable imperfections. Care must be taken when processing PLA plastic. But you should not grind with a drill, grinder or just long grinding. Friction will lead to an increase in the temperature of the treated area, the plastic will soften and begin to roll off. The quality of the surface will only suffer. Therefore, when processing products made of PLA plastic, you can use special resins for surface treatment (like XtC) or use solvents. Glue the parts fromPLA plastic can also be made using dichloromethane.

Good luck!

Greetings!

On the pages of thematic resources, questions still often appear about how to process and glue this or that plastic. Moreover, the answers sometimes cause bewilderment. Apparently, there are a lot of myths and confusion in this matter.

In this regard, I decided to write a short educational program on basic plastics and solvents, especially since I personally smelled almost all the chemicals that will be discussed.

So, let's go!

Dichloroethane

You can hear different opinions about dichloroethane. Some say that it is very poisonous, others claim that they have worked with it without gloves all their lives. Apparently, this is due to the fact that dichloroethanes come in different varieties.

1,2-dichloroethane (ethylene chloride) - dangerous toxin!(second class). 1,1-dichloroethane (ethylidene chloride) is 5 times less toxic, but also far from being an air freshener (hazard class 3). Personally, I do not recommend checking for yourself which dichloroethane was sold to you.

I mention this chemical only because it is quite common and cheap and is sold in small vials, so it can help out in a critical situation when there is no more at hand. suitable option. Don't forget about safety precautions!

Dichloromethane(methylene chloride, methylene chloride)

Colorless volatile liquid with a faint odor. The best option for working with PLA. It has the same hazard class as acetone - fourth. Cheap, but difficult to obtain at retail in the provinces.

For reference:

PLA is also soluble in tetrahydrofuran and 2-methyltetrahydrofuran (hazard class 3).

Acetone

Acetone does not dissolve PLA as we need, but with prolonged contact the plastic swells, warps and softens. This can be used if the nozzle is clogged when printing PLA. When soaked in dichloromethane, plastic turns into slime, which can be difficult to clean completely.

But after soaking in acetone, the softened PLA will be removed from the nozzle in one lump, along with the blockage.

I came across opinions online that PLA dissolves in limonene and high-octane gasoline such as Galoshi. It is not true! PLA does not interact with these substances in any way.

Again, dichloroethane and dichloromethane.

Acetone- I think it needs no introduction.

Ethyl acetate(4th hazard class) - not as smelly as acetone (rather even aromatic). It is more convenient to work with it, because... it does not evaporate as quickly as acetone and dichloromethane, but it can be difficult to find.

Dichloroethane, dichloromethane.

Limonene(d-limonene) is an oily liquid with a strong citrus odor. Expensive and difficult to obtain in the provinces. Compared to our other solvents, it evaporates very slowly, so it is convenient to work with, but you need to get used to it, because... it works for a long time. For example, after dipping for too long, the model will not “float” immediately.

The safest of our chemicals.

SBS (Filamentarno, Watson)

Here I will simply quote information from the Filamentarno website. Well done guys, they sorted everything out before me.

Solvent(nefras) GOST 10214-78

It dissolves perfectly and gives T-Soft series plastics a unique transparency similar to glass. Excellent fusion and leveling of layers. After processing, the plastic does not become cloudy. Solvent treatment is recommended in a dry, well-ventilated area.

D-limonene

Slowly and gently dissolves plastic, requires longer drying with warm air (using a hairdryer). IN pure form(citrus terpene) does not cloud the product when it dries. After processing it leaves a pleasant smell of tangerines on the plastic :)

Dichloromethane

Prototyper dissolves well; when dry, the plastic becomes cloudy, acquiring the effect of foggy glass. It evaporates quickly and has virtually no odor.

Safety precautions

For all of the plastics mentioned, there are solvents with a hazard class of 4 or lower. It's better to use them. These are mostly volatile and flammable substances, so work away from fire, ventilate, read the safety rules on the label.

In Ob it costs around 600 rubles.

Polypropylene gloves are suitable to protect your hands, because... polypropylene is resistant to all our solvents (therefore you can use polypropylene containers, syringes, etc.). But you can also use ordinary household ones, just be careful. Upon contact with dichloromethane, they begin to degrade, but not very quickly.

For example, it is quite possible to wet a cloth and walk over a medium-sized model.

It seems like I haven't forgotten anything. Thank you for your attention.