Forms for concrete products from elastomer, plastic

Construction and decorative concrete products in most cases are made by injection molding. The more refined the shape and finer the details of the products, the greater the requirements for the quality of the molding tool. Today, factories and small enterprises offer various forms for the production of concrete products of any category of complexity.

Areas of use

Since concrete began to be used as a building material, the possibilities of using products from it began to expand.

This is what comes out of shape and what we see daily.

1. Statues, flowerpots, borders in parks and squares.
2. Concrete building blocks.
3. Concrete paving slabs of various shapes.
4. Facsimile copies.
5. Architectural accessories.
6. Drainage trays.
7. Reinforced concrete slabs for construction.
8. Fences, including decorative.

Note! The higher the detail of the product, the better should be the form for its casting. The range of materials for form-making and relative ease of processing allows you to make a stamp for your own production with your own hands.

Mold making materials

Depending on the quality requirements of the finished product, the appropriate categories of raw materials are used. They have different technical characteristics, price and processing methods.

Elastomers

Elastomeric forms are used when fine detailing and the creation of the most accurate copies are necessary. These are complex volumetric products, high-quality, high-precision bas-reliefs or artistic products.

As components for the manufacture of forms used below.

1. Rubber from synthetic rubbers.
2. Compounds from polyurethane.
3. Formoplast (PVC plastic compounds and plastisols).
4. Compounds of silicone.

The consumption of these materials per 1 m2 varies in the range of 10-40 kg, depending on the depth and features of the relief.

Here is a brief overview of the main characteristics of this product.

1. Formoplast it is used as a tooling relatively recently (just over 50 years). Their main advantage is considered to be the possibility of multiple use and recycling. In the production of multi-turn forms, the instruction assumes a well-established technological process.

In this case, you will need specialized cooking and crushing equipment. In addition - high-class technologists.

1. Rubber (rubber) forms produced by hot vulcanization. Preliminary metal models for which the product is cast, as well as alkali-resistant rubber, are quite expensive. The method of precision casting is also not cheap. Therefore, in our country there is no widespread use of this product.
2. Polyurethane products very popular in the production of elastic block molds by cold vulcanization. The technology and costs are fairly simple and inexpensive, the quality and quantity of the molded products depends on the quality of the molding material.

1. Silicone forms popular with artists, sculptors and architects. Sculptures or bas-reliefs are poured in layers or by pouring under the casing. However, silicone is prone to shrinkage, and does not have sufficient alkaline resistance to work with concrete.

Plastics

For the production of large-sized products with lower requirements for high-precision geometric parameters, use plastic forms for concrete products.

However, many companies with a good reputation offer forms capable of producing high-precision products.

1. Fiberglass molds. They are made by hand, from epoxy or polyester resins and reinforced with fiberglass. Disadvantages - very low compatibility with the matrix of cement. Because of this, they are mainly used for the production of concrete products with immediate stripping. This adversely affects the quality of products.

1. Forms made of hard plastic. Produced from polypropylene and polyethylene copolymers, casting under high pressure. They are prone to warping, therefore, suitable for the production of products of small size and unexpressed relief. Paving slabs, concrete paving, curbs - this is the main range for this category.
2. ABS plastic sheet. As a rule, its thickness is from 2 mm to 4 mm. It has a feature of exfoliating. In addition, to reduce the adhesion to the concrete will require lubrication of silicone. It is clear that as a form for reinforced concrete products of large format it is not suitable.
3. Sheet and film polystyrene up to 1.5 mm accurately conveys texture, but is poorly compatible with cement matrices. Another disadvantage is the increased fragility of the material.

1. PVC plastics have different compositions and thickness from 0.3 mm to 0.9 mm. They are considered the most successful in quality in the line of analogues. They have the lowest possible adhesion to concrete, do not require cleaning the form and lubrication. Flexible forms are considered to be a worthy link between rigid plastic and elastomers.

Note! When using film plastics, rigid formwork (side equipment) is necessarily present. It gives the form the necessary rigidity, while plastic provides relief and easy exit of the finished billet.

Self-Manufacturing Tips

At first you should pay your attention to the fact that any actions on final processing of the finished product are done only after it has set.

For example, cutting reinforced concrete with diamond circles is illogical if the product is raw.

1. You can make the mold yourself from simple tools. For example, from foam. First, a stamp is cut out, then poured with a cement-sand mixture. The disadvantage is that you get the product only in one copy.

1. Forms for paving slabs of a simple form (square, rectangle, triangle) can be assembled by yourself from laminated wood or laminated wood scraps. Smooth surface makes it easy to pull out the frozen tile.
2. Very successful are the elements poured into used plastic containers. They are usually sold semi-finished products in stores. Having a few baths at hand, you can stamp the tiles for the garden path.
3. After diamond drilling of holes in concrete is done, you can decorate, for example, a fence or a facade. Here craftsmen often use children's molds for sandboxes. Excess holes or defects in the work of masters can be masked by cast figures. A starfish or a flower will perfectly fit into the role of a decorative element.

Conclusion

Если вы намерены заняться отливкой форм в крупных масштабах, лучше приобрести профессионально сделанные формы, рассчитанные на большое количество циклов. Но для частного использования вполне можно обойтись самодельными или подручными штампами. Не спешите покупать в магазине дорогие клише, оглянитесь по сторонам, все необходимое можно найти бесплатно (см.также статью «Потолочные перекрытия из бетона: монтаж перекрытий, сборка опалубки, армирование, схема заливки»).

The enclosed video in this article will clearly show how to make and how to use the molds for casting.