We manufacture more than 40 thousand
tonnes of regranulate every year
We are the largest manufacturer of polyethylene regranulates, produced from waste generated in households in Poland.
Our offer includes LDPE regranulates from recycling processes, applied, among others, in:
- blow moulding of foil with thickness range from 30 to 500 microns
- calendared sheet with thickness range from 150 microns to 1 mm
- injection process of finished products with complicated shape
In 2016 we started our own Research and Development Laboratory, whose priority is the Development of New Technologies. Its task consists in carrying out complex research work and analyses in the scope of determination of physical and chemical parameters, mechanical, processing and user parameters of plastic products. In this way, we continuously improve our technology.
Contalen regranulate guarantees quality. Our material is extensively tested, our product is always well-checked and it conforms to the declared parameters. This is confirmed by:
testing of compressive strength
dart-drop testing
testing of steam diffusion and SD value
testing of density
testing of flame retarding class
testing of puncture strength
testing of humidity
testing of mechanical properties
testing of properties after artificial ageing
testing of water resistance characteristics
testing of melt flow rate
infrared Fourier-transform spectrophotometry
Density (d) – the relationship of mass of a material sample to its volume at a given temperature. It is mass (in grams) / 1 cm3 of a given substance.
d = m / V
where m = mass, V = volume
Test is conducted according to the standard PN EN ISO 1183-1 – Method A: The immersion method is applicable for determination of density of materials (except for powders).
Measurement of Melt Flow Index can be conducted from:
- granulate / regranulate
- grinds
- powder/dry-blend
Test is conducted according to the standard PN-EN ISO 1133-1: putting of a small quantity of polymer of ca. 4–5 g to a device called plastometer. The sample is preliminary heated for a specific time: 5 minutes in 190°C for polyethylene and 6 minutes in 230°C for polypropylene. Subsequently, heated mass is inserted in a piston. Its standard weights are: 2,16 kg, 5 kg. The mass exerts force on melted polymer and immediately starts to flow through a nozzle. After a specific period of time, the sample of melt is weighted precisely
MFI – Melt Flow Index – it is a number that defines quantity of thermoplastic material, flowing through a circular nozzle with defined dimensions: over a specific time period, at a given pressure and at a given temperature.
Melt mass flow rate (MFR) and melt volume flow rate (MVR) can be distinguished
- Melt mass flow rate (MFR) is the mass of material flowing through a circular nozzle in normalised conditions: unit – gram/10 minutes
- Melt volume flow rate (MVR) is the volume of material flowing through a circular nozzle in normalised conditions: unit – cm³/10 minutes
MFI is expressed in grams of polymer/10 minutes of the total testing time. MFI is often used to determine, how a polymer will be processed. For example, whether regranulate will be appropriate for injection, or rather for extrusion moulding of pipes, foil or plates.
Humidity – humidity is defined as water content in a given material. It is expressed in percentage by weight or percentage by volume. Test is conducted using a weight method:
Classic measurement consists in drying of a weighted sample at a specific temperature to dry mass and in calculation of humidity index according to the formula:
W = (m1 – m2) / m2 *100%
Where: m1-mass of humid sample m2- mass of dried sample
Importance of degasification method for of the basic raw material
The specific problem consists in degassing of material during production. When a material moves in an extruder cylinder, pressure and temperature increase, and as a result, volatile compounds are released. Compressed gas particles result in formation of spaces filled with gas in the material, which results in worse quality of the finished product. The task of an absorber is to inactivate certain impurities (e.g. acid chlorine compounds) from grinds and granulates. PE, PP, ABS, PS, PVC, PA. Application of a humidity absorber totally excludes the necessity to dry raw material in a dryer. Reaction of active substance included in an additive takes place directly in the course of plasticisation process. The scope of application of an absorber is very broad and it covers almost every industry. These are the lines of trade that use: granulates, regranulates, grinds and agglomerates in the course of production. For example, in production of foil/sheet, pipes or in recycling of materials.
Impurities in raw material
The most typical impurities are: cardboard, other plastics, wood, glass and metal.
Shape and size of granules
They depend on:
- pressure on a head
- rotational speed of blades
- size of openings on the head (e.g. 3mm – for regranulates with low MFI)
- speed of an extruder
MFI – Melt Flow Index
Melt Flow Index (MFI) of ca. 0.20–0.3 g /10 minutes shows that a raw material will be characterised with substantial mechanical resistance. For this reason, it is perfectly suitable for: production of high-strength transport sacks, heat shrink film for pallets and for other applications.
Processing methods:
- tubular film
- extrusion blow moulding
- injection blow moulding
Typical applications:
- containers made with the method of extrusion blow moulding
- tubular film
- heat shrink film
Melt Flow Index (MFI) of ca. 1.5–1.9 g / 10 minutes is low-density polyethylene, aimed for production of highly transparent film. A raw material with such an MFI is suitable for thickness exceeding 25 µm, characterised with very good mechanic properties
Processing methods:
- tubular film
- cast film
Typical applications:
- flexible packaging
- tubular film
- packaging film
- film for food products
- hygienic film
- heat shrink film
Recommended film thickness: 25–100 μm
Melt flow Index (MFI) of ca. 0.50–0.7 g /10 minutes shows that the raw material is aimed for production of film and small-sized containers with extrusion blow moulding. For this reason, it is suitable for thickness exceeding 40 µm, characterised with very good mechanic properties.
Processing methods:
- tubular film
- extrusion blow moulding
Typical applications:
- containers made with the method of extrusion blow moulding
- tubular film
Melt Flow Index (MFI) of ca. 0.75– 0.8 g /10 minutes is aimed for production of packaging film of good quality and thickness exceeding 25 µm.
Processing methods:
- tubular film
Typical applications:
- standing bags and sacks
- heat shrink film
- tubular film
- food packaging film
- laminating film
