FR2490142A1 - PROCESS FOR THE PRODUCTION OF INSULATION BOARDS FROM FIBROUS AGRICULTURAL WASTE AND A BINDER - Google Patents

Abstract

AS A STARTING MATERIAL FOR THE MANUFACTURE OF INSULATION PANELS, FIBROUS AGRICULTURAL WASTE CONTAINING SILICIC ACID, MAINLY RICE BALLS, IS USED. THE SAID RICE BALLS ARE FIRST REDUCED IN FIBERS AND DEPARAFFINED. A FILLER, FOR EXAMPLE PERLITE, RICE STRAW OR ASBESTOS, AS WELL AS A BINDER, FOR EXAMPLE A TWO-COMPONENT GLUE BASED ON SYNTHETIC RESIN, ARE ADDED TO THE RICE BALLS REDUCED IN FIBERS AND DEPARAFFINED, AND THE WHOLE IS MIXED IN THE FORM OF A HOMOGENEOUS MASS. THE MIXTURE SO OBTAINED IN MOLDS IS SHAPED COLD OR HOT. APPLICATION: TO THE MANUFACTURING OF THERMAL AND / OR ACOUSTIC INSULATION PANELS AT A LOW COST FROM AN UNUSABLE STARTING MATERIAL, UNTIL NOW, THE PANELS PRODUCED HAVING A VERY GOOD RESISTANCE OVER TIME, TO WEATHER CONDITIONS, BEING NOT FLAMMABLE AND THAT CAN BE WORKED (SAWS, DRILLS, ETC.) WITHOUT PROBLEM.

Description

Process for the manufacture of insulating panels

  The present invention relates to a method for the manufacture of insulating panels that can be used in the building industry, mainly as insulating wall panels or as roof insulation panels. Thermal and acoustic insulation panels are used to a large extent. These panels are generally made of petroleum-based plastic foam or mineral wool, for example basalt wool. These panels have the common characteristics of involving costly manufacture and presenting only poor performance.

in time.

  Given the rising price of oil, there is a recent demand for insulating panels that can be made from

  starting material cheaper than oil.

  The purpose of the present invention is to respond to

this application.

  The subject of the present invention is therefore a process for the manufacture of insulating panels, making it possible to manufacture at relatively low cost insulating panels with good durability, the physical characteristics of which are at least as good or even better.

  than insulating panels known until now.

  The invention is based on the observation that the world rice crop produces several million tons of rice bales each year, which, because of their high silicic acid content, can not be used in agriculture as fodder or as litter and thus constitute pollutants. Given the fact that bullets

  rice are a difficult fuel material (their temperature

  inflammation is of the order of 800 ° C), their destructive

  incineration also entails considerable expenditure.

  Another characteristic of rice balls is that they do not rot, and are not sought after by

rodents and insects.

  According to the process according to the invention for manufacturing insulating panels, fibrous agricultural waste containing silicic acid, in particular rice balls, is used as the starting material. This material is first reduced in fiber and then dewaxed. Fillers, preferably perlite, rice straw or asbestos, and a binder, preferably a two-component synthetic resin glue, are then added to the reduced fiber and dewaxed rice husks. . The mixture is mixed in the form of a homogeneous mass and from the mixture thus obtained, insulating panels are produced by compression molding in

mussels.

  It is advantageous to dewax rice husks reduced in fiber by treatment with hydroxide

  calcium or calcium chloride.

  According to another characteristic of the process, compression molding is carried out under a pressure of 12 bar and a temperature of 80 to 120C. By such a hot compression, it is possible to considerably reduce the duration of hardening of the glue, so the cycle time

of manufacture.

  If necessary, it is also possible to reduce the curing time of the adhesive for the insulating panels by subjecting the insulating panels, after molding, to the action

  a hot air stream of 50 to 60C.

  To improve the quality of products, it is

  to remove, before dewaxing, the dust

  when fiber is reduced to rice husks, this

  dust is also harmful to health.

  The invention will be described in more detail below.

  using three exemplary embodiments.

Example 1

  By cold compression molding, insulation boards of 300 x 60 x 5 cm are produced. For this purpose, first of all, rice stacks are reduced on a roll mill known per se on the one hand to increase the surface area of the rice bales and on the other hand to eliminate the elasticity of the bales. rice balls. During the reduction in fiber, the rice balls are essentially torn into elementary fibers. The distribution of the sizes obtained after the fiber reduction of rice bales is as follows: 3.5 to 5 mm = 20% by weight 1.8 to 3.5 mm = 16% by weight

i to 1.8 mm = 64% by weight.

  After the fiber reduction, approximately 10%

  matter in the form of dust.

  Next, the reduced fiber rice husks are subjected to the action of a calcium chloride solution to remove the paraffin layer on their surfaces. This treatment with calcium chloride may for example be carried out

works in.a conveyor screw.

  A charge, in this case pearlite, and a binder constituted by the glue, known in the art, are then added to the reduced fiber and dewaxed rice husks.

  the name "ARBOCOL-NORMAL", based on urea-formaldehyde resin.

  These components are mixed together as a mixture

  homogeneous, for example in a rotary blade mixer.

  As a trigger for bonding or adhesiveness of the glue, ammonium chloride is used. The mixture thus prepared is then introduced into a mold and molded under a pressure of 1.5 bar in the form of an insulating panel. The duration of the curing of the adhesive is about 10 to 20 minutes;

  then, the panel can be removed from the mold.

  The following components are present in the following proportions: Fiber-reduced rice husks 120 parts by weight - Perlite, "type P 2" 40 parts by weight - Adhesive "ARBOCOL-NORMAL" 90 parts by weight Ammonium chloride 2 parts by weight Water 100 parts by weight Calcium chloride 5 parts by weight Example 2 Roof insulation panels 8 cm thick were manufactured. The manufacturing process differs from that of Example 1 only in that instead of using perlite as a filler, ground rice straw is used and the binder is used as the binder. thermosetting urea-formaldehyde adhesive "ARBOCOL-FKC" hardening at 120 ° C. The compression molding is carried out on a press heated to 1200, under a pressure of 20 to 25 bar. The various constituents are present in the following proportions: - Fiber-reduced rice balls 120 parts by weight - Chopped rice straw 80 parts by weight - Adhesive "ARBOCOL-FKC" 158 parts by weight - Ammonium chloride 6.25 parts by weight - Water 156 parts by weight - Calcium chloride 8 parts by weight

Example 3

  For buildings exposed to high thermal stress, it is to manufacture thermal insulation panels of 10 cm thick. The manufacturing process

  essentially corresponds to that of Example 1. A different

  However, in addition to perlite, there is also added asbestos powder or short-fiber asbestos to the mixture. In addition, we use

  as a binder for water glass and sodium silicofluoride.

  - - The various constituents are present in the following proportions: - Rice balls reduced in fiber 40 parts by weight Perlite "type P2" 20 parts by weight - Asbestos powder or short-fiber asbestos 95 parts by weight - Soluble glass 35 parts by weight Sodium silicofluoride 4 parts by weight - Water 10 parts by weight Calcium hydroxide 4 parts by weight The insulating panels manufactured according to the process according to the invention are very light. Their density

3

  is between 210 and 310 kg / m. The test results demonstrated that the panels have excellent thermal insulation properties. Their coefficient of thermal conduction

  is between 0.045 and 0.65 kcal / mhCO.

  The compressive strength of the insulating panels according to the invention is between 7 and 60 daN / cm; after 96 hours in a room saturated with 100% water vapor, the moisture content of the panels amounts to 3% of the mass. The other tests carried out using the panels according to the invention prove that the panels are weather-resistant, are hardly combustible, can be painted or covered with wallpaper, can be glued, can be easily sawn with the aid of a hacksaw blade, to be drilled, to be plated and can undergo superficial treatment by hot compression; in addition, the panels can receive by adhesive any insulating layers,

for example of the thin sheet.

  The insulating panels according to the invention can be used as wall panels for thermal and acoustic insulation, as roof insulation panels, as sandwich panels, as panels for the manufacture of false ceilings, as decorative panels and even as pieces. coating. By adding suitable adjuvants, it is possible to further improve certain physical characteristics of the panels, for example their flammability can still be

reduced by addition of asbestos.

  In comparison with insulating panels manufactured using known processes from mineral wool, the

  manufacture of the panels according to the process according to

  It requires only 25% of the oil and 6 to 8% of the electrical energy needed to carry out the processes.

known.

Claims (5)

  Process for the production of insulating panels, characterized in that fibrous agricultural waste containing silicic acid, preferably rice husks, is used as starting material and is reduced to fibers rice husks, which are deparaffinized, a filler, preferably pearlite or rice straw or asbestos and a binder, preferably added to the rice husks, reduced to fibers and dewaxed, preferably a two-component glue based on synthetic resin, which is mixed together in the form of a homogeneous mass and which is shaped into   mixture thus obtained by compression in molds.   2. Process according to claim 1, characterized in that dewaxing is carried out by treatment of rice husks reduced in fiber with hydroxide hydroxide. calcium or calcium chloride.   3. Process according to Claim 1 or 2, characterized in that the compression shaping is carried out   at a pressure of 12 to 25 bar and at temperatures its between 80 and 120 C.   4. Process according to any one of the claims   1 to 3, characterized by the fact that the hardening of the glue of the insulating panels is accelerated, after shaping, by subjecting the panels to the action of a stream of air at a temperature of temperature of 50 to 60 C.   5. Process according to any one of the claims   1 to 4, characterized in that before the depa-refining, the dust produced during the fiber reduction of the rice balls.