CN108773146B

CN108773146B - Production method of ultra-light PP glass fiber board

Info

Publication number: CN108773146B
Application number: CN201810557171.2A
Authority: CN
Inventors: 李海帆; 朱维珍; 单汝坤; 王克强; 韦明; 王国淑; 仲崇华; 韩军
Original assignee: Tianjin Zhenghai Guangrun Technology Co ltd
Current assignee: TIANJIN ZHENGHAI GUANGRUN TECHNOLOGY Co.,Ltd.
Priority date: 2018-06-01
Filing date: 2018-06-01
Publication date: 2020-11-03
Anticipated expiration: 2038-06-01
Also published as: CN108773146A

Abstract

The ultra-lightweight PP glass fiber board adopts a dry process and comprises the following steps that glass fibers and PP fibers form a sparse fiber web; spreading foaming microspheres on the sparse fiber web; stacking the sparse fiber webs into a plurality of layers of fiber webs without needling for reinforcement; heating the multilayer fiber web under the clamping of two layers of Teflon webs; pressing into a plate. The board is directly heated and pressed without needling reinforcement, so that the dropping of the foaming microspheres can be avoided, the expansion height of the PP glass fiber board can be increased, and a better lightweight effect can be obtained.

Description

Production method of ultra-light PP glass fiber board

Technical Field

The invention relates to a production method of a PP glass fiber board.

Background

A PP glass fiber board, also called as light gmt (glass Mat Reinforced thermoplastics), is a lightweight composite material, and is widely applied to products such as automobile interior ceilings, hat and coat stands and the like.

The main components of the PP glass fiber board are PP and glass fiber (glass fiber for short), and two production methods are mainly adopted, namely a dry method and a wet method.

The dry method adopts PP fiber and glass fiber as raw materials, and the raw materials are prepared into felt through opening, carding, lapping, laminating and needling, and then the felt is heated and cold-pressed into a plate. The dry method has simple process equipment, small investment, poorer uniformity of the produced plate, slightly smaller heating expansion height, and the base material used for the current ceiling is generally 1000 g/m²Left and right.

The wet process adopts PP powder and glass fiber as raw materials, the raw materials and the auxiliary agent are added into water, the glass fiber and the PP powder are uniformly dispersed in a medium under the action of the auxiliary agent and stirring, then a pulp flowing box and a forming net are used for filtering liquid, and the liquid is heated and cold pressed into a plate. By wet processesThe equipment investment is large, the process is complex, but the plate uniformity is good, the heating expansion height is large, and the ceiling base material can reach 800 g/m²And may be even lower.

The ultra-light PP glass fiber board is mainly characterized in that the board contains foaming microspheres. The foamed microsphere is of a core-shell structure, the shell on the surface has certain elasticity and can expand at high temperature, and the core inside has multiple times of volume expansion at high temperature, so that the expansion height of the board can be increased at high temperature, the forming characteristic is improved, the ultra-light weight is realized, and the 800 g/m is realized²Below, even 600 g/m²。

The production process of the ultra-light PP glass fiber board is also divided into a dry method and a wet method. The wet process is to add foaming microspheres into the traditional wet medium, and the glass fiber, the PP powder and the foaming microspheres form a net together. Because the size of the microspheres is very small, the microspheres are easy to run off in a water removal process and are more difficult to control than a traditional wet method.

The dry method includes an impregnation method and a powder spreading method. CN106427163A provides a method for producing ultra-lightweight PP glass fiber board by dipping process. The dipping method is to dip the PP glass fiber needled felt into liquid containing foaming microspheres so that the foaming microspheres penetrate between the PP fibers and the glass fibers. The process of removing liquid after impregnation requires a large amount of energy consumption, the permeability of the foamed microspheres is limited, and the impregnation cannot ensure the uniform distribution of the foamed microspheres, so the product quality and the economic effect are poor. In addition, compared with a wet process, the dry process adopts PP fibers as a thermoplastic material, so that the using amount of PP is large, and the light weight effect is influenced to a certain extent.

CN108068424A provides a process for producing ultra-lightweight PP glass fiber boards by a powder scattering method. The dusting process is to scatter the foamed microspheres during the production of the needled PP glass fiber mat, typically before the PP fibers and the fiber web are laminated. The foamed microspheres can be uniformly distributed in the PP glass fiber needled felt, and then the board is formed by heating and cold pressing. Compared with the impregnation method, the process does not need an expensive water removal process, and the product quality and the economic benefit are improved. However, the foamed microspheres have no strong adhesion to glass fibers and PP fibers at normal temperature, so the foamed microspheres are easy to fall off in the needling process, the quantity of the foamed microspheres is insufficient or the distribution is uneven, and the product quality is influenced.

Disclosure of Invention

The invention aims to provide a production method of an ultra-light PP glass fiber board, which solves the problems of foam microspheres falling off and uneven distribution.

The technical scheme of the invention is as follows:

a production method of an ultra-light PP glass fiber board comprises the following steps that glass fibers and PP fibers are mixed to form a sparse fiber web; spreading foaming microspheres on the sparse fiber web; stacking the sparse fiber webs into a plurality of layers of fiber webs without needling for reinforcement; heating the multilayer fiber web; pressing into a plate.

In a preferred embodiment, after the sparse web is stacked into a multi-layer web, the foaming microspheres are spread on the multi-layer web again.

In a preferred embodiment, the heating of the multi-layer web is carried out between two teflon webs.

In a preferred embodiment, the heating of the multi-layer web is carried out between two teflon belts.

According to a preferable scheme, after the multiple layers of fiber webs are heated, before the multiple layers of fiber webs are pressed into a plate, the upper surface and the lower surface of the multiple layers of fiber webs are respectively provided with a glue film and a non-woven fabric.

In the scheme of the application, the needling step in the existing dry process is omitted, the reduction and the uneven distribution of the utilization rate of the foaming microspheres caused by the falling off of the foaming microspheres in the needling process are avoided, and the better uniformity and the forming effect are achieved.

In the process of stacking the sparse fiber webs into the multilayer fiber webs, the foaming microspheres can fall off and settle to a certain degree, so that the density of the foaming microspheres is obviously lower on the outermost layers of the multilayer fiber webs than in the middle and the lower parts, and the uniformity of the distribution of the foaming microspheres can be better improved by means of spreading the foaming microspheres above the multilayer fiber webs again.

In the heating process, due to the flowing of hot air, the foam microspheres can fall off and float, so that the uniform distribution of the foam microspheres can be better kept by adopting a measure of clamping the multilayer fiber web between two layers of Teflon belts or Teflon nets for heating.

In addition, in a normal dry process, a fiber web is generally reinforced through a needling process to form a PP glass fiber needled felt, the better tensile strength is realized by means of the winding of glass fibers in the PP glass fiber needled felt, and the PP glass fiber needled felt can directly run by means of the driving of a roller without being supported by a Teflon belt or a Teflon net in the heating process. However, the multi-layer web of the present application lacks a needle felting step and has no tensile strength at all, so the use of teflon mesh or teflon tape support is also a good choice in the heating process of the multi-layer web of the present application.

The Teflon net is a net structure woven by glass fibers or other high-temperature resistant fibers, and then Teflon coating is carried out to obtain the high-temperature resistant net with the Teflon material on the surface. Adopt the centre gripping of teflon net, hot-air can get into in the multilayer fibre net through the mesh on the teflon net, and heating efficiency is high.

The Teflon tape is a high-temperature resistant tape with a Teflon material on the surface, which is obtained by weaving glass fibers or other high-temperature resistant fibers into a relatively dense fabric and then coating Teflon. The Teflon tape is used for clamping, so that the foaming microspheres can be prevented from scattering and flying due to hot air disturbance, but the heating efficiency can be influenced to a certain degree.

Detailed Description

Example 1

Mixing and loosening glass fiber and PP fiber according to the proportion of 50-55% of PP and 45-50% of glass fiber, and spreading to obtain the product with a gram weight of 50-80g/m²The sparse web of (a); spreading foaming microspheres on the sparse fiber web according to the proportion of 2-5% of the gram weight of the sparse fiber web; the sparse fiber webs are stacked on the Teflon net in a reciprocating mode to form a multi-layer fiber web; the surface of the multi-layer fiber web is 0.5-2 g/m²Spreading a layer of foaming microspheres; the multilayer fiber web continuously moves forwards along with the Teflon web at a certain speed, the upper surface of the multilayer fiber web is pressed by the Teflon web, the multilayer fiber web enters a heating process, PP fibers are melted, and 50-120 g/m is added to the upper surface and the lower surface of the multilayer fiber web respectively²The hot melt adhesive film (which can be a modified PE film) and 35-50 g/m²Is pressed to a thickness of 1.2-2mm, made into a sheet.

600 g/m produced by the above method²The left and right sheets, heated at 195-. Relative to 1000 g/m²The dry PP glass fiber board without the foaming microspheres and 800 g/m²The gram weight of the common wet-process PP glass fiber board is 600 g/m²The ultra-lightweight PP glass fiber board on the left and right sides has larger expansion height, better forming performance and smoother surface, and is particularly suitable for new energy automobiles with urgent light weight requirements.

In the traditional dry-method ultra-lightweight PP glass fiber board, because a plurality of longitudinally-inserted glass fibers are formed through the needling process, the expansion height of the board is limited by the longitudinally-inserted glass fibers in the expansion process of the board. By adopting the scheme of the application, the needling process is not carried out, the expansion of the plate is not bound by longitudinal fibers, the height can be larger, and the better forming characteristic is realized.

Example 2

Mixing and loosening glass fiber and PP fiber according to the proportion of 50-55% of PP and 45-50% of glass fiber, and spreading to obtain the product with a gram weight of 50-80g/m²The sparse web of (a); the sparse fiber webs are stacked on a Teflon belt in a reciprocating mode to form a plurality of layers of fiber webs; the surface of the multi-layer fiber web is 0.5-2 g/m²Spreading a layer of foaming microspheres; the multilayer fiber web continuously moves forwards along with the Teflon belt at a certain speed, the upper part of the multilayer fiber web is pressed by the Teflon belt and then enters a heating procedure, PP fibers are melted and pressed to the thickness of 1.2-2mm, and then the multilayer fiber web is made into a sheet.

80-120 g/m is respectively added on the upper surface and the lower surface of the sheet²The hot melt adhesive powder and the weight ratio of 50-70 g/m²The glue powder is melted, the film part on the film-coated non-woven fabric is melted, and the film-coated non-woven fabric is pressed into a plate.

Because a step-by-step process is adopted, PE rubber powder with a lower melting point can be used as the bonding material on the upper surface of the plate; the lower surface can be coated with non-woven fabric to improve the adhesion between the back layer non-woven fabric and the base material.

Claims

1. A production method of an ultra-light PP glass fiber board is characterized by comprising the following steps of mixing glass fibers and PP fibers to form a sparse fiber web; spreading foaming microspheres on the sparse fiber web; stacking the sparse fiber webs into a plurality of layers of fiber webs without needling for reinforcement; heating the multilayer fiber web under the clamping of two layers of Teflon belts or Teflon webs; pressing into a plate.

2. The method for producing an ultra lightweight PP fiberglass panel as claimed in claim 1, wherein after the sparse web is stacked into a multi-layered web, the foaming microspheres are sprinkled over the multi-layered web again.

3. The method for producing an ultra-lightweight PP glass fiber board as claimed in claim 1, wherein the adhesive film and the non-woven fabric are respectively applied to the upper and lower surfaces of the multi-layered web before pressing into a board after heating.