Molded Shaping

1. The principle of compression molding is a method of thermosetting plastic forming. It involves adding a certain amount of molding material to a preheated mold, then heating and pressurizing it to solidify and shape the plastic product. The basic process is as follows: place a certain amount of preprocessed molding material into a preheated mold, apply high pressure to fill the mold cavity. Under specific pressure and temperature, the molding material gradually solidifies, and then the product is removed from the mold. Following necessary auxiliary processing, the final product is obtained.

2. Molding Process Flow

The molding process is primarily divided into two stages: preparation before pressing and the pressing stage.

3. Molding Equipment

(1)胶浸机

The primary equipment for manufacturing adhesive tape is the immersion coater, which consists of several parts including a cloth feeding stand, heat treatment furnace, immersion tank, drying cabinet, and traction roller. Depending on the placement of the heat treatment furnace and drying cabinet, they can be categorized into horizontal immersion coaters and vertical immersion coaters.

(2) Pre-impregnated Material Line

The equipment used in this method includes cutting machines, kneading machines, and loosening machines. Common types of cutting machines are press brakes, abrasive disc, three-roll, and single-rotary knife roll. The kneading machine's function is to thoroughly mix the resin system with the fiber system uniformly. The mixing blades are generally of the Z-blade structure. During the kneading process, the main parameters controlled are the kneading time and the viscosity of the resin system. Sometimes, a jacket with heating and cooling water is installed in the mixing chamber to control the mixing temperature. The longer the mixing time, the greater the fiber strength loss. In some resin systems, excessive kneading time can also lead to significant thermal effects. Insufficient mixing time results in uneven mixing of resin and fibers. Improper control of resin viscosity affects the even wetting and penetration speed of the resin into the fibers, and it also has an impact on the fiber strength.

The main function of the tearing machine is to fluff up the clumps of material after kneading. The machine is mainly composed of an infeed roller and a pair of tearing rollers, which fluff up the incoming material clumps through the reverse movement of the tearing rollers.

(3) Sheet Molding Compound (SMC) Molding Line

A complete SMC (Sheet Molding Compound) assembly, generally consisting of 7 main components such as the frame, conveying system, PE film supply unit, scraper, glass fiber cutter, impregnation and compaction units, and winding equipment, as well as 3 essential auxiliary systems including the glass fiber yarn stand, resin paste preparation and feeding system, and static eliminator.

(4) Press Machine

Press machines are the primary equipment for mold forming. Their function is to provide the necessary pressure for the molding process and the demolding force required for extracting the finished product, with hydraulic presses being most commonly used now.