Analysis of processing technology of plastic bottle cap
Influence of processing technology on mold quality
The selection of reasonable processing technology has an extremely important influence on the quality of the mold. For example, when processing slender axle, thin and thick supporting parts, or if the clamping position is not appropriate, the deformation of the process will be caused during processing, resulting in the size difference and affecting the quality of the mold.The following are several typical problems that often occur in the process of mold processing.
(1) when the fillet processing mold cavity and core, if excessive feed will leave a deep thick knife mark, the mark will typically produce stress concentration, when quenching and tempering, tiny crack formation, working in the assembly to the injection molding machine, due to the use for a long time will produce crack propagation phenomenon, resulting in workpiece fracture.
(2) the heat treatment process of 32 pieces also has a great impact on the quality of the mold. For example, the quenching of the workpiece will affect the size of the workpiece, and the insufficient allowance caused by the quenching deformation should be taken into account in the finishing process.For example, when cutting carbon steel workpieces such as T1O, due to the poor hardenability of the material itself, the quenching position has great influence on the overall accuracy of the workpiece, and the improper quenching position will lead to serious deformation of the workpiece.
Selection of moulding material for plastic cap
Choosing mould material needs to consider the use of the mold condition and processing technology, general this kind of hot-work die material often choose 5 crmnmo and 5 crnimo, but because of its alloy material content is not high, when the size of the workpiece mold gets 300 iTIrn, its hardenability is poorer, heart can't hardening of ministries happen, so this kind of material generally applicable to the small size of the mould, if the mold size is larger, and the shape complicated generally choose 5 cr2nimovs and 3 cr2movni etc.
Reasonable processing technology of plastic cap mould
The basic requirement of plastic cap mold processing is to reduce workpiece deformation,nJnq- error and avoid cracks due to stress concentration.Support points should be added to maintain the workpiece stiffness when processing slender shafts or thin-walled parts.Other things to note are as follows.
(1) when the mold core of plastic bottle cap is chamfered, a sufficient margin is usually left after rough processing, usually 0.5 ~ 1 mm, followed by semi-finishing and finishing.A sufficient allowance is made to ensure that the workpiece has enough dimensional allowance after heat treatment for finishing.
(2) during the fine grinding, the grinding wheel with poor bonding and strong cutting force is generally selected. After several times running over the grinder, clean grinding can reduce the feed amount of grinding and use appropriate cooling agent. After the fine grinding, tempering is generally required to ensure the dimensional stability of the workpiece.
Common quality analysis problems of plastic bottle caps