{"id":2049,"date":"2024-05-16T16:15:36","date_gmt":"2024-05-16T08:15:36","guid":{"rendered":"https:\/\/taichungbro.com\/?p=2049"},"modified":"2024-05-23T21:41:58","modified_gmt":"2024-05-23T13:41:58","slug":"tooling-design-evaluation","status":"publish","type":"post","link":"https:\/\/www.taichungbro.com\/en\/2024\/05\/16\/tooling-design-evaluation\/","title":{"rendered":"Plastic Tooling Evaluation (3): Early Stage Design"},"content":{"rendered":"<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-wide\"\/>\n\n\n\n<div class=\"wp-block-rank-math-toc-block\" id=\"rank-math-toc\"><h2>Table of Content<\/h2><nav><ul><li class=\"\"><a href=\"#\u5206\u6a21\u8a2d\u8a08\">Parting Line Design<\/a><\/li><li class=\"\"><a href=\"#\u6a21\u7a74\u6392\u4f48\">Cavity Layout<\/a><\/li><\/ul><\/nav><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-wide\"\/>\n\n\n\n<p>Following the previous article: <a href=\"https:\/\/www.taichungbro.com\/en\/2024\/04\/28\/runner-selection\/\" target=\"_blank\" rel=\"noopener\"><strong>\"Plastic tooling evaluation (2) Gating Selection\"<\/strong><\/a>We determine the type of mold based on the gating system. Next, we proceed with the early stage design assessment and arrange the mold cavities rationally according to the required number of cavities.<\/p>\n\n\n\n<p>At this stage, we need to estimate the \"mold manufacturing costs,\" \"plastic material usage per mold,\" and \"production capacity.\" We make these estimates through two steps: \"parting line design\" and \"cavity layout.\"<\/p>\n\n\n\n<p>Through \"parting line design,\" we clarify the number of parts needed and confirm the form of mold components, then obtain the machining costs from the manufacturing unit. \"Cavity layout\" involves simulating the number of cavities and the design of the runners to determine the required amount of plastic material and assess the number of cavities needed to clarify production capacity requirements.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"\u5206\u6a21\u8a2d\u8a08\">Parting Line Design<\/h2>\n\n\n\n<p>First, let's understand the basic concepts of molds, which are divided into male and female halves; the female mold is referred to as the fixed side, and the male mold as the movable side. When combined, these two halves form a cavity, and the boundary where they meet is known as the parting line. Imagine playing with sand using a small bucket to make a sandcastle. This bucket acts like a mold, and the sand represents the material we are shaping. After filling the bucket, you would gently turn it upside down, tap it lightly a few times, then lift the bucket, leaving the sandcastle behind. This process is similar to using a mold to manufacture products. Suppose your bucket consists of two parts and needs to be opened in the middle to retrieve the sandcastle, much like opening it directly as described. The line where you now open the bucket is akin to the parting line. The parting line is where the two halves of the mold meet and also serves as the boundary line when opening the mold to extract the product, leaving a seam trace on the plastic product.<\/p>\n\n\n\n<p>How is the parting line design for a product generally determined?<\/p>\n\n\n\n<p>1.Avoid parting lines on visible surfaces: Since parting lines will be imprinted on the product, it is necessary to avoid placing them on surfaces that are important for the product's appearance as specified by the customer.<\/p>\n\n\n\n<p>2.Avoid parting lines on critical dimensional surfaces<\/p>\n\n\n\n<p>The parting line represents a seam in the mold assembly where plastic tends to seep into the gaps, often leading to issues with flash. Therefore, if the edge is a dimensionally critical area requiring measurement, it is likely to be inaccurate, especially when measured using projection equipment.<\/p>\n\n\n\n<p>3.The parting line location should facilitate demolding<\/p>\n\n\n\n<p>If the product is too deep within the mold cavity, it may stick to the cavity, preventing automated removal. Forcing it out can deform the product. Therefore, the product needs to be at an appropriate depth within the mold cavity, and if necessary, designs incorporating inserts and sliders should be implemented.<\/p>\n\n\n\n<p>4.Avoid creating complex mechanisms<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img fetchpriority=\"high\" decoding=\"async\" width=\"708\" height=\"363\" src=\"https:\/\/taichungbro.com\/wp-content\/uploads\/2024\/05\/Tooling_design-type.png\" alt=\"\" class=\"wp-image-2050\" srcset=\"https:\/\/www.taichungbro.com\/wp-content\/uploads\/2024\/05\/Tooling_design-type.png 708w, https:\/\/www.taichungbro.com\/wp-content\/uploads\/2024\/05\/Tooling_design-type-300x154.png 300w, https:\/\/www.taichungbro.com\/wp-content\/uploads\/2024\/05\/Tooling_design-type-18x9.png 18w, https:\/\/www.taichungbro.com\/wp-content\/uploads\/2024\/05\/Tooling_design-type-600x308.png 600w\" sizes=\"(max-width: 708px) 100vw, 708px\" \/><\/figure>\n<\/div>\n\n\n<p>As shown in the schematic diagram above, the blue represents the product. The left diagram indicates the need to construct a slider to complete the design, while the right diagram shows the product's recessed shape facing downward, requiring at most the creation of a single insert set, or even incorporating the recess feature directly into the cavity without an insert. The approach in the right diagram is more reasonable because slider mechanisms can complicate the mold structure design and even lead to poor assembly precision of the mold. If demolding allows, the insert can be securely locked onto the mold core without any movement, simplifying the mechanism.\nOf course, the actual design must still consider the limitations of the product's shape, as not every product can incorporate an appropriate draft angle for demolding. Discussions with the client are necessary to identify the most cost-effective mold design.<\/p>\n\n\n\n<p>The reason for determining the parting line design first is that it allows us to approximate the number of parts needed for mold construction, such as male and female mold cores, the number of inserts, and the number of sliders required, among others. These feature components often constitute a significant portion of the mold costs. Therefore, having a detailed count of these components is crucial for accurately calculating the cost estimates.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-wide\"\/>\n\n\n\n<h5 class=\"wp-block-heading has-text-align-center\">Would you like to learn about mold evaluation and manufacturing feasibility assessment? <br>Further Reading :<a href=\"https:\/\/www.taichungbro.com\/en\/2023\/10\/24\/manufacturing\/\" data-type=\"link\" data-id=\"https:\/\/taichungbro.com\/2023\/10\/28\/screw\/\" target=\"_blank\" rel=\"noopener\"><strong>\u300aDesign for Manufacture Evaluate\u300b<\/strong><\/a><\/h5>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-wide\"\/>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"\u6a21\u7a74\u6392\u4f48\">Cavity Layout<\/h2>\n\n\n\n<p>After determining the gate location and parting line design, the next step is to decide on the layout, primarily considering the arrangement of the runners. The layout of the runners essentially involves deciding how many cavities to open and how to arrange them. Based on the size of the injection machine previously determined, we can ascertain the mold area available and arrange the cavities within this limited space. Here, the direction of the runners is decided, and the approximate volume of plastic required is determined.<\/p>\n\n\n\n<p>Commonly, there are two types of runner layouts:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"807\" height=\"357\" src=\"https:\/\/taichungbro.com\/wp-content\/uploads\/2024\/05\/Runner_type.png\" alt=\"\" class=\"wp-image-2051\" srcset=\"https:\/\/www.taichungbro.com\/wp-content\/uploads\/2024\/05\/Runner_type.png 807w, https:\/\/www.taichungbro.com\/wp-content\/uploads\/2024\/05\/Runner_type-300x133.png 300w, https:\/\/www.taichungbro.com\/wp-content\/uploads\/2024\/05\/Runner_type-768x340.png 768w, https:\/\/www.taichungbro.com\/wp-content\/uploads\/2024\/05\/Runner_type-18x8.png 18w, https:\/\/www.taichungbro.com\/wp-content\/uploads\/2024\/05\/Runner_type-600x265.png 600w\" sizes=\"(max-width: 807px) 100vw, 807px\" \/><\/figure>\n\n\n\n<p>In runner design, it is essential to strive for equal flow distances between each cavity and the central sprue, primarily using H-type or radial type. However, depending on product requirements or to address issues like flow balance, runner layout designs can be quite diverse.<\/p>\n\n\n\n<p>Before simulating the layout, it is necessary to know how many cavities to make. If the client has no specific requirements, leaving the decision to us, we must first estimate the molding cycle to calculate the daily production capacity. This helps to determine how many cavities are needed to meet the delivery standards. Typically, roles like sales units or Project Managers make the final decision. (Please refer to<a href=\"https:\/\/www.taichungbro.com\/en\/2023\/11\/02\/injection-mold-assessment\/\" target=\"_blank\" rel=\"noopener\">Plastic tooling evaluation (1) Equipment selection<\/a> : Cycle Time Estimation)<\/p>\n\n\n\n<p>Generally, if the production capacity is met, it is advisable not to design more than four cavities. Within four cavities, the flow tends to be more balanced. When the number of cavities exceeds four, issues with flow imbalance become more pronounced.<\/p>\n\n\n\n<p>At this stage, our main objective is to calculate the quotation. Therefore, we only need to know approximately how the cavities are arranged and how long the runners will be. By adding the estimated weight of the runners to the weight of the product, we can determine the total weight of plastic ejected per mold cycle. With this information, we can calculate the total amount of plastic required.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-wide\"\/>\n\n\n\n<p class=\"has-text-align-center\">Would you like to learn about the principles of injection molding and strategies for dealing with short shots and other irregularities? <br>Further Reading :<a href=\"https:\/\/www.taichungbro.com\/en\/2023\/10\/28\/mold-shortshot\/\" data-type=\"link\" data-id=\"https:\/\/taichungbro.com\/2023\/10\/28\/screw\/\" target=\"_blank\" rel=\"noopener\"><strong>\u300aInjection Molding - Short Shot Countermeasures\u300b<\/strong><\/a><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-wide\"\/>","protected":false},"excerpt":{"rendered":"<p>At this stage, we need to estimate the \"mold manufacturing costs,\" \"plastic material usage per mold,\" and \"production capacity.\" We make these estimates through two steps: \"parting line design\" and \"cavity layout.\"<\/p>\n<p>Through \"parting line design,\" we clarify the number of parts needed and confirm the form of mold components, then obtain the machining costs from the manufacturing unit. \"Cavity layout\" involves simulating the number of cavities and the design of the runners to determine the required amount of plastic material and assess the number of cavities needed to clarify production capacity requirements.<\/p>","protected":false},"author":2,"featured_media":2056,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[45],"tags":[147,98,86,56,97],"class_list":["post-2049","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industrial-knowledge","tag-147","tag-98","tag-86","tag-tooling","tag-97"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/posts\/2049","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/comments?post=2049"}],"version-history":[{"count":0,"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/posts\/2049\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/media\/2056"}],"wp:attachment":[{"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/media?parent=2049"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/categories?post=2049"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/tags?post=2049"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}