Collapsible Core Molds and Energy Savings Plastics Caps & Closures Conference Chicago, Sept 17th, 2015 1
Collapsible Core History • Developed in 1968 by George Roehr • Roehr Tool has been the industry leader in c-core technology • Manufactured in MA, USA • Progressive Components purchased Roehr Tool in 2006 • Added mechanical line of Dove Tail Cores in 2009 2
Types of Collapsing Core Spring / Flexing Steel Type Mechanical / Dovetail Type 3
DT Core Applications Primary Markets • Packaging, caps and closures • Medical caps and fittings • Plumbing fittings • Irrigation products • Electrical connectors and fittings Materials and Temperatures • From simple Olefins & ABS to more demanding resins like PVC or PA+GF • Cores can be built to work with high temperature resins 4
Collapsible Core Trend Industry perception of C-Cores in the past, “Option 3” behind: • Jump or strip thread usually being the simplest method, but limits part design and can create part quality issues • Unscrewing with its rather complex and multi-component tools, long molding cycle times, high maintenance and only valid for threads Game has changed • In tough economic times traditional methods are challenged • Dove Tail Core, a fully-mechanical collapsible core that overcomes many misconceptions and limitations Result: increased performance and optimized part design 5
DT Core Construction Exploded view (11-piece assembly) 6
DT Core Construction Collapsing Segments Material: 1.2363, 55-57 HRC • Designed to mechanically collapse when the center pin is withdrawn • The fit between the segments is controlled to permit flash-free molding Center Pin Material: 1.2379, 59-61 HRC • Serves to expand the segments of the core to their molding position • The pin may be flush to the core face • Integrated cooling line Carrier Assembly Material: 1.2379, 59-61 HRC • Mounts DT Core assembly to the mold carrier plate • Provides guided and anti-rotational segment movement 7
DT Core Range Customs & Pre-Engineered Standards • Ranging from Ø 7mm - Ø 250mm 8
Part Optimization Part Design Advantages 9
Part Geometry Protruding Features • Parts with features like seals on closures typically can’t be done with collapsing cores • Exceptions include designs where the core, at the end of its collapse stroke, has resulting “Free Space” between the core and the protruding feature 10
Part Geometry Pancake Core • Used for seal ring applications and witness line free parts. • Pancake diameter must be smaller than undercut diameter for ejection. 11
Part Geometry Undercuts • Full diameter undercuts are common for threads, O-ring grooves or snap features • Segmented undercuts and internal geometrical features are possible, although need to be aligned with segment axes and correctly drafted 12
Collapse Movement Collapse Range Calculating required collapse vs. undercut depth • Typical collapse: 5-7% per side(min 1mm per side for diameter 20mm) • Undercut + Shrinkage + Clearance = Total Collapse Required • Max collapse area is produced at mid section of wide segments • Min collapse points are at intersection of wide segment edges 13
Part Retention Retention Sleeve(reg. patent) • Some designs require a feature to prevent part from hanging on one of the segments during collapse, which leads to part damage • Retention sleeve is integrated into the DT core and independent of the stripper, so the part is secured during collapse but easy to eject 14
Quick Lock System Assembly in the Mold: Quick Lock(reg. patent) • Makes DTs removable from parting line for maintenance or conversion 15
Mold Design & Sequencing Staging methods Side Action Cam or hydraulic actuation is possible • Press KO with latch lock • Hydraulic cylinders Molding Position • Press open and close Collapse and Retract 1 - Mold Open 2 – Collapse 3 - Eject 16
Mold Design & Sequencing Front Half actuation Reverse Gate • Actuation similar to 3-plate runner split before • Gating through the Center Pin main parting line opens Molding Position Collapse on Mold Open 17
DT Core Mold vs. Unscrewing Mold • Simplified Mold Design • Easier Mold Set-Up • Sequencing Options • Less Maintenance • Better Part Quality • Improved Part Design • Reduced Cycle Time • Reduced Carbon Footprint 18
Cost Saving Calculation Region: NA ($/lb) Part Cost ($/1000) MFG Costs and Capacity 26.1 DT Core Gains 1: DT Core Gains 2: DT Core Gains 3: Unscrewing Mold Cycle Time, Eff, QA + Smaller Press + Less Cavities 19.6 18.8 16.3 Part Cost: Annual Volume 15,000,000 15,000,000 15,000,000 15,000,000 Resin Price ($/lb) 1 1 1 1 Part Weight (g) 2 2 2 2 Molding: Mold Type Unscrew DT Core DT Core DT Core Cycle Time (s) 12.0 8.4 8.4 8.4 UNSCREWING MOLD DT CORE GAINS 1: DT CORE GAINS 2: DT CORE GAINS 3: Cavitation 16 16 16 12 CYCLE TIME, EFF, + SMALLER PRESS + LESS CAVITIES Productivity 80% 90% 90% 90% QA Threaded Core Cost 900 3200 3200 3200 Press Rate ($/hr) 50 50 40 40 Part Cost ($/1000) Maintenance Hrs/year 84 42 42 42 Quality, % defect 1.0% 0.3% 0.3% 0.3% Assumptions: Production Hrs per Week 96 96 96 96 Annual Part Savings ($) Production Weeks per Year 45 45 45 45 Toolroom Rate 50 50 50 50 Overhead (% upcharge) 25% 25% 25% 25% 152,544 Molder's Profit Margin (%) 20% 20% 20% 20% 115,994 103,811 DT Core Gains 1: DT Core Gains 2: DT Core Gains 3: Unscrewing Mold Cycle Time, Eff, QA + Smaller Press + Less Cavities Result: Part Cost ($/1000) 26.1 18.8 16.3 19.6 Capital Cost Est ($) 141,000 155,200 155,200 116,400 Capacity 16,588,800 26,660,571 26,660,571 19,995,429 Maint & QA Cost 8120.876927 2803.526523 2712.38069 2833.908468 DT Core Gains 1: DT Core Gains 2: DT Core Gains 3: Savings: Cycle Time, Eff, QA + Smaller Press + Less Cavities DT CORE GAINS 1: DT CORE GAINS 2: DT CORE GAINS 3: Annual Part Savings ($) 115,994 152,544 103,811 CYCLE TIME, EFF, QA + SMALLER PRESS + LESS CAVITIES ROI (1 Yr Savings) 101794.4337 138343.9129 128411.274 ROI 5 Yr ($) 565,772 748,520 543,656 Annual Part Savings ($) Capacity Gain 10071771.43 10071771.43 3406628.571 19
Cost Saving Calculation Region: NA ($/lb) Capital Cost Est ($) MFG Costs and Capacity 155,200 155,200 141,000 DT Core Gains 1: DT Core Gains 2: DT Core Gains 3: Unscrewing Mold Cycle Time, Eff, QA + Smaller Press + Less Cavities 116,400 Part Cost: Annual Volume 15,000,000 15,000,000 15,000,000 15,000,000 Resin Price ($/lb) 1 1 1 1 Part Weight (g) 2 2 2 2 Molding: Mold Type Unscrew DT Core DT Core DT Core UNSCREWING MOLD DT CORE GAINS 1: DT CORE GAINS 2: DT CORE GAINS 3: Cycle Time (s) 12.0 8.4 8.4 8.4 Cavitation 16 16 16 12 CYCLE TIME, EFF, + SMALLER PRESS + LESS CAVITIES Productivity 80% 90% 90% 90% QA Threaded Core Cost 900 3200 3200 3200 Press Rate ($/hr) 50 50 40 40 Capital Cost Est ($) Maintenance Hrs/year 84 42 42 42 Quality, % defect 1.0% 0.3% 0.3% 0.3% Assumptions: ROI 5 Yr ($) Production Hrs per Week 96 96 96 96 Production Weeks per Year 45 45 45 45 Toolroom Rate 50 50 50 50 748,520 Overhead (% upcharge) 25% 25% 25% 25% Molder's Profit Margin (%) 20% 20% 20% 20% 565,772 543,656 DT Core Gains 1: DT Core Gains 2: DT Core Gains 3: Unscrewing Mold Cycle Time, Eff, QA + Smaller Press + Less Cavities Result: Part Cost ($/1000) 26.1 18.8 16.3 19.6 Capital Cost Est ($) 141,000 155,200 155,200 116,400 Capacity 16,588,800 26,660,571 26,660,571 19,995,429 Maint & QA Cost 8120.876927 2803.526523 2712.38069 2833.908468 DT Core Gains 1: DT Core Gains 2: DT Core Gains 3: Savings: Cycle Time, Eff, QA + Smaller Press + Less Cavities DT CORE GAINS 1: DT CORE GAINS 2: DT CORE GAINS 3: Annual Part Savings ($) 115,994 152,544 103,811 CYCLE TIME, EFF, QA + SMALLER PRESS + LESS CAVITIES ROI (1 Yr Savings) 101794.4337 138343.9129 128411.274 ROI 5 Yr ($) 565,772 748,520 543,656 ROI 5 Yr ($) Capacity Gain 10071771.43 10071771.43 3406628.571 20
Energy Savings The use of DT Core molds allows for two things when compared to typical hydraulic unscrewing molds: 1. Since DT Core molds do not require a secondary hydraulic core pull, the molds are ideal to run in the latest all electric presses. 2. DT Core molds are much smaller and compact allowing to be run in a smaller press with the same cavitation. Often times a mold that would need to run in a 300t press can now be run in a 200t press. kWh usage varies between machine manufacturers but on an estimation, all-electric machines will use 1/3 rd less energy than its hydraulic counterpart. In addition, the savings of being able to run in a smaller tonnage machine result in considerable energy saving per press. Multiply that by a company running 10, 20 or even more machines and the savings can have a great positive impact on the company’s bottom line. 21
Prototype Options ProtoBridge • Pre-engineered 4 cavity molds, designed for convertibility and capable of production volumes • Intended for customers looking to trial DT Cores, proving out part and mold design as well as production capabilities • Protobridge molds can be inserted to trial customer’s own application 22
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